route provider fixes

zero.Core/Routing/PageRouteProvider/PageRouteProvider.cs

@@ -96,8 +96,12 @@ public class PageRouteProvider : ZeroRouteProvider<Page>
   /// <summary>
   /// Get parents for a page
   /// </summary>
-  protected virtual async Task<IList<Page>> GetParents(RoutingContext context, Page model)
+  protected virtual async Task<List<Page>> GetParents(RoutingContext context, Page model)
   {
+    if (model == null)
+    {
+      return new();
+    }
     zero_Pages_ByHierarchy.Result result = await context.Session.Query<zero_Pages_ByHierarchy.Result, zero_Pages_ByHierarchy>()
       .ProjectInto<zero_Pages_ByHierarchy.Result>()
       .Include<zero_Pages_ByHierarchy.Result, Page>(x => x.Path.Select(p => p.Id))
@@ -105,7 +109,7 @@ public class PageRouteProvider : ZeroRouteProvider<Page>
       
     if (result == null)
     {
-      return new List<Page>();
+      return new();
     }
 
     return (await context.Session.LoadAsync<Page>(result.Path.Select(x => x.Id))).Select(x => x.Value).ToList();

zero.Core/Routing/Routes.cs

@@ -94,6 +94,15 @@ public class Routes : IRoutes
   }
 
 
+  /// <inheritdoc />
+  public virtual bool TryGetProvider<T>(T model, bool forSeeding, out IRouteProvider provider) where T : ISupportsRouting
+  {
+    Type type = model.GetType();
+    provider = Providers.OrderByDescending(x => x.Priority).FirstOrDefault(x => x.CanHandle(type) && (!forSeeding || x.CanSeed(type)));
+    return provider != null;
+  }
+
+
   /// <inheritdoc />
   public virtual bool TryGetProvider(string alias, out IRouteProvider provider)
   {
@@ -178,6 +187,11 @@ public interface IRoutes
   /// </summary>
   bool TryGetProvider<T>(T model, out IRouteProvider provider) where T : ISupportsRouting;
 
+  /// <summary>
+  /// Find a provider for a certain entity
+  /// </summary>
+  bool TryGetProvider<T>(T model, bool forSeeding, out IRouteProvider provider) where T : ISupportsRouting;
+
   /// <summary>
   /// Find a provider by alias
   /// </summary>

zero.Core/Routing/ZeroEntityRouteInterceptor.cs

@@ -118,7 +118,7 @@ public class ZeroEntityRouteInterceptor : Interceptor<ZeroEntity>
 
 
     // find provider for this model
-    if (Routes.TryGetProvider(model, out IRouteProvider provider))
+    if (Routes.TryGetProvider(model, true, out IRouteProvider provider))
     {
       // return if the route is not stale
       if (args.PreviousModel is ZeroEntity previousZeroModel && !(await provider.IsRouteStale(context, previousZeroModel, model)))

zero.Core/Routing/ZeroRouteProvider.cs

@@ -7,6 +7,9 @@ public abstract class ZeroRouteProvider<T> : ZeroRouteProvider, IRouteProvider<T
   /// <inheritdoc />
   public override bool CanHandle(Type type) => typeof(T).IsAssignableFrom(type);
 
+  /// <inheritdoc />
+  public override bool CanSeed(Type type) => CanHandle(type);
+
   /// <inheritdoc />
   public virtual Task<Route> Create(RoutingContext context, T model) => base.Create(context, model);
 
@@ -80,6 +83,9 @@ public abstract class ZeroRouteProvider : IRouteProvider
   /// <inheritdoc />
   public virtual bool CanHandle(Type type) => false;
 
+  /// <inheritdoc />
+  public virtual bool CanSeed(Type type) => false;
+
   /// <inheritdoc />
   public virtual Task<Route> Create(RoutingContext context, ISupportsRouting model) => Task.FromResult(new Route()
   {
@@ -193,6 +199,11 @@ public interface IRouteProvider
   /// </summary>
   bool CanHandle(Type type);
 
+  /// <summary>
+  /// Whether this provider can handle seeding for a certain entity type
+  /// </summary>
+  bool CanSeed(Type type);
+
   /// <summary>
   /// Generate unique route key for a model
   /// </summary>