TempData property attribute

Addresses #5600

src/Microsoft.AspNetCore.Mvc.RazorPages/DependencyInjection/MvcRazorPagesMvcCoreBuilderExtensions.cs

@@ -8,6 +8,7 @@
 using Microsoft.AspNetCore.Mvc.RazorPages;
 using Microsoft.AspNetCore.Mvc.RazorPages.Infrastructure;
 using Microsoft.AspNetCore.Mvc.RazorPages.Internal;
+using Microsoft.AspNetCore.Mvc.ViewFeatures.Internal;
 using Microsoft.Extensions.DependencyInjection.Extensions;
 using Microsoft.Extensions.Options;
 

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

@@ -7,6 +7,7 @@
 using Microsoft.AspNetCore.Mvc.ApplicationModels;
 using Microsoft.AspNetCore.Mvc.Filters;
 using Microsoft.AspNetCore.Mvc.Routing;
+using Microsoft.AspNetCore.Mvc.ViewFeatures.Internal;
 using Microsoft.AspNetCore.Razor.Evolution;
 using Microsoft.Extensions.Options;
 
@@ -75,7 +76,7 @@ private void AddActionDescriptors(IList<ActionDescriptor> actions, RazorProjectI
                 var index = parentDirectoryPath.LastIndexOf('/');
                 if (index == -1)
                 {
-                    parentDirectoryPath = string.Empty; 
+                    parentDirectoryPath = string.Empty;
                 }
                 else
                 {

src/Microsoft.AspNetCore.Mvc.RazorPages/Internal/PageActionInvoker.cs

@@ -357,7 +357,6 @@ private async Task ExecutePageAsync()
             {
                 propertyFilter.OriginalValues = originalValues;
                 propertyFilter.Subject = _page;
-                propertyFilter.Prefix = TempDataPropertyProvider.Prefix;
             }
 
             IActionResult result = null;

src/Microsoft.AspNetCore.Mvc.RazorPages/Internal/PageActionInvokerProvider.cs

@@ -15,6 +15,7 @@
 using Microsoft.AspNetCore.Mvc.Razor;
 using Microsoft.AspNetCore.Mvc.RazorPages.Infrastructure;
 using Microsoft.AspNetCore.Mvc.ViewFeatures;
+using Microsoft.AspNetCore.Mvc.ViewFeatures.Internal;
 using Microsoft.AspNetCore.Razor.Evolution;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Options;

src/Microsoft.AspNetCore.Mvc.RazorPages/Internal/RazorPagesOptionsSetup.cs

@@ -18,7 +18,7 @@ public void Configure(RazorPagesOptions options)
             }
 
             // Support for [TempData] on properties
-            options.ConfigureFilter(new SaveTempDataPropertyFilter());
+            options.ConfigureFilter(new SaveTempDataPropertyFilterFactory());
             // Always require an antiforgery token on post
             options.ConfigureFilter(new AutoValidateAntiforgeryTokenAttribute());
         }

src/Microsoft.AspNetCore.Mvc.ViewFeatures/DependencyInjection/MvcViewFeaturesMvcCoreBuilderExtensions.cs

@@ -5,6 +5,7 @@
 using System.Buffers;
 using System.Linq;
 using Microsoft.AspNetCore.Mvc;
+using Microsoft.AspNetCore.Mvc.ApplicationModels;
 using Microsoft.AspNetCore.Mvc.ApplicationParts;
 using Microsoft.AspNetCore.Mvc.Formatters;
 using Microsoft.AspNetCore.Mvc.Internal;
@@ -197,6 +198,11 @@ internal static void AddViewServices(IServiceCollection services)
             //
             // Temp Data
             //
+            services.TryAddEnumerable(
+                ServiceDescriptor.Transient<IApplicationModelProvider, TempDataApplicationModelProvider>());
+            services.TryAddSingleton<SaveTempDataFilter>();
+            services.TryAddTransient<SaveTempDataPropertyFilter>();
+
             // This does caching so it should stay singleton
             services.TryAddSingleton<ITempDataProvider, CookieTempDataProvider>();
 
@@ -208,8 +214,6 @@ internal static void AddViewServices(IServiceCollection services)
 
             // These are stateless so their lifetime isn't really important.
             services.TryAddSingleton<ITempDataDictionaryFactory, TempDataDictionaryFactory>();
-            services.TryAddSingleton<SaveTempDataFilter>();
-
             services.TryAddSingleton(ArrayPool<ViewBufferValue>.Shared);
             services.TryAddScoped<IViewBufferScope, MemoryPoolViewBufferScope>();
         }

src/Microsoft.AspNetCore.Mvc.ViewFeatures/Internal/SaveTempDataFilter.cs

@@ -2,8 +2,8 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System.Collections.Generic;
-using Microsoft.AspNetCore.Mvc.Filters;
 using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Mvc.Filters;
 using Microsoft.AspNetCore.Mvc.Internal;
 
 namespace Microsoft.AspNetCore.Mvc.ViewFeatures.Internal

src/Microsoft.AspNetCore.Mvc.ViewFeatures/Internal/SaveTempDataPropertyFilter.cs

@@ -1,14 +1,26 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
+using System;
 using System.Collections.Generic;
 using System.Reflection;
+using Microsoft.AspNetCore.Mvc.Filters;
+using Microsoft.Extensions.Internal;
 
 namespace Microsoft.AspNetCore.Mvc.ViewFeatures.Internal
 {
-    public class SaveTempDataPropertyFilter : ISaveTempDataCallback
+    public class SaveTempDataPropertyFilter : ISaveTempDataCallback, IActionFilter
     {
-        public string Prefix { get; set; }
+        private const string Prefix = "TempDataProperty-";
+        private readonly ITempDataDictionaryFactory _factory;
+
+        public SaveTempDataPropertyFilter(ITempDataDictionaryFactory factory)
+        {
+            _factory = factory;
+        }
+
+        // Cannot be public as <c>PropertyHelper</c> is an internal shared source type
+        internal IList<PropertyHelper> PropertyHelpers { get; set; }
 
         public object Subject { get; set; }
 
@@ -24,12 +36,46 @@ public void OnTempDataSaving(ITempDataDictionary tempData)
                     var originalValue = kvp.Value;
 
                     var newValue = property.GetValue(Subject);
-                    if (newValue != null && newValue != originalValue)
+                    if (newValue != null && !newValue.Equals(originalValue))
                     {
                         tempData[Prefix + property.Name] = newValue;
                     }
                 }
             }
         }
+
+        public void OnActionExecuting(ActionExecutingContext context)
+        {
+            if (PropertyHelpers == null)
+            {
+                throw new ArgumentNullException(nameof(PropertyHelpers));
+            }
+
+            Subject = context.Controller;
+            var tempData = _factory.GetTempData(context.HttpContext);
+
+            OriginalValues = new Dictionary<PropertyInfo, object>();
+
+            for (var i = 0; i < PropertyHelpers.Count; i++)
+            {
+                var property = PropertyHelpers[i].Property;
+                var value = tempData[Prefix + property.Name];
+
+                OriginalValues[property] = value;
+
+                var propertyTypeInfo = property.PropertyType.GetTypeInfo();
+
+                var isReferenceTypeOrNullable = !propertyTypeInfo.IsValueType || Nullable.GetUnderlyingType(property.GetType()) != null;
+                if (value != null || isReferenceTypeOrNullable)
+                {
+                    property.SetValue(Subject, value);
+                }
+            }
+        }
+
+        public void OnActionExecuted(ActionExecutedContext context)
+        {
+        }
     }
 }
+

src/Microsoft.AspNetCore.Mvc.ViewFeatures/Internal/SaveTempDataPropertyFilterFactory.cs

@@ -0,0 +1,31 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System;
+using System.Collections.Generic;
+using Microsoft.AspNetCore.Mvc.Filters;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Internal;
+
+namespace Microsoft.AspNetCore.Mvc.ViewFeatures.Internal
+{
+    public class SaveTempDataPropertyFilterFactory : IFilterFactory
+    {
+        // Cannot be public as <c>PropertyHelper</c> is an internal shared source type
+        internal IList<PropertyHelper> TempDataProperties { get; set; }
+
+        public bool IsReusable => false;
+
+        public IFilterMetadata CreateInstance(IServiceProvider serviceProvider)
+        {
+            if (serviceProvider == null)
+            {
+                throw new ArgumentNullException(nameof(serviceProvider));
+            }
+
+            var service = serviceProvider.GetRequiredService<SaveTempDataPropertyFilter>();
+            service.PropertyHelpers = TempDataProperties;
+            return service;
+        }
+    }
+}

src/Microsoft.AspNetCore.Mvc.ViewFeatures/Internal/TempDataApplicationModelProvider.cs

@@ -0,0 +1,80 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System;
+using System.Collections.Generic;
+using System.Reflection;
+using Microsoft.AspNetCore.Mvc.ApplicationModels;
+using Microsoft.AspNetCore.Mvc.Internal;
+using Microsoft.Extensions.Internal;
+
+namespace Microsoft.AspNetCore.Mvc.ViewFeatures.Internal
+{
+    public class TempDataApplicationModelProvider : IApplicationModelProvider
+    {
+        /// <inheritdoc />
+        /// <remarks>This order ensures that <see cref="TempDataApplicationModelProvider"/> runs after the <see cref="DefaultApplicationModelProvider"/>.</remarks>
+        public int Order => -1000 + 10;
+
+        /// <inheritdoc />
+        public void OnProvidersExecuted(ApplicationModelProviderContext context)
+        {
+        }
+
+        /// <inheritdoc />
+        public void OnProvidersExecuting(ApplicationModelProviderContext context)
+        {
+            if (context == null)
+            {
+                throw new ArgumentNullException(nameof(context));
+            }
+
+            foreach (var controllerModel in context.Result.Controllers)
+            {
+                SaveTempDataPropertyFilterFactory factory = null;
+                var propertyHelpers = PropertyHelper.GetVisibleProperties(type: controllerModel.ControllerType.AsType());
+                for (var i = 0; i < propertyHelpers.Length; i++)
+                {
+                    var propertyHelper = propertyHelpers[i];
+                    if (propertyHelper.Property.IsDefined(typeof(TempDataAttribute)))
+                    {
+                        ValidateProperty(propertyHelper);
+                        if (factory == null)
+                        {
+                            factory = new SaveTempDataPropertyFilterFactory()
+                            {
+                                TempDataProperties = new List<PropertyHelper>()
+                            };
+                        }
+
+                        factory.TempDataProperties.Add(propertyHelper);
+                    }
+                }
+
+                if (factory != null)
+                {
+                    controllerModel.Filters.Add(factory);
+                }
+            }
+        }
+
+        private void ValidateProperty(PropertyHelper propertyHelper)
+        {
+            var property = propertyHelper.Property;
+            if (!(property.SetMethod != null &&
+                property.SetMethod.IsPublic &&
+                property.GetMethod != null &&
+                property.GetMethod.IsPublic))
+            {
+                throw new InvalidOperationException(
+                    Resources.FormatTempDataProperties_PublicGetterSetter(property.DeclaringType.FullName, property.Name, nameof(TempDataAttribute)));
+            }
+
+            if (!(property.PropertyType.GetTypeInfo().IsPrimitive || property.PropertyType == typeof(string)))
+            {
+                throw new InvalidOperationException(
+                    Resources.FormatTempDataProperties_PrimitiveTypeOrString(property.DeclaringType.FullName, property.Name, nameof(TempDataAttribute)));
+            }
+        }
+    }
+}

src/Microsoft.AspNetCore.Mvc.RazorPages/Infrastructure/TempDataPropertyProvider.cs → src/Microsoft.AspNetCore.Mvc.ViewFeatures/Internal/TempDataPropertyProvider.cs

@@ -6,10 +6,8 @@
 using System.Collections.Generic;
 using System.Linq;
 using System.Reflection;
-using Microsoft.AspNetCore.Mvc.Rendering;
-using Microsoft.AspNetCore.Mvc.ViewFeatures;
 
-namespace Microsoft.AspNetCore.Mvc.RazorPages
+namespace Microsoft.AspNetCore.Mvc.ViewFeatures.Internal
 {
     public class TempDataPropertyProvider
     {
@@ -18,6 +16,12 @@ public class TempDataPropertyProvider
         private ConcurrentDictionary<Type, IEnumerable<PropertyInfo>> _subjectProperties =
             new ConcurrentDictionary<Type, IEnumerable<PropertyInfo>>();
 
+        /// <summary>
+        /// Loads and tracks any changes to the properties of the <paramref name="subject"/>.
+        /// </summary>
+        /// <param name="subject">The properties of the subject are loaded and tracked. May be a <see cref="Controller"/>.</param>
+        /// <param name="tempData">The <see cref="ITempDataDictionary"/>.</param>
+        /// <returns></returns>
         public IDictionary<PropertyInfo, object> LoadAndTrackChanges(object subject, ITempDataDictionary tempData)
         {
             var properties = GetSubjectProperties(subject);