Fix null checks in HttpRequestCacheProvider

U4-8579: Replace linebreaks

.gitignore

@@ -56,6 +56,7 @@ build/*.nupkg
 src/Umbraco.Tests/config/applications.config
 src/Umbraco.Tests/config/trees.config
 src/Umbraco.Web.UI/web.config
+src/Umbraco.Web.UI/Config/ClientDependency.config
 *.orig
 src/Umbraco.Tests/config/404handlers.config
 src/Umbraco.Web.UI/[Vv]iews/*.cshtml
@@ -139,3 +140,4 @@ apidocs/api/*
 build/docs.zip
 build/ui-docs.zip
 build/csharp-docs.zip
+build/msbuild.log

appveyor.yml

@@ -8,39 +8,34 @@ build_script:
 
     FOR /F "skip=1 delims=" %%i IN (UmbracoVersion.txt) DO IF NOT DEFINED release SET "release=%%i"
 
-    SET PATH=C:\Program Files (x86)\MSBuild\14.0\Bin;%PATH%
-
-    ECHO %PATH%
-
-
-    ECHO Building Release %release% build%APPVEYOR_BUILD_NUMBER%
-
-
-    SET nuGetFolder=%CD%\..\src\packages\
+    SET nuGetFolder=C:\Users\appveyor\.nuget\packages
 
     ..\src\.nuget\NuGet.exe sources Add -Name MyGetUmbracoCore -Source https://www.myget.org/F/umbracocore/api/v2/ >NUL
 
     ..\src\.nuget\NuGet.exe install ..\src\Umbraco.Web.UI\packages.config -OutputDirectory %nuGetFolder% -Verbosity quiet
 
-
     IF EXIST ..\src\umbraco.businesslogic\packages.config ..\src\.nuget\NuGet.exe install ..\src\umbraco.businesslogic\packages.config -OutputDirectory %nuGetFolder% -Verbosity quiet
 
     ..\src\.nuget\NuGet.exe install ..\src\Umbraco.Core\packages.config -OutputDirectory %nuGetFolder% -Verbosity quiet
 
-
+    ECHO Building Release %release% build%APPVEYOR_BUILD_NUMBER%
+    
+    SET PATH=C:\Program Files (x86)\MSBuild\14.0\Bin;%PATH%
+    
     SET MSBUILD="C:\Program Files (x86)\MSBuild\14.0\Bin\MsBuild.exe"
 
-    %MSBUILD% "../src/Umbraco.Tests/Umbraco.Tests.csproj" /verbosity:minimal
-
-
-    build.bat %release% build%APPVEYOR_BUILD_NUMBER%
-
-
+    XCOPY "..\src\Umbraco.Tests\unit-test-log4net.CI.config" "..\src\Umbraco.Tests\unit-test-log4net.config" /Y
+    
+    %MSBUILD% "..\src\Umbraco.Tests\Umbraco.Tests.csproj" /consoleloggerparameters:Summary;ErrorsOnly
+    
+    build.bat nopause %release% build%APPVEYOR_BUILD_NUMBER%
+    
     ECHO %PATH%
 test:
   assemblies: src\Umbraco.Tests\bin\Debug\Umbraco.Tests.dll
 artifacts:
 - path: build\UmbracoCms.*
+- path: build\msbuild.log
 notifications:
 - provider: Slack
   auth_token:

build/Build.bat

@@ -11,20 +11,28 @@ FOR /F "skip=1 delims=" %%i IN (UmbracoVersion.txt) DO IF NOT DEFINED release SE
 FOR /F "skip=2 delims=" %%i IN (UmbracoVersion.txt) DO IF NOT DEFINED comment SET "comment=%%i"
 
 REM If there's arguments on the command line overrule UmbracoVersion.txt and use that as the version
-IF [%1] NEQ [] (SET release=%1)
-IF [%2] NEQ [] (SET comment=%2) ELSE (IF [%1] NEQ [] (SET "comment="))
+IF [%2] NEQ [] (SET release=%2)
+IF [%3] NEQ [] (SET comment=%3) ELSE (IF [%2] NEQ [] (SET "comment="))
+
+REM Get the "is continuous integration" from the parameters
+SET "isci=0"
+IF [%1] NEQ [] (SET isci=1)
 
 SET version=%release%
-
 IF [%comment%] EQU [] (SET version=%release%) ELSE (SET version=%release%-%comment%)
+
+ECHO.
 ECHO Building Umbraco %version%
+ECHO.
 
 ReplaceIISExpressPortNumber.exe ..\src\Umbraco.Web.UI\Umbraco.Web.UI.csproj %release%
 
+ECHO.
 ECHO Removing the belle build folder and bower_components folder to make sure everything is clean as a whistle
 RD ..\src\Umbraco.Web.UI.Client\build /Q /S
 RD ..\src\Umbraco.Web.UI.Client\bower_components /Q /S
 
+ECHO.
 ECHO Removing existing built files to make sure everything is clean as a whistle
 RMDIR /Q /S _BuildOutput
 DEL /F /Q UmbracoCms.*.zip
@@ -32,27 +40,56 @@ DEL /F /Q UmbracoExamine.*.zip
 DEL /F /Q UmbracoCms.*.nupkg
 DEL /F /Q webpihash.txt
 
+ECHO.
 ECHO Making sure Git is in the path so that the build can succeed
 CALL InstallGit.cmd
-ECHO Performing MSBuild and producing Umbraco binaries zip files
-%windir%\Microsoft.NET\Framework\v4.0.30319\msbuild.exe "Build.proj" /p:BUILD_RELEASE=%release% /p:BUILD_COMMENT=%comment% /verbosity:minimal
 
+REM Adding the default Git path so that if it's installed it can actually be found
+REM This is necessary because SETLOCAL is on in InstallGit.cmd so that one might find Git, 
+REM but the path setting is lost due to SETLOCAL 
+path=C:\Program Files (x86)\Git\cmd;C:\Program Files\Git\cmd;%PATH%
+
+ECHO.
+ECHO Making sure we have a web.config
+IF NOT EXIST %CD%\..\src\Umbraco.Web.UI\web.config COPY %CD%\..\src\Umbraco.Web.UI\web.Template.config %CD%\..\src\Umbraco.Web.UI\web.config
+
+ECHO.
+ECHO.
+ECHO Performing MSBuild and producing Umbraco binaries zip files
+ECHO This takes a few minutes and logging is set to report warnings
+ECHO and errors only so it might seems like nothing is happening for a while. 
+ECHO You can check the msbuild.log file for progress.
+ECHO.
+%windir%\Microsoft.NET\Framework\v4.0.30319\msbuild.exe "Build.proj" /p:BUILD_RELEASE=%release% /p:BUILD_COMMENT=%comment% /p:NugetPackagesDirectory=%nuGetFolder% /consoleloggerparameters:Summary;ErrorsOnly;WarningsOnly /fileLogger
+IF ERRORLEVEL 1 GOTO :error
+
+ECHO.
 ECHO Setting node_modules folder to hidden to prevent VS13 from crashing on it while loading the websites project
 attrib +h ..\src\Umbraco.Web.UI.Client\node_modules
 
+ECHO.
 ECHO Adding Web.config transform files to the NuGet package
 REN .\_BuildOutput\WebApp\Views\Web.config Web.config.transform
 REN .\_BuildOutput\WebApp\Xslt\Web.config Web.config.transform
 
+ECHO.
 ECHO Packing the NuGet release files
 ..\src\.nuget\NuGet.exe Pack NuSpecs\UmbracoCms.Core.nuspec -Version %version% -Symbols -Verbosity quiet
 ..\src\.nuget\NuGet.exe Pack NuSpecs\UmbracoCms.nuspec -Version %version% -Verbosity quiet
-                        
-IF ERRORLEVEL 1 GOTO :showerror
+IF ERRORLEVEL 1 GOTO :error
 
-ECHO No errors were detected but you still may see some in the output, then it's time to investigate.
-ECHO You might see some warnings but that is completely normal.
+:success
+ECHO.
+ECHO No errors were detected!
+ECHO There may still be some in the output, which you would need to investigate.
+ECHO Warnings are usually normal.
 GOTO :EOF
 
-:showerror
-PAUSE
+:error
+
+ECHO.
+ECHO Errors were detected!
+
+REM don't pause if continuous integration else the build server waits forever
+REM before cancelling the build (and, there is noone to read the output anyways)
+IF isci NEQ 1 PAUSE

build/BuildBelle.bat

@@ -23,6 +23,7 @@ ECHO Change directory to %CD%\..\src\Umbraco.Web.UI.Client\
 CD %CD%\..\src\Umbraco.Web.UI.Client\
 
 ECHO Do npm install and the grunt build of Belle
+call npm cache clean --quiet
 call npm install --quiet
 call npm install -g grunt-cli --quiet
 call npm install -g bower --quiet

build/InstallGit.cmd

@@ -2,13 +2,13 @@
 SETLOCAL
 REM SETLOCAL is on, so changes to the path not persist to the actual user's path
 
-git.exe 2> NUL
+git.exe --version
 if %ERRORLEVEL%==9009 GOTO :trydefaultpath
 GOTO :EOF
 
 :trydefaultpath
 path=C:\Program Files (x86)\Git\cmd;C:\Program Files\Git\cmd;%PATH%
-git.exe 2> NUL
+git.exe --version
 if %ERRORLEVEL%==9009 GOTO :showerror
 GOTO :EOF
 

build/NuSpecs/UmbracoCms.Core.nuspec

@@ -27,15 +27,17 @@
       <dependency id="SharpZipLib" version="[0.86.0, 1.0.0)" />
       <dependency id="MySql.Data" version="[6.9.8, 7.0.0)" />
       <dependency id="xmlrpcnet" version="[2.5.0, 3.0.0)" />
-      <dependency id="ClientDependency" version="[1.8.4, 2.0.0)" />
+      <dependency id="ClientDependency" version="[1.9.0-beta4, 2.0.0)" />
       <dependency id="ClientDependency-Mvc5" version="[1.8.0, 2.0.0)" />
+	  <!-- AutoMapper can not be updated due to: https://github.com/AutoMapper/AutoMapper/issues/373#issuecomment-127644405 -->
       <dependency id="AutoMapper" version="[3.0.0, 3.1.0)" />
       <dependency id="Newtonsoft.Json" version="[6.0.8, 9.0.0)" />
-      <dependency id="Examine" version="[0.1.68, 1.0.0)" />
-      <dependency id="ImageProcessor" version="[2.3.3, 3.0.0)" />
-      <dependency id="ImageProcessor.Web" version="[4.5.3, 5.0.0)" />
+      <dependency id="Examine" version="[0.1.69-beta, 1.0.0)" />
+      <dependency id="ImageProcessor" version="[2.4.3, 3.0.0)" />
+      <dependency id="ImageProcessor.Web" version="[4.6.3, 5.0.0)" />
       <dependency id="semver" version="[1.1.2, 2.0.0)" />
       <dependency id="UrlRewritingNet" version="[2.0.7, 3.0.0)" />	  
+	  <!-- Markdown can not be updated due to: https://github.com/hey-red/markdownsharp/issues/71#issuecomment-233585487 -->
       <dependency id="Markdown" version="[1.14.4, 2.0.0)" />	  
     </dependencies>
   </metadata>

build/NuSpecs/UmbracoCms.nuspec

@@ -17,7 +17,7 @@
     <dependencies>
       <dependency id="UmbracoCms.Core" version="[$version$]" />
       <dependency id="Newtonsoft.Json" version="[6.0.8, 9.0.0)" />
-      <dependency id="Umbraco.ModelsBuilder" version="[3.0.2, 4.0.0)" />
+      <dependency id="Umbraco.ModelsBuilder" version="[3.0.3, 4.0.0)" />
     </dependencies>
   </metadata>
   <files>
@@ -32,6 +32,7 @@
     <file src="..\_BuildOutput\WebApp\config\splashes\**" target="UmbracoFiles\Config\splashes" />
     <file src="..\_BuildOutput\WebApp\umbraco\**" target="UmbracoFiles\umbraco" />
     <file src="..\_BuildOutput\WebApp\umbraco_client\**" target="UmbracoFiles\umbraco_client" />
+    <file src="..\_BuildOutput\WebApp\Media\Web.config" target="Content\Media\Web.config" />
     <file src="tools\install.ps1" target="tools\install.ps1" />
     <file src="tools\Readme.txt" target="tools\Readme.txt" />
     <file src="tools\ReadmeUpgrade.txt" target="tools\ReadmeUpgrade.txt" />

build/NuSpecs/tools/install.ps1

@@ -97,7 +97,12 @@ if ($project) {
 		$umbracoUIXMLSource = Join-Path $installPath "UmbracoFiles\Umbraco\Config\Create\UI.xml"
 		$umbracoUIXMLDestination = Join-Path $projectPath "Umbraco\Config\Create\UI.xml"
 		Copy-Item $umbracoUIXMLSource $umbracoUIXMLDestination -Force
-	} 
+	} else {
+		$upgradeViewSource = Join-Path $umbracoFolderSource "Views\install\*"
+		$upgradeView = Join-Path $umbracoFolder "Views\install\"
+		Write-Host "Copying2 ${upgradeViewSource} to ${upgradeView}"
+		Copy-Item $upgradeViewSource $upgradeView -Force
+	}
 	
 	$installFolder = Join-Path $projectPath "Install"
 	if(Test-Path $installFolder) {

build/UmbracoVersion.txt

@@ -1,2 +1,3 @@
 # Usage: on line 2 put the release version, on line 3 put the version comment (example: beta)
-7.5.0
+7.5.0
+beta2

src/SQLCE4Umbraco/SqlCEHelper.cs

@@ -40,15 +40,10 @@ namespace SqlCE4Umbraco
             var localConnection = new SqlCeConnection(ConnectionString);
             if (!System.IO.File.Exists(ReplaceDataDirectory(localConnection.Database)))
             {
-                var sqlCeEngine = new SqlCeEngine(ConnectionString);
-                sqlCeEngine.CreateDatabase();
-
-                // SD: Pretty sure this should be in a using clause but i don't want to cause unknown side-effects here
-                // since it's been like this for quite some time
-                //using (var sqlCeEngine = new SqlCeEngine(ConnectionString))
-                //{
-                //    sqlCeEngine.CreateDatabase();    
-                //}
+                using (var sqlCeEngine = new SqlCeEngine(ConnectionString))
+                {
+                    sqlCeEngine.CreateDatabase();
+                }
             }
         }
 

src/SolutionInfo.cs

@@ -12,4 +12,4 @@ using System.Resources;
 [assembly: AssemblyVersion("1.0.*")]
 
 [assembly: AssemblyFileVersion("7.5.0")]
-[assembly: AssemblyInformationalVersion("7.5.0")]
+[assembly: AssemblyInformationalVersion("7.5.0-beta2")]

src/Umbraco.Core/ApplicationContext.cs

@@ -1,22 +1,18 @@
 using System;
-using System.Collections.Generic;
 using System.Configuration;
-using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
 using System.Web;
 using Umbraco.Core.Configuration;
 using Umbraco.Core.Logging;
 using Umbraco.Core.ObjectResolution;
-using Umbraco.Core.Packaging;
-using Umbraco.Core.Persistence.Migrations;
 using Umbraco.Core.Profiling;
 using Umbraco.Core.Services;
 using Umbraco.Core.Sync;
 
 namespace Umbraco.Core
 {
-    /// <summary>
+	/// <summary>
     /// the Umbraco Application context
     /// </summary>
     /// <remarks>
@@ -187,7 +183,6 @@ namespace Umbraco.Core
 		readonly ManualResetEventSlim _isReadyEvent = new ManualResetEventSlim(false);
 		private DatabaseContext _databaseContext;
 		private ServiceContext _services;
-        private PackageMigrationsContext _packageMigrationsContext;
 
 		public bool IsReady
         {
@@ -217,19 +212,17 @@ namespace Umbraco.Core
         
         public bool IsConfigured
         {
-            get { return _umbracoVersionConfigured.Value; }
+            get { return _configured.Value; }
         }
-        
 
         /// <summary>
-        /// If the db is configured, there is a database context and there is an umbraco schema, 
-        /// but we are: (not 'configured' OR there's pending migrations), then it means we are upgrading
+        /// If the db is configured, there is a database context and there is an umbraco schema, but we are not 'configured' , then it means we are upgrading
         /// </summary>
 	    public bool IsUpgrading
 	    {
             get
             {
-                if ((IsConfigured == false || PackageMigrationsContext.HasPendingPackageMigrations)
+                if (IsConfigured == false 
                     && DatabaseContext != null 
                     && DatabaseContext.IsDatabaseConfigured)
                 {
@@ -275,8 +268,7 @@ namespace Umbraco.Core
 	    // ReSharper disable once InconsistentNaming
 	    internal string _umbracoApplicationUrl;
 
-        private Lazy<bool> _umbracoVersionConfigured;
-        
+        private Lazy<bool> _configured;
         internal MainDom MainDom { get; private set; }
        
 	    private void Init()
@@ -285,7 +277,7 @@ namespace Umbraco.Core
             MainDom.Acquire();
             
             //Create the lazy value to resolve whether or not the application is 'configured'
-            _umbracoVersionConfigured = new Lazy<bool>(() =>
+            _configured = new Lazy<bool>(() =>
             {
                 try
                 {
@@ -326,10 +318,9 @@ namespace Umbraco.Core
                     LogHelper.Error<ApplicationContext>("Error determining if application is configured, returning false", ex);
                     return false;
                 }
-            });
 
-            _packageMigrationsContext = new PackageMigrationsContext(DatabaseContext, Services.MigrationEntryService, ProfilingLogger.Logger);
-        }
+            }); 
+		}
 
 		private string ConfigurationStatus
 		{
@@ -352,11 +343,6 @@ namespace Umbraco.Core
                 throw new Exception("ApplicationContext has already been initialized.");
         }
 
-        internal PackageMigrationsContext PackageMigrationsContext
-        {
-            get { return _packageMigrationsContext; }
-        }
-
 		/// <summary>
 		/// Gets the current DatabaseContext
 		/// </summary>

src/Umbraco.Core/Cache/HttpRequestCacheProvider.cs

@@ -9,6 +9,9 @@ namespace Umbraco.Core.Cache
     /// <summary>
     /// A cache provider that caches items in the HttpContext.Items
     /// </summary>
+    /// <remarks>
+    /// If the Items collection is null, then this provider has no effect
+    /// </remarks>
     internal class HttpRequestCacheProvider : DictionaryCacheProviderBase
     {
         // context provider
@@ -34,6 +37,11 @@ namespace Umbraco.Core.Cache
             get { return _context != null ? _context.Items : HttpContext.Current.Items; }
         }
 
+        private bool HasContextItems
+        {
+            get { return (_context != null && _context.Items != null) || HttpContext.Current != null; }
+        }
+
         // for unit tests
         public HttpRequestCacheProvider(HttpContextBase context)
         {
@@ -50,18 +58,23 @@ namespace Umbraco.Core.Cache
         protected override IEnumerable<DictionaryEntry> GetDictionaryEntries()
         {
             const string prefix = CacheItemPrefix + "-";
+
+            if (HasContextItems == false) return Enumerable.Empty<DictionaryEntry>();
+
             return ContextItems.Cast<DictionaryEntry>()
                 .Where(x => x.Key is string && ((string)x.Key).StartsWith(prefix));
         }
 
         protected override void RemoveEntry(string key)
         {
+            if (HasContextItems == false) return;
+
             ContextItems.Remove(key);
         }
 
         protected override object GetEntry(string key)
         {
-            return ContextItems[key];
+            return HasContextItems ? ContextItems[key] : null;
         }
 
         #region Lock
@@ -81,7 +94,9 @@ namespace Umbraco.Core.Cache
 
             get
             {
-                return new MonitorLock(ContextItems.SyncRoot);
+                return HasContextItems 
+                    ? (IDisposable) new MonitorLock(ContextItems.SyncRoot) 
+                    : new NoopLocker();
             }
         }
 
@@ -91,6 +106,9 @@ namespace Umbraco.Core.Cache
 
         public override object GetCacheItem(string cacheKey, Func<object> getCacheItem)
         {
+            //no place to cache so just return the callback result
+            if (HasContextItems == false) return getCacheItem();
+
             cacheKey = GetCacheKey(cacheKey);
 
             Lazy<object> result;
@@ -128,5 +146,10 @@ namespace Umbraco.Core.Cache
         #region Insert
         #endregion
 
+        private class NoopLocker : DisposableObject
+        {
+            protected override void DisposeResources()
+            { }
+        }
     }
 }

src/Umbraco.Core/Cache/NullCacheProvider.cs

@@ -5,38 +5,31 @@ using System.Web.Caching;
 
 namespace Umbraco.Core.Cache
 {
-    internal class NullCacheProvider : IRuntimeCacheProvider
+    /// <summary>
+    /// Represents a cache provider that does not cache anything.
+    /// </summary>
+    public class NullCacheProvider : IRuntimeCacheProvider
     {
         public virtual void ClearAllCache()
-        {
-        }
+        { }
 
         public virtual void ClearCacheItem(string key)
-        {
-        }
+        { }
 
         public virtual void ClearCacheObjectTypes(string typeName)
-        {
-        }
+        { }
 
         public virtual void ClearCacheObjectTypes<T>()
-        {
-        }
+        { }
 
         public virtual void ClearCacheObjectTypes<T>(Func<string, T, bool> predicate)
-        {
-        }
-
-
-
+        { }
 
         public virtual void ClearCacheByKeySearch(string keyStartsWith)
-        {
-        }
+        { }
 
         public virtual void ClearCacheByKeyExpression(string regexString)
-        {
-        }
+        { }
 
         public virtual IEnumerable<object> GetCacheItemsByKeySearch(string keyStartsWith)
         {
@@ -64,8 +57,6 @@ namespace Umbraco.Core.Cache
         }
 
         public void InsertCacheItem(string cacheKey, Func<object> getCacheItem, TimeSpan? timeout = null, bool isSliding = false, CacheItemPriority priority = CacheItemPriority.Normal, CacheItemRemovedCallback removedCallback = null, string[] dependentFiles = null)
-        {
-            
-        }
+        { }
     }
 }

src/Umbraco.Core/Cache/ObjectCacheRuntimeCacheProvider.cs

@@ -1,23 +1,23 @@
 using System;
 using System.Collections.Generic;
-using System.ComponentModel;
 using System.Linq;
-using System.Reflection;
 using System.Runtime.Caching;
 using System.Text.RegularExpressions;
 using System.Threading;
 using System.Web.Caching;
-using Umbraco.Core.Logging;
 using CacheItemPriority = System.Web.Caching.CacheItemPriority;
 
 namespace Umbraco.Core.Cache
 {
     /// <summary>
+    /// Represents a cache provider that caches item in a <see cref="MemoryCache"/>.
     /// A cache provider that wraps the logic of a System.Runtime.Caching.ObjectCache
     /// </summary>
-    internal class ObjectCacheRuntimeCacheProvider : IRuntimeCacheProvider
+    /// <remarks>The <see cref="MemoryCache"/> is created with name "in-memory". That name is
+    /// used to retrieve configuration options. It does not identify the memory cache, i.e.
+    /// each instance of this class has its own, independent, memory cache.</remarks>
+    public class ObjectCacheRuntimeCacheProvider : IRuntimeCacheProvider
     {
-
         private readonly ReaderWriterLockSlim _locker = new ReaderWriterLockSlim(LockRecursionPolicy.SupportsRecursion);
         internal ObjectCache MemoryCache;
 

src/Umbraco.Core/Cache/StaticCacheProvider.cs

@@ -3,14 +3,13 @@ using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Linq;
 using System.Text.RegularExpressions;
-using System.Web.Caching;
 
 namespace Umbraco.Core.Cache
 {
     /// <summary>
-    /// A cache provider that statically caches everything in an in memory dictionary
+    /// Represents a cache provider that statically caches item in a concurrent dictionary.
     /// </summary>
-    internal class StaticCacheProvider : ICacheProvider
+    public class StaticCacheProvider : ICacheProvider
     {
         internal readonly ConcurrentDictionary<string, object> StaticCache = new ConcurrentDictionary<string, object>();
 
@@ -75,7 +74,6 @@ namespace Umbraco.Core.Cache
         public virtual object GetCacheItem(string cacheKey, Func<object> getCacheItem)
         {
             return StaticCache.GetOrAdd(cacheKey, key => getCacheItem());
-        }
-        
+        }        
     }
 }

src/Umbraco.Core/Configuration/UmbracoVersion.cs

@@ -24,7 +24,7 @@ namespace Umbraco.Core.Configuration
         /// Gets the version comment (like beta or RC).
         /// </summary>
         /// <value>The version comment.</value>
-        public static string CurrentComment { get { return ""; } }
+        public static string CurrentComment { get { return "beta2"; } }
 
         // Get the version of the umbraco.dll by looking at a class in that dll
         // Had to do it like this due to medium trust issues, see: http://haacked.com/archive/2010/11/04/assembly-location-and-medium-trust.aspx
@@ -32,7 +32,12 @@ namespace Umbraco.Core.Configuration
 
         public static SemVersion GetSemanticVersion()
         {
-            return Current.GetSemanticVersion();
+            return new SemVersion(
+                Current.Major, 
+                Current.Minor,
+                Current.Build, 
+                CurrentComment.IsNullOrWhiteSpace() ? null : CurrentComment,
+                Current.Revision > 0 ? Current.Revision.ToInvariantString() : null);
         }
     }
 }

src/Umbraco.Core/Constants-Applications.cs

@@ -73,6 +73,11 @@
             /// </summary>
 			public const string DataTypes = "dataTypes";
 
+            /// <summary>
+            /// alias for the packages tree
+            /// </summary>
+            public const string Packages = "packager";
+
 			/// <summary>
 			/// alias for the dictionary tree.
 			/// </summary>

src/Umbraco.Core/CoreBootManager.cs

@@ -500,12 +500,7 @@ namespace Umbraco.Core
             //the database migration objects
             MigrationResolver.Current = new MigrationResolver(
                 ProfilingLogger.Logger,
-                () => PluginManager.ResolveTypes<IMigration>())
-            {
-                //This needs to be resolved before it's frozen because we need to find migrations to determine
-                // if Umbraco IsConfigured
-                CanResolveBeforeFrozen = true
-            };
+                () => PluginManager.ResolveTypes<IMigration>());
 
             // todo: remove once we drop IPropertyEditorValueConverter support.
             PropertyEditorValueConvertersResolver.Current = new PropertyEditorValueConvertersResolver(

src/Umbraco.Core/DecimalExtensions.cs

@@ -0,0 +1,23 @@
+namespace Umbraco.Core
+{
+    /// <summary>
+    /// Provides extension methods for System.Decimal.
+    /// </summary>
+    /// <remarks>See System.Decimal on MSDN and also 
+    /// http://stackoverflow.com/questions/4298719/parse-decimal-and-filter-extra-0-on-the-right/4298787#4298787.
+    /// </remarks>
+    public static class DecimalExtensions
+    {
+        /// <summary>
+        /// Gets the normalized value.
+        /// </summary>
+        /// <param name="value">The value to normalize.</param>
+        /// <returns>The normalized value.</returns>
+        /// <remarks>Normalizing changes the scaling factor and removes trailing zeroes,
+        /// so 1.2500m comes out as 1.25m.</remarks>
+        public static decimal Normalize(this decimal value)
+        {
+            return value / 1.000000000000000000000000000000000m;
+        }
+    }
+}

src/Umbraco.Core/IO/SystemDirectories.cs

@@ -69,7 +69,16 @@ namespace Umbraco.Core.IO
             }
         }
 
-		public static string AppPlugins
+        public static string AppCode
+        {
+            get
+            {
+                //NOTE: this is not configurable and shouldn't need to be
+                return "~/App_Code";
+            }
+        }
+
+        public static string AppPlugins
 		{
 			get
 			{

src/Umbraco.Core/Logging/AsyncForwardingAppenderBase.cs

@@ -1,20 +1,21 @@
-using System;
 using log4net.Appender;
 using log4net.Core;
 using log4net.Util;
+using System;
+using System.Runtime.Remoting.Messaging;
 
 namespace Umbraco.Core.Logging
 {
-    /// <remarks>
-    /// Based on https://github.com/cjbhaines/Log4Net.Async
-    /// </remarks>
+    /// <summary>
+    /// Borrowed from https://github.com/cjbhaines/Log4Net.Async - will reference Nuget packages directly in v8
+    /// </summary>
     public abstract class AsyncForwardingAppenderBase : ForwardingAppender
     {
         #region Private Members
 
         private const FixFlags DefaultFixFlags = FixFlags.Partial;
-        private FixFlags _fixFlags = DefaultFixFlags;
-        private LoggingEventHelper _loggingEventHelper;
+        private FixFlags fixFlags = DefaultFixFlags;
+        private LoggingEventHelper loggingEventHelper;
 
         #endregion Private Members
 
@@ -22,10 +23,25 @@ namespace Umbraco.Core.Logging
 
         public FixFlags Fix
         {
-            get { return _fixFlags; }
+            get { return fixFlags; }
             set { SetFixFlags(value); }
         }
 
+        /// <summary>
+        /// Returns HttpContext.Current
+        /// </summary>
+        protected internal object HttpContext
+        {
+            get
+            {
+                return CallContext.HostContext;
+            }
+            set
+            {
+                CallContext.HostContext = value;
+            }
+        }
+
         /// <summary>
         /// The logger name that will be used for logging internal errors.
         /// </summary>
@@ -38,7 +54,7 @@ namespace Umbraco.Core.Logging
         public override void ActivateOptions()
         {
             base.ActivateOptions();
-            _loggingEventHelper = new LoggingEventHelper(InternalLoggerName, DefaultFixFlags);
+            loggingEventHelper = new LoggingEventHelper(InternalLoggerName, DefaultFixFlags);
             InitializeAppenders();
         }
 
@@ -52,10 +68,10 @@ namespace Umbraco.Core.Logging
 
         private void SetFixFlags(FixFlags newFixFlags)
         {
-            if (newFixFlags != _fixFlags)
+            if (newFixFlags != fixFlags)
             {
-                _loggingEventHelper.Fix = newFixFlags;
-                _fixFlags = newFixFlags;
+                loggingEventHelper.Fix = newFixFlags;
+                fixFlags = newFixFlags;
                 InitializeAppenders();
             }
         }
@@ -84,7 +100,7 @@ namespace Umbraco.Core.Logging
         protected void ForwardInternalError(string message, Exception exception, Type thisType)
         {
             LogLog.Error(thisType, message, exception);
-            var loggingEvent = _loggingEventHelper.CreateLoggingEvent(Level.Error, message, exception);
+            var loggingEvent = loggingEventHelper.CreateLoggingEvent(Level.Error, message, exception);
             ForwardLoggingEvent(loggingEvent, thisType);
         }
 

src/Umbraco.Core/Logging/AsynchronousRollingFileAppender.cs

@@ -1,6 +1,7 @@
 using log4net.Core;
 using log4net.Util;
 using System;
+using System.ComponentModel;
 using System.Runtime.Remoting.Messaging;
 using System.Security.Principal;
 using System.Threading;
@@ -12,7 +13,11 @@ namespace Umbraco.Core.Logging
     /// <summary>
     /// Based on https://github.com/cjbhaines/Log4Net.Async
     /// which is based on code by Chris Haines http://cjbhaines.wordpress.com/2012/02/13/asynchronous-log4net-appenders/
+    /// This is an old/deprecated logger and has been superceded by ParallelForwardingAppender which is included in Umbraco and 
+    /// also by AsyncForwardingAppender in the Log4Net.Async library.
 	/// </summary>
+	[Obsolete("This is superceded by the ParallelForwardingAppender, this will be removed in v8")]
+    [EditorBrowsable(EditorBrowsableState.Never)]
 	public class AsynchronousRollingFileAppender : RollingFileAppender
 	{
 		private RingBuffer<LoggingEvent> pendingAppends;
@@ -198,79 +203,4 @@ namespace Umbraco.Core.Logging
         }
     }
 
-    internal interface IQueue<T>
-    {
-        void Enqueue(T item);
-        bool TryDequeue(out T ret);
-    }
-
-    internal class RingBuffer<T> : IQueue<T>
-    {
-        private readonly object lockObject = new object();
-        private readonly T[] buffer;
-        private readonly int size;
-        private int readIndex = 0;
-        private int writeIndex = 0;
-        private bool bufferFull = false;
-
-        public int Size { get { return size; } }
-
-        public event Action<object, EventArgs> BufferOverflow;
-
-        public RingBuffer(int size)
-        {
-            this.size = size;
-            buffer = new T[size];
-        }
-
-        public void Enqueue(T item)
-        {
-            var bufferWasFull = false;
-            lock (lockObject)
-            {
-                buffer[writeIndex] = item;
-                writeIndex = (++writeIndex) % size;
-                if (bufferFull)
-                {
-                    bufferWasFull = true;
-                    readIndex = writeIndex;
-                }
-                else if (writeIndex == readIndex)
-                {
-                    bufferFull = true;
-                }
-            }
-
-            if (bufferWasFull)
-            {
-                if (BufferOverflow != null)
-                {
-                    BufferOverflow(this, EventArgs.Empty);
-                }
-            }
-        }
-
-        public bool TryDequeue(out T ret)
-        {
-            if (readIndex == writeIndex && !bufferFull)
-            {
-                ret = default(T);
-                return false;
-            }
-            lock (lockObject)
-            {
-                if (readIndex == writeIndex && !bufferFull)
-                {
-                    ret = default(T);
-                    return false;
-                }
-
-                ret = buffer[readIndex];
-                buffer[readIndex] = default(T);
-                readIndex = (++readIndex) % size;
-                bufferFull = false;
-                return true;
-            }
-        }
-    }
 }

src/Umbraco.Core/Logging/IQueue.cs

@@ -0,0 +1,12 @@
+namespace Umbraco.Core.Logging
+{
+    /// <summary>
+    /// Borrowed from https://github.com/cjbhaines/Log4Net.Async - will reference Nuget packages directly in v8
+    /// </summary>
+    /// <typeparam name="T"></typeparam>
+    internal interface IQueue<T>
+    {
+        void Enqueue(T item);
+        bool TryDequeue(out T ret);
+    }
+}

src/Umbraco.Core/Logging/ImageProcessorLogger.cs

@@ -0,0 +1,46 @@
+namespace Umbraco.Core.Logging
+{
+    using System;
+    using System.Runtime.CompilerServices;
+
+    using ImageProcessor.Common.Exceptions;
+
+    /// <summary>
+    /// A logger for explicitly logging ImageProcessor exceptions.
+    /// <remarks>
+    /// Creating this logger is enough for ImageProcessor to find and replace its in-built debug logger
+    /// without any additional configuration required. This class currently has to be public in order 
+    /// to do so.
+    /// </remarks>
+    /// </summary>
+    public sealed class ImageProcessorLogger : ImageProcessor.Common.Exceptions.ILogger
+    {
+        /// <summary>
+        /// Logs the specified message as an error.
+        /// </summary>
+        /// <typeparam name="T">The type calling the logger.</typeparam>
+        /// <param name="text">The message to log.</param>
+        /// <param name="callerName">The property or method name calling the log.</param>
+        /// <param name="lineNumber">The line number where the method is called.</param>
+        public void Log<T>(string text, [CallerMemberName] string callerName = null, [CallerLineNumber] int lineNumber = 0)
+        {
+            // Using LogHelper since the ImageProcessor logger expects a parameterless constructor.
+            var message = string.Format("{0} {1} : {2}", callerName, lineNumber, text);
+            LogHelper.Error<T>(string.Empty, new ImageProcessingException(message));
+        }
+
+        /// <summary>
+        /// Logs the specified message as an error.
+        /// </summary>
+        /// <param name="type">The type calling the logger.</param>
+        /// <param name="text">The message to log.</param>
+        /// <param name="callerName">The property or method name calling the log.</param>
+        /// <param name="lineNumber">The line number where the method is called.</param>
+        public void Log(Type type, string text, [CallerMemberName] string callerName = null, [CallerLineNumber] int lineNumber = 0)
+        {
+            // Using LogHelper since the ImageProcessor logger expects a parameterless constructor.
+            var message = string.Format("{0} {1} : {2}", callerName, lineNumber, text);
+            LogHelper.Error(type, string.Empty, new ImageProcessingException(message));
+        }
+    }
+}

src/Umbraco.Core/Logging/LoggingEventContext.cs

@@ -3,15 +3,18 @@ using log4net.Core;
 namespace Umbraco.Core.Logging
 {
     /// <remarks>
-    /// Based on https://github.com/cjbhaines/Log4Net.Async
+    /// Borrowed from https://github.com/cjbhaines/Log4Net.Async - will reference Nuget packages directly in v8
     /// </remarks>
-    internal class LoggingEventContext
+    internal sealed class LoggingEventContext
     {
-        public LoggingEventContext(LoggingEvent loggingEvent)
+        public LoggingEventContext(LoggingEvent loggingEvent, object httpContext)
         {
             LoggingEvent = loggingEvent;
+            HttpContext = httpContext;
         }
 
         public LoggingEvent LoggingEvent { get; set; }
+
+        public object HttpContext { get; set; }
     }
 }

src/Umbraco.Core/Logging/LoggingEventHelper.cs

@@ -4,9 +4,9 @@ using log4net.Core;
 namespace Umbraco.Core.Logging
 {
     /// <remarks>
-    /// Based on https://github.com/cjbhaines/Log4Net.Async
+    /// Borrowed from https://github.com/cjbhaines/Log4Net.Async - will reference Nuget packages directly in v8
     /// </remarks>
-    internal class LoggingEventHelper
+    internal sealed class LoggingEventHelper
     {
         // needs to be a seperate class so that location is determined correctly by log4net when required
 
@@ -23,8 +23,10 @@ namespace Umbraco.Core.Logging
 
         public LoggingEvent CreateLoggingEvent(Level level, string message, Exception exception)
         {
-            var loggingEvent = new LoggingEvent(HelperType, null, loggerName, level, message, exception);
-            loggingEvent.Fix = Fix;
+            var loggingEvent = new LoggingEvent(HelperType, null, loggerName, level, message, exception)
+            {
+                Fix = Fix
+            };
             return loggingEvent;
         }
     }

src/Umbraco.Core/Logging/ParallelForwardingAppender.cs

@@ -1,9 +1,9 @@
+using log4net.Core;
+using log4net.Util;
 using System;
 using System.Collections.Concurrent;
 using System.Threading;
 using System.Threading.Tasks;
-using log4net.Core;
-using log4net.Util;
 
 namespace Umbraco.Core.Logging
 {
@@ -11,7 +11,7 @@ namespace Umbraco.Core.Logging
     /// An asynchronous appender based on <see cref="BlockingCollection{T}"/>
     /// </summary>
     /// <remarks>
-    /// Based on https://github.com/cjbhaines/Log4Net.Async
+    /// Borrowed from https://github.com/cjbhaines/Log4Net.Async - will reference Nuget packages directly in v8
     /// </remarks>
     public class ParallelForwardingAppender : AsyncForwardingAppenderBase, IDisposable
     {
@@ -22,11 +22,11 @@ namespace Umbraco.Core.Logging
         private CancellationTokenSource _loggingCancelationTokenSource;
         private CancellationToken _loggingCancelationToken;
         private Task _loggingTask;
-        private Double _shutdownFlushTimeout = 1;
-        private TimeSpan _shutdownFlushTimespan = TimeSpan.FromSeconds(1);
+        private Double _shutdownFlushTimeout = 2;
+        private TimeSpan _shutdownFlushTimespan = TimeSpan.FromSeconds(2);
         private static readonly Type ThisType = typeof(ParallelForwardingAppender);
-        private volatile bool _shutDownRequested;
-        private int? _bufferSize = DefaultBufferSize;
+        private volatile bool shutDownRequested;
+        private int? bufferSize = DefaultBufferSize;
 
         #endregion Private Members
 
@@ -37,8 +37,8 @@ namespace Umbraco.Core.Logging
         /// </summary>
         public override int? BufferSize
         {
-            get { return _bufferSize; }
-            set { _bufferSize = value; }
+            get { return bufferSize; }
+            set { bufferSize = value; }
         }
 
         public int BufferEntryCount
@@ -67,7 +67,12 @@ namespace Umbraco.Core.Logging
 
         protected override string InternalLoggerName
         {
-            get { return "ParallelForwardingAppender"; }
+            get
+            {
+                {
+                    return "ParallelForwardingAppender";
+                }
+            }
         }
 
         #endregion Properties
@@ -83,7 +88,7 @@ namespace Umbraco.Core.Logging
 
         private void StartForwarding()
         {
-            if (_shutDownRequested)
+            if (shutDownRequested)
             {
                 return;
             }
@@ -111,7 +116,7 @@ namespace Umbraco.Core.Logging
 
         private void CompleteSubscriberTask()
         {
-            _shutDownRequested = true;
+            shutDownRequested = true;
             if (_loggingEvents == null || _loggingEvents.IsAddingCompleted)
             {
                 return;
@@ -154,7 +159,7 @@ namespace Umbraco.Core.Logging
             loggingEvent.Fix = Fix;
             //In the case where blocking on a full collection, and the task is subsequently completed, the cancellation token
             //will prevent the entry from attempting to add to the completed collection which would result in an exception.
-            _loggingEvents.Add(new LoggingEventContext(loggingEvent), _loggingCancelationToken);
+            _loggingEvents.Add(new LoggingEventContext(loggingEvent, HttpContext), _loggingCancelationToken);
         }
 
         protected override void Append(LoggingEvent[] loggingEvents)
@@ -187,6 +192,7 @@ namespace Umbraco.Core.Logging
                 //This call blocks until an item is available or until adding is completed
                 foreach (var entry in _loggingEvents.GetConsumingEnumerable(_loggingCancelationToken))
                 {
+                    HttpContext = entry.HttpContext;
                     ForwardLoggingEvent(entry.LoggingEvent, ThisType);
                 }
             }

src/Umbraco.Core/Logging/RingBuffer.cs

@@ -0,0 +1,78 @@
+using System;
+
+namespace Umbraco.Core.Logging
+{
+    /// <summary>
+    /// Borrowed from https://github.com/cjbhaines/Log4Net.Async - will reference Nuget packages directly in v8
+    /// </summary>
+    /// <typeparam name="T"></typeparam>
+    internal sealed class RingBuffer<T> : IQueue<T>
+    {
+        private readonly object lockObject = new object();
+        private readonly T[] buffer;
+        private readonly int size;
+        private int readIndex = 0;
+        private int writeIndex = 0;
+        private bool bufferFull = false;
+
+        public int Size { get { return size; } }
+
+        public event Action<object, EventArgs> BufferOverflow;
+
+        public RingBuffer(int size)
+        {
+            this.size = size;
+            buffer = new T[size];
+        }
+
+        public void Enqueue(T item)
+        {
+            var bufferWasFull = false;
+            lock (lockObject)
+            {
+                buffer[writeIndex] = item;
+                writeIndex = (++writeIndex) % size;
+                if (bufferFull)
+                {
+                    bufferWasFull = true;
+                    readIndex = writeIndex;
+                }
+                else if (writeIndex == readIndex)
+                {
+                    bufferFull = true;
+                }
+            }
+
+            if (bufferWasFull)
+            {
+                if (BufferOverflow != null)
+                {
+                    BufferOverflow(this, EventArgs.Empty);
+                }
+            }
+        }
+
+        public bool TryDequeue(out T ret)
+        {
+            if (readIndex == writeIndex && !bufferFull)
+            {
+                ret = default(T);
+                return false;
+            }
+            lock (lockObject)
+            {
+                if (readIndex == writeIndex && !bufferFull)
+                {
+                    ret = default(T);
+                    return false;
+                }
+
+                ret = buffer[readIndex];
+                buffer[readIndex] = default(T);
+                readIndex = (++readIndex) % size;
+                bufferFull = false;
+                return true;
+            }
+        }
+    }
+}

src/Umbraco.Core/Models/Content.cs

@@ -76,14 +76,19 @@ namespace Umbraco.Core.Models
             _contentType = contentType;
         }
 
-        private static readonly PropertyInfo TemplateSelector = ExpressionHelper.GetPropertyInfo<Content, ITemplate>(x => x.Template);
-        private static readonly PropertyInfo PublishedSelector = ExpressionHelper.GetPropertyInfo<Content, bool>(x => x.Published);
-        private static readonly PropertyInfo LanguageSelector = ExpressionHelper.GetPropertyInfo<Content, string>(x => x.Language);
-        private static readonly PropertyInfo ReleaseDateSelector = ExpressionHelper.GetPropertyInfo<Content, DateTime?>(x => x.ReleaseDate);
-        private static readonly PropertyInfo ExpireDateSelector = ExpressionHelper.GetPropertyInfo<Content, DateTime?>(x => x.ExpireDate);
-        private static readonly PropertyInfo WriterSelector = ExpressionHelper.GetPropertyInfo<Content, int>(x => x.WriterId);
-        private static readonly PropertyInfo NodeNameSelector = ExpressionHelper.GetPropertyInfo<Content, string>(x => x.NodeName);
-        private static readonly PropertyInfo PermissionsChangedSelector = ExpressionHelper.GetPropertyInfo<Content, bool>(x => x.PermissionsChanged);
+        private static readonly Lazy<PropertySelectors> Ps = new Lazy<PropertySelectors>();
+
+        private class PropertySelectors
+        {
+            public readonly PropertyInfo TemplateSelector = ExpressionHelper.GetPropertyInfo<Content, ITemplate>(x => x.Template);
+            public readonly PropertyInfo PublishedSelector = ExpressionHelper.GetPropertyInfo<Content, bool>(x => x.Published);
+            public readonly PropertyInfo LanguageSelector = ExpressionHelper.GetPropertyInfo<Content, string>(x => x.Language);
+            public readonly PropertyInfo ReleaseDateSelector = ExpressionHelper.GetPropertyInfo<Content, DateTime?>(x => x.ReleaseDate);
+            public readonly PropertyInfo ExpireDateSelector = ExpressionHelper.GetPropertyInfo<Content, DateTime?>(x => x.ExpireDate);
+            public readonly PropertyInfo WriterSelector = ExpressionHelper.GetPropertyInfo<Content, int>(x => x.WriterId);
+            public readonly PropertyInfo NodeNameSelector = ExpressionHelper.GetPropertyInfo<Content, string>(x => x.NodeName);
+            public readonly PropertyInfo PermissionsChangedSelector = ExpressionHelper.GetPropertyInfo<Content, bool>(x => x.PermissionsChanged);
+        }
 
         /// <summary>
         /// Gets or sets the template used by the Content.
@@ -97,14 +102,7 @@ namespace Umbraco.Core.Models
         public virtual ITemplate Template
         {
             get { return _template; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _template = value;
-                    return _template;
-                }, _template, TemplateSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _template, Ps.Value.TemplateSelector); }
         }
 
         /// <summary>
@@ -142,14 +140,7 @@ namespace Umbraco.Core.Models
         public bool Published
         {
             get { return _published; }
-            internal set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _published = value;
-                    return _published;
-                }, _published, PublishedSelector);
-            }
+            internal set { SetPropertyValueAndDetectChanges(value, ref _published, Ps.Value.PublishedSelector); }
         }
 
         /// <summary>
@@ -160,14 +151,7 @@ namespace Umbraco.Core.Models
         public string Language
         {
             get { return _language; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _language = value;
-                    return _language;
-                }, _language, LanguageSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _language, Ps.Value.LanguageSelector); }
         }
 
         /// <summary>
@@ -177,14 +161,7 @@ namespace Umbraco.Core.Models
         public DateTime? ReleaseDate
         {
             get { return _releaseDate; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _releaseDate = value;
-                    return _releaseDate;
-                }, _releaseDate, ReleaseDateSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _releaseDate, Ps.Value.ReleaseDateSelector); }
         }
 
         /// <summary>
@@ -194,14 +171,7 @@ namespace Umbraco.Core.Models
         public DateTime? ExpireDate
         {
             get { return _expireDate; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _expireDate = value;
-                    return _expireDate;
-                }, _expireDate, ExpireDateSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _expireDate, Ps.Value.ExpireDateSelector); }
         }
 
         /// <summary>
@@ -211,14 +181,7 @@ namespace Umbraco.Core.Models
         public virtual int WriterId
         {
             get { return _writer; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _writer = value;
-                    return _writer;
-                }, _writer, WriterSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _writer, Ps.Value.WriterSelector); }
         }
 
         /// <summary>
@@ -231,14 +194,7 @@ namespace Umbraco.Core.Models
         internal string NodeName
         {
             get { return _nodeName; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _nodeName = value;
-                    return _nodeName;
-                }, _nodeName, NodeNameSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _nodeName, Ps.Value.NodeNameSelector); }
         }
 
         /// <summary>
@@ -248,14 +204,7 @@ namespace Umbraco.Core.Models
         internal bool PermissionsChanged
         {
             get { return _permissionsChanged; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _permissionsChanged = value;
-                    return _permissionsChanged;
-                }, _permissionsChanged, PermissionsChangedSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _permissionsChanged, Ps.Value.PermissionsChangedSelector); }
         }
 
         /// <summary>

src/Umbraco.Core/Models/ContentBase.cs

@@ -81,19 +81,24 @@ namespace Umbraco.Core.Models
             _additionalData = new Dictionary<string, object>();
 		}
 
-	    private static readonly PropertyInfo NameSelector = ExpressionHelper.GetPropertyInfo<ContentBase, string>(x => x.Name);
-        private static readonly PropertyInfo ParentIdSelector = ExpressionHelper.GetPropertyInfo<ContentBase, int>(x => x.ParentId);
-        private static readonly PropertyInfo SortOrderSelector = ExpressionHelper.GetPropertyInfo<ContentBase, int>(x => x.SortOrder);
-        private static readonly PropertyInfo LevelSelector = ExpressionHelper.GetPropertyInfo<ContentBase, int>(x => x.Level);
-        private static readonly PropertyInfo PathSelector = ExpressionHelper.GetPropertyInfo<ContentBase, string>(x => x.Path);
-        private static readonly PropertyInfo CreatorIdSelector = ExpressionHelper.GetPropertyInfo<ContentBase, int>(x => x.CreatorId);
-        private static readonly PropertyInfo TrashedSelector = ExpressionHelper.GetPropertyInfo<ContentBase, bool>(x => x.Trashed);
-        private static readonly PropertyInfo DefaultContentTypeIdSelector = ExpressionHelper.GetPropertyInfo<ContentBase, int>(x => x.ContentTypeId);
-        private readonly static PropertyInfo PropertyCollectionSelector = ExpressionHelper.GetPropertyInfo<ContentBase, PropertyCollection>(x => x.Properties);
+        private static readonly Lazy<PropertySelectors> Ps = new Lazy<PropertySelectors>();
+
+        private class PropertySelectors
+        {
+            public readonly PropertyInfo NameSelector = ExpressionHelper.GetPropertyInfo<ContentBase, string>(x => x.Name);
+            public readonly PropertyInfo ParentIdSelector = ExpressionHelper.GetPropertyInfo<ContentBase, int>(x => x.ParentId);
+            public readonly PropertyInfo SortOrderSelector = ExpressionHelper.GetPropertyInfo<ContentBase, int>(x => x.SortOrder);
+            public readonly PropertyInfo LevelSelector = ExpressionHelper.GetPropertyInfo<ContentBase, int>(x => x.Level);
+            public readonly PropertyInfo PathSelector = ExpressionHelper.GetPropertyInfo<ContentBase, string>(x => x.Path);
+            public readonly PropertyInfo CreatorIdSelector = ExpressionHelper.GetPropertyInfo<ContentBase, int>(x => x.CreatorId);
+            public readonly PropertyInfo TrashedSelector = ExpressionHelper.GetPropertyInfo<ContentBase, bool>(x => x.Trashed);
+            public readonly PropertyInfo DefaultContentTypeIdSelector = ExpressionHelper.GetPropertyInfo<ContentBase, int>(x => x.ContentTypeId);
+            public readonly PropertyInfo PropertyCollectionSelector = ExpressionHelper.GetPropertyInfo<ContentBase, PropertyCollection>(x => x.Properties);
+        }        
 
         protected void PropertiesChanged(object sender, NotifyCollectionChangedEventArgs e)
         {
-            OnPropertyChanged(PropertyCollectionSelector);
+            OnPropertyChanged(Ps.Value.PropertyCollectionSelector);
         }
 
         /// <summary>
@@ -114,7 +119,7 @@ namespace Umbraco.Core.Models
             set
             {
                 _parentId = new Lazy<int>(() => value);
-                OnPropertyChanged(ParentIdSelector);
+                OnPropertyChanged(Ps.Value.ParentIdSelector);
             }
         }
 
@@ -125,14 +130,7 @@ namespace Umbraco.Core.Models
         public virtual string Name
         {
             get { return _name; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _name = value;
-                    return _name;
-                }, _name, NameSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _name, Ps.Value.NameSelector); }
         }
 
         /// <summary>
@@ -142,14 +140,7 @@ namespace Umbraco.Core.Models
         public virtual int SortOrder
         {
             get { return _sortOrder; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _sortOrder = value;
-                    return _sortOrder;
-                }, _sortOrder, SortOrderSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _sortOrder, Ps.Value.SortOrderSelector); }
         }
 
         /// <summary>
@@ -159,14 +150,7 @@ namespace Umbraco.Core.Models
         public virtual int Level
         {
             get { return _level; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _level = value;
-                    return _level;
-                }, _level, LevelSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _level, Ps.Value.LevelSelector); }
         }
 
         /// <summary>
@@ -176,14 +160,7 @@ namespace Umbraco.Core.Models
         public virtual string Path //Setting this value should be handled by the class not the user
         {
             get { return _path; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _path = value;
-                    return _path;
-                }, _path, PathSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _path, Ps.Value.PathSelector); }
         }
 
         /// <summary>
@@ -193,14 +170,7 @@ namespace Umbraco.Core.Models
         public virtual int CreatorId
         {
             get { return _creatorId; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _creatorId = value;
-                    return _creatorId;
-                }, _creatorId, CreatorIdSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _creatorId, Ps.Value.CreatorIdSelector); }
         }
         
         /// <summary>
@@ -212,14 +182,7 @@ namespace Umbraco.Core.Models
         public virtual bool Trashed //Setting this value should be handled by the class not the user
         {
             get { return _trashed; }
-            internal set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _trashed = value;
-                    return _trashed;
-                }, _trashed, TrashedSelector);
-            }
+            internal set { SetPropertyValueAndDetectChanges(value, ref _trashed, Ps.Value.TrashedSelector); }
         }
 
         /// <summary>
@@ -244,14 +207,7 @@ namespace Umbraco.Core.Models
                 }
                 return _contentTypeId;
             }
-            protected set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _contentTypeId = value;
-                    return _contentTypeId;
-                }, _contentTypeId, DefaultContentTypeIdSelector);
-            }
+            protected set { SetPropertyValueAndDetectChanges(value, ref _contentTypeId, Ps.Value.DefaultContentTypeIdSelector); }
         }
 
         /// <summary>

src/Umbraco.Core/Models/ContentType.cs

@@ -48,8 +48,13 @@ namespace Umbraco.Core.Models
             _allowedTemplates = new List<ITemplate>();
         }
 
-        private static readonly PropertyInfo DefaultTemplateSelector = ExpressionHelper.GetPropertyInfo<ContentType, int>(x => x.DefaultTemplateId);
-        private static readonly PropertyInfo AllowedTemplatesSelector = ExpressionHelper.GetPropertyInfo<ContentType, IEnumerable<ITemplate>>(x => x.AllowedTemplates);
+        private static readonly Lazy<PropertySelectors> Ps = new Lazy<PropertySelectors>();
+
+        private class PropertySelectors
+        {
+            public readonly PropertyInfo DefaultTemplateSelector = ExpressionHelper.GetPropertyInfo<ContentType, int>(x => x.DefaultTemplateId);
+            public readonly PropertyInfo AllowedTemplatesSelector = ExpressionHelper.GetPropertyInfo<ContentType, IEnumerable<ITemplate>>(x => x.AllowedTemplates);
+        }
 
         /// <summary>
         /// Gets or sets the alias of the default Template.
@@ -70,14 +75,7 @@ namespace Umbraco.Core.Models
         internal int DefaultTemplateId
         {
             get { return _defaultTemplate; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _defaultTemplate = value;
-                    return _defaultTemplate;
-                }, _defaultTemplate, DefaultTemplateSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _defaultTemplate, Ps.Value.DefaultTemplateSelector); }
         }
 
         /// <summary>
@@ -92,11 +90,7 @@ namespace Umbraco.Core.Models
             get { return _allowedTemplates; }
             set
             {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _allowedTemplates = value;
-                    return _allowedTemplates;
-                }, _allowedTemplates, AllowedTemplatesSelector,
+                SetPropertyValueAndDetectChanges(value, ref _allowedTemplates, Ps.Value.AllowedTemplatesSelector,
                     //Custom comparer for enumerable
                     new DelegateEqualityComparer<IEnumerable<ITemplate>>(
                         (templates, enumerable) => templates.UnsortedSequenceEqual(enumerable),

src/Umbraco.Core/Models/ContentTypeBase.cs

@@ -67,33 +67,38 @@ namespace Umbraco.Core.Models
             _additionalData = new Dictionary<string, object>();
         }
 
-        private static readonly PropertyInfo NameSelector = ExpressionHelper.GetPropertyInfo<ContentTypeBase, string>(x => x.Name);
-        private static readonly PropertyInfo ParentIdSelector = ExpressionHelper.GetPropertyInfo<ContentTypeBase, int>(x => x.ParentId);
-        private static readonly PropertyInfo SortOrderSelector = ExpressionHelper.GetPropertyInfo<ContentTypeBase, int>(x => x.SortOrder);
-        private static readonly PropertyInfo LevelSelector = ExpressionHelper.GetPropertyInfo<ContentTypeBase, int>(x => x.Level);
-        private static readonly PropertyInfo PathSelector = ExpressionHelper.GetPropertyInfo<ContentTypeBase, string>(x => x.Path);
-        private static readonly PropertyInfo AliasSelector = ExpressionHelper.GetPropertyInfo<ContentTypeBase, string>(x => x.Alias);
-        private static readonly PropertyInfo DescriptionSelector = ExpressionHelper.GetPropertyInfo<ContentTypeBase, string>(x => x.Description);
-        private static readonly PropertyInfo IconSelector = ExpressionHelper.GetPropertyInfo<ContentTypeBase, string>(x => x.Icon);
-        private static readonly PropertyInfo ThumbnailSelector = ExpressionHelper.GetPropertyInfo<ContentTypeBase, string>(x => x.Thumbnail);
-        private static readonly PropertyInfo CreatorIdSelector = ExpressionHelper.GetPropertyInfo<ContentTypeBase, int>(x => x.CreatorId);
-        private static readonly PropertyInfo AllowedAsRootSelector = ExpressionHelper.GetPropertyInfo<ContentTypeBase, bool>(x => x.AllowedAsRoot);
-        private static readonly PropertyInfo IsContainerSelector = ExpressionHelper.GetPropertyInfo<ContentTypeBase, bool>(x => x.IsContainer);
-        private static readonly PropertyInfo TrashedSelector = ExpressionHelper.GetPropertyInfo<ContentTypeBase, bool>(x => x.Trashed);
-        private static readonly PropertyInfo AllowedContentTypesSelector = ExpressionHelper.GetPropertyInfo<ContentTypeBase, IEnumerable<ContentTypeSort>>(x => x.AllowedContentTypes);
-        private static readonly PropertyInfo PropertyGroupCollectionSelector = ExpressionHelper.GetPropertyInfo<ContentTypeBase, PropertyGroupCollection>(x => x.PropertyGroups);
-        private static readonly PropertyInfo PropertyTypeCollectionSelector = ExpressionHelper.GetPropertyInfo<ContentTypeBase, IEnumerable<PropertyType>>(x => x.PropertyTypes);
-        private static readonly PropertyInfo HasPropertyTypeBeenRemovedSelector = ExpressionHelper.GetPropertyInfo<ContentTypeBase, bool>(x => x.HasPropertyTypeBeenRemoved);
+        private static readonly Lazy<PropertySelectors> Ps = new Lazy<PropertySelectors>();
+
+        private class PropertySelectors
+        {
+            public readonly PropertyInfo NameSelector = ExpressionHelper.GetPropertyInfo<ContentTypeBase, string>(x => x.Name);
+            public readonly PropertyInfo ParentIdSelector = ExpressionHelper.GetPropertyInfo<ContentTypeBase, int>(x => x.ParentId);
+            public readonly PropertyInfo SortOrderSelector = ExpressionHelper.GetPropertyInfo<ContentTypeBase, int>(x => x.SortOrder);
+            public readonly PropertyInfo LevelSelector = ExpressionHelper.GetPropertyInfo<ContentTypeBase, int>(x => x.Level);
+            public readonly PropertyInfo PathSelector = ExpressionHelper.GetPropertyInfo<ContentTypeBase, string>(x => x.Path);
+            public readonly PropertyInfo AliasSelector = ExpressionHelper.GetPropertyInfo<ContentTypeBase, string>(x => x.Alias);
+            public readonly PropertyInfo DescriptionSelector = ExpressionHelper.GetPropertyInfo<ContentTypeBase, string>(x => x.Description);
+            public readonly PropertyInfo IconSelector = ExpressionHelper.GetPropertyInfo<ContentTypeBase, string>(x => x.Icon);
+            public readonly PropertyInfo ThumbnailSelector = ExpressionHelper.GetPropertyInfo<ContentTypeBase, string>(x => x.Thumbnail);
+            public readonly PropertyInfo CreatorIdSelector = ExpressionHelper.GetPropertyInfo<ContentTypeBase, int>(x => x.CreatorId);
+            public readonly PropertyInfo AllowedAsRootSelector = ExpressionHelper.GetPropertyInfo<ContentTypeBase, bool>(x => x.AllowedAsRoot);
+            public readonly PropertyInfo IsContainerSelector = ExpressionHelper.GetPropertyInfo<ContentTypeBase, bool>(x => x.IsContainer);
+            public readonly PropertyInfo TrashedSelector = ExpressionHelper.GetPropertyInfo<ContentTypeBase, bool>(x => x.Trashed);
+            public readonly PropertyInfo AllowedContentTypesSelector = ExpressionHelper.GetPropertyInfo<ContentTypeBase, IEnumerable<ContentTypeSort>>(x => x.AllowedContentTypes);
+            public readonly PropertyInfo PropertyGroupCollectionSelector = ExpressionHelper.GetPropertyInfo<ContentTypeBase, PropertyGroupCollection>(x => x.PropertyGroups);
+            public readonly PropertyInfo PropertyTypeCollectionSelector = ExpressionHelper.GetPropertyInfo<ContentTypeBase, IEnumerable<PropertyType>>(x => x.PropertyTypes);
+            public readonly PropertyInfo HasPropertyTypeBeenRemovedSelector = ExpressionHelper.GetPropertyInfo<ContentTypeBase, bool>(x => x.HasPropertyTypeBeenRemoved);
+        }
 
 
         protected void PropertyGroupsChanged(object sender, NotifyCollectionChangedEventArgs e)
         {
-            OnPropertyChanged(PropertyGroupCollectionSelector);
+            OnPropertyChanged(Ps.Value.PropertyGroupCollectionSelector);
         }
 
         protected void PropertyTypesChanged(object sender, NotifyCollectionChangedEventArgs e)
         {
-            OnPropertyChanged(PropertyTypeCollectionSelector);
+            OnPropertyChanged(Ps.Value.PropertyTypeCollectionSelector);
         }
 
         /// <summary>
@@ -115,7 +120,7 @@ namespace Umbraco.Core.Models
             set
             {
                 _parentId = new Lazy<int>(() => value);
-                OnPropertyChanged(ParentIdSelector);
+                OnPropertyChanged(Ps.Value.ParentIdSelector);
             }
         }
 
@@ -126,14 +131,7 @@ namespace Umbraco.Core.Models
         public virtual string Name
         {
             get { return _name; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _name = value;
-                    return _name;
-                }, _name, NameSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _name, Ps.Value.NameSelector); }
         }
 
         /// <summary>
@@ -143,14 +141,7 @@ namespace Umbraco.Core.Models
         public virtual int Level //NOTE Is this relevant for a ContentType?
         {
             get { return _level; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _level = value;
-                    return _level;
-                }, _level, LevelSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _level, Ps.Value.LevelSelector); }
         }
 
         /// <summary>
@@ -160,14 +151,7 @@ namespace Umbraco.Core.Models
         public virtual string Path //NOTE Is this relevant for a ContentType?
         {
             get { return _path; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _path = value;
-                    return _path;
-                }, _path, PathSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _path, Ps.Value.PathSelector); }
         }
 
         /// <summary>
@@ -179,12 +163,10 @@ namespace Umbraco.Core.Models
             get { return _alias; }
             set
             {
-                SetPropertyValueAndDetectChanges(o =>
-                    {
-                        //_alias = value.ToSafeAlias();
-                        _alias = value.ToCleanString(CleanStringType.Alias | CleanStringType.UmbracoCase);
-                        return _alias;
-                    }, _alias, AliasSelector);
+                SetPropertyValueAndDetectChanges(
+                    value.ToCleanString(CleanStringType.Alias | CleanStringType.UmbracoCase), 
+                    ref _alias, 
+                    Ps.Value.AliasSelector);
             }
         }
 
@@ -195,14 +177,7 @@ namespace Umbraco.Core.Models
         public virtual string Description
         {
             get { return _description; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _description = value;
-                    return _description;
-                }, _description, DescriptionSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _description, Ps.Value.DescriptionSelector); }
         }
 
         /// <summary>
@@ -212,14 +187,7 @@ namespace Umbraco.Core.Models
         public virtual int SortOrder
         {
             get { return _sortOrder; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _sortOrder = value;
-                    return _sortOrder;
-                }, _sortOrder, SortOrderSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _sortOrder, Ps.Value.SortOrderSelector); }
         }
 
         /// <summary>
@@ -229,14 +197,7 @@ namespace Umbraco.Core.Models
         public virtual string Icon
         {
             get { return _icon; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _icon = value;
-                    return _icon;
-                }, _icon, IconSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _icon, Ps.Value.IconSelector); }
         }
 
         /// <summary>
@@ -246,14 +207,7 @@ namespace Umbraco.Core.Models
         public virtual string Thumbnail
         {
             get { return _thumbnail; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _thumbnail = value;
-                    return _thumbnail;
-                }, _thumbnail, ThumbnailSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _thumbnail, Ps.Value.ThumbnailSelector); }
         }
 
         /// <summary>
@@ -263,14 +217,7 @@ namespace Umbraco.Core.Models
         public virtual int CreatorId
         {
             get { return _creatorId; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _creatorId = value;
-                    return _creatorId;
-                }, _creatorId, CreatorIdSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _creatorId, Ps.Value.CreatorIdSelector); }
         }
 
         /// <summary>
@@ -280,14 +227,7 @@ namespace Umbraco.Core.Models
         public virtual bool AllowedAsRoot
         {
             get { return _allowedAsRoot; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _allowedAsRoot = value;
-                    return _allowedAsRoot;
-                }, _allowedAsRoot, AllowedAsRootSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _allowedAsRoot, Ps.Value.AllowedAsRootSelector); }
         }
 
         /// <summary>
@@ -300,14 +240,7 @@ namespace Umbraco.Core.Models
         public virtual bool IsContainer
         {
             get { return _isContainer; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _isContainer = value;
-                    return _isContainer;
-                }, _isContainer, IsContainerSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _isContainer, Ps.Value.IsContainerSelector); }
         }
 
         /// <summary>
@@ -318,14 +251,7 @@ namespace Umbraco.Core.Models
         public virtual bool Trashed //NOTE Is this relevant for a ContentType?
         {
             get { return _trashed; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _trashed = value;
-                    return _trashed;
-                }, _trashed, TrashedSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _trashed, Ps.Value.TrashedSelector); }
         }
 
         private IDictionary<string, object> _additionalData;
@@ -347,15 +273,11 @@ namespace Umbraco.Core.Models
             get { return _allowedContentTypes; }
             set
             {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _allowedContentTypes = value;
-                    return _allowedContentTypes;
-                }, _allowedContentTypes, AllowedContentTypesSelector,
+                SetPropertyValueAndDetectChanges(value, ref _allowedContentTypes, Ps.Value.AllowedContentTypesSelector,
                     //Custom comparer for enumerable
                     new DelegateEqualityComparer<IEnumerable<ContentTypeSort>>(
                         (sorts, enumerable) => sorts.UnsortedSequenceEqual(enumerable),
-                        sorts => sorts.GetHashCode()));
+                        sorts => sorts.GetHashCode()));                
             }
         }
 
@@ -418,7 +340,7 @@ namespace Umbraco.Core.Models
             private set
             {
                 _hasPropertyTypeBeenRemoved = value;
-                OnPropertyChanged(HasPropertyTypeBeenRemovedSelector);
+                OnPropertyChanged(Ps.Value.HasPropertyTypeBeenRemovedSelector);
             }
         }
 
@@ -543,7 +465,7 @@ namespace Umbraco.Core.Models
 
             // actually remove the group
             PropertyGroups.RemoveItem(propertyGroupName);
-            OnPropertyChanged(PropertyGroupCollectionSelector);
+            OnPropertyChanged(Ps.Value.PropertyGroupCollectionSelector);
         }
 
         /// <summary>

src/Umbraco.Core/Models/ContentTypeCompositionBase.cs

@@ -32,9 +32,13 @@ namespace Umbraco.Core.Models
             AddContentType(parent);
         }
 
-        private static readonly PropertyInfo ContentTypeCompositionSelector =
-            ExpressionHelper.GetPropertyInfo<ContentTypeCompositionBase, IEnumerable<IContentTypeComposition>>(
-                x => x.ContentTypeComposition);
+        private static readonly Lazy<PropertySelectors> Ps = new Lazy<PropertySelectors>();
+
+        private class PropertySelectors
+        {
+            public readonly PropertyInfo ContentTypeCompositionSelector =
+                ExpressionHelper.GetPropertyInfo<ContentTypeCompositionBase, IEnumerable<IContentTypeComposition>>(x => x.ContentTypeComposition);
+        }
 
         /// <summary>
         /// Gets or sets the content types that compose this content type.
@@ -46,7 +50,7 @@ namespace Umbraco.Core.Models
             set
             {
                 _contentTypeComposition = value.ToList();
-                OnPropertyChanged(ContentTypeCompositionSelector);
+                OnPropertyChanged(Ps.Value.ContentTypeCompositionSelector);
             }
         }
 
@@ -102,7 +106,7 @@ namespace Umbraco.Core.Models
                     throw new InvalidCompositionException(Alias, contentType.Alias, conflictingPropertyTypeAliases.ToArray());
 
                 _contentTypeComposition.Add(contentType);
-                OnPropertyChanged(ContentTypeCompositionSelector);
+                OnPropertyChanged(Ps.Value.ContentTypeCompositionSelector);
                 return true;
             }
             return false;
@@ -128,7 +132,7 @@ namespace Umbraco.Core.Models
                 if (compositionIdsToRemove.Any())
                     RemovedContentTypeKeyTracker.AddRange(compositionIdsToRemove);
 
-                OnPropertyChanged(ContentTypeCompositionSelector);
+                OnPropertyChanged(Ps.Value.ContentTypeCompositionSelector);
                 return _contentTypeComposition.Remove(contentTypeComposition);
             }
             return false;

src/Umbraco.Core/Models/DataTypeDefinition.cs

@@ -65,15 +65,20 @@ namespace Umbraco.Core.Models
             _additionalData = new Dictionary<string, object>();
         }
 
-        private static readonly PropertyInfo NameSelector = ExpressionHelper.GetPropertyInfo<DataTypeDefinition, string>(x => x.Name);
-        private static readonly PropertyInfo ParentIdSelector = ExpressionHelper.GetPropertyInfo<DataTypeDefinition, int>(x => x.ParentId);
-        private static readonly PropertyInfo SortOrderSelector = ExpressionHelper.GetPropertyInfo<DataTypeDefinition, int>(x => x.SortOrder);
-        private static readonly PropertyInfo LevelSelector = ExpressionHelper.GetPropertyInfo<DataTypeDefinition, int>(x => x.Level);
-        private static readonly PropertyInfo PathSelector = ExpressionHelper.GetPropertyInfo<DataTypeDefinition, string>(x => x.Path);
-        private static readonly PropertyInfo UserIdSelector = ExpressionHelper.GetPropertyInfo<DataTypeDefinition, int>(x => x.CreatorId);
-        private static readonly PropertyInfo TrashedSelector = ExpressionHelper.GetPropertyInfo<DataTypeDefinition, bool>(x => x.Trashed);
-        private static readonly PropertyInfo PropertyEditorAliasSelector = ExpressionHelper.GetPropertyInfo<DataTypeDefinition, string>(x => x.PropertyEditorAlias);
-        private static readonly PropertyInfo DatabaseTypeSelector = ExpressionHelper.GetPropertyInfo<DataTypeDefinition, DataTypeDatabaseType>(x => x.DatabaseType);
+        private static readonly Lazy<PropertySelectors> Ps = new Lazy<PropertySelectors>();
+
+        private class PropertySelectors
+        {
+            public readonly PropertyInfo NameSelector = ExpressionHelper.GetPropertyInfo<DataTypeDefinition, string>(x => x.Name);
+            public readonly PropertyInfo ParentIdSelector = ExpressionHelper.GetPropertyInfo<DataTypeDefinition, int>(x => x.ParentId);
+            public readonly PropertyInfo SortOrderSelector = ExpressionHelper.GetPropertyInfo<DataTypeDefinition, int>(x => x.SortOrder);
+            public readonly PropertyInfo LevelSelector = ExpressionHelper.GetPropertyInfo<DataTypeDefinition, int>(x => x.Level);
+            public readonly PropertyInfo PathSelector = ExpressionHelper.GetPropertyInfo<DataTypeDefinition, string>(x => x.Path);
+            public readonly PropertyInfo UserIdSelector = ExpressionHelper.GetPropertyInfo<DataTypeDefinition, int>(x => x.CreatorId);
+            public readonly PropertyInfo TrashedSelector = ExpressionHelper.GetPropertyInfo<DataTypeDefinition, bool>(x => x.Trashed);
+            public readonly PropertyInfo PropertyEditorAliasSelector = ExpressionHelper.GetPropertyInfo<DataTypeDefinition, string>(x => x.PropertyEditorAlias);
+            public readonly PropertyInfo DatabaseTypeSelector = ExpressionHelper.GetPropertyInfo<DataTypeDefinition, DataTypeDatabaseType>(x => x.DatabaseType);
+        }
 
         /// <summary>
         /// Gets or sets the Id of the Parent entity
@@ -83,14 +88,7 @@ namespace Umbraco.Core.Models
         public int ParentId
         {
             get { return _parentId; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _parentId = value;
-                    return _parentId;
-                }, _parentId, ParentIdSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _parentId, Ps.Value.ParentIdSelector); }
         }
 
         /// <summary>
@@ -100,14 +98,7 @@ namespace Umbraco.Core.Models
         public string Name
         {
             get { return _name; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _name = value;
-                    return _name;
-                }, _name, NameSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _name, Ps.Value.NameSelector); }
         }
 
         /// <summary>
@@ -117,14 +108,7 @@ namespace Umbraco.Core.Models
         public int SortOrder
         {
             get { return _sortOrder; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _sortOrder = value;
-                    return _sortOrder;
-                }, _sortOrder, SortOrderSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _sortOrder, Ps.Value.SortOrderSelector); }
         }
 
         /// <summary>
@@ -134,14 +118,7 @@ namespace Umbraco.Core.Models
         public int Level
         {
             get { return _level; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _level = value;
-                    return _level;
-                }, _level, LevelSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _level, Ps.Value.LevelSelector); }
         }
 
         /// <summary>
@@ -151,14 +128,7 @@ namespace Umbraco.Core.Models
         public string Path //Setting this value should be handled by the class not the user
         {
             get { return _path; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _path = value;
-                    return _path;
-                }, _path, PathSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _path, Ps.Value.PathSelector); }
         }
 
         /// <summary>
@@ -168,14 +138,7 @@ namespace Umbraco.Core.Models
         public int CreatorId
         {
             get { return _creatorId; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _creatorId = value;
-                    return _creatorId;
-                }, _creatorId, UserIdSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _creatorId, Ps.Value.UserIdSelector); }
         }
 
         //NOTE: SD: Why do we have this ??
@@ -189,11 +152,7 @@ namespace Umbraco.Core.Models
             get { return _trashed; }
             internal set
             {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _trashed = value;
-                    return _trashed;
-                }, _trashed, TrashedSelector);
+                SetPropertyValueAndDetectChanges(value, ref _trashed, Ps.Value.TrashedSelector);
                 //This is a custom property that is not exposed in IUmbracoEntity so add it to the additional data
                 _additionalData["Trashed"] = value;
             }
@@ -205,11 +164,7 @@ namespace Umbraco.Core.Models
             get { return _propertyEditorAlias; }
             set
             {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _propertyEditorAlias = value;
-                    return _propertyEditorAlias;
-                }, _propertyEditorAlias, PropertyEditorAliasSelector);
+                SetPropertyValueAndDetectChanges(value, ref _propertyEditorAlias, Ps.Value.PropertyEditorAliasSelector);
                 //This is a custom property that is not exposed in IUmbracoEntity so add it to the additional data
                 _additionalData["DatabaseType"] = value;
             }
@@ -245,12 +200,7 @@ namespace Umbraco.Core.Models
             get { return _databaseType; }
             set 
             {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _databaseType = value;
-                    return _databaseType;
-                }, _databaseType, DatabaseTypeSelector);
-
+                SetPropertyValueAndDetectChanges(value, ref _databaseType, Ps.Value.DatabaseTypeSelector);                
                 //This is a custom property that is not exposed in IUmbracoEntity so add it to the additional data
                 _additionalData["DatabaseType"] = value;
             }

src/Umbraco.Core/Models/DictionaryItem.cs

@@ -30,9 +30,14 @@ namespace Umbraco.Core.Models
             _translations = new List<IDictionaryTranslation>();
         }
 
-        private static readonly PropertyInfo ParentIdSelector = ExpressionHelper.GetPropertyInfo<DictionaryItem, Guid?>(x => x.ParentId);
-        private static readonly PropertyInfo ItemKeySelector = ExpressionHelper.GetPropertyInfo<DictionaryItem, string>(x => x.ItemKey);
-        private static readonly PropertyInfo TranslationsSelector = ExpressionHelper.GetPropertyInfo<DictionaryItem, IEnumerable<IDictionaryTranslation>>(x => x.Translations);
+        private static readonly Lazy<PropertySelectors> Ps = new Lazy<PropertySelectors>();
+
+        private class PropertySelectors
+        {
+            public readonly PropertyInfo ParentIdSelector = ExpressionHelper.GetPropertyInfo<DictionaryItem, Guid?>(x => x.ParentId);
+            public readonly PropertyInfo ItemKeySelector = ExpressionHelper.GetPropertyInfo<DictionaryItem, string>(x => x.ItemKey);
+            public readonly PropertyInfo TranslationsSelector = ExpressionHelper.GetPropertyInfo<DictionaryItem, IEnumerable<IDictionaryTranslation>>(x => x.Translations);
+        }
 
         /// <summary>
         /// Gets or Sets the Parent Id of the Dictionary Item
@@ -41,14 +46,7 @@ namespace Umbraco.Core.Models
         public Guid? ParentId
         {
             get { return _parentId; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _parentId = value;
-                    return _parentId;
-                }, _parentId, ParentIdSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _parentId, Ps.Value.ParentIdSelector); }
         }
 
         /// <summary>
@@ -58,14 +56,7 @@ namespace Umbraco.Core.Models
         public string ItemKey
         {
             get { return _itemKey; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _itemKey = value;
-                    return _itemKey;
-                }, _itemKey, ItemKeySelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _itemKey, Ps.Value.ItemKeySelector); }
         }
 
         /// <summary>
@@ -77,25 +68,21 @@ namespace Umbraco.Core.Models
             get { return _translations; }
             set
             {
-                SetPropertyValueAndDetectChanges(o =>
+                var asArray = value.ToArray();
+                //ensure the language callback is set on each translation
+                if (GetLanguage != null)
                 {
-                    var asArray = value.ToArray();
-                    //ensure the language callback is set on each translation
-                    if (GetLanguage != null)
+                    foreach (var translation in asArray.OfType<DictionaryTranslation>())
                     {
-                        foreach (var translation in asArray.OfType<DictionaryTranslation>())
-                        {
-                            translation.GetLanguage = GetLanguage;
-                        }
+                        translation.GetLanguage = GetLanguage;
                     }
+                }
 
-                    _translations = asArray;                    
-                    return _translations;
-                }, _translations, TranslationsSelector,
+                SetPropertyValueAndDetectChanges(asArray, ref _translations, Ps.Value.TranslationsSelector,
                     //Custom comparer for enumerable
                     new DelegateEqualityComparer<IEnumerable<IDictionaryTranslation>>(
                         (enumerable, translations) => enumerable.UnsortedSequenceEqual(translations),
-                        enumerable => enumerable.GetHashCode()));
+                        enumerable => enumerable.GetHashCode()));                
             }
         }
     }

src/Umbraco.Core/Models/DictionaryTranslation.cs

@@ -19,7 +19,7 @@ namespace Umbraco.Core.Models
         private string _value;
         //note: this will be memberwise cloned
         private int _languageId;
-
+        
         public DictionaryTranslation(ILanguage language, string value)
         {
             if (language == null) throw new ArgumentNullException("language");
@@ -50,8 +50,13 @@ namespace Umbraco.Core.Models
             Key = uniqueId;
         }
 
-        private static readonly PropertyInfo LanguageSelector = ExpressionHelper.GetPropertyInfo<DictionaryTranslation, ILanguage>(x => x.Language);
-        private static readonly PropertyInfo ValueSelector = ExpressionHelper.GetPropertyInfo<DictionaryTranslation, string>(x => x.Value);
+        private static readonly Lazy<PropertySelectors> Ps = new Lazy<PropertySelectors>();
+
+        private class PropertySelectors
+        {
+            public readonly PropertyInfo LanguageSelector = ExpressionHelper.GetPropertyInfo<DictionaryTranslation, ILanguage>(x => x.Language);
+            public readonly PropertyInfo ValueSelector = ExpressionHelper.GetPropertyInfo<DictionaryTranslation, string>(x => x.Value);
+        }
 
         /// <summary>
         /// Gets or sets the <see cref="Language"/> for the translation
@@ -79,12 +84,8 @@ namespace Umbraco.Core.Models
             }
             set
             {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _language = value;
-                    _languageId = _language == null ? -1 : _language.Id;
-                    return _language;
-                }, _language, LanguageSelector);
+                SetPropertyValueAndDetectChanges(value, ref _language, Ps.Value.LanguageSelector);
+                _languageId = _language == null ? -1 : _language.Id;                
             }
         }
 
@@ -100,14 +101,7 @@ namespace Umbraco.Core.Models
         public string Value
         {
             get { return _value; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _value = value;
-                    return _value;
-                }, _value, ValueSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _value, Ps.Value.ValueSelector); }
         }
 
         public override object DeepClone()

src/Umbraco.Core/Models/EntityBase/Entity.cs

@@ -23,13 +23,17 @@ namespace Umbraco.Core.Models.EntityBase
         private DateTime _updateDate;
         private bool _wasCancelled;
 
-        private static readonly PropertyInfo IdSelector = ExpressionHelper.GetPropertyInfo<Entity, int>(x => x.Id);
-        private static readonly PropertyInfo KeySelector = ExpressionHelper.GetPropertyInfo<Entity, Guid>(x => x.Key);
-        private static readonly PropertyInfo CreateDateSelector = ExpressionHelper.GetPropertyInfo<Entity, DateTime>(x => x.CreateDate);
-        private static readonly PropertyInfo UpdateDateSelector = ExpressionHelper.GetPropertyInfo<Entity, DateTime>(x => x.UpdateDate);
-        private static readonly PropertyInfo HasIdentitySelector = ExpressionHelper.GetPropertyInfo<Entity, bool>(x => x.HasIdentity);
-        private static readonly PropertyInfo WasCancelledSelector = ExpressionHelper.GetPropertyInfo<Entity, bool>(x => x.WasCancelled);
-        
+        private static readonly Lazy<PropertySelectors> Ps = new Lazy<PropertySelectors>();
+
+        private class PropertySelectors
+        {
+            public readonly PropertyInfo IdSelector = ExpressionHelper.GetPropertyInfo<Entity, int>(x => x.Id);
+            public readonly PropertyInfo KeySelector = ExpressionHelper.GetPropertyInfo<Entity, Guid>(x => x.Key);
+            public readonly PropertyInfo CreateDateSelector = ExpressionHelper.GetPropertyInfo<Entity, DateTime>(x => x.CreateDate);
+            public readonly PropertyInfo UpdateDateSelector = ExpressionHelper.GetPropertyInfo<Entity, DateTime>(x => x.UpdateDate);
+            public readonly PropertyInfo HasIdentitySelector = ExpressionHelper.GetPropertyInfo<Entity, bool>(x => x.HasIdentity);
+            public readonly PropertyInfo WasCancelledSelector = ExpressionHelper.GetPropertyInfo<Entity, bool>(x => x.WasCancelled);
+        }
 
         /// <summary>
         /// Integer Id
@@ -37,18 +41,11 @@ namespace Umbraco.Core.Models.EntityBase
         [DataMember]
         public int Id
         {
-            get
-            {
-                return _id;
-            }
+            get { return _id; }
             set
             {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _id = value;
-                    HasIdentity = true; //set the has Identity
-                    return _id;
-                }, _id, IdSelector);
+                SetPropertyValueAndDetectChanges(value, ref _id, Ps.Value.IdSelector);
+                HasIdentity = true; //set the has Identity
             }
         }
         
@@ -67,14 +64,7 @@ namespace Umbraco.Core.Models.EntityBase
                     _key = Guid.NewGuid();
                 return _key;
             }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _key = value;
-                    return _key;
-                }, _key, KeySelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _key, Ps.Value.KeySelector); }
         }
 
         /// <summary>
@@ -84,14 +74,7 @@ namespace Umbraco.Core.Models.EntityBase
         public DateTime CreateDate
         {
             get { return _createDate; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _createDate = value;
-                    return _createDate;
-                }, _createDate, CreateDateSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _createDate, Ps.Value.CreateDateSelector); }            
         }
 
         /// <summary>
@@ -105,14 +88,7 @@ namespace Umbraco.Core.Models.EntityBase
         internal bool WasCancelled
         {
             get { return _wasCancelled; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _wasCancelled = value;
-                    return _wasCancelled;
-                }, _wasCancelled, WasCancelledSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _wasCancelled, Ps.Value.WasCancelledSelector); }            
         }
 
         /// <summary>
@@ -122,14 +98,7 @@ namespace Umbraco.Core.Models.EntityBase
         public DateTime UpdateDate
         {
             get { return _updateDate; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _updateDate = value;
-                    return _updateDate;
-                }, _updateDate, UpdateDateSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _updateDate, Ps.Value.UpdateDateSelector); }           
         }
 
         internal virtual void ResetIdentity()
@@ -166,14 +135,7 @@ namespace Umbraco.Core.Models.EntityBase
             {
                 return _hasIdentity;
             }
-            protected set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _hasIdentity = value;
-                    return _hasIdentity;
-                }, _hasIdentity, HasIdentitySelector);
-            }
+            protected set { SetPropertyValueAndDetectChanges(value, ref _hasIdentity, Ps.Value.HasIdentitySelector); }
         }
 
         //TODO: Make this NOT virtual or even exist really!

src/Umbraco.Core/Models/EntityBase/TracksChangesEntityBase.cs

@@ -18,7 +18,9 @@ namespace Umbraco.Core.Models.EntityBase
         //TODO: This needs to go on to ICanBeDirty http://issues.umbraco.org/issue/U4-5662
         public virtual IEnumerable<string> GetDirtyProperties()
         {
-            return _propertyChangedInfo.Where(x => x.Value).Select(x => x.Key);
+            return _propertyChangedInfo == null
+                ? Enumerable.Empty<string>()
+                : _propertyChangedInfo.Where(x => x.Value).Select(x => x.Key);
         }
 
         private bool _changeTrackingEnabled = true;
@@ -26,12 +28,12 @@ namespace Umbraco.Core.Models.EntityBase
         /// <summary>
         /// Tracks the properties that have changed
         /// </summary>
-        private IDictionary<string, bool> _propertyChangedInfo = new Dictionary<string, bool>();
+        private IDictionary<string, bool> _propertyChangedInfo;
 
         /// <summary>
         /// Tracks the properties that we're changed before the last commit (or last call to ResetDirtyProperties)
         /// </summary>
-        private IDictionary<string, bool> _lastPropertyChangedInfo = null;
+        private IDictionary<string, bool> _lastPropertyChangedInfo;
 
         /// <summary>
         /// Property changed event
@@ -47,12 +49,13 @@ namespace Umbraco.Core.Models.EntityBase
             //return if we're not tracking changes
             if (_changeTrackingEnabled == false) return;
 
+            if (_propertyChangedInfo == null)
+                _propertyChangedInfo = new Dictionary<string, bool>();
+
             _propertyChangedInfo[propertyInfo.Name] = true;
 
             if (PropertyChanged != null)
-            {
-                PropertyChanged(this, new PropertyChangedEventArgs(propertyInfo.Name));
-            }
+                PropertyChanged.Invoke(this, new PropertyChangedEventArgs(propertyInfo.Name));
         }
 
         /// <summary>
@@ -62,7 +65,7 @@ namespace Umbraco.Core.Models.EntityBase
         /// <returns>True if Property is dirty, otherwise False</returns>
         public virtual bool IsPropertyDirty(string propertyName)
         {
-            return _propertyChangedInfo.Any(x => x.Key == propertyName);
+            return _propertyChangedInfo != null && _propertyChangedInfo.Any(x => x.Key == propertyName);
         }
 
         /// <summary>
@@ -71,7 +74,7 @@ namespace Umbraco.Core.Models.EntityBase
         /// <returns>True if entity is dirty, otherwise False</returns>
         public virtual bool IsDirty()
         {
-            return _propertyChangedInfo.Any();
+            return _propertyChangedInfo != null && _propertyChangedInfo.Any();
         }
 
         /// <summary>
@@ -90,7 +93,7 @@ namespace Umbraco.Core.Models.EntityBase
         /// <returns>True if Property was changed, otherwise False. Returns false if the entity had not been previously changed.</returns>
         public virtual bool WasPropertyDirty(string propertyName)
         {
-            return WasDirty() && _lastPropertyChangedInfo.Any(x => x.Key == propertyName);
+            return _lastPropertyChangedInfo != null && _lastPropertyChangedInfo.Any(x => x.Key == propertyName);
         }
 
         /// <summary>
@@ -100,7 +103,7 @@ namespace Umbraco.Core.Models.EntityBase
         {
             //NOTE: We cannot .Clear() because when we memberwise clone this will be the SAME
             // instance as the one on the clone, so we need to create a new instance.
-            _lastPropertyChangedInfo = new Dictionary<string, bool>();
+            _lastPropertyChangedInfo = null;
         }
 
         /// <summary>
@@ -130,26 +133,29 @@ namespace Umbraco.Core.Models.EntityBase
             if (rememberPreviouslyChangedProperties)
             {
                 //copy the changed properties to the last changed properties
-                _lastPropertyChangedInfo = _propertyChangedInfo.ToDictionary(v => v.Key, v => v.Value);
+                if (_propertyChangedInfo != null)
+                {
+                    _lastPropertyChangedInfo = _propertyChangedInfo.ToDictionary(v => v.Key, v => v.Value);
+                }
             }
 
             //NOTE: We cannot .Clear() because when we memberwise clone this will be the SAME
             // instance as the one on the clone, so we need to create a new instance.
-            _propertyChangedInfo = new Dictionary<string, bool>();
+            _propertyChangedInfo = null;
         }
 
-        protected void ResetChangeTrackingCollections()
+        public void ResetChangeTrackingCollections()
         {
-            _propertyChangedInfo = new Dictionary<string, bool>();
-            _lastPropertyChangedInfo = new Dictionary<string, bool>();
+            _propertyChangedInfo = null;
+            _lastPropertyChangedInfo = null;
         }
 
-        protected void DisableChangeTracking()
+        public void DisableChangeTracking()
         {
             _changeTrackingEnabled = false;
         }
 
-        protected void EnableChangeTracking()
+        public void EnableChangeTracking()
         {
             _changeTrackingEnabled = true;
         }
@@ -158,60 +164,61 @@ namespace Umbraco.Core.Models.EntityBase
         /// Used by inheritors to set the value of properties, this will detect if the property value actually changed and if it did
         /// it will ensure that the property has a dirty flag set.
         /// </summary>
-        /// <param name="setValue"></param>
-        /// <param name="value"></param>
+        /// <param name="newVal"></param>
+        /// <param name="origVal"></param>
         /// <param name="propertySelector"></param>
         /// <returns>returns true if the value changed</returns>
         /// <remarks>
-        /// This is required because we don't want a property to show up as "dirty" if the value is the same. For example, when we 
-        /// save a document type, nearly all properties are flagged as dirty just because we've 'reset' them, but they are all set 
+        /// This is required because we don't want a property to show up as "dirty" if the value is the same. For example, when we
+        /// save a document type, nearly all properties are flagged as dirty just because we've 'reset' them, but they are all set
         /// to the same value, so it's really not dirty.
         /// </remarks>
-        internal bool SetPropertyValueAndDetectChanges<T>(Func<T, T> setValue, T value, PropertyInfo propertySelector)
+        internal void SetPropertyValueAndDetectChanges<T>(T newVal, ref T origVal, PropertyInfo propertySelector)
         {
             if ((typeof(T) == typeof(string) == false) && TypeHelper.IsTypeAssignableFrom<IEnumerable>(typeof(T)))
             {
                 throw new InvalidOperationException("This method does not support IEnumerable instances. For IEnumerable instances a manual custom equality check will be required");
             }
 
-            return SetPropertyValueAndDetectChanges(setValue, value, propertySelector,
-                new DelegateEqualityComparer<T>(
-                    //Standard Equals comparison
-                    (arg1, arg2) => Equals(arg1, arg2),
-                    arg => arg.GetHashCode()));
-
+            SetPropertyValueAndDetectChanges(newVal, ref origVal, propertySelector, EqualityComparer<T>.Default);
         }
 
         /// <summary>
         /// Used by inheritors to set the value of properties, this will detect if the property value actually changed and if it did
         /// it will ensure that the property has a dirty flag set.
         /// </summary>
-        /// <param name="setValue"></param>
-        /// <param name="value"></param>
+        /// <param name="newVal"></param>
+        /// <param name="origVal"></param>
         /// <param name="propertySelector"></param>
         /// <param name="comparer">The equality comparer to use</param>
         /// <returns>returns true if the value changed</returns>
         /// <remarks>
-        /// This is required because we don't want a property to show up as "dirty" if the value is the same. For example, when we 
-        /// save a document type, nearly all properties are flagged as dirty just because we've 'reset' them, but they are all set 
+        /// This is required because we don't want a property to show up as "dirty" if the value is the same. For example, when we
+        /// save a document type, nearly all properties are flagged as dirty just because we've 'reset' them, but they are all set
         /// to the same value, so it's really not dirty.
         /// </remarks>
-        internal bool SetPropertyValueAndDetectChanges<T>(Func<T, T> setValue, T value, PropertyInfo propertySelector, IEqualityComparer<T> comparer)
+        internal void SetPropertyValueAndDetectChanges<T>(T newVal, ref T origVal, PropertyInfo propertySelector, IEqualityComparer<T> comparer)
         {
-            var initVal = value;
-            var newVal = setValue(value);
-
-            //don't track changes, just set the value (above)
-            if (_changeTrackingEnabled == false) return false;
-
-            if (comparer.Equals(initVal, newVal) == false)
+            //don't track changes, just set the value
+            if (_changeTrackingEnabled == false)
             {
-                OnPropertyChanged(propertySelector);
-                return true;
+                //set the original value
+                origVal = newVal;
+            }
+            else
+            {
+                //check changed
+                var changed = comparer.Equals(origVal, newVal) == false;
+
+                //set the original value
+                origVal = newVal;
+
+                //raise the event if it was changed
+                if (changed)
+                {
+                    OnPropertyChanged(propertySelector);
+                }
             }
-            return false;
         }
-
-
     }
 }

src/Umbraco.Core/Models/File.cs

@@ -33,8 +33,14 @@ namespace Umbraco.Core.Models
             _content = getFileContent != null ? null : string.Empty;
         }
 
-        private static readonly PropertyInfo ContentSelector = ExpressionHelper.GetPropertyInfo<File, string>(x => x.Content);
-        private static readonly PropertyInfo PathSelector = ExpressionHelper.GetPropertyInfo<File, string>(x => x.Path);
+        private static readonly Lazy<PropertySelectors> Ps = new Lazy<PropertySelectors>();
+
+        private class PropertySelectors
+        {
+            public readonly PropertyInfo ContentSelector = ExpressionHelper.GetPropertyInfo<File, string>(x => x.Content);
+            public readonly PropertyInfo PathSelector = ExpressionHelper.GetPropertyInfo<File, string>(x => x.Path);
+        }
+
         private string _alias;
         private string _name;
 
@@ -87,11 +93,7 @@ namespace Umbraco.Core.Models
                 _alias = null;
                 _name = null;
 
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _path = SanitizePath(value);
-                    return _path;
-                }, _path, PathSelector);
+                SetPropertyValueAndDetectChanges(SanitizePath(value), ref _path, Ps.Value.PathSelector);                
             }
         }
 
@@ -131,11 +133,9 @@ namespace Umbraco.Core.Models
             }
             set
             {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _content = value ?? string.Empty; // cannot set to null
-                    return _content;
-                }, _content, ContentSelector);
+                SetPropertyValueAndDetectChanges(
+                    value ?? string.Empty, // cannot set to null
+                    ref _content, Ps.Value.ContentSelector);                
             }
         }
 

src/Umbraco.Core/Models/IMigrationEntry.cs

@@ -1,4 +1,5 @@
-using Semver;
+using System;
+using Semver;
 using Umbraco.Core.Models.EntityBase;
 
 namespace Umbraco.Core.Models

src/Umbraco.Core/Models/IRedirectUrl.cs

@@ -0,0 +1,37 @@
+using System;
+using System.Runtime.Serialization;
+using Umbraco.Core.Models.EntityBase;
+
+namespace Umbraco.Core.Models
+{
+    /// <summary>
+    /// Represents a redirect url.
+    /// </summary>
+    public interface IRedirectUrl : IAggregateRoot, IRememberBeingDirty
+    {
+        /// <summary>
+        /// Gets or sets the identifier of the content item.
+        /// </summary>
+        [DataMember]
+        int ContentId { get; set; }
+
+        /// <summary>
+        /// Gets or sets the unique key identifying the content item.
+        /// </summary>
+        [DataMember]
+        Guid ContentKey { get; set; }
+
+        /// <summary>
+        /// Gets or sets the redirect url creation date.
+        /// </summary>
+        [DataMember]
+        DateTime CreateDateUtc { get; set; }
+
+        /// <summary>
+        /// Gets or sets the redirect url route.
+        /// </summary>
+        /// <remarks>Is a proper Umbraco route eg /path/to/foo or 123/path/tofoo.</remarks>
+        [DataMember]
+        string Url { get; set; }
+    }
+}

src/Umbraco.Core/Models/Language.cs

@@ -21,8 +21,13 @@ namespace Umbraco.Core.Models
             IsoCode = isoCode;
         }
 
-        private static readonly PropertyInfo IsoCodeSelector = ExpressionHelper.GetPropertyInfo<Language, string>(x => x.IsoCode);
-        private static readonly PropertyInfo CultureNameSelector = ExpressionHelper.GetPropertyInfo<Language, string>(x => x.CultureName);
+        private static readonly Lazy<PropertySelectors> Ps = new Lazy<PropertySelectors>();
+
+        private class PropertySelectors
+        {
+            public readonly PropertyInfo IsoCodeSelector = ExpressionHelper.GetPropertyInfo<Language, string>(x => x.IsoCode);
+            public readonly PropertyInfo CultureNameSelector = ExpressionHelper.GetPropertyInfo<Language, string>(x => x.CultureName);
+        }
 
         /// <summary>
         /// Gets or sets the Iso Code for the Language
@@ -31,14 +36,7 @@ namespace Umbraco.Core.Models
         public string IsoCode
         {
             get { return _isoCode; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _isoCode = value;
-                    return _isoCode;
-                }, _isoCode, IsoCodeSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _isoCode, Ps.Value.IsoCodeSelector); }
         }
 
         /// <summary>
@@ -48,14 +46,7 @@ namespace Umbraco.Core.Models
         public string CultureName
         {
             get { return _cultureName; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _cultureName = value;
-                    return _cultureName;
-                }, _cultureName, CultureNameSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _cultureName, Ps.Value.CultureNameSelector); }
         }
 
         /// <summary>

src/Umbraco.Core/Models/Macro.cs

@@ -114,22 +114,27 @@ namespace Umbraco.Core.Models
         private List<string> _addedProperties;
         private List<string> _removedProperties;
 
-        private static readonly PropertyInfo AliasSelector = ExpressionHelper.GetPropertyInfo<Macro, string>(x => x.Alias);
-        private static readonly PropertyInfo NameSelector = ExpressionHelper.GetPropertyInfo<Macro, string>(x => x.Name);
-        private static readonly PropertyInfo UseInEditorSelector = ExpressionHelper.GetPropertyInfo<Macro, bool>(x => x.UseInEditor);
-        private static readonly PropertyInfo CacheDurationSelector = ExpressionHelper.GetPropertyInfo<Macro, int>(x => x.CacheDuration);
-        private static readonly PropertyInfo CacheByPageSelector = ExpressionHelper.GetPropertyInfo<Macro, bool>(x => x.CacheByPage);
-        private static readonly PropertyInfo CacheByMemberSelector = ExpressionHelper.GetPropertyInfo<Macro, bool>(x => x.CacheByMember);
-        private static readonly PropertyInfo DontRenderSelector = ExpressionHelper.GetPropertyInfo<Macro, bool>(x => x.DontRender);
-        private static readonly PropertyInfo ControlPathSelector = ExpressionHelper.GetPropertyInfo<Macro, string>(x => x.ControlType);
-        private static readonly PropertyInfo ControlAssemblySelector = ExpressionHelper.GetPropertyInfo<Macro, string>(x => x.ControlAssembly);
-        private static readonly PropertyInfo ScriptPathSelector = ExpressionHelper.GetPropertyInfo<Macro, string>(x => x.ScriptPath);
-        private static readonly PropertyInfo XsltPathSelector = ExpressionHelper.GetPropertyInfo<Macro, string>(x => x.XsltPath);
-        private static readonly PropertyInfo PropertiesSelector = ExpressionHelper.GetPropertyInfo<Macro, MacroPropertyCollection>(x => x.Properties);
+        private static readonly Lazy<PropertySelectors> Ps = new Lazy<PropertySelectors>();
+
+        private class PropertySelectors
+        {
+            public readonly PropertyInfo AliasSelector = ExpressionHelper.GetPropertyInfo<Macro, string>(x => x.Alias);
+            public readonly PropertyInfo NameSelector = ExpressionHelper.GetPropertyInfo<Macro, string>(x => x.Name);
+            public readonly PropertyInfo UseInEditorSelector = ExpressionHelper.GetPropertyInfo<Macro, bool>(x => x.UseInEditor);
+            public readonly PropertyInfo CacheDurationSelector = ExpressionHelper.GetPropertyInfo<Macro, int>(x => x.CacheDuration);
+            public readonly PropertyInfo CacheByPageSelector = ExpressionHelper.GetPropertyInfo<Macro, bool>(x => x.CacheByPage);
+            public readonly PropertyInfo CacheByMemberSelector = ExpressionHelper.GetPropertyInfo<Macro, bool>(x => x.CacheByMember);
+            public readonly PropertyInfo DontRenderSelector = ExpressionHelper.GetPropertyInfo<Macro, bool>(x => x.DontRender);
+            public readonly PropertyInfo ControlPathSelector = ExpressionHelper.GetPropertyInfo<Macro, string>(x => x.ControlType);
+            public readonly PropertyInfo ControlAssemblySelector = ExpressionHelper.GetPropertyInfo<Macro, string>(x => x.ControlAssembly);
+            public readonly PropertyInfo ScriptPathSelector = ExpressionHelper.GetPropertyInfo<Macro, string>(x => x.ScriptPath);
+            public readonly PropertyInfo XsltPathSelector = ExpressionHelper.GetPropertyInfo<Macro, string>(x => x.XsltPath);
+            public readonly PropertyInfo PropertiesSelector = ExpressionHelper.GetPropertyInfo<Macro, MacroPropertyCollection>(x => x.Properties);
+        }
 
         void PropertiesChanged(object sender, NotifyCollectionChangedEventArgs e)
         {
-            OnPropertyChanged(PropertiesSelector);
+            OnPropertyChanged(Ps.Value.PropertiesSelector);
 
             if (e.Action == NotifyCollectionChangedAction.Add)
             {
@@ -167,7 +172,7 @@ namespace Umbraco.Core.Models
         /// <param name="e"></param>
         void PropertyDataChanged(object sender, PropertyChangedEventArgs e)
         {
-            OnPropertyChanged(PropertiesSelector);
+            OnPropertyChanged(Ps.Value.PropertiesSelector);
         }
         
         public override void ResetDirtyProperties(bool rememberPreviouslyChangedProperties)
@@ -204,14 +209,7 @@ namespace Umbraco.Core.Models
         public string Alias
         {
             get { return _alias; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _alias = value.ToCleanString(CleanStringType.Alias);
-                    return _alias;
-                }, _alias, AliasSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value.ToCleanString(CleanStringType.Alias), ref _alias, Ps.Value.AliasSelector); }
         }
 
         /// <summary>
@@ -221,14 +219,7 @@ namespace Umbraco.Core.Models
         public string Name
         {
             get { return _name; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _name = value;
-                    return _name;
-                }, _name, NameSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _name, Ps.Value.NameSelector); }
         }
 
         /// <summary>
@@ -238,14 +229,7 @@ namespace Umbraco.Core.Models
         public bool UseInEditor
         {
             get { return _useInEditor; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _useInEditor = value;
-                    return _useInEditor;
-                }, _useInEditor, UseInEditorSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _useInEditor, Ps.Value.UseInEditorSelector); }
         }
 
         /// <summary>
@@ -255,14 +239,7 @@ namespace Umbraco.Core.Models
         public int CacheDuration
         {
             get { return _cacheDuration; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _cacheDuration = value;
-                    return _cacheDuration;
-                }, _cacheDuration, CacheDurationSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _cacheDuration, Ps.Value.CacheDurationSelector); }
         }
 
         /// <summary>
@@ -272,14 +249,7 @@ namespace Umbraco.Core.Models
         public bool CacheByPage
         {
             get { return _cacheByPage; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _cacheByPage = value;
-                    return _cacheByPage;
-                }, _cacheByPage, CacheByPageSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _cacheByPage, Ps.Value.CacheByPageSelector); }
         }
 
         /// <summary>
@@ -289,14 +259,7 @@ namespace Umbraco.Core.Models
         public bool CacheByMember
         {
             get { return _cacheByMember; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _cacheByMember = value;
-                    return _cacheByMember;
-                }, _cacheByMember, CacheByMemberSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _cacheByMember, Ps.Value.CacheByMemberSelector); }
         }
 
         /// <summary>
@@ -306,14 +269,7 @@ namespace Umbraco.Core.Models
         public bool DontRender
         {
             get { return _dontRender; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _dontRender = value;
-                    return _dontRender;
-                }, _dontRender, DontRenderSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _dontRender, Ps.Value.DontRenderSelector); }
         }
 
         /// <summary>
@@ -323,14 +279,7 @@ namespace Umbraco.Core.Models
         public string ControlType
         {
             get { return _scriptFile; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _scriptFile = value;
-                    return _scriptFile;
-                }, _scriptFile, ControlPathSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _scriptFile, Ps.Value.ControlPathSelector); }
         }
 
         /// <summary>
@@ -341,14 +290,7 @@ namespace Umbraco.Core.Models
         public string ControlAssembly
         {
             get { return _scriptAssembly; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _scriptAssembly = value;
-                    return _scriptAssembly;
-                }, _scriptAssembly, ControlAssemblySelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _scriptAssembly, Ps.Value.ControlAssemblySelector); }
         }
 
         /// <summary>
@@ -359,14 +301,7 @@ namespace Umbraco.Core.Models
         public string ScriptPath
         {
             get { return _scriptPath; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _scriptPath = value;
-                    return _scriptPath;
-                }, _scriptPath, ScriptPathSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _scriptPath, Ps.Value.ScriptPathSelector); }
         }
 
         /// <summary>
@@ -377,14 +312,7 @@ namespace Umbraco.Core.Models
         public string XsltPath
         {
             get { return _xslt; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _xslt = value;
-                    return _xslt;
-                }, _xslt, XsltPathSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _xslt, Ps.Value.XsltPathSelector); }
         }
 
         /// <summary>

src/Umbraco.Core/Models/MacroProperty.cs

@@ -72,11 +72,16 @@ namespace Umbraco.Core.Models
         private int _id;
         private string _editorAlias;
 
-        private static readonly PropertyInfo AliasSelector = ExpressionHelper.GetPropertyInfo<MacroProperty, string>(x => x.Alias);
-        private static readonly PropertyInfo NameSelector = ExpressionHelper.GetPropertyInfo<MacroProperty, string>(x => x.Name);
-        private static readonly PropertyInfo SortOrderSelector = ExpressionHelper.GetPropertyInfo<MacroProperty, int>(x => x.SortOrder);
-        private static readonly PropertyInfo IdSelector = ExpressionHelper.GetPropertyInfo<Entity, int>(x => x.Id);
-        private static readonly PropertyInfo PropertyTypeSelector = ExpressionHelper.GetPropertyInfo<MacroProperty, string>(x => x.EditorAlias);
+        private static readonly Lazy<PropertySelectors> Ps = new Lazy<PropertySelectors>();
+
+        private class PropertySelectors
+        {
+            public readonly PropertyInfo AliasSelector = ExpressionHelper.GetPropertyInfo<MacroProperty, string>(x => x.Alias);
+            public readonly PropertyInfo NameSelector = ExpressionHelper.GetPropertyInfo<MacroProperty, string>(x => x.Name);
+            public readonly PropertyInfo SortOrderSelector = ExpressionHelper.GetPropertyInfo<MacroProperty, int>(x => x.SortOrder);
+            public readonly PropertyInfo IdSelector = ExpressionHelper.GetPropertyInfo<Entity, int>(x => x.Id);
+            public readonly PropertyInfo PropertyTypeSelector = ExpressionHelper.GetPropertyInfo<MacroProperty, string>(x => x.EditorAlias);
+        }
 
         /// <summary>
         /// Gets or sets the Alias of the Property
@@ -85,14 +90,7 @@ namespace Umbraco.Core.Models
         public int Id
         {
             get { return _id; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _id = value;
-                    return _alias;
-                }, _alias, IdSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _id, Ps.Value.IdSelector); }
         }
 
         /// <summary>
@@ -102,14 +100,7 @@ namespace Umbraco.Core.Models
         public string Alias
         {
             get { return _alias; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _alias = value;
-                    return _alias;
-                }, _alias, AliasSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _alias, Ps.Value.AliasSelector); }
         }
 
         /// <summary>
@@ -119,14 +110,7 @@ namespace Umbraco.Core.Models
         public string Name
         {
             get { return _name; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _name = value;
-                    return _name;
-                }, _name, NameSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _name, Ps.Value.NameSelector); }
         }
 
         /// <summary>
@@ -136,14 +120,7 @@ namespace Umbraco.Core.Models
         public int SortOrder
         {
             get { return _sortOrder; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _sortOrder = value;
-                    return _sortOrder;
-                }, _sortOrder, SortOrderSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _sortOrder, Ps.Value.SortOrderSelector); }
         }
 
         /// <summary>
@@ -159,21 +136,10 @@ namespace Umbraco.Core.Models
             get { return _editorAlias; }
             set
             {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    //try to get the new mapped parameter editor
-                    var mapped = LegacyParameterEditorAliasConverter.GetNewAliasFromLegacyAlias(value, false);
-                    if (mapped.IsNullOrWhiteSpace() == false)
-                    {
-                        _editorAlias = mapped;
-                    }
-                    else
-                    {
-                        _editorAlias = value;
-                    }
-
-                    return _editorAlias;
-                }, _editorAlias, PropertyTypeSelector);
+                //try to get the new mapped parameter editor
+                var mapped = LegacyParameterEditorAliasConverter.GetNewAliasFromLegacyAlias(value, false);
+                var newVal = mapped.IsNullOrWhiteSpace() == false ? mapped : value;
+                SetPropertyValueAndDetectChanges(newVal, ref _editorAlias, Ps.Value.PropertyTypeSelector);                
             }
         }
 

src/Umbraco.Core/Models/Member.cs

@@ -109,10 +109,15 @@ namespace Umbraco.Core.Models
             IsApproved = true;
         }
 
-        private static readonly PropertyInfo UsernameSelector = ExpressionHelper.GetPropertyInfo<Member, string>(x => x.Username);
-        private static readonly PropertyInfo EmailSelector = ExpressionHelper.GetPropertyInfo<Member, string>(x => x.Email);
-        private static readonly PropertyInfo PasswordSelector = ExpressionHelper.GetPropertyInfo<Member, string>(x => x.RawPasswordValue);
-        private static readonly PropertyInfo ProviderUserKeySelector = ExpressionHelper.GetPropertyInfo<Member, object>(x => x.ProviderUserKey);
+        private static readonly Lazy<PropertySelectors> Ps = new Lazy<PropertySelectors>();
+
+        private class PropertySelectors
+        {
+            public readonly PropertyInfo UsernameSelector = ExpressionHelper.GetPropertyInfo<Member, string>(x => x.Username);
+            public readonly PropertyInfo EmailSelector = ExpressionHelper.GetPropertyInfo<Member, string>(x => x.Email);
+            public readonly PropertyInfo PasswordSelector = ExpressionHelper.GetPropertyInfo<Member, string>(x => x.RawPasswordValue);
+            public readonly PropertyInfo ProviderUserKeySelector = ExpressionHelper.GetPropertyInfo<Member, object>(x => x.ProviderUserKey);
+        }
 
         /// <summary>
         /// Gets or sets the Username
@@ -121,14 +126,7 @@ namespace Umbraco.Core.Models
         public string Username
         {
             get { return _username; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _username = value;
-                    return _username;
-                }, _username, UsernameSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _username, Ps.Value.UsernameSelector); }
         }
 
         /// <summary>
@@ -138,14 +136,7 @@ namespace Umbraco.Core.Models
         public string Email
         {
             get { return _email; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _email = value;
-                    return _email;
-                }, _email, EmailSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _email, Ps.Value.EmailSelector); }
         }
 
         /// <summary>
@@ -155,14 +146,7 @@ namespace Umbraco.Core.Models
         public string RawPasswordValue
         {
             get { return _rawPasswordValue; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _rawPasswordValue = value;
-                    return _rawPasswordValue;
-                }, _rawPasswordValue, PasswordSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _rawPasswordValue, Ps.Value.PasswordSelector); }
         }
 
         /// <summary>
@@ -490,14 +474,7 @@ namespace Umbraco.Core.Models
             {
                 return _providerUserKey;
             }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _providerUserKey = value;
-                    return _providerUserKey;
-                }, _providerUserKey, ProviderUserKeySelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _providerUserKey, Ps.Value.ProviderUserKeySelector); }
         }
 
       

src/Umbraco.Core/Models/MemberGroup.cs

@@ -21,8 +21,13 @@ namespace Umbraco.Core.Models
         private string _name;
         private int _creatorId;
 
-        private static readonly PropertyInfo NameSelector = ExpressionHelper.GetPropertyInfo<MemberGroup, string>(x => x.Name);
-        private static readonly PropertyInfo CreatorIdSelector = ExpressionHelper.GetPropertyInfo<MemberGroup, int>(x => x.CreatorId);
+        private static readonly Lazy<PropertySelectors> Ps = new Lazy<PropertySelectors>();
+
+        private class PropertySelectors
+        {
+            public readonly PropertyInfo NameSelector = ExpressionHelper.GetPropertyInfo<MemberGroup, string>(x => x.Name);
+            public readonly PropertyInfo CreatorIdSelector = ExpressionHelper.GetPropertyInfo<MemberGroup, int>(x => x.CreatorId);
+        }
 
         [DataMember]
         public string Name
@@ -30,33 +35,22 @@ namespace Umbraco.Core.Models
             get { return _name; }
             set
             {
-                SetPropertyValueAndDetectChanges(o =>
+                if (_name != value)
                 {
-                    if (_name != value)
-                    {
-                        //if the name has changed, add the value to the additional data,
-                        //this is required purely for event handlers to know the previous name of the group
-                        //so we can keep the public access up to date.
-                        AdditionalData["previousName"] = _name;
-                    }
+                    //if the name has changed, add the value to the additional data,
+                    //this is required purely for event handlers to know the previous name of the group
+                    //so we can keep the public access up to date.
+                    AdditionalData["previousName"] = _name;
+                }
 
-                    _name = value;
-                    return _name;
-                }, _name, NameSelector);
+                SetPropertyValueAndDetectChanges(value, ref _name, Ps.Value.NameSelector);                
             }
         }
 
         public int CreatorId
         {
             get { return _creatorId; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _creatorId = value;
-                    return _creatorId;
-                }, _creatorId, CreatorIdSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _creatorId, Ps.Value.CreatorIdSelector); }
         }
 
         public IDictionary<string, object> AdditionalData { get; private set; }

src/Umbraco.Core/Models/MemberType.cs

@@ -30,7 +30,12 @@ namespace Umbraco.Core.Models
             MemberTypePropertyTypes = new Dictionary<string, MemberTypePropertyProfileAccess>();
         }
 
-        private static readonly PropertyInfo AliasSelector = ExpressionHelper.GetPropertyInfo<MemberType, string>(x => x.Alias);
+        private static readonly Lazy<PropertySelectors> Ps = new Lazy<PropertySelectors>();
+
+        private class PropertySelectors
+        {
+            public readonly PropertyInfo AliasSelector = ExpressionHelper.GetPropertyInfo<MemberType, string>(x => x.Alias);
+        }
 
         /// <summary>
         /// The Alias of the ContentType
@@ -50,13 +55,11 @@ namespace Umbraco.Core.Models
                 // .ToCleanString(CleanStringType.Alias | CleanStringType.UmbracoCase)
                 // Need to ask Stephen
 
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _alias = value == "_umbracoSystemDefaultProtectType" 
-                        ? value 
-                        : (value == null ? string.Empty : value.ToSafeAlias() );
-                    return _alias;
-                }, _alias, AliasSelector);
+                var newVal = value == "_umbracoSystemDefaultProtectType"
+                        ? value
+                        : (value == null ? string.Empty : value.ToSafeAlias());
+
+                SetPropertyValueAndDetectChanges(newVal, ref _alias, Ps.Value.AliasSelector);
             }
         }
 

src/Umbraco.Core/Models/Membership/User.cs

@@ -77,27 +77,32 @@ namespace Umbraco.Core.Models.Membership
         
         private bool _defaultToLiveEditing;
 
-        private static readonly PropertyInfo FailedPasswordAttemptsSelector = ExpressionHelper.GetPropertyInfo<User, int>(x => x.FailedPasswordAttempts);
-        private static readonly PropertyInfo LastLockoutDateSelector = ExpressionHelper.GetPropertyInfo<User, DateTime>(x => x.LastLockoutDate);
-        private static readonly PropertyInfo LastLoginDateSelector = ExpressionHelper.GetPropertyInfo<User, DateTime>(x => x.LastLoginDate);
-        private static readonly PropertyInfo LastPasswordChangeDateSelector = ExpressionHelper.GetPropertyInfo<User, DateTime>(x => x.LastPasswordChangeDate);
+        private static readonly Lazy<PropertySelectors> Ps = new Lazy<PropertySelectors>();
 
-        private static readonly PropertyInfo SecurityStampSelector = ExpressionHelper.GetPropertyInfo<User, string>(x => x.SecurityStamp);
-        private static readonly PropertyInfo SessionTimeoutSelector = ExpressionHelper.GetPropertyInfo<User, int>(x => x.SessionTimeout);
-        private static readonly PropertyInfo StartContentIdSelector = ExpressionHelper.GetPropertyInfo<User, int>(x => x.StartContentId);
-        private static readonly PropertyInfo StartMediaIdSelector = ExpressionHelper.GetPropertyInfo<User, int>(x => x.StartMediaId);        
-        private static readonly PropertyInfo AllowedSectionsSelector = ExpressionHelper.GetPropertyInfo<User, IEnumerable<string>>(x => x.AllowedSections);
-        private static readonly PropertyInfo NameSelector = ExpressionHelper.GetPropertyInfo<User, string>(x => x.Name);
-        
-        private static readonly PropertyInfo UsernameSelector = ExpressionHelper.GetPropertyInfo<User, string>(x => x.Username);
-        private static readonly PropertyInfo EmailSelector = ExpressionHelper.GetPropertyInfo<User, string>(x => x.Email);
-        private static readonly PropertyInfo PasswordSelector = ExpressionHelper.GetPropertyInfo<User, string>(x => x.RawPasswordValue);
-        private static readonly PropertyInfo IsLockedOutSelector = ExpressionHelper.GetPropertyInfo<User, bool>(x => x.IsLockedOut);
-        private static readonly PropertyInfo IsApprovedSelector = ExpressionHelper.GetPropertyInfo<User, bool>(x => x.IsApproved);
-        private static readonly PropertyInfo LanguageSelector = ExpressionHelper.GetPropertyInfo<User, string>(x => x.Language);
+        private class PropertySelectors
+        {
+            public readonly PropertyInfo FailedPasswordAttemptsSelector = ExpressionHelper.GetPropertyInfo<User, int>(x => x.FailedPasswordAttempts);
+            public readonly PropertyInfo LastLockoutDateSelector = ExpressionHelper.GetPropertyInfo<User, DateTime>(x => x.LastLockoutDate);
+            public readonly PropertyInfo LastLoginDateSelector = ExpressionHelper.GetPropertyInfo<User, DateTime>(x => x.LastLoginDate);
+            public readonly PropertyInfo LastPasswordChangeDateSelector = ExpressionHelper.GetPropertyInfo<User, DateTime>(x => x.LastPasswordChangeDate);
 
-        private static readonly PropertyInfo DefaultToLiveEditingSelector = ExpressionHelper.GetPropertyInfo<User, bool>(x => x.DefaultToLiveEditing);
-        private static readonly PropertyInfo UserTypeSelector = ExpressionHelper.GetPropertyInfo<User, IUserType>(x => x.UserType);
+            public readonly PropertyInfo SecurityStampSelector = ExpressionHelper.GetPropertyInfo<User, string>(x => x.SecurityStamp);
+            public readonly PropertyInfo SessionTimeoutSelector = ExpressionHelper.GetPropertyInfo<User, int>(x => x.SessionTimeout);
+            public readonly PropertyInfo StartContentIdSelector = ExpressionHelper.GetPropertyInfo<User, int>(x => x.StartContentId);
+            public readonly PropertyInfo StartMediaIdSelector = ExpressionHelper.GetPropertyInfo<User, int>(x => x.StartMediaId);
+            public readonly PropertyInfo AllowedSectionsSelector = ExpressionHelper.GetPropertyInfo<User, IEnumerable<string>>(x => x.AllowedSections);
+            public readonly PropertyInfo NameSelector = ExpressionHelper.GetPropertyInfo<User, string>(x => x.Name);
+
+            public readonly PropertyInfo UsernameSelector = ExpressionHelper.GetPropertyInfo<User, string>(x => x.Username);
+            public readonly PropertyInfo EmailSelector = ExpressionHelper.GetPropertyInfo<User, string>(x => x.Email);
+            public readonly PropertyInfo PasswordSelector = ExpressionHelper.GetPropertyInfo<User, string>(x => x.RawPasswordValue);
+            public readonly PropertyInfo IsLockedOutSelector = ExpressionHelper.GetPropertyInfo<User, bool>(x => x.IsLockedOut);
+            public readonly PropertyInfo IsApprovedSelector = ExpressionHelper.GetPropertyInfo<User, bool>(x => x.IsApproved);
+            public readonly PropertyInfo LanguageSelector = ExpressionHelper.GetPropertyInfo<User, string>(x => x.Language);
+
+            public readonly PropertyInfo DefaultToLiveEditingSelector = ExpressionHelper.GetPropertyInfo<User, bool>(x => x.DefaultToLiveEditing);
+            public readonly PropertyInfo UserTypeSelector = ExpressionHelper.GetPropertyInfo<User, IUserType>(x => x.UserType);
+        }
         
         #region Implementation of IMembershipUser
 
@@ -113,124 +118,61 @@ namespace Umbraco.Core.Models.Membership
         public string Username
         {
             get { return _username; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _username = value;
-                    return _username;
-                }, _username, UsernameSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _username, Ps.Value.UsernameSelector); }
         }
         [DataMember]
         public string Email
         {
             get { return _email; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _email = value;
-                    return _email;
-                }, _email, EmailSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _email, Ps.Value.EmailSelector); }
         }
         [DataMember]
         public string RawPasswordValue
         {
             get { return _rawPasswordValue; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _rawPasswordValue = value;
-                    return _rawPasswordValue;
-                }, _rawPasswordValue, PasswordSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _rawPasswordValue, Ps.Value.PasswordSelector); }
         }
 
         [DataMember]
         public bool IsApproved
         {
             get { return _isApproved; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _isApproved = value;
-                    return _isApproved;
-                }, _isApproved, IsApprovedSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _isApproved, Ps.Value.IsApprovedSelector); }
         }
 
         [IgnoreDataMember]
         public bool IsLockedOut
         {
             get { return _isLockedOut; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _isLockedOut = value;
-                    return _isLockedOut;
-                }, _isLockedOut, IsLockedOutSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _isLockedOut, Ps.Value.IsLockedOutSelector); }
         }
 
         [IgnoreDataMember]
         public DateTime LastLoginDate
         {
             get { return _lastLoginDate; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _lastLoginDate = value;
-                    return _lastLoginDate;
-                }, _lastLoginDate, LastLoginDateSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _lastLoginDate, Ps.Value.LastLoginDateSelector); }
         }
 
         [IgnoreDataMember]
         public DateTime LastPasswordChangeDate
         {
             get { return _lastPasswordChangedDate; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _lastPasswordChangedDate = value;
-                    return _lastPasswordChangedDate;
-                }, _lastPasswordChangedDate, LastPasswordChangeDateSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _lastPasswordChangedDate, Ps.Value.LastPasswordChangeDateSelector); }
         }
 
         [IgnoreDataMember]
         public DateTime LastLockoutDate
         {
             get { return _lastLockoutDate; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _lastLockoutDate = value;
-                    return _lastLockoutDate;
-                }, _lastLockoutDate, LastLockoutDateSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _lastLockoutDate, Ps.Value.LastLockoutDateSelector); }
         }
 
         [IgnoreDataMember]
         public int FailedPasswordAttempts
         {
             get { return _failedLoginAttempts; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _failedLoginAttempts = value;
-                    return _failedLoginAttempts;
-                }, _failedLoginAttempts, FailedPasswordAttemptsSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _failedLoginAttempts, Ps.Value.FailedPasswordAttemptsSelector); }
         }
 
         //TODO: Figure out how to support all of this! - we cannot have NotImplementedExceptions because these get used by the IMembershipMemberService<IUser> service so
@@ -251,14 +193,7 @@ namespace Umbraco.Core.Models.Membership
         public string Name
         {
             get { return _name; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _name = value;
-                    return _name;
-                }, _name, NameSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _name, Ps.Value.NameSelector); }
         }
 
         public IEnumerable<string> AllowedSections
@@ -294,14 +229,7 @@ namespace Umbraco.Core.Models.Membership
         public string SecurityStamp
         {
             get { return _securityStamp; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _securityStamp = value;
-                    return _securityStamp;
-                }, _securityStamp, SecurityStampSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _securityStamp, Ps.Value.SecurityStampSelector); }
         }
 
         /// <summary>
@@ -330,14 +258,7 @@ namespace Umbraco.Core.Models.Membership
         public int SessionTimeout
         {
             get { return _sessionTimeout; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                    {
-                        _sessionTimeout = value;
-                        return _sessionTimeout;
-                    }, _sessionTimeout, SessionTimeoutSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _sessionTimeout, Ps.Value.SessionTimeoutSelector); }
         }
 
         /// <summary>
@@ -350,14 +271,7 @@ namespace Umbraco.Core.Models.Membership
         public int StartContentId
         {
             get { return _startContentId; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                    {
-                        _startContentId = value;
-                        return _startContentId;
-                    }, _startContentId, StartContentIdSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _startContentId, Ps.Value.StartContentIdSelector); }
         }
 
         /// <summary>
@@ -370,28 +284,14 @@ namespace Umbraco.Core.Models.Membership
         public int StartMediaId
         {
             get { return _startMediaId; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                    {
-                        _startMediaId = value;
-                        return _startMediaId;
-                    }, _startMediaId, StartMediaIdSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _startMediaId, Ps.Value.StartMediaIdSelector); }
         }
 
         [DataMember]
         public string Language
         {
             get { return _language; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _language = value;
-                    return _language;
-                }, _language, LanguageSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _language, Ps.Value.LanguageSelector); }
         }
 
         //TODO: This should be a private set
@@ -406,14 +306,7 @@ namespace Umbraco.Core.Models.Membership
         internal bool DefaultToLiveEditing
         {
             get { return _defaultToLiveEditing; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _defaultToLiveEditing = value;
-                    return _defaultToLiveEditing;
-                }, _defaultToLiveEditing, DefaultToLiveEditingSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _defaultToLiveEditing, Ps.Value.DefaultToLiveEditingSelector); }
         }
 
         [IgnoreDataMember]
@@ -427,11 +320,7 @@ namespace Umbraco.Core.Models.Membership
                     throw new InvalidOperationException("Cannot assign a User Type that has not been persisted");
                 }
 
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _userType = value;
-                    return _userType;
-                }, _userType, UserTypeSelector);
+                SetPropertyValueAndDetectChanges(value, ref _userType, Ps.Value.UserTypeSelector);                
             }
         }
 
@@ -457,7 +346,7 @@ namespace Umbraco.Core.Models.Membership
         /// <param name="e"></param>
         void SectionCollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
         {
-            OnPropertyChanged(AllowedSectionsSelector);
+            OnPropertyChanged(Ps.Value.AllowedSectionsSelector);
 
             if (e.Action == NotifyCollectionChangedAction.Add)
             {

src/Umbraco.Core/Models/Membership/UserType.cs

@@ -20,9 +20,14 @@ namespace Umbraco.Core.Models.Membership
         private string _name;
         private IEnumerable<string> _permissions;
 
-        private static readonly PropertyInfo NameSelector = ExpressionHelper.GetPropertyInfo<UserType, string>(x => x.Name);
-        private static readonly PropertyInfo AliasSelector = ExpressionHelper.GetPropertyInfo<UserType, string>(x => x.Alias);
-        private static readonly PropertyInfo PermissionsSelector = ExpressionHelper.GetPropertyInfo<UserType, IEnumerable<string>>(x => x.Permissions);
+        private static readonly Lazy<PropertySelectors> Ps = new Lazy<PropertySelectors>();
+
+        private class PropertySelectors
+        {
+            public readonly PropertyInfo NameSelector = ExpressionHelper.GetPropertyInfo<UserType, string>(x => x.Name);
+            public readonly PropertyInfo AliasSelector = ExpressionHelper.GetPropertyInfo<UserType, string>(x => x.Alias);
+            public readonly PropertyInfo PermissionsSelector = ExpressionHelper.GetPropertyInfo<UserType, IEnumerable<string>>(x => x.Permissions);
+        }
 
         [DataMember]
         public string Alias
@@ -30,11 +35,10 @@ namespace Umbraco.Core.Models.Membership
             get { return _alias; }
             set
             {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _alias = value.ToCleanString(CleanStringType.Alias | CleanStringType.UmbracoCase);
-                    return _alias;
-                }, _alias, AliasSelector);
+                SetPropertyValueAndDetectChanges(
+                    value.ToCleanString(CleanStringType.Alias | CleanStringType.UmbracoCase), 
+                    ref _alias, 
+                    Ps.Value.AliasSelector);                
             }
         }
 
@@ -42,14 +46,7 @@ namespace Umbraco.Core.Models.Membership
         public string Name
         {
             get { return _name; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _name = value;
-                    return _name;
-                }, _name, NameSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _name, Ps.Value.NameSelector); }
         }
 
         /// <summary>
@@ -64,11 +61,7 @@ namespace Umbraco.Core.Models.Membership
             get { return _permissions; }
             set
             {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _permissions = value;
-                    return _permissions;
-                }, _permissions, PermissionsSelector,
+                SetPropertyValueAndDetectChanges(value, ref _permissions, Ps.Value.PermissionsSelector,
                     //Custom comparer for enumerable
                     new DelegateEqualityComparer<IEnumerable<string>>(
                         (enum1, enum2) => enum1.UnsortedSequenceEqual(enum2),

src/Umbraco.Core/Models/MigrationEntry.cs

@@ -19,35 +19,27 @@ namespace Umbraco.Core.Models
             _version = version;
         }
 
-        private static readonly PropertyInfo NameSelector = ExpressionHelper.GetPropertyInfo<MigrationEntry, string>(x => x.MigrationName);
-        private static readonly PropertyInfo VersionSelector = ExpressionHelper.GetPropertyInfo<MigrationEntry, SemVersion>(x => x.Version);
+        private static readonly Lazy<PropertySelectors> Ps = new Lazy<PropertySelectors>();
+
+        private class PropertySelectors
+        {
+            public readonly PropertyInfo NameSelector = ExpressionHelper.GetPropertyInfo<MigrationEntry, string>(x => x.MigrationName);
+            public readonly PropertyInfo VersionSelector = ExpressionHelper.GetPropertyInfo<MigrationEntry, SemVersion>(x => x.Version);
+        }
+
         private string _migrationName;
         private SemVersion _version;
 
         public string MigrationName
         {
             get { return _migrationName; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _migrationName = value;
-                    return _migrationName;
-                }, _migrationName, NameSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _migrationName, Ps.Value.NameSelector); }
         }
 
         public SemVersion Version
         {
             get { return _version; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _version = value;
-                    return _version;
-                }, _version, VersionSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _version, Ps.Value.VersionSelector); }
         }
     }
 }

src/Umbraco.Core/Models/Property.cs

@@ -1,11 +1,9 @@
 using System;
 using System.Collections;
-using System.Collections.Generic;
 using System.Linq;
 using System.Reflection;
 using System.Runtime.Serialization;
 using Umbraco.Core.Models.EntityBase;
-using Umbraco.Core.Persistence.Mappers;
 
 namespace Umbraco.Core.Models
 {
@@ -45,8 +43,42 @@ namespace Umbraco.Core.Models
             Value = value;
         }
 
-        private static readonly PropertyInfo ValueSelector = ExpressionHelper.GetPropertyInfo<Property, object>(x => x.Value);
-        private static readonly PropertyInfo VersionSelector = ExpressionHelper.GetPropertyInfo<Property, Guid>(x => x.Version);
+        private static readonly Lazy<PropertySelectors> Ps = new Lazy<PropertySelectors>();
+
+        private class PropertySelectors
+        {
+            public readonly PropertyInfo ValueSelector = ExpressionHelper.GetPropertyInfo<Property, object>(x => x.Value);
+            public readonly PropertyInfo VersionSelector = ExpressionHelper.GetPropertyInfo<Property, Guid>(x => x.Version);
+        }
+
+        private static readonly DelegateEqualityComparer<object> ValueComparer = new DelegateEqualityComparer<object>(
+            (o, o1) =>
+            {
+                if (o == null && o1 == null) return true;
+
+                //custom comparer for strings.                        
+                if (o is string || o1 is string)
+                {
+                    //if one is null and another is empty then they are the same
+                    if ((o as string).IsNullOrWhiteSpace() && (o1 as string).IsNullOrWhiteSpace())
+                    {
+                        return true;
+                    }
+                    if (o == null || o1 == null) return false;
+                    return o.Equals(o1);
+                }
+
+                if (o == null || o1 == null) return false;
+
+                //Custom comparer for enumerable if it is enumerable
+                var enum1 = o as IEnumerable;
+                var enum2 = o1 as IEnumerable;
+                if (enum1 != null && enum2 != null)
+                {
+                    return enum1.Cast<object>().UnsortedSequenceEqual(enum2.Cast<object>());
+                }
+                return o.Equals(o1);
+            }, o => o.GetHashCode());
         
         /// <summary>
         /// Returns the instance of the tag support, by default tags are not enabled
@@ -98,14 +130,14 @@ namespace Umbraco.Core.Models
         public Guid Version
         {
             get { return _version; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _version = value;
-                    return _version;
-                }, _version, VersionSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _version, Ps.Value.VersionSelector); }
+        }
+
+        private static void ThrowTypeException(object value, Type expected, string alias)
+        {
+            throw new Exception(string.Format("Value \"{0}\" of type \"{1}\" could not be converted"
+                + " to type \"{2}\" which is expected by property type \"{3}\".",
+                value, value.GetType(), expected, alias));
         }
 
         /// <summary>
@@ -121,91 +153,54 @@ namespace Umbraco.Core.Models
             get { return _value; }
             set
             {
-                bool typeValidation = _propertyType.IsPropertyTypeValid(value);
+                var isOfExpectedType = _propertyType.IsPropertyTypeValid(value);
 
-                if (typeValidation == false)
+                if (isOfExpectedType == false) // isOfExpectedType is true if value is null - so if false, value is *not* null
                 {
-                    // Normally we'll throw an exception here.  However if the property is of a type that can have it's data field (dataInt, dataVarchar etc.)
-                    // changed, we might have a value of the now "wrong" type.  As of May 2016 Label is the only built-in property editor that supports this.
-                    // In that case we should try to parse the value and return null if that's not possible rather than throwing an exception.
-                    if (value != null && _propertyType.CanHaveDataValueTypeChanged())
-                    {
-                        var stringValue = value.ToString();
-                        switch (_propertyType.DataTypeDatabaseType)
-                        {
-                            case DataTypeDatabaseType.Nvarchar:
-                            case DataTypeDatabaseType.Ntext:
-                                value = stringValue;
-                                break;
-                            case DataTypeDatabaseType.Integer:
-                                int integerValue;
-                                if (int.TryParse(stringValue, out integerValue) == false)
-                                {
-                                    // Edge case, but if changed from decimal --> integer, the above tryparse will fail.  So we'll try going
-                                    // via decimal too to return the integer value rather than zero.
-                                    decimal decimalForIntegerValue;
-                                    if (decimal.TryParse(stringValue, out decimalForIntegerValue))
-                                    {
-                                        integerValue = (int)decimalForIntegerValue;
-                                    }
-                                }
+                    // "garbage-in", accept what we can & convert
+                    // throw only if conversion is not possible
 
-                                value = integerValue;
-                                break;
-                            case DataTypeDatabaseType.Decimal:
-                                decimal decimalValue;
-                                decimal.TryParse(stringValue, out decimalValue);
-                                value = decimalValue;
-                                break;
-                            case DataTypeDatabaseType.Date:
-                                DateTime dateValue;
-                                DateTime.TryParse(stringValue, out dateValue);
-                                value = dateValue;
-                                break;
-                        }
-                    }
-                    else
+                    var s = value.ToString();
+
+                    switch (_propertyType.DataTypeDatabaseType)
                     {
-                        throw new Exception(
-                            string.Format(
-                                "Type validation failed. The value type: '{0}' does not match the DataType in PropertyType with alias: '{1}'",
-                                value == null ? "null" : value.GetType().Name, Alias));
+                        case DataTypeDatabaseType.Nvarchar:
+                        case DataTypeDatabaseType.Ntext:
+                            value = s;
+                            break;
+                        case DataTypeDatabaseType.Integer:
+                            if (s.IsNullOrWhiteSpace()) value = null; // assume empty means null
+                            else
+                            {
+                                var convInt = value.TryConvertTo<int>();
+                                if (convInt == false) ThrowTypeException(value, typeof(int), _propertyType.Alias);
+                                value = convInt.Result;
+                            }
+                            break;
+                        case DataTypeDatabaseType.Decimal:
+                            if (s.IsNullOrWhiteSpace()) value = null; // assume empty means null
+                            else
+                            {
+                                var convDecimal = value.TryConvertTo<decimal>();
+                                if (convDecimal == false) ThrowTypeException(value, typeof (decimal), _propertyType.Alias);
+                                // need to normalize the value (change the scaling factor and remove trailing zeroes)
+                                // because the underlying database is going to mess with the scaling factor anyways.
+                                value = convDecimal.Result.Normalize();
+                            }
+                            break;
+                        case DataTypeDatabaseType.Date:
+                            if (s.IsNullOrWhiteSpace()) value = null; // assume empty means null
+                            else
+                            {
+                                var convDateTime = value.TryConvertTo<DateTime>();
+                                if (convDateTime == false) ThrowTypeException(value, typeof (DateTime), _propertyType.Alias);
+                                value = convDateTime.Result;
+                            }
+                            break;
                     }
                 }
 
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _value = value;
-                    return _value;
-                }, _value, ValueSelector, 
-                new DelegateEqualityComparer<object>(
-                    (o, o1) =>
-                    {
-                        if (o == null && o1 == null) return true;
-
-                        //custom comparer for strings.                        
-                        if (o is string || o1 is string)                            
-                        {
-                            //if one is null and another is empty then they are the same
-                            if ((o as string).IsNullOrWhiteSpace() && (o1 as string).IsNullOrWhiteSpace())
-                            {
-                                return true;   
-                            }
-                            if (o == null || o1 == null) return false;
-                            return o.Equals(o1);
-                        }
-                        
-                        if (o == null || o1 == null) return false;
-
-                        //Custom comparer for enumerable if it is enumerable
-                        var enum1 = o as IEnumerable;
-                        var enum2 = o1 as IEnumerable;
-                        if (enum1 != null && enum2 != null)
-                        {
-                            return enum1.Cast<object>().UnsortedSequenceEqual(enum2.Cast<object>());
-                        }
-                        return o.Equals(o1);
-                    }, o => o.GetHashCode()));
+                SetPropertyValueAndDetectChanges(value, ref _value, Ps.Value.ValueSelector, ValueComparer);
             }
         }
 

src/Umbraco.Core/Models/PropertyGroup.cs

@@ -29,12 +29,18 @@ namespace Umbraco.Core.Models
             PropertyTypes = propertyTypeCollection;
         }
 
-        private static readonly PropertyInfo NameSelector = ExpressionHelper.GetPropertyInfo<PropertyGroup, string>(x => x.Name);
-        private static readonly PropertyInfo SortOrderSelector = ExpressionHelper.GetPropertyInfo<PropertyGroup, int>(x => x.SortOrder);
-        private readonly static PropertyInfo PropertyTypeCollectionSelector = ExpressionHelper.GetPropertyInfo<PropertyGroup, PropertyTypeCollection>(x => x.PropertyTypes);
+        private static readonly Lazy<PropertySelectors> Ps = new Lazy<PropertySelectors>();
+
+        private class PropertySelectors
+        {
+            public readonly PropertyInfo NameSelector = ExpressionHelper.GetPropertyInfo<PropertyGroup, string>(x => x.Name);
+            public readonly PropertyInfo SortOrderSelector = ExpressionHelper.GetPropertyInfo<PropertyGroup, int>(x => x.SortOrder);
+            public readonly PropertyInfo PropertyTypeCollectionSelector = ExpressionHelper.GetPropertyInfo<PropertyGroup, PropertyTypeCollection>(x => x.PropertyTypes);
+        }
+
         void PropertyTypesChanged(object sender, NotifyCollectionChangedEventArgs e)
         {
-            OnPropertyChanged(PropertyTypeCollectionSelector);
+            OnPropertyChanged(Ps.Value.PropertyTypeCollectionSelector);
         }
 
         /// <summary>
@@ -44,14 +50,7 @@ namespace Umbraco.Core.Models
         public string Name
         {
             get { return _name; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _name = value;
-                    return _name;
-                }, _name, NameSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _name, Ps.Value.NameSelector); }
         }
 
         /// <summary>
@@ -61,14 +60,7 @@ namespace Umbraco.Core.Models
         public int SortOrder
         {
             get { return _sortOrder; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _sortOrder = value;
-                    return _sortOrder;
-                }, _sortOrder, SortOrderSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _sortOrder, Ps.Value.SortOrderSelector); }
         }
 
         /// <summary>

src/Umbraco.Core/Models/PropertyType.cs

@@ -46,9 +46,9 @@ namespace Umbraco.Core.Models
         public PropertyType(IDataTypeDefinition dataTypeDefinition, string propertyTypeAlias)
             : this(dataTypeDefinition)
         {
-            SetAlias(propertyTypeAlias);
+            _alias = GetAlias(propertyTypeAlias);
         }
-        
+
         public PropertyType(string propertyEditorAlias, DataTypeDatabaseType dataTypeDatabaseType)
             : this(propertyEditorAlias, dataTypeDatabaseType, false)
         {
@@ -56,7 +56,7 @@ namespace Umbraco.Core.Models
 
         public PropertyType(string propertyEditorAlias, DataTypeDatabaseType dataTypeDatabaseType, string propertyTypeAlias)
             : this(propertyEditorAlias, dataTypeDatabaseType, false, propertyTypeAlias)
-        {           
+        {
         }
 
         /// <summary>
@@ -84,20 +84,25 @@ namespace Umbraco.Core.Models
             _isExplicitDbType = isExplicitDbType;
             _propertyEditorAlias = propertyEditorAlias;
             _dataTypeDatabaseType = dataTypeDatabaseType;
-            SetAlias(propertyTypeAlias);
+            _alias = GetAlias(propertyTypeAlias);
         }
 
-        private static readonly PropertyInfo NameSelector = ExpressionHelper.GetPropertyInfo<PropertyType, string>(x => x.Name);
-        private static readonly PropertyInfo AliasSelector = ExpressionHelper.GetPropertyInfo<PropertyType, string>(x => x.Alias);
-        private static readonly PropertyInfo DescriptionSelector = ExpressionHelper.GetPropertyInfo<PropertyType, string>(x => x.Description);
-        private static readonly PropertyInfo DataTypeDefinitionIdSelector = ExpressionHelper.GetPropertyInfo<PropertyType, int>(x => x.DataTypeDefinitionId);
-        private static readonly PropertyInfo PropertyEditorAliasSelector = ExpressionHelper.GetPropertyInfo<PropertyType, string>(x => x.PropertyEditorAlias);
-        private static readonly PropertyInfo DataTypeDatabaseTypeSelector = ExpressionHelper.GetPropertyInfo<PropertyType, DataTypeDatabaseType>(x => x.DataTypeDatabaseType);
-        private static readonly PropertyInfo MandatorySelector = ExpressionHelper.GetPropertyInfo<PropertyType, bool>(x => x.Mandatory);
-        private static readonly PropertyInfo HelpTextSelector = ExpressionHelper.GetPropertyInfo<PropertyType, string>(x => x.HelpText);
-        private static readonly PropertyInfo SortOrderSelector = ExpressionHelper.GetPropertyInfo<PropertyType, int>(x => x.SortOrder);
-        private static readonly PropertyInfo ValidationRegExpSelector = ExpressionHelper.GetPropertyInfo<PropertyType, string>(x => x.ValidationRegExp);
-        private static readonly PropertyInfo PropertyGroupIdSelector = ExpressionHelper.GetPropertyInfo<PropertyType, Lazy<int>>(x => x.PropertyGroupId);
+        private static readonly Lazy<PropertySelectors> Ps = new Lazy<PropertySelectors>();
+
+        private class PropertySelectors
+        {
+            public readonly PropertyInfo NameSelector = ExpressionHelper.GetPropertyInfo<PropertyType, string>(x => x.Name);
+            public readonly PropertyInfo AliasSelector = ExpressionHelper.GetPropertyInfo<PropertyType, string>(x => x.Alias);
+            public readonly PropertyInfo DescriptionSelector = ExpressionHelper.GetPropertyInfo<PropertyType, string>(x => x.Description);
+            public readonly PropertyInfo DataTypeDefinitionIdSelector = ExpressionHelper.GetPropertyInfo<PropertyType, int>(x => x.DataTypeDefinitionId);
+            public readonly PropertyInfo PropertyEditorAliasSelector = ExpressionHelper.GetPropertyInfo<PropertyType, string>(x => x.PropertyEditorAlias);
+            public readonly PropertyInfo DataTypeDatabaseTypeSelector = ExpressionHelper.GetPropertyInfo<PropertyType, DataTypeDatabaseType>(x => x.DataTypeDatabaseType);
+            public readonly PropertyInfo MandatorySelector = ExpressionHelper.GetPropertyInfo<PropertyType, bool>(x => x.Mandatory);
+            public readonly PropertyInfo HelpTextSelector = ExpressionHelper.GetPropertyInfo<PropertyType, string>(x => x.HelpText);
+            public readonly PropertyInfo SortOrderSelector = ExpressionHelper.GetPropertyInfo<PropertyType, int>(x => x.SortOrder);
+            public readonly PropertyInfo ValidationRegExpSelector = ExpressionHelper.GetPropertyInfo<PropertyType, string>(x => x.ValidationRegExp);
+            public readonly PropertyInfo PropertyGroupIdSelector = ExpressionHelper.GetPropertyInfo<PropertyType, Lazy<int>>(x => x.PropertyGroupId);
+        }
 
         /// <summary>
         /// Gets of Sets the Name of the PropertyType
@@ -106,14 +111,7 @@ namespace Umbraco.Core.Models
         public string Name
         {
             get { return _name; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _name = value;
-                    return _name;
-                }, _name, NameSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _name, Ps.Value.NameSelector); }
         }
 
         /// <summary>
@@ -123,14 +121,7 @@ namespace Umbraco.Core.Models
         public string Alias
         {
             get { return _alias; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    SetAlias(value);
-                    return _alias;
-                }, _alias, AliasSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(GetAlias(value), ref _alias, Ps.Value.AliasSelector); }
         }
 
         /// <summary>
@@ -140,14 +131,7 @@ namespace Umbraco.Core.Models
         public string Description
         {
             get { return _description; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _description = value;
-                    return _description;
-                }, _description, DescriptionSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _description, Ps.Value.DescriptionSelector); }
         }
 
         /// <summary>
@@ -158,28 +142,14 @@ namespace Umbraco.Core.Models
         public int DataTypeDefinitionId
         {
             get { return _dataTypeDefinitionId; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _dataTypeDefinitionId = value;
-                    return _dataTypeDefinitionId;
-                }, _dataTypeDefinitionId, DataTypeDefinitionIdSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _dataTypeDefinitionId, Ps.Value.DataTypeDefinitionIdSelector); }
         }
 
         [DataMember]
         public string PropertyEditorAlias
         {
             get { return _propertyEditorAlias; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _propertyEditorAlias = value;
-                    return _propertyEditorAlias;
-                }, _propertyEditorAlias, PropertyEditorAliasSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _propertyEditorAlias, Ps.Value.PropertyEditorAliasSelector); }
         }
 
         /// <summary>
@@ -213,11 +183,7 @@ namespace Umbraco.Core.Models
                 //don't allow setting this if an explicit declaration has been made in the ctor
                 if (_isExplicitDbType) return;
 
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _dataTypeDatabaseType = value;
-                    return _dataTypeDatabaseType;
-                }, _dataTypeDatabaseType, DataTypeDatabaseTypeSelector);
+                SetPropertyValueAndDetectChanges(value, ref _dataTypeDatabaseType, Ps.Value.DataTypeDatabaseTypeSelector);                
             }
         }
 
@@ -229,14 +195,7 @@ namespace Umbraco.Core.Models
         internal Lazy<int> PropertyGroupId
         {
             get { return _propertyGroupId; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _propertyGroupId = value;
-                    return _propertyGroupId;
-                }, _propertyGroupId, PropertyGroupIdSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _propertyGroupId, Ps.Value.PropertyGroupIdSelector); }
         }
 
         /// <summary>
@@ -246,14 +205,7 @@ namespace Umbraco.Core.Models
         public bool Mandatory
         {
             get { return _mandatory; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _mandatory = value;
-                    return _mandatory;
-                }, _mandatory, MandatorySelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _mandatory, Ps.Value.MandatorySelector); }
         }
 
         /// <summary>
@@ -264,14 +216,7 @@ namespace Umbraco.Core.Models
         public string HelpText
         {
             get { return _helpText; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _helpText = value;
-                    return _helpText;
-                }, _helpText, HelpTextSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _helpText, Ps.Value.HelpTextSelector); }
         }
 
         /// <summary>
@@ -281,14 +226,7 @@ namespace Umbraco.Core.Models
         public int SortOrder
         {
             get { return _sortOrder; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _sortOrder = value;
-                    return _sortOrder;
-                }, _sortOrder, SortOrderSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _sortOrder, Ps.Value.SortOrderSelector); }
         }
 
         /// <summary>
@@ -298,23 +236,16 @@ namespace Umbraco.Core.Models
         public string ValidationRegExp
         {
             get { return _validationRegExp; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _validationRegExp = value;
-                    return _validationRegExp;
-                }, _validationRegExp, ValidationRegExpSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _validationRegExp, Ps.Value.ValidationRegExpSelector); }
         }
 
-        private void SetAlias(string value)
+        private string GetAlias(string value)
         {
             //NOTE: WE are doing this because we don't want to do a ToSafeAlias when the alias is the special case of
             // being prefixed with Constants.PropertyEditors.InternalGenericPropertiesPrefix
             // which is used internally
 
-            _alias = value.StartsWith(Constants.PropertyEditors.InternalGenericPropertiesPrefix)
+            return value.StartsWith(Constants.PropertyEditors.InternalGenericPropertiesPrefix)
                         ? value
                         : value.ToCleanString(CleanStringType.Alias | CleanStringType.UmbracoCase);
         }
@@ -367,18 +298,21 @@ namespace Umbraco.Core.Models
         }
 
         /// <summary>
-        /// Validates the Value from a Property according to its type
+        /// Gets a value indicating whether the value is of the expected type
+        /// for the property, and can be assigned to the property "as is".
         /// </summary>
-        /// <param name="value"></param>
-        /// <returns>True if valid, otherwise false</returns>
+        /// <param name="value">The value.</param>
+        /// <returns>True if the value is of the expected type for the property,
+        /// and can be assigned to the property "as is". Otherwise, false, to indicate
+        /// that some conversion is required.</returns>
         public bool IsPropertyTypeValid(object value)
         {
-            //Can't validate null values, so just allow it to pass the current validation
+            // null values are assumed to be ok
             if (value == null)
                 return true;
 
-            //Check type if the type of the value match the type from the DataType/PropertyEditor
-            Type type = value.GetType();
+            // check if the type of the value matches the type from the DataType/PropertyEditor
+            var valueType = value.GetType();
 
             //TODO Add PropertyEditor Type validation when its relevant to introduce
             /*bool isEditorModel = value is IEditorModel;
@@ -395,50 +329,34 @@ namespace Umbraco.Core.Models
                 return argument == type;
             }*/
 
-            if (PropertyEditorAlias.IsNullOrWhiteSpace() == false)
+            if (PropertyEditorAlias.IsNullOrWhiteSpace() == false) // fixme - always true?
             {
-                //Find DataType by Id
-                //IDataType dataType = DataTypesResolver.Current.GetById(DataTypeControlId);
-                //Check if dataType is null (meaning that the ControlId is valid) ?
-                //Possibly cast to BaseDataType and get the DbType from there (which might not be possible because it lives in umbraco.cms.businesslogic.datatype) ?
-
-                //Simple validation using the DatabaseType from the DataTypeDefinition and Type of the passed in value
-                if (DataTypeDatabaseType == DataTypeDatabaseType.Integer && type == typeof(int))
-                    return true;
-
-                if (DataTypeDatabaseType == DataTypeDatabaseType.Decimal && type == typeof(decimal))
-                    return true;
-
-                if (DataTypeDatabaseType == DataTypeDatabaseType.Date && type == typeof(DateTime))
-                    return true;
-
-                if (DataTypeDatabaseType == DataTypeDatabaseType.Nvarchar && type == typeof(string))
-                    return true;
-
-                if (DataTypeDatabaseType == DataTypeDatabaseType.Ntext && type == typeof(string))
-                    return true;
+                // simple validation using the DatabaseType from the DataTypeDefinition
+                // and the Type of the passed in value
+                switch (DataTypeDatabaseType)
+                {
+                    // fixme breaking!
+                    case DataTypeDatabaseType.Integer:
+                        return valueType == typeof(int);
+                    case DataTypeDatabaseType.Decimal:
+                        return valueType == typeof(decimal);
+                    case DataTypeDatabaseType.Date:
+                        return valueType == typeof(DateTime);
+                    case DataTypeDatabaseType.Nvarchar:
+                        return valueType == typeof(string);
+                    case DataTypeDatabaseType.Ntext:
+                        return valueType == typeof(string);
+                }
             }
 
-            //Fallback for simple value types when no Control Id or Database Type is set
-            if (type.IsPrimitive || value is string)
+            // fixme - never reached + makes no sense?
+            // fallback for simple value types when no Control Id or Database Type is set
+            if (valueType.IsPrimitive || value is string)
                 return true;
 
             return false;
         }
 
-        /// <summary>
-        /// Checks the underlying property editor prevalues to see if the one that allows changing of the database field
-        /// to which data is saved (dataInt, dataVarchar etc.) is included.  If so that means the field could be changed when the data
-        /// type is saved.
-        /// </summary>
-        /// <returns></returns>
-        internal bool CanHaveDataValueTypeChanged()
-        {
-            var propertyEditor = PropertyEditorResolver.Current.GetByAlias(_propertyEditorAlias);
-            return propertyEditor.PreValueEditor.Fields
-                .SingleOrDefault(x => x.Key == Constants.PropertyEditors.PreValueKeys.DataValueType) != null;
-        }
-
         /// <summary>
         /// Validates the Value from a Property according to the validation settings
         /// </summary>
@@ -458,15 +376,15 @@ namespace Umbraco.Core.Models
                     var regexPattern = new Regex(ValidationRegExp);
                     return regexPattern.IsMatch(value.ToString());
                 }
-                catch 
+                catch
                 {
                          throw new Exception(string .Format("Invalid validation expression on property {0}",this.Alias));
                 }
-                
+
             }
-            
+
             //TODO: We must ensure that the property value can actually be saved based on the specified database type
-            
+
             //TODO Add PropertyEditor validation when its relevant to introduce
             /*if (value is IEditorModel && DataTypeControlId != Guid.Empty)
             {
@@ -484,19 +402,19 @@ namespace Umbraco.Core.Models
         {
             if (base.Equals(other)) return true;
 
-            //Check whether the PropertyType's properties are equal. 
+            //Check whether the PropertyType's properties are equal.
             return Alias.InvariantEquals(other.Alias);
         }
 
         public override int GetHashCode()
         {
-            //Get hash code for the Name field if it is not null. 
+            //Get hash code for the Name field if it is not null.
             int baseHash = base.GetHashCode();
 
-            //Get hash code for the Alias field. 
+            //Get hash code for the Alias field.
             int hashAlias = Alias.ToLowerInvariant().GetHashCode();
 
-            //Calculate the hash code for the product. 
+            //Calculate the hash code for the product.
             return baseHash ^ hashAlias;
         }
 
@@ -508,7 +426,7 @@ namespace Umbraco.Core.Models
             //need to manually assign the Lazy value as it will not be automatically mapped
             if (PropertyGroupId != null)
             {
-                clone._propertyGroupId = new Lazy<int>(() => PropertyGroupId.Value);    
+                clone._propertyGroupId = new Lazy<int>(() => PropertyGroupId.Value);
             }
             //this shouldn't really be needed since we're not tracking
             clone.ResetDirtyProperties(false);

src/Umbraco.Core/Models/PublicAccessEntry.cs

@@ -44,7 +44,7 @@ namespace Umbraco.Core.Models
 
         void _ruleCollection_CollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
         {
-            OnPropertyChanged(AllowedSectionsSelector);
+            OnPropertyChanged(Ps.Value.AllowedSectionsSelector);
 
             //if (e.Action == NotifyCollectionChangedAction.Add)
             //{
@@ -68,10 +68,15 @@ namespace Umbraco.Core.Models
             }
         }
 
-        private static readonly PropertyInfo ProtectedNodeIdSelector = ExpressionHelper.GetPropertyInfo<PublicAccessEntry, int>(x => x.ProtectedNodeId);
-        private static readonly PropertyInfo LoginNodeIdSelector = ExpressionHelper.GetPropertyInfo<PublicAccessEntry, int>(x => x.LoginNodeId);
-        private static readonly PropertyInfo NoAccessNodeIdSelector = ExpressionHelper.GetPropertyInfo<PublicAccessEntry, int>(x => x.NoAccessNodeId);
-        private static readonly PropertyInfo AllowedSectionsSelector = ExpressionHelper.GetPropertyInfo<PublicAccessEntry, IEnumerable<PublicAccessRule>>(x => x.Rules);
+        private static readonly Lazy<PropertySelectors> Ps = new Lazy<PropertySelectors>();
+
+        private class PropertySelectors
+        {
+            public readonly PropertyInfo ProtectedNodeIdSelector = ExpressionHelper.GetPropertyInfo<PublicAccessEntry, int>(x => x.ProtectedNodeId);
+            public readonly PropertyInfo LoginNodeIdSelector = ExpressionHelper.GetPropertyInfo<PublicAccessEntry, int>(x => x.LoginNodeId);
+            public readonly PropertyInfo NoAccessNodeIdSelector = ExpressionHelper.GetPropertyInfo<PublicAccessEntry, int>(x => x.NoAccessNodeId);
+            public readonly PropertyInfo AllowedSectionsSelector = ExpressionHelper.GetPropertyInfo<PublicAccessEntry, IEnumerable<PublicAccessRule>>(x => x.Rules);
+        }
 
         internal IEnumerable<Guid> RemovedRules
         {
@@ -112,42 +117,21 @@ namespace Umbraco.Core.Models
         public int LoginNodeId
         {
             get { return _loginNodeId; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _loginNodeId = value;
-                    return _loginNodeId;
-                }, _loginNodeId, LoginNodeIdSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _loginNodeId, Ps.Value.LoginNodeIdSelector); }
         }
 
         [DataMember]
         public int NoAccessNodeId
         {
             get { return _noAccessNodeId; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _noAccessNodeId = value;
-                    return _noAccessNodeId;
-                }, _noAccessNodeId, NoAccessNodeIdSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _noAccessNodeId, Ps.Value.NoAccessNodeIdSelector); }
         }
        
         [DataMember]
         public int ProtectedNodeId
         {
             get { return _protectedNodeId; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _protectedNodeId = value;
-                    return _protectedNodeId;
-                }, _protectedNodeId, ProtectedNodeIdSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _protectedNodeId, Ps.Value.ProtectedNodeIdSelector); }
         }
 
         public override void ResetDirtyProperties(bool rememberPreviouslyChangedProperties)

src/Umbraco.Core/Models/PublicAccessRule.cs

@@ -23,35 +23,26 @@ namespace Umbraco.Core.Models
         {
         }
 
-        private static readonly PropertyInfo RuleValueSelector = ExpressionHelper.GetPropertyInfo<PublicAccessRule, string>(x => x.RuleValue);
-        private static readonly PropertyInfo RuleTypeSelector = ExpressionHelper.GetPropertyInfo<PublicAccessRule, string>(x => x.RuleType);
+        private static readonly Lazy<PropertySelectors> Ps = new Lazy<PropertySelectors>();
+
+        private class PropertySelectors
+        {
+            public readonly PropertyInfo RuleValueSelector = ExpressionHelper.GetPropertyInfo<PublicAccessRule, string>(x => x.RuleValue);
+            public readonly PropertyInfo RuleTypeSelector = ExpressionHelper.GetPropertyInfo<PublicAccessRule, string>(x => x.RuleType);
+        }
        
         public Guid AccessEntryId { get; internal set; }
 
         public string RuleValue
         {
             get { return _ruleValue; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _ruleValue = value;
-                    return _ruleValue;
-                }, _ruleValue, RuleValueSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _ruleValue, Ps.Value.RuleValueSelector); }
         }
 
         public string RuleType
         {
             get { return _ruleType; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _ruleType = value;
-                    return _ruleType;
-                }, _ruleType, RuleTypeSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _ruleType, Ps.Value.RuleTypeSelector); }
         }
 
         

src/Umbraco.Core/Models/Rdbms/PropertyDataDto.cs

@@ -16,7 +16,7 @@ namespace Umbraco.Core.Models.Rdbms
 
         [Column("contentNodeId")]
         [ForeignKey(typeof(NodeDto))]
-        [Index(IndexTypes.NonClustered, Name = "IX_cmsPropertyData_1")]
+        [Index(IndexTypes.UniqueNonClustered, Name = "IX_cmsPropertyData_1", ForColumns = "contentNodeId,versionId,propertytypeid")]
         public int NodeId { get; set; }
 
         [Column("versionId")]
@@ -33,9 +33,23 @@ namespace Umbraco.Core.Models.Rdbms
         [NullSetting(NullSetting = NullSettings.Null)]
         public int? Integer { get; set; }
 
+        private decimal? _decimalValue;
+
         [Column("dataDecimal")]
         [NullSetting(NullSetting = NullSettings.Null)]
-        public decimal? Decimal { get; set; }
+        public decimal? Decimal
+        {
+            get
+            {
+                return _decimalValue;
+            }
+            set
+            {
+                // need to normalize the value (change the scaling factor and remove trailing zeroes)
+                // because the underlying database probably has messed with the scaling factor.
+                _decimalValue = value.HasValue ? (decimal?) value.Value.Normalize() : null;
+            }
+        }
 
         [Column("dataDate")]
         [NullSetting(NullSetting = NullSettings.Null)]

src/Umbraco.Core/Models/Rdbms/RedirectUrlDto.cs

@@ -0,0 +1,50 @@
+using System;
+using Umbraco.Core.Persistence;
+using Umbraco.Core.Persistence.DatabaseAnnotations;
+
+namespace Umbraco.Core.Models.Rdbms
+{
+    [TableName("umbracoRedirectUrl")]
+    [PrimaryKey("id")]
+    [ExplicitColumns]
+    class RedirectUrlDto
+    {
+        public RedirectUrlDto()
+        {
+            CreateDateUtc = DateTime.UtcNow;
+        }
+
+        // notes
+        //
+        // we want a unique, non-clustered  index on (url ASC, contentId ASC, createDate DESC) but the
+        // problem is that the index key must be 900 bytes max. should we run without an index? done
+        // some perfs comparisons, and running with an index on a hash is only slightly slower on
+        // inserts, and much faster on reads, so... we have an index on a hash.
+
+        [Column("id")]
+        [PrimaryKeyColumn(IdentitySeed = 1, Name = "PK_umbracoRedirectUrl")]
+        public int Id { get; set; }
+
+        [ResultColumn]
+        public int ContentId { get; set; }
+
+        [Column("contentKey")]
+        [NullSetting(NullSetting = NullSettings.NotNull)]
+        [ForeignKey(typeof(NodeDto), Column = "uniqueID")]
+        public Guid ContentKey { get; set; }
+
+        [Column("createDateUtc")]
+        [NullSetting(NullSetting = NullSettings.NotNull)]
+        public DateTime CreateDateUtc { get; set; }
+
+        [Column("url")]
+        [NullSetting(NullSetting = NullSettings.NotNull)]
+        //[Index(IndexTypes.UniqueNonClustered, Name = "IX_umbracoRedirectUrl", ForColumns = "url, createDateUtc")]
+        public string Url { get; set; }
+
+        [Column("urlHash")]
+        [NullSetting(NullSetting = NullSettings.NotNull)]
+        [Index(IndexTypes.UniqueNonClustered, Name = "IX_umbracoRedirectUrl", ForColumns = "urlHash, contentKey, createDateUtc")]
+        public string UrlHash { get; set; }
+    }
+}

src/Umbraco.Core/Models/Rdbms/StylesheetDto.cs

@@ -1,11 +1,10 @@
-using Umbraco.Core.Persistence;
+using System;
+using Umbraco.Core.Persistence;
 using Umbraco.Core.Persistence.DatabaseAnnotations;
 
 namespace Umbraco.Core.Models.Rdbms
 {
-    [TableName("cmsStylesheet")]
-    [PrimaryKey("nodeId", autoIncrement = false)]
-    [ExplicitColumns]
+    [Obsolete("This is no longer used and will be removed from Umbraco in future versions")]
     internal class StylesheetDto
     {
         [Column("nodeId")]

src/Umbraco.Core/Models/Rdbms/StylesheetPropertyDto.cs

@@ -1,11 +1,10 @@
-using Umbraco.Core.Persistence;
+using System;
+using Umbraco.Core.Persistence;
 using Umbraco.Core.Persistence.DatabaseAnnotations;
 
 namespace Umbraco.Core.Models.Rdbms
 {
-    [TableName("cmsStylesheetProperty")]
-    [PrimaryKey("nodeId", autoIncrement = false)]
-    [ExplicitColumns]
+    [Obsolete("This is no longer used and will be removed from Umbraco in future versions")]
     internal class StylesheetPropertyDto
     {
         [Column("nodeId")]

src/Umbraco.Core/Models/RedirectUrl.cs

@@ -0,0 +1,67 @@
+using System;
+using System.Reflection;
+using System.Runtime.Serialization;
+using Umbraco.Core.Models.EntityBase;
+
+namespace Umbraco.Core.Models
+{
+    /// <summary>
+    /// Implements <see cref="IRedirectUrl"/>.
+    /// </summary>
+    [Serializable]
+    [DataContract(IsReference = true)]
+    public class RedirectUrl : Entity, IRedirectUrl
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="RedirectUrl"/> class.
+        /// </summary>
+        public RedirectUrl()
+        {
+            CreateDateUtc = DateTime.UtcNow;
+        }
+
+        private static readonly Lazy<PropertySelectors> Ps = new Lazy<PropertySelectors>();
+
+        // ReSharper disable once ClassNeverInstantiated.Local
+        private class PropertySelectors
+        {
+            public readonly PropertyInfo ContentIdSelector = ExpressionHelper.GetPropertyInfo<RedirectUrl, int>(x => x.ContentId);
+            public readonly PropertyInfo ContentKeySelector = ExpressionHelper.GetPropertyInfo<RedirectUrl, Guid>(x => x.ContentKey);
+            public readonly PropertyInfo CreateDateUtcSelector = ExpressionHelper.GetPropertyInfo<RedirectUrl, DateTime>(x => x.CreateDateUtc);
+            public readonly PropertyInfo UrlSelector = ExpressionHelper.GetPropertyInfo<RedirectUrl, string>(x => x.Url);
+        }
+
+        private int _contentId;
+        private Guid _contentKey;
+        private DateTime _createDateUtc;
+        private string _url;
+
+        /// <inheritdoc />
+        public int ContentId
+        {
+            get { return _contentId; }
+            set { SetPropertyValueAndDetectChanges(value, ref _contentId, Ps.Value.ContentIdSelector); }
+        }
+
+        /// <inheritdoc />
+        public Guid ContentKey
+        {
+            get { return _contentKey; }
+            set { SetPropertyValueAndDetectChanges(value, ref _contentKey, Ps.Value.ContentKeySelector); }
+        }
+
+        /// <inheritdoc />
+        public DateTime CreateDateUtc
+        {
+            get {  return _createDateUtc; }
+            set { SetPropertyValueAndDetectChanges(value, ref _createDateUtc, Ps.Value.CreateDateUtcSelector); }
+        }
+
+        /// <inheritdoc />
+        public string Url
+        {
+            get { return _url; }
+            set { SetPropertyValueAndDetectChanges(value, ref _url, Ps.Value.UrlSelector); }
+        }
+    }
+}

src/Umbraco.Core/Models/Relation.cs

@@ -26,10 +26,15 @@ namespace Umbraco.Core.Models
             _relationType = relationType;
         }
 
-        private static readonly PropertyInfo ParentIdSelector = ExpressionHelper.GetPropertyInfo<Relation, int>(x => x.ParentId);
-        private static readonly PropertyInfo ChildIdSelector = ExpressionHelper.GetPropertyInfo<Relation, int>(x => x.ChildId);
-        private static readonly PropertyInfo RelationTypeSelector = ExpressionHelper.GetPropertyInfo<Relation, IRelationType>(x => x.RelationType);
-        private static readonly PropertyInfo CommentSelector = ExpressionHelper.GetPropertyInfo<Relation, string>(x => x.Comment);
+        private static readonly Lazy<PropertySelectors> Ps = new Lazy<PropertySelectors>();
+
+        private class PropertySelectors
+        {
+            public readonly PropertyInfo ParentIdSelector = ExpressionHelper.GetPropertyInfo<Relation, int>(x => x.ParentId);
+            public readonly PropertyInfo ChildIdSelector = ExpressionHelper.GetPropertyInfo<Relation, int>(x => x.ChildId);
+            public readonly PropertyInfo RelationTypeSelector = ExpressionHelper.GetPropertyInfo<Relation, IRelationType>(x => x.RelationType);
+            public readonly PropertyInfo CommentSelector = ExpressionHelper.GetPropertyInfo<Relation, string>(x => x.Comment);
+        }
 
         /// <summary>
         /// Gets or sets the Parent Id of the Relation (Source)
@@ -38,14 +43,7 @@ namespace Umbraco.Core.Models
         public int ParentId
         {
             get { return _parentId; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _parentId = value;
-                    return _parentId;
-                }, _parentId, ParentIdSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _parentId, Ps.Value.ParentIdSelector); }
         }
 
         /// <summary>
@@ -55,14 +53,7 @@ namespace Umbraco.Core.Models
         public int ChildId
         {
             get { return _childId; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _childId = value;
-                    return _childId;
-                }, _childId, ChildIdSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _childId, Ps.Value.ChildIdSelector); }
         }
 
         /// <summary>
@@ -72,14 +63,7 @@ namespace Umbraco.Core.Models
         public IRelationType RelationType
         {
             get { return _relationType; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _relationType = value;
-                    return _relationType;
-                }, _relationType, RelationTypeSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _relationType, Ps.Value.RelationTypeSelector); }
         }
 
         /// <summary>
@@ -89,14 +73,7 @@ namespace Umbraco.Core.Models
         public string Comment
         {
             get { return _comment; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _comment = value;
-                    return _comment;
-                }, _comment, CommentSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _comment, Ps.Value.CommentSelector); }
         }
 
         /// <summary>

src/Umbraco.Core/Models/RelationType.cs

@@ -35,11 +35,16 @@ namespace Umbraco.Core.Models
             Name = name;
         }
 
-        private static readonly PropertyInfo NameSelector = ExpressionHelper.GetPropertyInfo<RelationType, string>(x => x.Name);
-        private static readonly PropertyInfo AliasSelector = ExpressionHelper.GetPropertyInfo<RelationType, string>(x => x.Alias);
-        private static readonly PropertyInfo IsBidirectionalSelector = ExpressionHelper.GetPropertyInfo<RelationType, bool>(x => x.IsBidirectional);
-        private static readonly PropertyInfo ParentObjectTypeSelector = ExpressionHelper.GetPropertyInfo<RelationType, Guid>(x => x.ParentObjectType);
-        private static readonly PropertyInfo ChildObjectTypeSelector = ExpressionHelper.GetPropertyInfo<RelationType, Guid>(x => x.ChildObjectType);
+        private static readonly Lazy<PropertySelectors> Ps = new Lazy<PropertySelectors>();
+
+        private class PropertySelectors
+        {
+            public readonly PropertyInfo NameSelector = ExpressionHelper.GetPropertyInfo<RelationType, string>(x => x.Name);
+            public readonly PropertyInfo AliasSelector = ExpressionHelper.GetPropertyInfo<RelationType, string>(x => x.Alias);
+            public readonly PropertyInfo IsBidirectionalSelector = ExpressionHelper.GetPropertyInfo<RelationType, bool>(x => x.IsBidirectional);
+            public readonly PropertyInfo ParentObjectTypeSelector = ExpressionHelper.GetPropertyInfo<RelationType, Guid>(x => x.ParentObjectType);
+            public readonly PropertyInfo ChildObjectTypeSelector = ExpressionHelper.GetPropertyInfo<RelationType, Guid>(x => x.ChildObjectType);
+        }
 
         /// <summary>
         /// Gets or sets the Name of the RelationType
@@ -48,14 +53,7 @@ namespace Umbraco.Core.Models
         public string Name
         {
             get { return _name; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _name = value;
-                    return _name;
-                }, _name, NameSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _name, Ps.Value.NameSelector); }
         }
 
         /// <summary>
@@ -65,14 +63,7 @@ namespace Umbraco.Core.Models
         public string Alias
         {
             get { return _alias; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _alias = value;
-                    return _alias;
-                }, _alias, AliasSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _alias, Ps.Value.AliasSelector); }
         }
 
         /// <summary>
@@ -82,14 +73,7 @@ namespace Umbraco.Core.Models
         public bool IsBidirectional
         {
             get { return _isBidrectional; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _isBidrectional = value;
-                    return _isBidrectional;
-                }, _isBidrectional, IsBidirectionalSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _isBidrectional, Ps.Value.IsBidirectionalSelector); }
         }
 
         /// <summary>
@@ -100,14 +84,7 @@ namespace Umbraco.Core.Models
         public Guid ParentObjectType
         {
             get { return _parentObjectType; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _parentObjectType = value;
-                    return _parentObjectType;
-                }, _parentObjectType, ParentObjectTypeSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _parentObjectType, Ps.Value.ParentObjectTypeSelector); }
         }
 
         /// <summary>
@@ -118,14 +95,7 @@ namespace Umbraco.Core.Models
         public Guid ChildObjectType
         {
             get { return _childObjectType; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _childObjectType = value;
-                    return _childObjectType;
-                }, _childObjectType, ChildObjectTypeSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _childObjectType, Ps.Value.ChildObjectTypeSelector); }
         }
 
     }

src/Umbraco.Core/Models/ServerRegistration.cs

@@ -15,10 +15,15 @@ namespace Umbraco.Core.Models
         private bool _isActive;
         private bool _isMaster;
 
-        private static readonly PropertyInfo ServerAddressSelector = ExpressionHelper.GetPropertyInfo<ServerRegistration, string>(x => x.ServerAddress);
-        private static readonly PropertyInfo ServerIdentitySelector = ExpressionHelper.GetPropertyInfo<ServerRegistration, string>(x => x.ServerIdentity);
-        private static readonly PropertyInfo IsActiveSelector = ExpressionHelper.GetPropertyInfo<ServerRegistration, bool>(x => x.IsActive);
-        private static readonly PropertyInfo IsMasterSelector = ExpressionHelper.GetPropertyInfo<ServerRegistration, bool>(x => x.IsMaster);
+        private static readonly Lazy<PropertySelectors> Ps = new Lazy<PropertySelectors>();
+
+        private class PropertySelectors
+        {
+            public readonly PropertyInfo ServerAddressSelector = ExpressionHelper.GetPropertyInfo<ServerRegistration, string>(x => x.ServerAddress);
+            public readonly PropertyInfo ServerIdentitySelector = ExpressionHelper.GetPropertyInfo<ServerRegistration, string>(x => x.ServerIdentity);
+            public readonly PropertyInfo IsActiveSelector = ExpressionHelper.GetPropertyInfo<ServerRegistration, bool>(x => x.IsActive);
+            public readonly PropertyInfo IsMasterSelector = ExpressionHelper.GetPropertyInfo<ServerRegistration, bool>(x => x.IsMaster);
+        }
 
         /// <summary>
         /// Initialiazes a new instance of the <see cref="ServerRegistration"/> class.
@@ -69,14 +74,7 @@ namespace Umbraco.Core.Models
         public string ServerAddress
         {
             get { return _serverAddress; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _serverAddress = value;
-                    return _serverAddress;
-                }, _serverAddress, ServerAddressSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _serverAddress, Ps.Value.ServerAddressSelector); }
         }
 
         /// <summary>
@@ -85,14 +83,7 @@ namespace Umbraco.Core.Models
         public string ServerIdentity
         {
             get { return _serverIdentity; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _serverIdentity = value;
-                    return _serverIdentity;
-                }, _serverIdentity, ServerIdentitySelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _serverIdentity, Ps.Value.ServerIdentitySelector); }
         }
 
         /// <summary>
@@ -101,14 +92,7 @@ namespace Umbraco.Core.Models
         public bool IsActive
         {
             get { return _isActive; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _isActive = value;
-                    return _isActive;
-                }, _isActive, IsActiveSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _isActive, Ps.Value.IsActiveSelector); }
         }
 
         /// <summary>
@@ -117,14 +101,7 @@ namespace Umbraco.Core.Models
         public bool IsMaster
         {
             get { return _isMaster; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _isMaster = value;
-                    return _isMaster;
-                }, _isMaster, IsMasterSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _isMaster, Ps.Value.IsMasterSelector); }
         }
 
         /// <summary>

src/Umbraco.Core/Models/StylesheetProperty.cs

@@ -25,8 +25,13 @@ namespace Umbraco.Core.Models
             _value = value;
         }
 
-        private static readonly PropertyInfo AliasSelector = ExpressionHelper.GetPropertyInfo<StylesheetProperty, string>(x => x.Alias);
-        private static readonly PropertyInfo ValueSelector = ExpressionHelper.GetPropertyInfo<StylesheetProperty, string>(x => x.Value);
+        private static readonly Lazy<PropertySelectors> Ps = new Lazy<PropertySelectors>();
+
+        private class PropertySelectors
+        {
+            public readonly PropertyInfo AliasSelector = ExpressionHelper.GetPropertyInfo<StylesheetProperty, string>(x => x.Alias);
+            public readonly PropertyInfo ValueSelector = ExpressionHelper.GetPropertyInfo<StylesheetProperty, string>(x => x.Value);
+        }
 
         /// <summary>
         /// The CSS rule name that can be used by Umbraco in the back office
@@ -39,14 +44,7 @@ namespace Umbraco.Core.Models
         public string Alias
         {
             get { return _alias; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _alias = value;
-                    return _alias;
-                }, _alias, AliasSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _alias, Ps.Value.AliasSelector); }
         }
 
         /// <summary>
@@ -55,14 +53,7 @@ namespace Umbraco.Core.Models
         public string Value
         {
             get { return _value; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _value = value;
-                    return _value;
-                }, _value, ValueSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _value, Ps.Value.ValueSelector); }
         }
 
     }

src/Umbraco.Core/Models/Tag.cs

@@ -27,35 +27,27 @@ namespace Umbraco.Core.Models
             NodeCount = nodeCount;            
         }
 
-        private static readonly PropertyInfo TextSelector = ExpressionHelper.GetPropertyInfo<Tag, string>(x => x.Text);
-        private static readonly PropertyInfo GroupSelector = ExpressionHelper.GetPropertyInfo<Tag, string>(x => x.Group);
+        private static readonly Lazy<PropertySelectors> Ps = new Lazy<PropertySelectors>();
+
+        private class PropertySelectors
+        {
+            public readonly PropertyInfo TextSelector = ExpressionHelper.GetPropertyInfo<Tag, string>(x => x.Text);
+            public readonly PropertyInfo GroupSelector = ExpressionHelper.GetPropertyInfo<Tag, string>(x => x.Group);
+        }
+
         private string _text;
         private string _group;
 
         public string Text
         {
             get { return _text; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _text = value;
-                    return _text;
-                }, _text, TextSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _text, Ps.Value.TextSelector); }
         }
 
         public string Group
         {
             get { return _group; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _group = value;
-                    return _group;
-                }, _group, GroupSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _group, Ps.Value.GroupSelector); }
         }
 
         public int NodeCount { get; internal set; }

src/Umbraco.Core/Models/Task.cs

@@ -24,12 +24,17 @@ namespace Umbraco.Core.Models
             _taskType = taskType;
         }
 
-        private static readonly PropertyInfo ClosedSelector = ExpressionHelper.GetPropertyInfo<Task, bool>(x => x.Closed);
-        private static readonly PropertyInfo TaskTypeSelector = ExpressionHelper.GetPropertyInfo<Task, TaskType>(x => x.TaskType);
-        private static readonly PropertyInfo EntityIdSelector = ExpressionHelper.GetPropertyInfo<Task, int>(x => x.EntityId);
-        private static readonly PropertyInfo OwnerUserIdSelector = ExpressionHelper.GetPropertyInfo<Task, int>(x => x.OwnerUserId);
-        private static readonly PropertyInfo AssigneeUserIdSelector = ExpressionHelper.GetPropertyInfo<Task, int>(x => x.AssigneeUserId);
-        private static readonly PropertyInfo CommentSelector = ExpressionHelper.GetPropertyInfo<Task, string>(x => x.Comment);
+        private static readonly Lazy<PropertySelectors> Ps = new Lazy<PropertySelectors>();
+
+        private class PropertySelectors
+        {
+            public readonly PropertyInfo ClosedSelector = ExpressionHelper.GetPropertyInfo<Task, bool>(x => x.Closed);
+            public readonly PropertyInfo TaskTypeSelector = ExpressionHelper.GetPropertyInfo<Task, TaskType>(x => x.TaskType);
+            public readonly PropertyInfo EntityIdSelector = ExpressionHelper.GetPropertyInfo<Task, int>(x => x.EntityId);
+            public readonly PropertyInfo OwnerUserIdSelector = ExpressionHelper.GetPropertyInfo<Task, int>(x => x.OwnerUserId);
+            public readonly PropertyInfo AssigneeUserIdSelector = ExpressionHelper.GetPropertyInfo<Task, int>(x => x.AssigneeUserId);
+            public readonly PropertyInfo CommentSelector = ExpressionHelper.GetPropertyInfo<Task, string>(x => x.Comment);
+        }
 
         /// <summary>
         /// Gets or sets a boolean indicating whether the task is closed
@@ -38,14 +43,7 @@ namespace Umbraco.Core.Models
         public bool Closed
         {
             get { return _closed; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _closed = value;
-                    return _closed;
-                }, _closed, ClosedSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _closed, Ps.Value.ClosedSelector); }
         }
 
         /// <summary>
@@ -55,14 +53,7 @@ namespace Umbraco.Core.Models
         public TaskType TaskType
         {
             get { return _taskType; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _taskType = value;
-                    return _taskType;
-                }, _taskType, TaskTypeSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _taskType, Ps.Value.TaskTypeSelector); }
         }
 
         /// <summary>
@@ -72,14 +63,7 @@ namespace Umbraco.Core.Models
         public int EntityId
         {
             get { return _entityId; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _entityId = value;
-                    return _entityId;
-                }, _entityId, EntityIdSelector);                
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _entityId, Ps.Value.EntityIdSelector); }
         }
 
         /// <summary>
@@ -89,14 +73,7 @@ namespace Umbraco.Core.Models
         public int OwnerUserId
         {
             get { return _ownerUserId; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _ownerUserId = value;
-                    return _ownerUserId;
-                }, _ownerUserId, OwnerUserIdSelector);    
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _ownerUserId, Ps.Value.OwnerUserIdSelector); }
         }
 
         /// <summary>
@@ -106,14 +83,7 @@ namespace Umbraco.Core.Models
         public int AssigneeUserId
         {
             get { return _assigneeUserId; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _assigneeUserId = value;
-                    return _assigneeUserId;
-                }, _assigneeUserId, AssigneeUserIdSelector);    
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _assigneeUserId, Ps.Value.AssigneeUserIdSelector); }
         }
 
         /// <summary>
@@ -123,14 +93,7 @@ namespace Umbraco.Core.Models
         public string Comment
         {
             get { return _comment; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _comment = value;
-                    return _comment;
-                }, _comment, CommentSelector);    
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _comment, Ps.Value.CommentSelector); }
         }
 
     }

src/Umbraco.Core/Models/TaskType.cs

@@ -19,7 +19,12 @@ namespace Umbraco.Core.Models
             _alias = alias;
         }
 
-        private static readonly PropertyInfo AliasSelector = ExpressionHelper.GetPropertyInfo<TaskType, string>(x => x.Alias);
+        private static readonly Lazy<PropertySelectors> Ps = new Lazy<PropertySelectors>();
+
+        private class PropertySelectors
+        {
+            public readonly PropertyInfo AliasSelector = ExpressionHelper.GetPropertyInfo<TaskType, string>(x => x.Alias);
+        }
 
         /// <summary>
         /// Gets or sets the Alias of the TaskType
@@ -28,14 +33,7 @@ namespace Umbraco.Core.Models
         public string Alias
         {
             get { return _alias; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _alias = value;
-                    return _alias;
-                }, _alias, AliasSelector);    
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _alias, Ps.Value.AliasSelector); }
         }
     }
 }

src/Umbraco.Core/Models/Template.cs

@@ -26,10 +26,15 @@ namespace Umbraco.Core.Models
         private string _masterTemplateAlias;
         private Lazy<int> _masterTemplateId;
 
-        private static readonly PropertyInfo MasterTemplateAliasSelector = ExpressionHelper.GetPropertyInfo<Template, string>(x => x.MasterTemplateAlias);
-        private static readonly PropertyInfo MasterTemplateIdSelector = ExpressionHelper.GetPropertyInfo<Template, Lazy<int>>(x => x.MasterTemplateId);
-        private static readonly PropertyInfo AliasSelector = ExpressionHelper.GetPropertyInfo<Template, string>(x => x.Alias);
-        private static readonly PropertyInfo NameSelector = ExpressionHelper.GetPropertyInfo<Template, string>(x => x.Name);
+        private static readonly Lazy<PropertySelectors> Ps = new Lazy<PropertySelectors>();
+
+        private class PropertySelectors
+        {
+            public readonly PropertyInfo MasterTemplateAliasSelector = ExpressionHelper.GetPropertyInfo<Template, string>(x => x.MasterTemplateAlias);
+            public readonly PropertyInfo MasterTemplateIdSelector = ExpressionHelper.GetPropertyInfo<Template, Lazy<int>>(x => x.MasterTemplateId);
+            public readonly PropertyInfo AliasSelector = ExpressionHelper.GetPropertyInfo<Template, string>(x => x.Alias);
+            public readonly PropertyInfo NameSelector = ExpressionHelper.GetPropertyInfo<Template, string>(x => x.Name);
+        }
 
         public Template(string name, string alias)
             : this(name, alias, (Func<File, string>) null)
@@ -53,57 +58,27 @@ namespace Umbraco.Core.Models
         public Lazy<int> MasterTemplateId
         {
             get { return _masterTemplateId; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _masterTemplateId = value;
-                    return _masterTemplateId;
-                }, _masterTemplateId, MasterTemplateIdSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _masterTemplateId, Ps.Value.MasterTemplateIdSelector); }
         }
 
         public string MasterTemplateAlias
         {
             get { return _masterTemplateAlias; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _masterTemplateAlias = value;
-                    return _masterTemplateAlias;
-                }, _masterTemplateAlias, MasterTemplateAliasSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _masterTemplateAlias, Ps.Value.MasterTemplateAliasSelector); }
         }
 
         [DataMember]
         public new string Name
         {
             get { return _name; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _name = value;
-                    return _name;
-                }, _name, NameSelector);
-                
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _name, Ps.Value.NameSelector); }
         }
 
         [DataMember]
         public new string Alias
         {
             get { return _alias; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _alias = value.ToCleanString(CleanStringType.UnderscoreAlias);
-                    return _alias;
-                }, _alias, AliasSelector);
-                
-            }
+            set { SetPropertyValueAndDetectChanges(value.ToCleanString(CleanStringType.UnderscoreAlias), ref _alias, Ps.Value.AliasSelector); }
         }
 
         /// <summary>

src/Umbraco.Core/Models/UmbracoDomain.cs

@@ -24,51 +24,34 @@ namespace Umbraco.Core.Models
         private int? _languageId;
         private string _domainName;
 
-        private static readonly PropertyInfo ContentSelector = ExpressionHelper.GetPropertyInfo<UmbracoDomain, int?>(x => x.RootContentId);
-        private static readonly PropertyInfo DefaultLanguageSelector = ExpressionHelper.GetPropertyInfo<UmbracoDomain, int?>(x => x.LanguageId);
-        private static readonly PropertyInfo DomainNameSelector = ExpressionHelper.GetPropertyInfo<UmbracoDomain, string>(x => x.DomainName);
-        
+        private static readonly Lazy<PropertySelectors> Ps = new Lazy<PropertySelectors>();
+
+        private class PropertySelectors
+        {
+            public readonly PropertyInfo ContentSelector = ExpressionHelper.GetPropertyInfo<UmbracoDomain, int?>(x => x.RootContentId);
+            public readonly PropertyInfo DefaultLanguageSelector = ExpressionHelper.GetPropertyInfo<UmbracoDomain, int?>(x => x.LanguageId);
+            public readonly PropertyInfo DomainNameSelector = ExpressionHelper.GetPropertyInfo<UmbracoDomain, string>(x => x.DomainName);
+        }
 
         [DataMember]
         public int? LanguageId
         {
             get { return _languageId; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _languageId = value;
-                    return _languageId;
-                }, _languageId, DefaultLanguageSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _languageId, Ps.Value.DefaultLanguageSelector); }
         }
 
         [DataMember]
         public string DomainName
         {
             get { return _domainName; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _domainName = value;
-                    return _domainName;
-                }, _domainName, DomainNameSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _domainName, Ps.Value.DomainNameSelector); }
         }
 
         [DataMember]
         public int? RootContentId
         {
             get { return _contentId; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _contentId = value;
-                    return _contentId;
-                }, _contentId, ContentSelector);
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _contentId, Ps.Value.ContentSelector); }
         }
 
         public bool IsWildcard

src/Umbraco.Core/Models/UmbracoEntity.cs

@@ -26,22 +26,28 @@ namespace Umbraco.Core.Models
         private bool _hasPendingChanges;
         private string _contentTypeAlias;
         private Guid _nodeObjectTypeId;
+        
+        private static readonly Lazy<PropertySelectors> Ps = new Lazy<PropertySelectors>();
+
+        private class PropertySelectors
+        {
+            public readonly PropertyInfo CreatorIdSelector = ExpressionHelper.GetPropertyInfo<UmbracoEntity, int>(x => x.CreatorId);
+            public readonly PropertyInfo LevelSelector = ExpressionHelper.GetPropertyInfo<UmbracoEntity, int>(x => x.Level);
+            public readonly PropertyInfo NameSelector = ExpressionHelper.GetPropertyInfo<UmbracoEntity, string>(x => x.Name);
+            public readonly PropertyInfo ParentIdSelector = ExpressionHelper.GetPropertyInfo<UmbracoEntity, int>(x => x.ParentId);
+            public readonly PropertyInfo PathSelector = ExpressionHelper.GetPropertyInfo<UmbracoEntity, string>(x => x.Path);
+            public readonly PropertyInfo SortOrderSelector = ExpressionHelper.GetPropertyInfo<UmbracoEntity, int>(x => x.SortOrder);
+            public readonly PropertyInfo TrashedSelector = ExpressionHelper.GetPropertyInfo<UmbracoEntity, bool>(x => x.Trashed);
+            public readonly PropertyInfo HasChildrenSelector = ExpressionHelper.GetPropertyInfo<UmbracoEntity, bool>(x => x.HasChildren);
+            public readonly PropertyInfo IsPublishedSelector = ExpressionHelper.GetPropertyInfo<UmbracoEntity, bool>(x => x.IsPublished);
+            public readonly PropertyInfo IsDraftSelector = ExpressionHelper.GetPropertyInfo<UmbracoEntity, bool>(x => x.IsDraft);
+            public readonly PropertyInfo HasPendingChangesSelector = ExpressionHelper.GetPropertyInfo<UmbracoEntity, bool>(x => x.HasPendingChanges);
+            public readonly PropertyInfo ContentTypeAliasSelector = ExpressionHelper.GetPropertyInfo<UmbracoEntity, string>(x => x.ContentTypeAlias);
+            public readonly PropertyInfo ContentTypeIconSelector = ExpressionHelper.GetPropertyInfo<UmbracoEntity, string>(x => x.ContentTypeIcon);
+            public readonly PropertyInfo ContentTypeThumbnailSelector = ExpressionHelper.GetPropertyInfo<UmbracoEntity, string>(x => x.ContentTypeThumbnail);
+            public readonly PropertyInfo NodeObjectTypeIdSelector = ExpressionHelper.GetPropertyInfo<UmbracoEntity, Guid>(x => x.NodeObjectTypeId);
+        }
 
-        private static readonly PropertyInfo CreatorIdSelector = ExpressionHelper.GetPropertyInfo<UmbracoEntity, int>(x => x.CreatorId);
-        private static readonly PropertyInfo LevelSelector = ExpressionHelper.GetPropertyInfo<UmbracoEntity, int>(x => x.Level);
-        private static readonly PropertyInfo NameSelector = ExpressionHelper.GetPropertyInfo<UmbracoEntity, string>(x => x.Name);
-        private static readonly PropertyInfo ParentIdSelector = ExpressionHelper.GetPropertyInfo<UmbracoEntity, int>(x => x.ParentId);
-        private static readonly PropertyInfo PathSelector = ExpressionHelper.GetPropertyInfo<UmbracoEntity, string>(x => x.Path);
-        private static readonly PropertyInfo SortOrderSelector = ExpressionHelper.GetPropertyInfo<UmbracoEntity, int>(x => x.SortOrder);
-        private static readonly PropertyInfo TrashedSelector = ExpressionHelper.GetPropertyInfo<UmbracoEntity, bool>(x => x.Trashed);
-        private static readonly PropertyInfo HasChildrenSelector = ExpressionHelper.GetPropertyInfo<UmbracoEntity, bool>(x => x.HasChildren);
-        private static readonly PropertyInfo IsPublishedSelector = ExpressionHelper.GetPropertyInfo<UmbracoEntity, bool>(x => x.IsPublished);
-        private static readonly PropertyInfo IsDraftSelector = ExpressionHelper.GetPropertyInfo<UmbracoEntity, bool>(x => x.IsDraft);
-        private static readonly PropertyInfo HasPendingChangesSelector = ExpressionHelper.GetPropertyInfo<UmbracoEntity, bool>(x => x.HasPendingChanges);
-        private static readonly PropertyInfo ContentTypeAliasSelector = ExpressionHelper.GetPropertyInfo<UmbracoEntity, string>(x => x.ContentTypeAlias);
-        private static readonly PropertyInfo ContentTypeIconSelector = ExpressionHelper.GetPropertyInfo<UmbracoEntity, string>(x => x.ContentTypeIcon);
-        private static readonly PropertyInfo ContentTypeThumbnailSelector = ExpressionHelper.GetPropertyInfo<UmbracoEntity, string>(x => x.ContentTypeThumbnail);
-        private static readonly PropertyInfo NodeObjectTypeIdSelector = ExpressionHelper.GetPropertyInfo<UmbracoEntity, Guid>(x => x.NodeObjectTypeId);
         private string _contentTypeIcon;
         private string _contentTypeThumbnail;
 
@@ -66,92 +72,43 @@ namespace Umbraco.Core.Models
         public int CreatorId
         {
             get { return _creatorId; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _creatorId = value;
-                    return _creatorId;
-                }, _creatorId, CreatorIdSelector);  
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _creatorId, Ps.Value.CreatorIdSelector); }
         }
 
         public int Level
         {
             get { return _level; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _level = value;
-                    return _level;
-                }, _level, LevelSelector);  
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _level, Ps.Value.LevelSelector); }
         }
 
         public string Name
         {
             get { return _name; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _name = value;
-                    return _name;
-                }, _name, NameSelector);  
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _name, Ps.Value.NameSelector); }
         }
 
         public int ParentId
         {
             get { return _parentId; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _parentId = value;
-                    return _parentId;
-                }, _parentId, ParentIdSelector);  
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _parentId, Ps.Value.ParentIdSelector); }
         }
 
         public string Path
         {
             get { return _path; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _path = value;
-                    return _path;
-                }, _path, PathSelector);  
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _path, Ps.Value.PathSelector); }
         }
 
         public int SortOrder
         {
             get { return _sortOrder; }
-            set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _sortOrder = value;
-                    return _sortOrder;
-                }, _sortOrder, SortOrderSelector);  
-            }
+            set { SetPropertyValueAndDetectChanges(value, ref _sortOrder, Ps.Value.SortOrderSelector); }
         }
 
         public bool Trashed
         {
             get { return _trashed; }
-            private set
-            {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _trashed = value;
-                    return _trashed;
-                }, _trashed, TrashedSelector);  
-            }
+            private set { SetPropertyValueAndDetectChanges(value, ref _trashed, Ps.Value.TrashedSelector); }
         }
 
         public IDictionary<string, object> AdditionalData { get; private set; }
@@ -162,12 +119,7 @@ namespace Umbraco.Core.Models
             get { return _hasChildren; }
             set
             {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _hasChildren = value;
-                    return _hasChildren;
-                }, _hasChildren, HasChildrenSelector);  
-
+                SetPropertyValueAndDetectChanges(value, ref _hasChildren, Ps.Value.HasChildrenSelector);
                 //This is a custom property that is not exposed in IUmbracoEntity so add it to the additional data
                 AdditionalData["HasChildren"] = value;
             }
@@ -178,12 +130,7 @@ namespace Umbraco.Core.Models
             get { return _isPublished; }
             set
             {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _isPublished = value;
-                    return _isPublished;
-                }, _isPublished, IsPublishedSelector);
-
+                SetPropertyValueAndDetectChanges(value, ref _isPublished, Ps.Value.IsPublishedSelector);
                 //This is a custom property that is not exposed in IUmbracoEntity so add it to the additional data
                 AdditionalData["IsPublished"] = value;
             }
@@ -194,12 +141,7 @@ namespace Umbraco.Core.Models
             get { return _isDraft; }
             set
             {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _isDraft = value;
-                    return _isDraft;
-                }, _isDraft, IsDraftSelector);
-
+                SetPropertyValueAndDetectChanges(value, ref _isDraft, Ps.Value.IsDraftSelector);
                 //This is a custom property that is not exposed in IUmbracoEntity so add it to the additional data
                 AdditionalData["IsDraft"] = value;
             }
@@ -210,12 +152,7 @@ namespace Umbraco.Core.Models
             get { return _hasPendingChanges; }
             set
             {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _hasPendingChanges = value;
-                    return _hasPendingChanges;
-                }, _hasPendingChanges, HasPendingChangesSelector);
-
+                SetPropertyValueAndDetectChanges(value, ref _hasPendingChanges, Ps.Value.HasPendingChangesSelector);                
                 //This is a custom property that is not exposed in IUmbracoEntity so add it to the additional data
                 AdditionalData["HasPendingChanges"] = value;
             }
@@ -226,12 +163,7 @@ namespace Umbraco.Core.Models
             get { return _contentTypeAlias; }
             set
             {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _contentTypeAlias = value;
-                    return _contentTypeAlias;
-                }, _contentTypeAlias, ContentTypeAliasSelector);
-
+                SetPropertyValueAndDetectChanges(value, ref _contentTypeAlias, Ps.Value.ContentTypeAliasSelector);                
                 //This is a custom property that is not exposed in IUmbracoEntity so add it to the additional data
                 AdditionalData["ContentTypeAlias"] = value;
             }
@@ -242,12 +174,7 @@ namespace Umbraco.Core.Models
             get { return _contentTypeIcon; }
             set
             {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _contentTypeIcon = value;
-                    return _contentTypeIcon;
-                }, _contentTypeIcon, ContentTypeIconSelector);
-
+                SetPropertyValueAndDetectChanges(value, ref _contentTypeIcon, Ps.Value.ContentTypeIconSelector);                
                 //This is a custom property that is not exposed in IUmbracoEntity so add it to the additional data
                 AdditionalData["ContentTypeIcon"] = value;
             }
@@ -258,12 +185,7 @@ namespace Umbraco.Core.Models
             get { return _contentTypeThumbnail; }
             set
             {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _contentTypeThumbnail = value;
-                    return _contentTypeThumbnail;
-                }, _contentTypeThumbnail, ContentTypeThumbnailSelector);
-
+                SetPropertyValueAndDetectChanges(value, ref _contentTypeThumbnail, Ps.Value.ContentTypeThumbnailSelector);                
                 //This is a custom property that is not exposed in IUmbracoEntity so add it to the additional data
                 AdditionalData["ContentTypeThumbnail"] = value;
             }
@@ -274,12 +196,7 @@ namespace Umbraco.Core.Models
             get { return _nodeObjectTypeId; }
             set
             {
-                SetPropertyValueAndDetectChanges(o =>
-                {
-                    _nodeObjectTypeId = value;
-                    return _nodeObjectTypeId;
-                }, _nodeObjectTypeId, NodeObjectTypeIdSelector);
-
+                SetPropertyValueAndDetectChanges(value, ref _nodeObjectTypeId, Ps.Value.NodeObjectTypeIdSelector);
                 //This is a custom property that is not exposed in IUmbracoEntity so add it to the additional data
                 AdditionalData["NodeObjectTypeId"] = value;
             }

src/Umbraco.Core/ObjectExtensions.cs

@@ -9,15 +9,28 @@ using System.Xml;
 
 namespace Umbraco.Core
 {
+	/// <summary>
+	/// Provides object extension methods.
+	/// </summary>
 	public static class ObjectExtensions
 	{
 		//private static readonly ConcurrentDictionary<Type, Func<object>> ObjectFactoryCache = new ConcurrentDictionary<Type, Func<object>>();
 
+		/// <summary>
+		/// 
+		/// </summary>
+		/// <param name="input"></param>
+		/// <typeparam name="T"></typeparam>
+		/// <returns></returns>
 		public static IEnumerable<T> AsEnumerableOfOne<T>(this T input)
 		{
 			return Enumerable.Repeat(input, 1);
 		}
 
+		/// <summary>
+		/// 
+		/// </summary>
+		/// <param name="input"></param>
 		public static void DisposeIfDisposable(this object input)
 		{
 			var disposable = input as IDisposable;
@@ -25,7 +38,8 @@ namespace Umbraco.Core
 		}
 
 		/// <summary>
-		/// Provides a shortcut way of safely casting an input when you cannot guarantee the <typeparam name="T"></typeparam> is an instance type (i.e., when the C# AS keyword is not applicable)
+		/// Provides a shortcut way of safely casting an input when you cannot guarantee the <typeparamref name="T"/> is
+		/// an instance type (i.e., when the C# AS keyword is not applicable).
 		/// </summary>
 		/// <typeparam name="T"></typeparam>
 		/// <param name="input">The input.</param>
@@ -63,30 +77,30 @@ namespace Umbraco.Core
 		}
 
 		/// <summary>
-		/// Tries to convert the input object to the output type using TypeConverters. If the destination type is a superclass of the input type,
-		/// if will use <see cref="Convert.ChangeType(object,System.Type)"/>.
+		/// Tries to convert the input object to the output type using TypeConverters. If the destination
+		/// type is a superclass of the input type, if will use <see cref="Convert.ChangeType(object,System.Type)"/>.
 		/// </summary>
 		/// <param name="input">The input.</param>
 		/// <param name="destinationType">Type of the destination.</param>
 		/// <returns></returns>
 		public static Attempt<object> TryConvertTo(this object input, Type destinationType)
 		{
-            //if it is null and it is nullable, then return success with null
-            if (input == null && destinationType.IsGenericType && destinationType.GetGenericTypeDefinition() == typeof (Nullable<>))
-            {
-                return Attempt<object>.Succeed(null);
+            // if null...
+		    if (input == null)
+		    {
+		        // nullable is ok
+                if (destinationType.IsGenericType && destinationType.GetGenericTypeDefinition() == typeof(Nullable<>))
+                    return Attempt<object>.Succeed(null);
+
+                // value type is nok, else can be null, so is ok
+		        return Attempt<object>.SucceedIf(destinationType.IsValueType == false, null);
             }
-			
-            //if its not nullable and it is a value type
-			if (input == null && destinationType.IsValueType) return Attempt<object>.Fail();
-            //if the type can be null, then no problem
-            if (input == null && destinationType.IsValueType == false) return Attempt<object>.Succeed(null);
 
+            // easy
 			if (destinationType == typeof(object)) return Attempt.Succeed(input);
-
 			if (input.GetType() == destinationType) return Attempt.Succeed(input);
 
-            //check for string so that overloaders of ToString() can take advantage of the conversion.
+            // check for string so that overloaders of ToString() can take advantage of the conversion.
             if (destinationType == typeof(string)) return Attempt<object>.Succeed(input.ToString());
 
 			// if we've got a nullable of something, we try to convert directly to that thing.
@@ -116,9 +130,10 @@ namespace Umbraco.Core
 			{
 				if (input is string)
 				{
+                    // try convert from string, returns an Attempt if the string could be
+                    // processed (either succeeded or failed), else null if we need to try
+                    // other methods
 					var result = TryConvertToFromString(input as string, destinationType);
-
-					// if we processed the string (succeed or fail), we're done
 					if (result.HasValue) return result.Value;
 				}
 
@@ -201,90 +216,124 @@ namespace Umbraco.Core
 			return Attempt<object>.Fail();
 		}
 
-		private static Nullable<Attempt<object>> TryConvertToFromString(this string input, Type destinationType)
+        // returns an attempt if the string has been processed (either succeeded or failed)
+        // returns null if we need to try other methods
+		private static Attempt<object>? TryConvertToFromString(this string input, Type destinationType)
 		{
+            // easy
 			if (destinationType == typeof(string))
 				return Attempt<object>.Succeed(input);
 
-			if (string.IsNullOrEmpty(input))
+            // null, empty, whitespaces
+			if (string.IsNullOrWhiteSpace(input))
 			{
-				if (destinationType == typeof(Boolean))
-					return Attempt<object>.Succeed(false);   // special case for booleans, null/empty == false
-				if (destinationType == typeof(DateTime))
+				if (destinationType == typeof(bool)) // null/empty = bool false
+					return Attempt<object>.Succeed(false);
+				if (destinationType == typeof(DateTime)) // null/empty = min DateTime value
                     return Attempt<object>.Succeed(DateTime.MinValue);
+
+			    // cannot decide here,
+                // any of the types below will fail parsing and will return a failed attempt
+                // but anything else will not be processed and will return null
+                // so even though the string is null/empty we have to proceed
 			}
 
-			// we have a non-empty string, look for type conversions in the expected order of frequency of use...
+			// look for type conversions in the expected order of frequency of use...
 			if (destinationType.IsPrimitive)
 			{
-			    if (destinationType == typeof(Int32))
+			    if (destinationType == typeof(int)) // aka Int32
 				{
-					Int32 value;
-					return Int32.TryParse(input, out value) ? Attempt<object>.Succeed(value) : Attempt<object>.Fail();
-				}
-			    if (destinationType == typeof(Int64))
-			    {
-			        Int64 value;
-			        return Int64.TryParse(input, out value) ? Attempt<object>.Succeed(value) : Attempt<object>.Fail();
-			    }
-			    if (destinationType == typeof(Boolean))
-			    {
-			        Boolean value;
-			        if (Boolean.TryParse(input, out value))
-			            return Attempt<object>.Succeed(value);  // don't declare failure so the CustomBooleanTypeConverter can try
-			    }
-			    else if (destinationType == typeof(Int16))
-			    {
-			        Int16 value;
-			        return Int16.TryParse(input, out value) ? Attempt<object>.Succeed(value) : Attempt<object>.Fail();
-			    }
-			    else if (destinationType == typeof(Double))
-			    {
-			        Double value;
-			        var input2 = NormalizeNumberDecimalSeparator(input);
-			        return Double.TryParse(input2, out value) ? Attempt<object>.Succeed(value) : Attempt<object>.Fail();
-			    }
-			    else if (destinationType == typeof(Single))
-			    {
-			        Single value;
+					int value;
+				    if (int.TryParse(input, out value)) return Attempt<object>.Succeed(value);
+
+                    // because decimal 100.01m will happily convert to integer 100, it
+                    // makes sense that string "100.01" *also* converts to integer 100.
+                    decimal value2;
                     var input2 = NormalizeNumberDecimalSeparator(input);
-                    return Single.TryParse(input2, out value) ? Attempt<object>.Succeed(value) : Attempt<object>.Fail();
-			    }
-			    else if (destinationType == typeof(Char))
+                    return Attempt<object>.SucceedIf(decimal.TryParse(input2, out value2), Convert.ToInt32(value2));
+                }
+
+                if (destinationType == typeof(long)) // aka Int64
 			    {
-			        Char value;
-			        return Char.TryParse(input, out value) ? Attempt<object>.Succeed(value) : Attempt<object>.Fail();
+			        long value;
+			        if (long.TryParse(input, out value)) return Attempt<object>.Succeed(value);
+
+                    // same as int
+                    decimal value2;
+                    var input2 = NormalizeNumberDecimalSeparator(input);
+			        return Attempt<object>.SucceedIf(decimal.TryParse(input2, out value2), Convert.ToInt64(value2));
 			    }
-			    else if (destinationType == typeof(Byte))
+
+                // fixme - should we do the decimal trick for short, byte, unsigned?
+
+			    if (destinationType == typeof(bool)) // aka Boolean
 			    {
-			        Byte value;
-			        return Byte.TryParse(input, out value) ? Attempt<object>.Succeed(value) : Attempt<object>.Fail();
+			        bool value;
+			        if (bool.TryParse(input, out value)) return Attempt<object>.Succeed(value);
+                    // don't declare failure so the CustomBooleanTypeConverter can try
+                    return null;
 			    }
-			    else if (destinationType == typeof(SByte))
+
+			    if (destinationType == typeof(short)) // aka Int16
 			    {
-			        SByte value;
-			        return SByte.TryParse(input, out value) ? Attempt<object>.Succeed(value) : Attempt<object>.Fail();
+			        short value;
+			        return Attempt<object>.SucceedIf(short.TryParse(input, out value), value);
 			    }
-			    else if (destinationType == typeof(UInt32))
+
+			    if (destinationType == typeof(double)) // aka Double
 			    {
-			        UInt32 value;
-			        return UInt32.TryParse(input, out value) ? Attempt<object>.Succeed(value) : Attempt<object>.Fail();
+			        double value;
+			        var input2 = NormalizeNumberDecimalSeparator(input);
+			        return Attempt<object>.SucceedIf(double.TryParse(input2, out value), value);
 			    }
-			    else if (destinationType == typeof(UInt16))
+
+			    if (destinationType == typeof(float)) // aka Single
 			    {
-			        UInt16 value;
-			        return UInt16.TryParse(input, out value) ? Attempt<object>.Succeed(value) : Attempt<object>.Fail();
+			        float value;
+			        var input2 = NormalizeNumberDecimalSeparator(input);
+			        return Attempt<object>.SucceedIf(float.TryParse(input2, out value), value);
 			    }
-			    else if (destinationType == typeof(UInt64))
+
+			    if (destinationType == typeof(char)) // aka Char
 			    {
-			        UInt64 value;
-			        return UInt64.TryParse(input, out value) ? Attempt<object>.Succeed(value) : Attempt<object>.Fail();
+			        char value;
+			        return Attempt<object>.SucceedIf(char.TryParse(input, out value), value);
+			    }
+
+			    if (destinationType == typeof(byte)) // aka Byte
+			    {
+			        byte value;
+			        return Attempt<object>.SucceedIf(byte.TryParse(input, out value), value);
+			    }
+
+			    if (destinationType == typeof(sbyte)) // aka SByte
+                {
+			        sbyte value;
+			        return Attempt<object>.SucceedIf(sbyte.TryParse(input, out value), value);
+                }
+
+			    if (destinationType == typeof(uint)) // aka UInt32
+                {
+			        uint value;
+			        return Attempt<object>.SucceedIf(uint.TryParse(input, out value), value);
+                }
+
+			    if (destinationType == typeof(ushort)) // aka UInt16
+                {
+			        ushort value;
+			        return Attempt<object>.SucceedIf(ushort.TryParse(input, out value), value);
+                }
+
+			    if (destinationType == typeof(ulong)) // aka UInt64
+                {
+			        ulong value;
+                    return Attempt<object>.SucceedIf(ulong.TryParse(input, out value), value);
 			    }
 			}
 			else if (destinationType == typeof(Guid))
 			{
 				Guid value;
-				return Guid.TryParse(input, out value) ? Attempt<object>.Succeed(value) : Attempt<object>.Fail();
+			    return Attempt<object>.SucceedIf(Guid.TryParse(input, out value), value);
 			}
 			else if (destinationType == typeof(DateTime))
 			{
@@ -307,30 +356,30 @@ namespace Umbraco.Core
 			else if (destinationType == typeof(DateTimeOffset))
 			{
 				DateTimeOffset value;
-				return DateTimeOffset.TryParse(input, out value) ? Attempt<object>.Succeed(value) : Attempt<object>.Fail();
+			    return Attempt<object>.SucceedIf(DateTimeOffset.TryParse(input, out value), value);
 			}
 			else if (destinationType == typeof(TimeSpan))
 			{
 				TimeSpan value;
-				return TimeSpan.TryParse(input, out value) ? Attempt<object>.Succeed(value) : Attempt<object>.Fail();
+			    return Attempt<object>.SucceedIf(TimeSpan.TryParse(input, out value), value);
 			}
-			else if (destinationType == typeof(Decimal))
+			else if (destinationType == typeof(decimal)) // aka Decimal
 			{
-				Decimal value;
+				decimal value;
                 var input2 = NormalizeNumberDecimalSeparator(input);
-                return Decimal.TryParse(input2, out value) ? Attempt<object>.Succeed(value) : Attempt<object>.Fail();
+                return Attempt<object>.SucceedIf(decimal.TryParse(input2, out value), value);
 			}
 			else if (destinationType == typeof(Version))
 			{
 				Version value;
-				return Version.TryParse(input, out value) ? Attempt<object>.Succeed(value) : Attempt<object>.Fail();
+			    return Attempt<object>.SucceedIf(Version.TryParse(input, out value), value);
 			}
 			// E_NOTIMPL IPAddress, BigInteger
 
 			return null; // we can't decide...
 		}
 
-        private static readonly char[] NumberDecimalSeparatorsToNormalize = new[] {'.', ','};
+        private static readonly char[] NumberDecimalSeparatorsToNormalize = {'.', ','};
 
 	    private static string NormalizeNumberDecimalSeparator(string s)
 	    {

src/Umbraco.Core/Packaging/PackageMigrationsContext.cs

@@ -1,114 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.Collections.ObjectModel;
-using System.Linq;
-using Semver;
-using Umbraco.Core.Configuration;
-using Umbraco.Core.Logging;
-using Umbraco.Core.Persistence.Migrations;
-using Umbraco.Core.Services;
-
-namespace Umbraco.Core.Packaging
-{
-    internal class PackageMigrationsContext
-    {
-        private readonly DatabaseContext _dbContext;
-        private readonly IMigrationEntryService _migrationEntryService;
-        private readonly ILogger _logger;
-
-        public PackageMigrationsContext(DatabaseContext dbContext, 
-            IMigrationEntryService migrationEntryService, 
-            ILogger logger)
-        {
-            _dbContext = dbContext;
-            _migrationEntryService = migrationEntryService;
-            _logger = logger;
-            ResetPendingPackageMigrations();
-        }
-
-        //List of product names and their maximum sem version registered in migrations
-        private Lazy<ReadOnlyDictionary<string, SemVersion>> _packageVersionsConfigured;
-
-        /// <summary>
-        /// Called to initialize or when package migrations have executed - since an app restart is mandatory
-        /// </summary>
-        internal void ResetPendingPackageMigrations()
-        {
-            _packageVersionsConfigured = new Lazy<ReadOnlyDictionary<string, SemVersion>>(() =>
-            {
-                var result = new Dictionary<string, SemVersion>();
-
-                //The versions are the same in config, but are they the same in the database. We can only check this
-                // if we have a db context available, if we don't then we are not installed anyways
-                if (_dbContext.IsDatabaseConfigured && _dbContext.CanConnect)
-                {
-                    //Now we can check if there are any package migrations that haven't been executed.
-
-                    //Find and group the packages that have migrations.
-                    //Then we need to determine if there are outstanding migrations that need to be run based on the
-                    // migration versions stored in the db compared to the available migrations.
-                    var packageMigrations = MigrationResolver.Current.MigrationMetaData
-                        .Where(x => x.ProductName != GlobalSettings.UmbracoMigrationName)
-                        .GroupBy(x => x.ProductName)
-                        .ToArray();
-
-                    var packageMigrationProductNames = packageMigrations.Select(x => x.Key).Distinct().ToArray();
-
-                    var allPackageDbEntries = _migrationEntryService.FindEntries(packageMigrationProductNames)
-                        .ToArray();
-
-                    foreach (var packageMigration in packageMigrations)
-                    {
-                        var packageDbVersions = allPackageDbEntries
-                            .Where(x => x.MigrationName.InvariantEquals(packageMigration.Key))
-                            .Select(x => x.Version);
-
-                        var notExecuted = packageMigration
-                            .Select(x => x.TargetVersion.GetSemanticVersion())
-                            .Except(packageDbVersions)
-                            .ToArray();
-
-                        if (notExecuted.Any())
-                        {
-                            var maxVersion = notExecuted.Max();
-                            result.Add(packageMigration.Key, maxVersion);
-
-                            _logger.Debug<ApplicationContext>(
-                                    string.Format("The migration {0} for version: '{1} has not been executed, there is no record in the database",
-                                    packageMigration.Key,
-                                    maxVersion.ToSemanticString()));
-                        }
-                    }
-                }
-
-                return new ReadOnlyDictionary<string, SemVersion>(result);
-            });
-        }
-
-        /// <summary>
-        /// Returns true if there are pending package migrations that need to be executed
-        /// </summary>
-        internal bool HasPendingPackageMigrations
-        {
-            get { return _packageVersionsConfigured.Value.Any(); }
-        }
-
-        /// <summary>
-        /// Returns the list of package migration names that need to be executed
-        /// </summary>
-        internal ReadOnlyDictionary<string, SemVersion> GetPendingPackageMigrations()
-        {
-            return _packageVersionsConfigured.Value;
-        }
-
-        /// <summary>
-        /// Returns the list of package migration names and versions that need to be executed
-        /// with the following format: PackageProductName (2.0.0)
-        /// </summary>
-        /// <returns></returns>
-        internal IEnumerable<string> GetPendingPackageMigrationFriendlyNames()
-        {
-            return _packageVersionsConfigured.Value.Select(x => string.Format("{0} ({1})", x.Key, x.Value));
-        }
-    }
-}

src/Umbraco.Core/Persistence/DefaultDatabaseFactory.cs

@@ -102,5 +102,14 @@ namespace Umbraco.Core.Persistence
 				}
 			}
 		}
+
+        // during tests, the thread static var can leak between tests
+        // this method provides a way to force-reset the variable
+	    internal void ResetForTests()
+	    {
+	        if (_nonHttpInstance == null) return;
+	        _nonHttpInstance.Dispose();
+	        _nonHttpInstance = null;
+	    }
 	}
 }

src/Umbraco.Core/Persistence/Factories/ContentFactory.cs

@@ -29,32 +29,41 @@ namespace Umbraco.Core.Persistence.Factories
 
         public IContent BuildEntity(DocumentDto dto)
         {
-            var content = new Content(dto.Text, dto.ContentVersionDto.ContentDto.NodeDto.ParentId, _contentType)
+            var content = new Content(dto.Text, dto.ContentVersionDto.ContentDto.NodeDto.ParentId, _contentType);
+
+            try
             {
-                Id = _id,
-                Key = dto.ContentVersionDto.ContentDto.NodeDto.UniqueId,
-                Name = dto.Text,
-                NodeName = dto.ContentVersionDto.ContentDto.NodeDto.Text,
-                Path = dto.ContentVersionDto.ContentDto.NodeDto.Path,
-                CreatorId = dto.ContentVersionDto.ContentDto.NodeDto.UserId.Value,
-                WriterId = dto.WriterUserId,
-                Level = dto.ContentVersionDto.ContentDto.NodeDto.Level,
-                ParentId = dto.ContentVersionDto.ContentDto.NodeDto.ParentId,
-                SortOrder = dto.ContentVersionDto.ContentDto.NodeDto.SortOrder,
-                Trashed = dto.ContentVersionDto.ContentDto.NodeDto.Trashed,
-                Published = dto.Published,
-                CreateDate = dto.ContentVersionDto.ContentDto.NodeDto.CreateDate,
-                UpdateDate = dto.ContentVersionDto.VersionDate,
-                ExpireDate = dto.ExpiresDate.HasValue ? dto.ExpiresDate.Value : (DateTime?)null,
-                ReleaseDate = dto.ReleaseDate.HasValue ? dto.ReleaseDate.Value : (DateTime?)null,
-                Version = dto.ContentVersionDto.VersionId,
-                PublishedState = dto.Published ? PublishedState.Published : PublishedState.Unpublished,
-                PublishedVersionGuid = dto.DocumentPublishedReadOnlyDto == null ? default(Guid) : dto.DocumentPublishedReadOnlyDto.VersionId
-            };
-            //on initial construction we don't want to have dirty properties tracked
-            // http://issues.umbraco.org/issue/U4-1946
-            content.ResetDirtyProperties(false);
-            return content;
+                content.DisableChangeTracking();
+
+                content.Id = _id;
+                content.Key = dto.ContentVersionDto.ContentDto.NodeDto.UniqueId;
+                content.Name = dto.Text;
+                content.NodeName = dto.ContentVersionDto.ContentDto.NodeDto.Text;
+                content.Path = dto.ContentVersionDto.ContentDto.NodeDto.Path;
+                content.CreatorId = dto.ContentVersionDto.ContentDto.NodeDto.UserId.Value;
+                content.WriterId = dto.WriterUserId;
+                content.Level = dto.ContentVersionDto.ContentDto.NodeDto.Level;
+                content.ParentId = dto.ContentVersionDto.ContentDto.NodeDto.ParentId;
+                content.SortOrder = dto.ContentVersionDto.ContentDto.NodeDto.SortOrder;
+                content.Trashed = dto.ContentVersionDto.ContentDto.NodeDto.Trashed;
+                content.Published = dto.Published;
+                content.CreateDate = dto.ContentVersionDto.ContentDto.NodeDto.CreateDate;
+                content.UpdateDate = dto.ContentVersionDto.VersionDate;
+                content.ExpireDate = dto.ExpiresDate.HasValue ? dto.ExpiresDate.Value : (DateTime?) null;
+                content.ReleaseDate = dto.ReleaseDate.HasValue ? dto.ReleaseDate.Value : (DateTime?) null;
+                content.Version = dto.ContentVersionDto.VersionId;
+                content.PublishedState = dto.Published ? PublishedState.Published : PublishedState.Unpublished;
+                content.PublishedVersionGuid = dto.DocumentPublishedReadOnlyDto == null ? default(Guid) : dto.DocumentPublishedReadOnlyDto.VersionId;
+
+                //on initial construction we don't want to have dirty properties tracked
+                // http://issues.umbraco.org/issue/U4-1946
+                content.ResetDirtyProperties(false);
+                return content;
+            }
+            finally
+            {
+                content.EnableChangeTracking();
+            }
         }
 
         public DocumentDto BuildDto(IContent entity)

src/Umbraco.Core/Persistence/Factories/ContentTypeFactory.cs

@@ -21,13 +21,22 @@ namespace Umbraco.Core.Persistence.Factories
         public IContentType BuildContentTypeEntity(ContentTypeDto dto)
         {
             var contentType = new ContentType(dto.NodeDto.ParentId);
-            BuildCommonEntity(contentType, dto);
 
-            //on initial construction we don't want to have dirty properties tracked
-            // http://issues.umbraco.org/issue/U4-1946
-            contentType.ResetDirtyProperties(false);
+            try
+            {
+                contentType.DisableChangeTracking();
 
-            return contentType;
+                BuildCommonEntity(contentType, dto);
+
+                //on initial construction we don't want to have dirty properties tracked
+                // http://issues.umbraco.org/issue/U4-1946
+                contentType.ResetDirtyProperties(false);
+                return contentType;
+            }
+            finally
+            {
+                contentType.EnableChangeTracking();
+            }
         }
 
         #endregion
@@ -37,11 +46,20 @@ namespace Umbraco.Core.Persistence.Factories
         public IMediaType BuildMediaTypeEntity(ContentTypeDto dto)
         {
             var contentType = new MediaType(dto.NodeDto.ParentId);
-            BuildCommonEntity(contentType, dto);
+            try
+            {
+                contentType.DisableChangeTracking();
 
-            //on initial construction we don't want to have dirty properties tracked
-            // http://issues.umbraco.org/issue/U4-1946
-            contentType.ResetDirtyProperties(false);
+                BuildCommonEntity(contentType, dto);
+
+                //on initial construction we don't want to have dirty properties tracked
+                // http://issues.umbraco.org/issue/U4-1946
+                contentType.ResetDirtyProperties(false);
+            }
+            finally
+            {
+                contentType.EnableChangeTracking();
+            }
 
             return contentType;
         }

src/Umbraco.Core/Persistence/Factories/DataTypeDefinitionFactory.cs

@@ -19,25 +19,35 @@ namespace Umbraco.Core.Persistence.Factories
 
         public IDataTypeDefinition BuildEntity(DataTypeDto dto)
         {
-            var dataTypeDefinition = new DataTypeDefinition(dto.PropertyEditorAlias)
-                                         {
-                                             CreateDate = dto.NodeDto.CreateDate,
-                                             DatabaseType = dto.DbType.EnumParse<DataTypeDatabaseType>(true),
-                                             Id = dto.DataTypeId,
-                                             Key = dto.NodeDto.UniqueId,
-                                             Level = dto.NodeDto.Level,
-                                             UpdateDate = dto.NodeDto.CreateDate,
-                                             Name = dto.NodeDto.Text,
-                                             ParentId = dto.NodeDto.ParentId,
-                                             Path = dto.NodeDto.Path,
-                                             SortOrder = dto.NodeDto.SortOrder,
-                                             Trashed = dto.NodeDto.Trashed,
-                                             CreatorId = dto.NodeDto.UserId.Value
-                                         };
-            //on initial construction we don't want to have dirty properties tracked
-            // http://issues.umbraco.org/issue/U4-1946
-            dataTypeDefinition.ResetDirtyProperties(false);
-            return dataTypeDefinition;
+            var dataTypeDefinition = new DataTypeDefinition(dto.PropertyEditorAlias);
+
+
+            try
+            {
+                dataTypeDefinition.DisableChangeTracking();
+
+                dataTypeDefinition.CreateDate = dto.NodeDto.CreateDate;
+                dataTypeDefinition.DatabaseType = dto.DbType.EnumParse<DataTypeDatabaseType>(true);
+                dataTypeDefinition.Id = dto.DataTypeId;
+                dataTypeDefinition.Key = dto.NodeDto.UniqueId;
+                dataTypeDefinition.Level = dto.NodeDto.Level;
+                dataTypeDefinition.UpdateDate = dto.NodeDto.CreateDate;
+                dataTypeDefinition.Name = dto.NodeDto.Text;
+                dataTypeDefinition.ParentId = dto.NodeDto.ParentId;
+                dataTypeDefinition.Path = dto.NodeDto.Path;
+                dataTypeDefinition.SortOrder = dto.NodeDto.SortOrder;
+                dataTypeDefinition.Trashed = dto.NodeDto.Trashed;
+                dataTypeDefinition.CreatorId = dto.NodeDto.UserId.Value;
+
+                //on initial construction we don't want to have dirty properties tracked
+                // http://issues.umbraco.org/issue/U4-1946
+                dataTypeDefinition.ResetDirtyProperties(false);
+                return dataTypeDefinition;
+            }
+            finally
+            {
+                dataTypeDefinition.EnableChangeTracking();
+            }
         }
 
         public DataTypeDto BuildDto(IDataTypeDefinition entity)

src/Umbraco.Core/Persistence/Factories/DictionaryItemFactory.cs

@@ -10,15 +10,23 @@ namespace Umbraco.Core.Persistence.Factories
 
         public IDictionaryItem BuildEntity(DictionaryDto dto)
         {
-            var item = new DictionaryItem(dto.Parent, dto.Key)
-                       {
-                           Id = dto.PrimaryKey, 
-                           Key = dto.UniqueId
-                       };
-            //on initial construction we don't want to have dirty properties tracked
-            // http://issues.umbraco.org/issue/U4-1946
-            item.ResetDirtyProperties(false);
-            return item;
+            var item = new DictionaryItem(dto.Parent, dto.Key);
+
+            try
+            {
+                item.DisableChangeTracking();
+
+                item.Id = dto.PrimaryKey;
+                item.Key = dto.UniqueId;
+                //on initial construction we don't want to have dirty properties tracked
+                // http://issues.umbraco.org/issue/U4-1946
+                item.ResetDirtyProperties(false);
+                return item;
+            }
+            finally
+            {
+                item.EnableChangeTracking();
+            }
         }
 
         public DictionaryDto BuildDto(IDictionaryItem entity)

src/Umbraco.Core/Persistence/Factories/DictionaryTranslationFactory.cs

@@ -17,13 +17,23 @@ namespace Umbraco.Core.Persistence.Factories
 
         public IDictionaryTranslation BuildEntity(LanguageTextDto dto)
         {
-            var item = new DictionaryTranslation(dto.LanguageId, dto.Value, _uniqueId) 
-                                            {Id = dto.PrimaryKey};
+            var item = new DictionaryTranslation(dto.LanguageId, dto.Value, _uniqueId);
 
-            //on initial construction we don't want to have dirty properties tracked
-            // http://issues.umbraco.org/issue/U4-1946
-            item.ResetDirtyProperties(false);
-            return item;
+            try
+            {
+                item.DisableChangeTracking();
+
+                item.Id = dto.PrimaryKey;
+
+                //on initial construction we don't want to have dirty properties tracked
+                // http://issues.umbraco.org/issue/U4-1946
+                item.ResetDirtyProperties(false);
+                return item;
+            }
+            finally
+            {
+                item.EnableChangeTracking();
+            }
         }
 
         public LanguageTextDto BuildDto(IDictionaryTranslation entity)

src/Umbraco.Core/Persistence/Factories/MacroFactory.cs

@@ -12,15 +12,26 @@ namespace Umbraco.Core.Persistence.Factories
         public IMacro BuildEntity(MacroDto dto)
         {
             var model = new Macro(dto.Id, dto.UseInEditor, dto.RefreshRate, dto.Alias, dto.Name, dto.ScriptType, dto.ScriptAssembly, dto.Xslt, dto.CacheByPage, dto.CachePersonalized, dto.DontRender, dto.Python);
-            foreach (var p in dto.MacroPropertyDtos)
+
+
+            try
             {
-                model.Properties.Add(new MacroProperty(p.Id, p.Alias, p.Name, p.SortOrder, p.EditorAlias));
+                model.DisableChangeTracking();
+
+                foreach (var p in dto.MacroPropertyDtos)
+                {
+                    model.Properties.Add(new MacroProperty(p.Id, p.Alias, p.Name, p.SortOrder, p.EditorAlias));
+                }
+
+                //on initial construction we don't want to have dirty properties tracked
+                // http://issues.umbraco.org/issue/U4-1946
+                model.ResetDirtyProperties(false);
+                return model;
+            }
+            finally
+            {
+                model.EnableChangeTracking();
             }
-            
-            //on initial construction we don't want to have dirty properties tracked
-            // http://issues.umbraco.org/issue/U4-1946
-            model.ResetDirtyProperties(false);
-            return model;
         }
 
         public MacroDto BuildDto(IMacro entity)

src/Umbraco.Core/Persistence/Factories/MediaFactory.cs

@@ -29,24 +29,32 @@ namespace Umbraco.Core.Persistence.Factories
 
         public IMedia BuildEntity(ContentVersionDto dto)
         {
-            var media = new Models.Media(dto.ContentDto.NodeDto.Text, dto.ContentDto.NodeDto.ParentId, _contentType)
-                       {
-                           Id = _id,
-                           Key = dto.ContentDto.NodeDto.UniqueId,
-                           Path = dto.ContentDto.NodeDto.Path,
-                           CreatorId = dto.ContentDto.NodeDto.UserId.Value,
-                           Level = dto.ContentDto.NodeDto.Level,
-                           ParentId = dto.ContentDto.NodeDto.ParentId,
-                           SortOrder = dto.ContentDto.NodeDto.SortOrder,
-                           Trashed = dto.ContentDto.NodeDto.Trashed,
-                           CreateDate = dto.ContentDto.NodeDto.CreateDate,
-                           UpdateDate = dto.VersionDate,
-                           Version = dto.VersionId
-                       };
-            //on initial construction we don't want to have dirty properties tracked
-            // http://issues.umbraco.org/issue/U4-1946
-            media.ResetDirtyProperties(false);
-            return media;
+            var media = new Models.Media(dto.ContentDto.NodeDto.Text, dto.ContentDto.NodeDto.ParentId, _contentType);
+
+            try
+            {
+                media.DisableChangeTracking();
+
+                media.Id = _id;
+                media.Key = dto.ContentDto.NodeDto.UniqueId;
+                media.Path = dto.ContentDto.NodeDto.Path;
+                media.CreatorId = dto.ContentDto.NodeDto.UserId.Value;
+                media.Level = dto.ContentDto.NodeDto.Level;
+                media.ParentId = dto.ContentDto.NodeDto.ParentId;
+                media.SortOrder = dto.ContentDto.NodeDto.SortOrder;
+                media.Trashed = dto.ContentDto.NodeDto.Trashed;
+                media.CreateDate = dto.ContentDto.NodeDto.CreateDate;
+                media.UpdateDate = dto.VersionDate;
+                media.Version = dto.VersionId;
+                //on initial construction we don't want to have dirty properties tracked
+                // http://issues.umbraco.org/issue/U4-1946
+                media.ResetDirtyProperties(false);
+                return media;
+            }
+            finally
+            {
+                media.EnableChangeTracking();
+            }
         }
 
         public ContentVersionDto BuildDto(IMedia entity)

src/Umbraco.Core/Persistence/Factories/MemberFactory.cs

@@ -31,26 +31,35 @@ namespace Umbraco.Core.Persistence.Factories
         public IMember BuildEntity(MemberDto dto)
         {
             var member = new Member(
-                dto.ContentVersionDto.ContentDto.NodeDto.Text, 
-                dto.Email,dto.LoginName,dto.Password, _contentType)
+                dto.ContentVersionDto.ContentDto.NodeDto.Text,
+                dto.Email, dto.LoginName, dto.Password, _contentType);
+
+            try
             {
-                Id = _id,
-                Key = dto.ContentVersionDto.ContentDto.NodeDto.UniqueId,
-                Path = dto.ContentVersionDto.ContentDto.NodeDto.Path,
-                CreatorId = dto.ContentVersionDto.ContentDto.NodeDto.UserId.Value,
-                Level = dto.ContentVersionDto.ContentDto.NodeDto.Level,
-                ParentId = dto.ContentVersionDto.ContentDto.NodeDto.ParentId,
-                SortOrder = dto.ContentVersionDto.ContentDto.NodeDto.SortOrder,
-                Trashed = dto.ContentVersionDto.ContentDto.NodeDto.Trashed,
-                CreateDate = dto.ContentVersionDto.ContentDto.NodeDto.CreateDate,
-                UpdateDate = dto.ContentVersionDto.VersionDate,
-                Version = dto.ContentVersionDto.VersionId
-            };
-            member.ProviderUserKey = member.Key;
-            //on initial construction we don't want to have dirty properties tracked
-            // http://issues.umbraco.org/issue/U4-1946
-            member.ResetDirtyProperties(false);
-            return member;
+                member.DisableChangeTracking();
+
+                member.Id = _id;
+                member.Key = dto.ContentVersionDto.ContentDto.NodeDto.UniqueId;
+                member.Path = dto.ContentVersionDto.ContentDto.NodeDto.Path;
+                member.CreatorId = dto.ContentVersionDto.ContentDto.NodeDto.UserId.Value;
+                member.Level = dto.ContentVersionDto.ContentDto.NodeDto.Level;
+                member.ParentId = dto.ContentVersionDto.ContentDto.NodeDto.ParentId;
+                member.SortOrder = dto.ContentVersionDto.ContentDto.NodeDto.SortOrder;
+                member.Trashed = dto.ContentVersionDto.ContentDto.NodeDto.Trashed;
+                member.CreateDate = dto.ContentVersionDto.ContentDto.NodeDto.CreateDate;
+                member.UpdateDate = dto.ContentVersionDto.VersionDate;
+                member.Version = dto.ContentVersionDto.VersionId;
+
+                member.ProviderUserKey = member.Key;
+                //on initial construction we don't want to have dirty properties tracked
+                // http://issues.umbraco.org/issue/U4-1946
+                member.ResetDirtyProperties(false);
+                return member;
+            }
+            finally
+            {
+                member.EnableChangeTracking();
+            }
         }
 
         public MemberDto BuildDto(IMember entity)

src/Umbraco.Core/Persistence/Factories/MemberGroupFactory.cs

@@ -18,18 +18,26 @@ namespace Umbraco.Core.Persistence.Factories
 
         public IMemberGroup BuildEntity(NodeDto dto)
         {
-            var template = new MemberGroup
+            var group = new MemberGroup();
+            
+            try
             {
-                CreateDate = dto.CreateDate,
-                Id = dto.NodeId,
-                Key = dto.UniqueId,
-                Name = dto.Text                
-            };
+                group.DisableChangeTracking();
 
-            //on initial construction we don't want to have dirty properties tracked
-            // http://issues.umbraco.org/issue/U4-1946
-            template.ResetDirtyProperties(false);
-            return template;
+                group.CreateDate = dto.CreateDate;
+                group.Id = dto.NodeId;
+                group.Key = dto.UniqueId;
+                group.Name = dto.Text;
+
+                //on initial construction we don't want to have dirty properties tracked
+                // http://issues.umbraco.org/issue/U4-1946
+                group.ResetDirtyProperties(false);
+                return group;
+            }
+            finally
+            {
+                group.EnableChangeTracking();
+            }
         }
 
         public NodeDto BuildDto(IMemberGroup entity)

src/Umbraco.Core/Persistence/Factories/MemberTypeReadOnlyFactory.cs

@@ -12,48 +12,56 @@ namespace Umbraco.Core.Persistence.Factories
         public IMemberType BuildEntity(MemberTypeReadOnlyDto dto)
         {
             var standardPropertyTypes = Constants.Conventions.Member.GetStandardPropertyTypeStubs();
-            
-            var memberType = new MemberType(dto.ParentId)
-                             {
-                                 Alias = dto.Alias,
-                                 AllowedAsRoot = dto.AllowAtRoot,
-                                 CreateDate = dto.CreateDate,
-                                 CreatorId = dto.UserId.HasValue ? dto.UserId.Value : 0,
-                                 Description = dto.Description,
-                                 Icon = dto.Icon,
-                                 Id = dto.NodeId,
-                                 IsContainer = dto.IsContainer,
-                                 Key = dto.UniqueId.Value,
-                                 Level = dto.Level,
-                                 Name = dto.Text,
-                                 Path = dto.Path,
-                                 SortOrder = dto.SortOrder,
-                                 Thumbnail = dto.Thumbnail,
-                                 Trashed = dto.Trashed,
-                                 UpdateDate = dto.CreateDate,
-                                 AllowedContentTypes = Enumerable.Empty<ContentTypeSort>()
-                             };
 
-            var propertyTypeGroupCollection = GetPropertyTypeGroupCollection(dto, memberType, standardPropertyTypes);
-            memberType.PropertyGroups = propertyTypeGroupCollection;
+            var memberType = new MemberType(dto.ParentId);
 
-            var propertyTypes = GetPropertyTypes(dto, memberType, standardPropertyTypes);
-
-            //By Convention we add 9 stnd PropertyTypes - This is only here to support loading of types that didn't have these conventions before.            
-            foreach (var standardPropertyType in standardPropertyTypes)
+            try
             {
-                if(dto.PropertyTypes.Any(x => x.Alias.Equals(standardPropertyType.Key))) continue;
-                
-                //Add the standard PropertyType to the current list
-                propertyTypes.Add(standardPropertyType.Value);
+                memberType.DisableChangeTracking();
 
-                //Internal dictionary for adding "MemberCanEdit" and "VisibleOnProfile" properties to each PropertyType
-                memberType.MemberTypePropertyTypes.Add(standardPropertyType.Key,
-                    new MemberTypePropertyProfileAccess(false, false));
+                memberType.Alias = dto.Alias;
+                memberType.AllowedAsRoot = dto.AllowAtRoot;
+                memberType.CreateDate = dto.CreateDate;
+                memberType.CreatorId = dto.UserId.HasValue ? dto.UserId.Value : 0;
+                memberType.Description = dto.Description;
+                memberType.Icon = dto.Icon;
+                memberType.Id = dto.NodeId;
+                memberType.IsContainer = dto.IsContainer;
+                memberType.Key = dto.UniqueId.Value;
+                memberType.Level = dto.Level;
+                memberType.Name = dto.Text;
+                memberType.Path = dto.Path;
+                memberType.SortOrder = dto.SortOrder;
+                memberType.Thumbnail = dto.Thumbnail;
+                memberType.Trashed = dto.Trashed;
+                memberType.UpdateDate = dto.CreateDate;
+                memberType.AllowedContentTypes = Enumerable.Empty<ContentTypeSort>();
+
+                var propertyTypeGroupCollection = GetPropertyTypeGroupCollection(dto, memberType, standardPropertyTypes);
+                memberType.PropertyGroups = propertyTypeGroupCollection;
+
+                var propertyTypes = GetPropertyTypes(dto, memberType, standardPropertyTypes);
+
+                //By Convention we add 9 stnd PropertyTypes - This is only here to support loading of types that didn't have these conventions before.            
+                foreach (var standardPropertyType in standardPropertyTypes)
+                {
+                    if (dto.PropertyTypes.Any(x => x.Alias.Equals(standardPropertyType.Key))) continue;
+
+                    //Add the standard PropertyType to the current list
+                    propertyTypes.Add(standardPropertyType.Value);
+
+                    //Internal dictionary for adding "MemberCanEdit" and "VisibleOnProfile" properties to each PropertyType
+                    memberType.MemberTypePropertyTypes.Add(standardPropertyType.Key,
+                        new MemberTypePropertyProfileAccess(false, false));
+                }
+                memberType.NoGroupPropertyTypes = propertyTypes;
+
+                return memberType;
+            }
+            finally
+            {
+                memberType.EnableChangeTracking();
             }
-            memberType.NoGroupPropertyTypes = propertyTypes;
-
-            return memberType;
         }
 
         private PropertyGroupCollection GetPropertyTypeGroupCollection(MemberTypeReadOnlyDto dto, MemberType memberType, Dictionary<string, PropertyType> standardProps)

src/Umbraco.Core/Persistence/Factories/PropertyFactory.cs

@@ -42,12 +42,22 @@ namespace Umbraco.Core.Persistence.Factories
                                    : propertyType.CreatePropertyFromRawValue(propertyDataDto.GetValue,
                                                                              propertyDataDto.VersionId.Value,
                                                                              propertyDataDto.Id);
-                //on initial construction we don't want to have dirty properties tracked
-                property.CreateDate = _createDate;
-                property.UpdateDate = _updateDate;
-                // http://issues.umbraco.org/issue/U4-1946
-                property.ResetDirtyProperties(false);
-                properties.Add(property);
+                try
+                {
+                    //on initial construction we don't want to have dirty properties tracked
+                    property.DisableChangeTracking();
+
+                    property.CreateDate = _createDate;
+                    property.UpdateDate = _updateDate;
+                    // http://issues.umbraco.org/issue/U4-1946
+                    property.ResetDirtyProperties(false);
+                    properties.Add(property);
+                }
+                finally
+                {
+                    property.EnableChangeTracking();
+                }
+                
             }
 
             return properties;
@@ -89,7 +99,7 @@ namespace Umbraco.Core.Persistence.Factories
                     decimal val;
                     if (decimal.TryParse(property.Value.ToString(), out val))
                     {
-                        dto.Decimal = val;
+                        dto.Decimal = val; // property value should be normalized already
                     }
                 }
                 else if (property.DataTypeDatabaseType == DataTypeDatabaseType.Date && property.Value != null && string.IsNullOrWhiteSpace(property.Value.ToString()) == false)

src/Umbraco.Core/Persistence/Factories/PropertyGroupFactory.cs

@@ -39,47 +39,65 @@ namespace Umbraco.Core.Persistence.Factories
             {
                 var group = new PropertyGroup();
 
-                // if the group is defined on the current content type,
-                // assign its identifier, else it will be zero
-                if (groupDto.ContentTypeNodeId == _contentTypeId)
-                    group.Id = groupDto.Id;
-
-                group.Name = groupDto.Text;
-                group.SortOrder = groupDto.SortOrder;
-                group.PropertyTypes = new PropertyTypeCollection();
-                group.Key = groupDto.UniqueId;
-
-                //Because we are likely to have a group with no PropertyTypes we need to ensure that these are excluded
-                var typeDtos = groupDto.PropertyTypeDtos.Where(x => x.Id > 0);
-                foreach (var typeDto in typeDtos)
+                try
                 {
-                    var tempGroupDto = groupDto;
-                    var propertyType = _propertyTypeCtor(typeDto.DataTypeDto.PropertyEditorAlias,
-                        typeDto.DataTypeDto.DbType.EnumParse<DataTypeDatabaseType>(true),
-                        typeDto.Alias);
+                    group.DisableChangeTracking();
 
-                    propertyType.Alias = typeDto.Alias;
-                    propertyType.DataTypeDefinitionId = typeDto.DataTypeId;
-                    propertyType.Description = typeDto.Description;
-                    propertyType.Id = typeDto.Id;
-                    propertyType.Key = typeDto.UniqueId;
-                    propertyType.Name = typeDto.Name;
-                    propertyType.Mandatory = typeDto.Mandatory;
-                    propertyType.SortOrder = typeDto.SortOrder;
-                    propertyType.ValidationRegExp = typeDto.ValidationRegExp;
-                    propertyType.PropertyGroupId = new Lazy<int>(() => tempGroupDto.Id);
-                    propertyType.CreateDate = _createDate;
-                    propertyType.UpdateDate = _updateDate;
+                    // if the group is defined on the current content type,
+                    // assign its identifier, else it will be zero
+                    if (groupDto.ContentTypeNodeId == _contentTypeId)
+                        group.Id = groupDto.Id;
 
+                    group.Name = groupDto.Text;
+                    group.SortOrder = groupDto.SortOrder;
+                    group.PropertyTypes = new PropertyTypeCollection();
+                    group.Key = groupDto.UniqueId;
+
+                    //Because we are likely to have a group with no PropertyTypes we need to ensure that these are excluded
+                    var typeDtos = groupDto.PropertyTypeDtos.Where(x => x.Id > 0);
+                    foreach (var typeDto in typeDtos)
+                    {
+                        var tempGroupDto = groupDto;
+                        var propertyType = _propertyTypeCtor(typeDto.DataTypeDto.PropertyEditorAlias,
+                            typeDto.DataTypeDto.DbType.EnumParse<DataTypeDatabaseType>(true),
+                            typeDto.Alias);
+
+                        try
+                        {
+                            propertyType.DisableChangeTracking();
+
+                            propertyType.Alias = typeDto.Alias;
+                            propertyType.DataTypeDefinitionId = typeDto.DataTypeId;
+                            propertyType.Description = typeDto.Description;
+                            propertyType.Id = typeDto.Id;
+                            propertyType.Key = typeDto.UniqueId;
+                            propertyType.Name = typeDto.Name;
+                            propertyType.Mandatory = typeDto.Mandatory;
+                            propertyType.SortOrder = typeDto.SortOrder;
+                            propertyType.ValidationRegExp = typeDto.ValidationRegExp;
+                            propertyType.PropertyGroupId = new Lazy<int>(() => tempGroupDto.Id);
+                            propertyType.CreateDate = _createDate;
+                            propertyType.UpdateDate = _updateDate;
+
+                            //on initial construction we don't want to have dirty properties tracked
+                            // http://issues.umbraco.org/issue/U4-1946
+                            propertyType.ResetDirtyProperties(false);
+                            group.PropertyTypes.Add(propertyType);
+                        }
+                        finally
+                        {
+                            propertyType.EnableChangeTracking();
+                        }
+                    }
                     //on initial construction we don't want to have dirty properties tracked
                     // http://issues.umbraco.org/issue/U4-1946
-                    propertyType.ResetDirtyProperties(false);
-                    group.PropertyTypes.Add(propertyType);
+                    group.ResetDirtyProperties(false);
+                    propertyGroups.Add(group);
+                }
+                finally
+                {
+                    group.EnableChangeTracking();
                 }
-                //on initial construction we don't want to have dirty properties tracked
-                // http://issues.umbraco.org/issue/U4-1946
-                group.ResetDirtyProperties(false);
-                propertyGroups.Add(group);
             }
 
             return propertyGroups;

src/Umbraco.Core/Persistence/Factories/RelationFactory.cs

@@ -16,17 +16,26 @@ namespace Umbraco.Core.Persistence.Factories
 
         public IRelation BuildEntity(RelationDto dto)
         {
-            var entity = new Relation(dto.ParentId, dto.ChildId, _relationType)
+            var entity = new Relation(dto.ParentId, dto.ChildId, _relationType);
+
+            try
             {
-                Comment = dto.Comment,
-                CreateDate = dto.Datetime,
-                Id = dto.Id,
-                UpdateDate = dto.Datetime
-            };
-            //on initial construction we don't want to have dirty properties tracked
-            // http://issues.umbraco.org/issue/U4-1946
-            entity.ResetDirtyProperties(false);
-            return entity;
+                entity.DisableChangeTracking();
+
+                entity.Comment = dto.Comment;
+                entity.CreateDate = dto.Datetime;
+                entity.Id = dto.Id;
+                entity.UpdateDate = dto.Datetime;
+
+                //on initial construction we don't want to have dirty properties tracked
+                // http://issues.umbraco.org/issue/U4-1946
+                entity.ResetDirtyProperties(false);
+                return entity;
+            }
+            finally
+            {
+                entity.EnableChangeTracking();
+            }
         }
 
         public RelationDto BuildDto(IRelation entity)

src/Umbraco.Core/Persistence/Factories/RelationTypeFactory.cs

@@ -9,16 +9,25 @@ namespace Umbraco.Core.Persistence.Factories
 
         public IRelationType BuildEntity(RelationTypeDto dto)
         {
-            var entity = new RelationType(dto.ChildObjectType, dto.ParentObjectType, dto.Alias)
+            var entity = new RelationType(dto.ChildObjectType, dto.ParentObjectType, dto.Alias);
+
+            try
             {
-                Id = dto.Id,
-                IsBidirectional = dto.Dual,
-                Name = dto.Name
-            };
-            //on initial construction we don't want to have dirty properties tracked
-            // http://issues.umbraco.org/issue/U4-1946
-            entity.ResetDirtyProperties(false);
-            return entity;
+                entity.DisableChangeTracking();
+
+                entity.Id = dto.Id;
+                entity.IsBidirectional = dto.Dual;
+                entity.Name = dto.Name;
+
+                //on initial construction we don't want to have dirty properties tracked
+                // http://issues.umbraco.org/issue/U4-1946
+                entity.ResetDirtyProperties(false);
+                return entity;
+            }
+            finally
+            {
+                entity.EnableChangeTracking();
+            }
         }
 
         public RelationTypeDto BuildDto(IRelationType entity)

src/Umbraco.Core/Persistence/Factories/TaskFactory.cs

@@ -12,20 +12,28 @@ namespace Umbraco.Core.Persistence.Factories
     {
         public Task BuildEntity(TaskDto dto)
         {
-            var entity = new Task(new TaskType(dto.TaskTypeDto.Alias) { Id = dto.TaskTypeDto.Id })
+            var entity = new Task(new TaskType(dto.TaskTypeDto.Alias) { Id = dto.TaskTypeDto.Id });
+
+            try
             {
-                Closed = dto.Closed,
-                AssigneeUserId = dto.UserId,
-                Comment = dto.Comment,
-                CreateDate = dto.DateTime,
-                EntityId = dto.NodeId,
-                Id = dto.Id,
-                OwnerUserId = dto.ParentUserId,
-            };
-            //on initial construction we don't want to have dirty properties tracked
-            // http://issues.umbraco.org/issue/U4-1946
-            entity.ResetDirtyProperties(false);
-            return entity;
+                entity.DisableChangeTracking();
+
+                entity.Closed = dto.Closed;
+                entity.AssigneeUserId = dto.UserId;
+                entity.Comment = dto.Comment;
+                entity.CreateDate = dto.DateTime;
+                entity.EntityId = dto.NodeId;
+                entity.Id = dto.Id;
+                entity.OwnerUserId = dto.ParentUserId;
+                //on initial construction we don't want to have dirty properties tracked
+                // http://issues.umbraco.org/issue/U4-1946
+                entity.ResetDirtyProperties(false);
+                return entity;
+            }
+            finally
+            {
+                entity.EnableChangeTracking();
+            }
         }
 
         public TaskDto BuildDto(Task entity)

src/Umbraco.Core/Persistence/Factories/TemplateFactory.cs

@@ -35,23 +35,31 @@ namespace Umbraco.Core.Persistence.Factories
 
         public Template BuildEntity(TemplateDto dto, IEnumerable<IUmbracoEntity> childDefinitions, Func<File, string> getFileContent)
         {
-            var template = new Template(dto.NodeDto.Text, dto.Alias, getFileContent)
-                               {
-                                   CreateDate = dto.NodeDto.CreateDate,
-                                   Id = dto.NodeId,
-                                   Key = dto.NodeDto.UniqueId,                                   
-                                   Path = dto.NodeDto.Path
-                               };
+            var template = new Template(dto.NodeDto.Text, dto.Alias, getFileContent);
 
-            template.IsMasterTemplate = childDefinitions.Any(x => x.ParentId == dto.NodeId);
+            try
+            {
+                template.DisableChangeTracking();
 
-            if(dto.NodeDto.ParentId > 0)
-                template.MasterTemplateId = new Lazy<int>(() => dto.NodeDto.ParentId);
+                template.CreateDate = dto.NodeDto.CreateDate;
+                template.Id = dto.NodeId;
+                template.Key = dto.NodeDto.UniqueId;
+                template.Path = dto.NodeDto.Path;
 
-            //on initial construction we don't want to have dirty properties tracked
-            // http://issues.umbraco.org/issue/U4-1946
-            template.ResetDirtyProperties(false);
-            return template;
+                template.IsMasterTemplate = childDefinitions.Any(x => x.ParentId == dto.NodeId);
+
+                if (dto.NodeDto.ParentId > 0)
+                    template.MasterTemplateId = new Lazy<int>(() => dto.NodeDto.ParentId);
+
+                //on initial construction we don't want to have dirty properties tracked
+                // http://issues.umbraco.org/issue/U4-1946
+                template.ResetDirtyProperties(false);
+                return template;
+            }
+            finally
+            {
+                template.EnableChangeTracking();
+            }
         }
 
         public TemplateDto BuildDto(Template entity)

src/Umbraco.Core/Persistence/Factories/UmbracoEntityFactory.cs

@@ -28,44 +28,52 @@ namespace Umbraco.Core.Persistence.Factories
         {
             var asDictionary = (IDictionary<string, object>)d;
 
-            var entity = new UmbracoEntity(d.trashed)
-            {
-                CreateDate = d.createDate,
-                CreatorId = d.nodeUser,
-                Id = d.id,
-                Key = d.uniqueID,
-                Level = d.level,
-                Name = d.text,
-                NodeObjectTypeId = d.nodeObjectType,
-                ParentId = d.parentID,
-                Path = d.path,
-                SortOrder = d.sortOrder,
-                HasChildren = d.children > 0,
-                ContentTypeAlias = asDictionary.ContainsKey("alias") ? (d.alias ?? string.Empty) : string.Empty,
-                ContentTypeIcon = asDictionary.ContainsKey("icon") ? (d.icon ?? string.Empty) : string.Empty,
-                ContentTypeThumbnail = asDictionary.ContainsKey("thumbnail") ? (d.thumbnail ?? string.Empty) : string.Empty,
-            };
+            var entity = new UmbracoEntity(d.trashed);
 
-            var publishedVersion = default(Guid);            
-            //some content items don't have a published version
-            if (asDictionary.ContainsKey("publishedVersion") && asDictionary["publishedVersion"] != null)
+            try
             {
-                Guid.TryParse(d.publishedVersion.ToString(), out publishedVersion);    
-            }
-            var newestVersion = default(Guid);
-            if (asDictionary.ContainsKey("newestVersion") && d.newestVersion != null)
-            {
-                Guid.TryParse(d.newestVersion.ToString(), out newestVersion);    
-            }
+                entity.DisableChangeTracking();
 
-            entity.IsPublished = publishedVersion != default(Guid) || (newestVersion != default(Guid) && publishedVersion == newestVersion);
-            entity.IsDraft = newestVersion != default(Guid) && (publishedVersion == default(Guid) || publishedVersion != newestVersion);
-            entity.HasPendingChanges = (publishedVersion != default(Guid) && newestVersion != default(Guid)) && publishedVersion != newestVersion;
-            
-            //Now we can assign the additional data!                        
-            AddAdditionalData(entity, asDictionary);
-            
-            return entity;
+                entity.CreateDate = d.createDate;
+                entity.CreatorId = d.nodeUser;
+                entity.Id = d.id;
+                entity.Key = d.uniqueID;
+                entity.Level = d.level;
+                entity.Name = d.text;
+                entity.NodeObjectTypeId = d.nodeObjectType;
+                entity.ParentId = d.parentID;
+                entity.Path = d.path;
+                entity.SortOrder = d.sortOrder;
+                entity.HasChildren = d.children > 0;
+                entity.ContentTypeAlias = asDictionary.ContainsKey("alias") ? (d.alias ?? string.Empty) : string.Empty;
+                entity.ContentTypeIcon = asDictionary.ContainsKey("icon") ? (d.icon ?? string.Empty) : string.Empty;
+                entity.ContentTypeThumbnail = asDictionary.ContainsKey("thumbnail") ? (d.thumbnail ?? string.Empty) : string.Empty;
+
+                var publishedVersion = default(Guid);
+                //some content items don't have a published version
+                if (asDictionary.ContainsKey("publishedVersion") && asDictionary["publishedVersion"] != null)
+                {
+                    Guid.TryParse(d.publishedVersion.ToString(), out publishedVersion);
+                }
+                var newestVersion = default(Guid);
+                if (asDictionary.ContainsKey("newestVersion") && d.newestVersion != null)
+                {
+                    Guid.TryParse(d.newestVersion.ToString(), out newestVersion);
+                }
+
+                entity.IsPublished = publishedVersion != default(Guid) || (newestVersion != default(Guid) && publishedVersion == newestVersion);
+                entity.IsDraft = newestVersion != default(Guid) && (publishedVersion == default(Guid) || publishedVersion != newestVersion);
+                entity.HasPendingChanges = (publishedVersion != default(Guid) && newestVersion != default(Guid)) && publishedVersion != newestVersion;
+
+                //Now we can assign the additional data!                        
+                AddAdditionalData(entity, asDictionary);
+
+                return entity;
+            }
+            finally
+            {
+                entity.EnableChangeTracking();
+            }
         }
 
         public UmbracoEntity BuildEntity(EntityRepository.UmbracoEntityDto dto)

src/Umbraco.Core/Persistence/Factories/UserFactory.cs

@@ -21,36 +21,44 @@ namespace Umbraco.Core.Persistence.Factories
         public IUser BuildEntity(UserDto dto)
         {
             var guidId = dto.Id.ToGuid();
-            var user = new User(_userType)
-                {
-                    Id = dto.Id,
-                    Key = guidId,
-                    StartContentId = dto.ContentStartId,
-                    StartMediaId = dto.MediaStartId.HasValue ? dto.MediaStartId.Value : -1,
-                    RawPasswordValue = dto.Password,
-                    Username = dto.Login,
-                    Name = dto.UserName,
-                    IsLockedOut = dto.NoConsole,
-                    IsApproved = dto.Disabled == false,
-                    Email = dto.Email,
-                    Language = dto.UserLanguage,
-                    SecurityStamp = dto.SecurityStampToken,
-                    FailedPasswordAttempts = dto.FailedLoginAttempts ?? 0,
-                    LastLockoutDate = dto.LastLockoutDate ?? DateTime.MinValue,
-                    LastLoginDate = dto.LastLoginDate ?? DateTime.MinValue,
-                    LastPasswordChangeDate = dto.LastPasswordChangeDate ?? DateTime.MinValue
-                };
+            var user = new User(_userType);
 
-            foreach (var app in dto.User2AppDtos)
+            try
             {
-                user.AddAllowedSection(app.AppAlias);
+                user.DisableChangeTracking();
+
+                user.Id = dto.Id;
+                user.Key = guidId;
+                user.StartContentId = dto.ContentStartId;
+                user.StartMediaId = dto.MediaStartId.HasValue ? dto.MediaStartId.Value : -1;
+                user.RawPasswordValue = dto.Password;
+                user.Username = dto.Login;
+                user.Name = dto.UserName;
+                user.IsLockedOut = dto.NoConsole;
+                user.IsApproved = dto.Disabled == false;
+                user.Email = dto.Email;
+                user.Language = dto.UserLanguage;
+                user.SecurityStamp = dto.SecurityStampToken;
+                user.FailedPasswordAttempts = dto.FailedLoginAttempts ?? 0;
+                user.LastLockoutDate = dto.LastLockoutDate ?? DateTime.MinValue;
+                user.LastLoginDate = dto.LastLoginDate ?? DateTime.MinValue;
+                user.LastPasswordChangeDate = dto.LastPasswordChangeDate ?? DateTime.MinValue;
+
+                foreach (var app in dto.User2AppDtos)
+                {
+                    user.AddAllowedSection(app.AppAlias);
+                }
+
+                //on initial construction we don't want to have dirty properties tracked
+                // http://issues.umbraco.org/issue/U4-1946
+                user.ResetDirtyProperties(false);
+
+                return user;
+            }
+            finally
+            {
+                user.EnableChangeTracking();
             }
-
-            //on initial construction we don't want to have dirty properties tracked
-            // http://issues.umbraco.org/issue/U4-1946
-            user.ResetDirtyProperties(false);
-
-            return user;
         }
 
         public UserDto BuildDto(IUser entity)

src/Umbraco.Core/Persistence/Factories/UserTypeFactory.cs

@@ -11,19 +11,27 @@ namespace Umbraco.Core.Persistence.Factories
 
         public IUserType BuildEntity(UserTypeDto dto)
         {
-            var userType = new UserType
-                {
-                    Alias = dto.Alias,
-                    Id = dto.Id,
-                    Name = dto.Name,
-                    Permissions = dto.DefaultPermissions.IsNullOrWhiteSpace()
-                                      ? Enumerable.Empty<string>()
-                                      : dto.DefaultPermissions.ToCharArray().Select(x => x.ToString(CultureInfo.InvariantCulture))
-                };
-            //on initial construction we don't want to have dirty properties tracked
-            // http://issues.umbraco.org/issue/U4-1946
-            userType.ResetDirtyProperties(false);
-            return userType;
+            var userType = new UserType();
+
+            try
+            {
+                userType.DisableChangeTracking();
+
+                userType.Alias = dto.Alias;
+                userType.Id = dto.Id;
+                userType.Name = dto.Name;
+                userType.Permissions = dto.DefaultPermissions.IsNullOrWhiteSpace()
+                    ? Enumerable.Empty<string>()
+                    : dto.DefaultPermissions.ToCharArray().Select(x => x.ToString(CultureInfo.InvariantCulture));
+                //on initial construction we don't want to have dirty properties tracked
+                // http://issues.umbraco.org/issue/U4-1946
+                userType.ResetDirtyProperties(false);
+                return userType;
+            }
+            finally
+            {
+                userType.EnableChangeTracking();
+            }
         }
 
         public UserTypeDto BuildDto(IUserType entity)

src/Umbraco.Core/Persistence/Migrations/Initial/DatabaseSchemaCreation.cs

@@ -64,8 +64,7 @@ namespace Umbraco.Core.Persistence.Migrations.Initial
                                                                               {23, typeof (PropertyDataDto)},
                                                                               {24, typeof (RelationTypeDto)},
                                                                               {25, typeof (RelationDto)},
-                                                                              {26, typeof (StylesheetDto)},
-                                                                              {27, typeof (StylesheetPropertyDto)},
+                                                                              
                                                                               {28, typeof (TagDto)},
                                                                               {29, typeof (TagRelationshipDto)},
                                                                               {31, typeof (UserTypeDto)},
@@ -80,11 +79,12 @@ namespace Umbraco.Core.Persistence.Migrations.Initial
                                                                               {40, typeof (ServerRegistrationDto)},
                                                                               {41, typeof (AccessDto)},
                                                                               {42, typeof (AccessRuleDto)},
-                                                                              {43, typeof(CacheInstructionDto)},
+                                                                              {43, typeof (CacheInstructionDto)},
                                                                               {44, typeof (ExternalLoginDto)},
                                                                               {45, typeof (MigrationDto)},
                                                                               {46, typeof (UmbracoDeployChecksumDto)},
-                                                                              {47, typeof (UmbracoDeployDependencyDto)}
+                                                                              {47, typeof (UmbracoDeployDependencyDto)},
+                                                                              {48, typeof (RedirectUrlDto) }
                                                                           };
         #endregion
         

src/Umbraco.Core/Persistence/Migrations/LocalMigrationContext.cs

@@ -0,0 +1,54 @@
+using System.Linq;
+using System.Text;
+using Umbraco.Core.Logging;
+using Umbraco.Core.Persistence.Migrations.Syntax.Alter;
+using Umbraco.Core.Persistence.Migrations.Syntax.Create;
+using Umbraco.Core.Persistence.Migrations.Syntax.Delete;
+using Umbraco.Core.Persistence.Migrations.Syntax.Execute;
+using Umbraco.Core.Persistence.SqlSyntax;
+
+namespace Umbraco.Core.Persistence.Migrations
+{
+    internal class LocalMigrationContext : MigrationContext
+    {
+        private readonly ISqlSyntaxProvider _sqlSyntax;
+
+        public LocalMigrationContext(DatabaseProviders databaseProvider, Database database, ISqlSyntaxProvider sqlSyntax, ILogger logger)
+            : base(databaseProvider, database, logger)
+        {
+            _sqlSyntax = sqlSyntax;
+        }
+
+        public IExecuteBuilder Execute
+        {
+            get { return new ExecuteBuilder(this, _sqlSyntax); }
+        }
+
+        public IDeleteBuilder Delete
+        {
+            get { return new DeleteBuilder(this, _sqlSyntax); }
+        }
+
+        public IAlterSyntaxBuilder Alter
+        {
+            get { return new AlterSyntaxBuilder(this, _sqlSyntax); }
+        }
+
+        public ICreateBuilder Create
+        {
+            get { return new CreateBuilder(this, _sqlSyntax); }
+        }
+
+        public string GetSql()
+        {
+            var sb = new StringBuilder();
+            foreach (var sql in Expressions.Select(x => x.Process(Database)))
+            {
+                sb.Append(sql);
+                sb.AppendLine();
+                sb.AppendLine("GO");
+            }
+            return sb.ToString();
+        }
+    }
+}

src/Umbraco.Core/Persistence/Migrations/MigrationResolver.cs

@@ -33,11 +33,6 @@ namespace Umbraco.Core.Persistence.Migrations
 			get { return Values; }
 		}
 
-	    public IEnumerable<MigrationAttribute> MigrationMetaData
-	    {
-	        get { return Values.SelectMany(x => x.GetType().GetCustomAttributes<MigrationAttribute>(false)).WhereNotNull(); }
-	    } 
-
 
         /// <summary>
         /// This will ctor the IMigration instances

src/Umbraco.Core/Persistence/Migrations/MigrationRunner.cs

@@ -63,7 +63,7 @@ namespace Umbraco.Core.Persistence.Migrations
             _targetVersion = targetVersion;
             _productName = productName;
             //ensure this is null if there aren't any
-            _migrations = migrations.Length == 0 ? null : migrations;
+            _migrations = migrations == null || migrations.Length == 0 ? null : migrations;
         }
 
         /// <summary>
@@ -94,6 +94,7 @@ namespace Umbraco.Core.Persistence.Migrations
             var migrations = isUpgrade
                                  ? OrderedUpgradeMigrations(foundMigrations).ToList()
                                  : OrderedDowngradeMigrations(foundMigrations).ToList();
+
             
             if (Migrating.IsRaisedEventCancelled(new MigrationEventArgs(migrations, _currentVersion, _targetVersion, _productName, true), this))
             {
@@ -297,6 +298,7 @@ namespace Umbraco.Core.Persistence.Migrations
                 {
                     _migrationEntryService.CreateEntry(_productName, _targetVersion);    
                 }
+               
             }
         }
 

src/Umbraco.Core/Persistence/Migrations/Syntax/Delete/Index/DeleteIndexBuilder.cs

@@ -1,4 +1,5 @@
-using Umbraco.Core.Persistence.DatabaseModelDefinitions;
+using System;
+using Umbraco.Core.Persistence.DatabaseModelDefinitions;
 using Umbraco.Core.Persistence.Migrations.Syntax.Delete.Expressions;
 
 namespace Umbraco.Core.Persistence.Migrations.Syntax.Delete.Index
@@ -17,12 +18,14 @@ namespace Umbraco.Core.Persistence.Migrations.Syntax.Delete.Index
             return this;
         }
 
+        [Obsolete("I don't think this would ever be used when dropping an index, see DeleteIndexExpression.ToString")]
         public void OnColumn(string columnName)
         {
             var column = new IndexColumnDefinition { Name = columnName };
             Expression.Index.Columns.Add(column);
         }
 
+        [Obsolete("I don't think this would ever be used when dropping an index, see DeleteIndexExpression.ToString")]
         public void OnColumns(params string[] columnNames)
         {
             foreach (string columnName in columnNames)

src/Umbraco.Core/Persistence/Migrations/Syntax/Delete/Index/IDeleteIndexOnColumnSyntax.cs

@@ -1,8 +1,13 @@
-namespace Umbraco.Core.Persistence.Migrations.Syntax.Delete.Index
+using System;
+
+namespace Umbraco.Core.Persistence.Migrations.Syntax.Delete.Index
 {
     public interface IDeleteIndexOnColumnSyntax : IFluentSyntax
     {
+        [Obsolete("I don't think this would ever be used when dropping an index, see DeleteIndexExpression.ToString")]
         void OnColumn(string columnName);
+
+        [Obsolete("I don't think this would ever be used when dropping an index, see DeleteIndexExpression.ToString")]
         void OnColumns(params string[] columnNames);
     }
 }

src/Umbraco.Core/Persistence/Migrations/Upgrades/TargetVersionSevenFiveZero/AddRedirectUrlTable.cs

@@ -0,0 +1,48 @@
+using System.Linq;
+using Umbraco.Core.Configuration;
+using Umbraco.Core.Logging;
+using Umbraco.Core.Persistence.Migrations.Syntax.Create;
+using Umbraco.Core.Persistence.SqlSyntax;
+
+namespace Umbraco.Core.Persistence.Migrations.Upgrades.TargetVersionSevenFiveZero
+{
+    [Migration("7.5.0", 100, GlobalSettings.UmbracoMigrationName)]
+    public class AddRedirectUrlTable : MigrationBase
+    {
+        public AddRedirectUrlTable(ISqlSyntaxProvider sqlSyntax, ILogger logger)
+            : base(sqlSyntax, logger)
+        { }
+
+        public override void Up()
+        {
+            // defer, because we are making decisions based upon what's in the database
+            Execute.Code(MigrationCode);
+        }
+
+        private string MigrationCode(Database database)
+        {
+            // don't execute if the table is already there
+            var tables = SqlSyntax.GetTablesInSchema(database).ToArray();
+            if (tables.InvariantContains("umbracoRedirectUrl")) return null;
+
+            var localContext = new LocalMigrationContext(Context.CurrentDatabaseProvider, database, SqlSyntax, Logger);
+
+            localContext.Create.Table("umbracoRedirectUrl")
+                .WithColumn("id").AsInt32().Identity().PrimaryKey("PK_umbracoRedirectUrl")
+                .WithColumn("contentId").AsInt32().NotNullable()
+                .WithColumn("createDateUtc").AsDateTime().NotNullable()
+                .WithColumn("url").AsString(2048).NotNullable();
+
+            localContext.Create.Index("IX_umbracoRedirectUrl")
+                .OnTable("umbracoRedirectUrl")
+                .OnColumn("url").Ascending()
+                .OnColumn("createDateUtc").Ascending()
+                .WithOptions().NonClustered();
+
+            return localContext.GetSql();
+        }
+
+        public override void Down()
+        { }
+    }
+}