Simplify parameter transformer usage

src/Microsoft.AspNetCore.Mvc.Core/ApplicationModels/ActionModel.cs

@@ -50,6 +50,7 @@ namespace Microsoft.AspNetCore.Mvc.ApplicationModels
 
             ActionMethod = other.ActionMethod;
             ActionName = other.ActionName;
+            RouteParameterTransformer = other.RouteParameterTransformer;
 
             // Not making a deep copy of the controller, this action still belongs to the same controller.
             Controller = other.Controller;
@@ -93,6 +94,18 @@ namespace Microsoft.AspNetCore.Mvc.ApplicationModels
 
         public IList<ParameterModel> Parameters { get; }
 
+        /// <summary>
+        /// Gets or sets an <see cref="IOutboundParameterTransformer"/> that will be used to transform 
+        /// built-in route parameters such as <c>action</c>, <c>controller</c>, and <c>area</c> as well as
+        /// additional parameters specified by <see cref="RouteValues"/> into static segments in the route template.
+        /// </summary>
+        /// <remarks>
+        /// <para>
+        /// This feature only applies when using endpoint routing.
+        /// </para>
+        /// </remarks>
+        public IOutboundParameterTransformer RouteParameterTransformer { get; set; }
+
         /// <summary>
         /// Gets a collection of route values that must be present in the 
         /// <see cref="RouteData.Values"/> for the corresponding action to be selected.

src/Microsoft.AspNetCore.Mvc.Core/ApplicationModels/ApplicationModelFactory.cs

@@ -159,20 +159,17 @@ namespace Microsoft.AspNetCore.Mvc.ApplicationModels
                     routeValues.TryAdd(kvp.Key, kvp.Value);
                 }
 
-                action.Properties.TryGetValue(typeof(IOutboundParameterTransformer), out var obj);
-                var transformer = obj as IOutboundParameterTransformer;
-
                 selector.AttributeRouteModel.Template = AttributeRouteModel.ReplaceTokens(
                     selector.AttributeRouteModel.Template,
                     routeValues,
-                    transformer);
+                    action.RouteParameterTransformer);
 
                 if (selector.AttributeRouteModel.Name != null)
                 {
                     selector.AttributeRouteModel.Name = AttributeRouteModel.ReplaceTokens(
                         selector.AttributeRouteModel.Name,
                         routeValues,
-                        transformer);
+                        action.RouteParameterTransformer);
                 }
             }
             catch (InvalidOperationException ex)

src/Microsoft.AspNetCore.Mvc.Core/ApplicationModels/RouteTokenTransformerConvention.cs

@@ -33,7 +33,7 @@ namespace Microsoft.AspNetCore.Mvc.ApplicationModels
         {
             if (ShouldApply(action))
             {
-                action.Properties[typeof(IOutboundParameterTransformer)] = _parameterTransformer;
+                action.RouteParameterTransformer = _parameterTransformer;
             }
         }
 

src/Microsoft.AspNetCore.Mvc.RazorPages/ApplicationModels/PageRouteModel.cs

@@ -55,6 +55,7 @@ namespace Microsoft.AspNetCore.Mvc.ApplicationModels
             RelativePath = other.RelativePath;
             ViewEnginePath = other.ViewEnginePath;
             AreaName = other.AreaName;
+            RouteParameterTransformer = other.RouteParameterTransformer;
 
             Properties = new Dictionary<object, object>(other.Properties);
             Selectors = new List<SelectorModel>(other.Selectors.Select(m => new SelectorModel(m)));
@@ -113,5 +114,17 @@ namespace Microsoft.AspNetCore.Mvc.ApplicationModels
         /// </para>
         /// </remarks>
         public IDictionary<string, string> RouteValues { get; }
+
+        /// <summary>
+        /// Gets or sets an <see cref="IOutboundParameterTransformer"/> that will be used to transform 
+        /// built-in route parameters such as <c>action</c>, <c>controller</c>, and <c>area</c> as well as
+        /// additional parameters specified by <see cref="RouteValues"/> into static segments in the route template.
+        /// </summary>
+        /// <remarks>
+        /// <para>
+        /// This feature only applies when using endpoint routing.
+        /// </para>
+        /// </remarks>
+        public IOutboundParameterTransformer RouteParameterTransformer { get; set; }
     }
 }

src/Microsoft.AspNetCore.Mvc.RazorPages/ApplicationModels/PageRouteTransformerConvention.cs

@@ -33,7 +33,7 @@ namespace Microsoft.AspNetCore.Mvc.ApplicationModels
         {
             if (ShouldApply(model))
             {
-                model.Properties[typeof(IOutboundParameterTransformer)] = _parameterTransformer;
+                model.RouteParameterTransformer = _parameterTransformer;
             }
         }
 

src/Microsoft.AspNetCore.Mvc.RazorPages/Infrastructure/PageActionDescriptorProvider.cs

@@ -113,11 +113,8 @@ namespace Microsoft.AspNetCore.Mvc.RazorPages.Infrastructure
 
         private static string TransformPageRoute(PageRouteModel model, SelectorModel selectorModel)
         {
-            model.Properties.TryGetValue(typeof(IOutboundParameterTransformer), out var transformer);
-            var pageRouteTransformer = transformer as IOutboundParameterTransformer;
-
             // Transformer not set on page route
-            if (pageRouteTransformer == null)
+            if (model.RouteParameterTransformer == null)
             {
                 return selectorModel.AttributeRouteModel.Template;
             }
@@ -134,7 +131,7 @@ namespace Microsoft.AspNetCore.Mvc.RazorPages.Infrastructure
             var segments = pageRouteMetadata.PageRoute.Split('/');
             for (var i = 0; i < segments.Length; i++)
             {
-                segments[i] = pageRouteTransformer.TransformOutbound(segments[i]);
+                segments[i] = model.RouteParameterTransformer.TransformOutbound(segments[i]);
             }
 
             var transformedPageRoute = string.Join("/", segments);

test/Microsoft.AspNetCore.Mvc.Core.Test/ApplicationModels/ActionModelTest.cs

@@ -7,6 +7,8 @@ using System.Reflection;
 using Microsoft.AspNetCore.Mvc.ActionConstraints;
 using Microsoft.AspNetCore.Mvc.Filters;
 using Microsoft.AspNetCore.Mvc.Routing;
+using Microsoft.AspNetCore.Routing;
+using Moq;
 using Xunit;
 
 namespace Microsoft.AspNetCore.Mvc.ApplicationModels
@@ -75,6 +77,7 @@ namespace Microsoft.AspNetCore.Mvc.ApplicationModels
                 (typeof(TestController).GetTypeInfo(),
                 new List<object>());
             action.Filters.Add(new MyFilterAttribute());
+            action.RouteParameterTransformer = Mock.Of<IOutboundParameterTransformer>();
             action.RouteValues.Add("key", "value");
             action.Properties.Add(new KeyValuePair<object, object>("test key", "test value"));
 

test/Microsoft.AspNetCore.Mvc.Core.Test/ApplicationModels/RouteTokenTransformerConventionTest.cs

@@ -3,11 +3,10 @@
 
 using System;
 using System.Reflection;
-using Microsoft.AspNetCore.Mvc.ApplicationModels;
 using Microsoft.AspNetCore.Routing;
 using Xunit;
 
-namespace Microsoft.AspNetCore.Mvc.Test.ApplicationModels
+namespace Microsoft.AspNetCore.Mvc.ApplicationModels
 {
     public class RouteTokenTransformerConventionTest
     {
@@ -28,8 +27,7 @@ namespace Microsoft.AspNetCore.Mvc.Test.ApplicationModels
             convention.Apply(model);
 
             // Assert
-            Assert.True(model.Properties.TryGetValue(typeof(IOutboundParameterTransformer), out var routeTokenTransformer));
+            Assert.Same(transformer, model.RouteParameterTransformer);
-            Assert.Equal(transformer, routeTokenTransformer);
         }
 
         [Fact]
@@ -49,7 +47,7 @@ namespace Microsoft.AspNetCore.Mvc.Test.ApplicationModels
             convention.Apply(model);
 
             // Assert
-            Assert.False(model.Properties.TryGetValue(typeof(IOutboundParameterTransformer), out _));
+            Assert.Null(model.RouteParameterTransformer);
         }
 
         private MethodInfo GetMethodInfo()

test/Microsoft.AspNetCore.Mvc.RazorPages.Test/ApplicationModels/PageRouteTransformerConventionTest.cs

@@ -24,8 +24,7 @@ namespace Microsoft.AspNetCore.Mvc.Test.ApplicationModels
             convention.Apply(model);
 
             // Assert
-            Assert.True(model.Properties.TryGetValue(typeof(IOutboundParameterTransformer), out var routeTokenTransformer));
+            Assert.Same(transformer, model.RouteParameterTransformer);
-            Assert.Equal(transformer, routeTokenTransformer);
         }
 
         [Fact]
@@ -41,7 +40,7 @@ namespace Microsoft.AspNetCore.Mvc.Test.ApplicationModels
             convention.Apply(model);
 
             // Assert
-            Assert.False(model.Properties.TryGetValue(typeof(IOutboundParameterTransformer), out _));
+            Assert.Null(model.RouteParameterTransformer);
         }
 
         private class TestParameterTransformer : IOutboundParameterTransformer

test/WebSites/RoutingWebSite/ControllerRouteTokenTransformerConvention.cs

@@ -8,12 +8,12 @@ using Microsoft.AspNetCore.Routing;
 
 namespace RoutingWebSite
 {
-    public class ControllerRouteTokenTransformerConvention : IApplicationModelConvention
+    public class ControllerRouteTokenTransformerConvention : RouteTokenTransformerConvention
     {
         private readonly Type _controllerType;
-        private readonly IOutboundParameterTransformer _parameterTransformer;
 
         public ControllerRouteTokenTransformerConvention(Type controllerType, IOutboundParameterTransformer parameterTransformer)
+            : base(parameterTransformer)
         {
             if (parameterTransformer == null)
             {
@@ -21,18 +21,11 @@ namespace RoutingWebSite
             }
 
             _controllerType = controllerType;
-            _parameterTransformer = parameterTransformer;
         }
 
-        public void Apply(ApplicationModel application)
+        protected override bool ShouldApply(ActionModel action)
         {
-            foreach (var controller in application.Controllers.Where(c => c.ControllerType == _controllerType))
+            return action.Controller.ControllerType == _controllerType;
-            {
-                foreach (var action in controller.Actions)
-                {
-                    action.Properties[typeof(IOutboundParameterTransformer)] = _parameterTransformer;
-                }
-            }
         }
     }
 }