Umbraco-CMS/src/Umbraco.Web/Models/PartialViewMacroModelExtensions.cs

using Umbraco.Core;

namespace Umbraco.Web.Models
{
    /// <summary>
    /// Extension methods for the PartialViewMacroModel object
    /// </summary>
    public static class PartialViewMacroModelExtensions
    {
        /// <summary>
        /// Attempt to get a Marco parameter from a PartialViewMacroModel and return a default value otherwise
        /// </summary>
        /// <param name="partialViewMacroModel"></param>
        /// <param name="parameterAlias"></param>
        /// <param name="defaultValue"></param>
        /// <returns>Parameter value if available, the default value that was passed otherwise.</returns>       
        public static T GetParameterValue<T>(this PartialViewMacroModel partialViewMacroModel, string parameterAlias, T defaultValue)
        {
            if (partialViewMacroModel.MacroParameters.ContainsKey(parameterAlias) == false || string.IsNullOrEmpty(partialViewMacroModel.MacroParameters[parameterAlias].ToString())) 
                return defaultValue;

            var attempt = partialViewMacroModel.MacroParameters[parameterAlias].TryConvertTo(typeof(T));

            return attempt.Success ? (T) attempt.Result : defaultValue;
        }

        /// <summary> 
        /// Attempt to get a Marco parameter from a PartialViewMacroModel
        /// </summary>
        /// <param name="partialViewMacroModel"></param>
        /// <param name="parameterAlias"></param>
        /// <returns>Parameter value if available, the default value for the type otherwise.</returns>       
        public static T GetParameterValue<T>(this PartialViewMacroModel partialViewMacroModel, string parameterAlias)
        {
            return partialViewMacroModel.GetParameterValue(parameterAlias, default(T));
        }
    }
}