Add TempData property support for Pages

samples/MvcSandbox/Pages/Index.cshtml

@@ -1,12 +1,22 @@
 @page Test
 @model TestModel
 
+@functions {
+
+    [TempData]
+    public string Message { get; set; }
+}
+
 <div class="row">
     <div class="col-md-3">
         <h2>RazorPages says Hello @Model.Name!</h2>
         <ul>
-            <li>This file should give you a quick view of a Mvc Raor Page in action.</li>
+            <li>This file should give you a quick view of a Mvc Razor Page in action.</li>
         </ul>
+        <p>Message from TempData: @Message</p>
+        @{ 
+            Message = $"You visited this page at {DateTime.Now}.";
+        }
     </div>
 
     <form method="post">

samples/MvcSandbox/Startup.cs

@@ -16,7 +16,7 @@ namespace MvcSandbox
         // This method gets called by the runtime. Use this method to add services to the container.
         public void ConfigureServices(IServiceCollection services)
         {
-            services.AddMvc();
+            services.AddMvc().AddCookieTempDataProvider();
 
             services.Insert(0, ServiceDescriptor.Singleton(
                 typeof(IConfigureOptions<AntiforgeryOptions>),

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

@@ -66,8 +66,12 @@ namespace Microsoft.Extensions.DependencyInjection
             services.TryAddSingleton<IPageLoader, DefaultPageLoader>();
             services.TryAddSingleton<IPageHandlerMethodSelector, DefaultPageHandlerMethodSelector>();
             services.TryAddSingleton<PageResultExecutor>();
+
             services.TryAddSingleton<PageArgumentBinder, DefaultPageArgumentBinder>();
+
             services.TryAddSingleton<IActionDescriptorChangeProvider, PageActionDescriptorChangeProvider>();
+
+            services.TryAddSingleton<TempDataPropertyProvider>();
         }
     }
 }

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

@@ -7,6 +7,7 @@ using Microsoft.AspNetCore.Mvc.Abstractions;
 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;
 
@@ -84,6 +85,9 @@ namespace Microsoft.AspNetCore.Mvc.RazorPages.Infrastructure
                 model.Selectors.Add(CreateSelectorModel(parentDirectoryPath, template));
             }
 
+            model.Filters.Add(new SaveTempDataPropertyFilter()); // Support for [TempData] on properties
+            model.Filters.Add(new AutoValidateAntiforgeryTokenAttribute()); // Always require an antiforgery token on post
+
             for (var i = 0; i < _pagesOptions.Conventions.Count; i++)
             {
                 _pagesOptions.Conventions[i].Apply(model);

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

@@ -0,0 +1,63 @@
+// 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.Concurrent;
+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
+{
+    public class TempDataPropertyProvider
+    {
+        public static readonly string Prefix = "TempDataProperty-";
+
+        private ConcurrentDictionary<Type, IEnumerable<PropertyInfo>> _subjectProperties =
+            new ConcurrentDictionary<Type, IEnumerable<PropertyInfo>>();
+
+        public IDictionary<PropertyInfo, object> LoadAndTrackChanges(object subject, ITempDataDictionary tempData)
+        {
+            var properties = GetSubjectProperties(subject);
+            var result = new Dictionary<PropertyInfo, object>();
+
+            foreach (var property in properties)
+            {
+                var value = tempData[Prefix + property.Name];
+
+                result[property] = value;
+
+                // TODO: Clarify what behavior should be for null values here
+                if (value != null && property.PropertyType.IsAssignableFrom(value.GetType()))
+                {
+                    property.SetValue(subject, value);
+                }
+            }
+
+            return result;
+        }
+
+        private IEnumerable<PropertyInfo> GetSubjectProperties(object subject)
+        {
+            return _subjectProperties.GetOrAdd(subject.GetType(), subjectType =>
+            {
+                var properties = subjectType.GetRuntimeProperties()
+                    .Where(pi => pi.GetCustomAttribute<TempDataAttribute>() != null);
+
+                if (properties.Any(pi => !(pi.SetMethod != null && pi.SetMethod.IsPublic && pi.GetMethod != null && pi.GetMethod.IsPublic)))
+                {
+                    throw new InvalidOperationException("TempData properties must have a public getter and setter.");
+                }
+
+                if (properties.Any(pi => !(pi.PropertyType.GetTypeInfo().IsPrimitive || pi.PropertyType == typeof(string))))
+                {
+                    throw new InvalidOperationException("TempData properties must be declared as primitive types or string only.");
+                }
+
+                return properties;
+            });
+        }
+    }
+}

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

@@ -13,6 +13,7 @@ using Microsoft.AspNetCore.Mvc.Internal;
 using Microsoft.AspNetCore.Mvc.ModelBinding;
 using Microsoft.AspNetCore.Mvc.Razor;
 using Microsoft.AspNetCore.Mvc.RazorPages.Infrastructure;
+using Microsoft.AspNetCore.Mvc.ViewFeatures.Internal;
 using Microsoft.Extensions.Logging;
 
 namespace Microsoft.AspNetCore.Mvc.RazorPages.Internal
@@ -21,6 +22,7 @@ namespace Microsoft.AspNetCore.Mvc.RazorPages.Internal
     {
         private readonly IPageHandlerMethodSelector _selector;
         private readonly PageContext _pageContext;
+        private readonly TempDataPropertyProvider _propertyProvider;
 
         private Page _page;
         private object _model;
@@ -28,6 +30,7 @@ namespace Microsoft.AspNetCore.Mvc.RazorPages.Internal
 
         public PageActionInvoker(
             IPageHandlerMethodSelector handlerMethodSelector,
+            TempDataPropertyProvider propertyProvider,
             DiagnosticSource diagnosticSource,
             ILogger logger,
             PageContext pageContext,
@@ -42,6 +45,7 @@ namespace Microsoft.AspNetCore.Mvc.RazorPages.Internal
                   valueProviderFactories)
         {
             _selector = handlerMethodSelector;
+            _propertyProvider = propertyProvider;
             _pageContext = pageContext;
             CacheEntry = cacheEntry;
         }
@@ -337,6 +341,25 @@ namespace Microsoft.AspNetCore.Mvc.RazorPages.Internal
                 _pageContext.ViewData.Model = _model;
             }
 
+            // This is a workaround for not yet having proper filter for Pages.
+            SaveTempDataPropertyFilter propertyFilter = null;
+            for (var i = 0; i < _filters.Length; i++)
+            {
+                propertyFilter = _filters[i] as SaveTempDataPropertyFilter;
+                if (propertyFilter != null)
+                {
+                    break;
+                }
+            }
+
+            var originalValues = _propertyProvider.LoadAndTrackChanges(_page, _pageContext.TempData);
+            if (propertyFilter != null)
+            {
+                propertyFilter.OriginalValues = originalValues;
+                propertyFilter.Subject = _page;
+                propertyFilter.Prefix = TempDataPropertyProvider.Prefix;
+            }
+
             IActionResult result = null;
 
             var handler = _selector.Select(_pageContext);

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

@@ -36,6 +36,7 @@ namespace Microsoft.AspNetCore.Mvc.RazorPages.Internal
         private readonly ITempDataDictionaryFactory _tempDataFactory;
         private readonly HtmlHelperOptions _htmlHelperOptions;
         private readonly IPageHandlerMethodSelector _selector;
+        private readonly TempDataPropertyProvider _propertyProvider;
         private readonly RazorProject _razorProject;
         private readonly DiagnosticSource _diagnosticSource;
         private readonly ILogger<PageActionInvoker> _logger;
@@ -53,6 +54,7 @@ namespace Microsoft.AspNetCore.Mvc.RazorPages.Internal
             IOptions<MvcOptions> mvcOptions,
             IOptions<HtmlHelperOptions> htmlHelperOptions,
             IPageHandlerMethodSelector selector,
+            TempDataPropertyProvider propertyProvider,
             RazorProject razorProject,
             DiagnosticSource diagnosticSource,
             ILoggerFactory loggerFactory)
@@ -68,6 +70,7 @@ namespace Microsoft.AspNetCore.Mvc.RazorPages.Internal
             _tempDataFactory = tempDataFactory;
             _htmlHelperOptions = htmlHelperOptions.Value;
             _selector = selector;
+            _propertyProvider = propertyProvider;
             _razorProject = razorProject;
             _diagnosticSource = diagnosticSource;
             _logger = loggerFactory.CreateLogger<PageActionInvoker>();
@@ -149,6 +152,7 @@ namespace Microsoft.AspNetCore.Mvc.RazorPages.Internal
 
             return new PageActionInvoker(
                 _selector,
+                _propertyProvider,
                 _diagnosticSource,
                 _logger,
                 pageContext,

src/Microsoft.AspNetCore.Mvc.RazorPages/TempDataAttribute.cs

@@ -0,0 +1,13 @@
+// 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;
+
+namespace Microsoft.AspNetCore.Mvc.Rendering
+{
+    [AttributeUsage(AttributeTargets.Property, Inherited = false, AllowMultiple = false)]
+    public sealed class TempDataAttribute : Attribute
+    {
+
+    }
+}

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

@@ -0,0 +1,12 @@
+// 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 Microsoft.AspNetCore.Mvc.Filters;
+
+namespace Microsoft.AspNetCore.Mvc.ViewFeatures.Internal
+{
+    public interface ISaveTempDataCallback : IFilterMetadata
+    {
+        void OnTempDataSaving(ITempDataDictionary tempData);
+    }
+}

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

@@ -1,6 +1,7 @@
 // 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.Collections.Generic;
 using Microsoft.AspNetCore.Mvc.Filters;
 using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Mvc.Internal;
@@ -49,15 +50,17 @@ namespace Microsoft.AspNetCore.Mvc.ViewFeatures.Internal
                     SaveTempData(
                         result: null,
                         factory: saveTempDataContext.TempDataDictionaryFactory,
+                        filters: saveTempDataContext.Filters,
                         httpContext: saveTempDataContext.HttpContext);
 
                     return TaskCache.CompletedTask;
                 },
-               state: new SaveTempDataContext()
+                state: new SaveTempDataContext()
-               {
+                {
-                   HttpContext = context.HttpContext,
+                    Filters = context.Filters,
-                   TempDataDictionaryFactory = _factory
+                    HttpContext = context.HttpContext,
-               });
+                    TempDataDictionaryFactory = _factory
+                });
             }
         }
 
@@ -79,7 +82,7 @@ namespace Microsoft.AspNetCore.Mvc.ViewFeatures.Internal
             // late in the pipeline at which point SessionFeature would not be available.
             if (!context.HttpContext.Response.HasStarted)
             {
-                SaveTempData(context.Result, _factory, context.HttpContext);
+                SaveTempData(context.Result, _factory, context.Filters, context.HttpContext);
                 // If SaveTempDataFilter got added twice this might already be in there.
                 if (!context.HttpContext.Items.ContainsKey(TempDataSavedKey))
                 {
@@ -88,17 +91,34 @@ namespace Microsoft.AspNetCore.Mvc.ViewFeatures.Internal
             }
         }
 
-        private static void SaveTempData(IActionResult result, ITempDataDictionaryFactory factory, HttpContext httpContext)
+        private static void SaveTempData(
+            IActionResult result,
+            ITempDataDictionaryFactory factory,
+            IList<IFilterMetadata> filters,
+            HttpContext httpContext)
         {
+            var tempData = factory.GetTempData(httpContext);
+
+            for (var i = 0; i < filters.Count; i++)
+            {
+                var callback = filters[i] as ISaveTempDataCallback;
+                if (callback != null)
+                {
+                    callback.OnTempDataSaving(tempData);
+                }
+            }
+
             if (result is IKeepTempDataResult)
             {
-                factory.GetTempData(httpContext).Keep();
+                tempData.Keep();
             }
-            factory.GetTempData(httpContext).Save();
+
+            tempData.Save();
         }
 
         private class SaveTempDataContext
         {
+            public IList<IFilterMetadata> Filters { get; set; }
             public HttpContext HttpContext { get; set; }
             public ITempDataDictionaryFactory TempDataDictionaryFactory { get; set; }
         }

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

@@ -0,0 +1,35 @@
+// 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.Collections.Generic;
+using System.Reflection;
+
+namespace Microsoft.AspNetCore.Mvc.ViewFeatures.Internal
+{
+    public class SaveTempDataPropertyFilter : ISaveTempDataCallback
+    {
+        public string Prefix { get; set; }
+
+        public object Subject { get; set; }
+
+        public IDictionary<PropertyInfo, object> OriginalValues { get; set; }
+
+        public void OnTempDataSaving(ITempDataDictionary tempData)
+        {
+            if (Subject != null && OriginalValues != null)
+            {
+                foreach (var kvp in OriginalValues)
+                {
+                    var property = kvp.Key;
+                    var originalValue = kvp.Value;
+
+                    var newValue = property.GetValue(Subject);
+                    if (newValue != null && newValue != originalValue)
+                    {
+                        tempData[Prefix + property.Name] = newValue;
+                    }
+                }
+            }
+        }
+    }
+}

test/Microsoft.AspNetCore.Mvc.FunctionalTests/MvcSandboxTest.cs

@@ -32,7 +32,7 @@ namespace Microsoft.AspNetCore.Mvc.FunctionalTests
             var response = await Client.GetStringAsync("http://localhost/Pages/Test");
 
             // Assert
-            Assert.Contains("This file should give you a quick view of a Mvc Raor Page in action.", response);
+            Assert.Contains("This file should give you a quick view of a Mvc Razor Page in action.", response);
         }
     }
 }

test/Microsoft.AspNetCore.Mvc.RazorPages.Test/Infrastructure/PageActionDescriptorProviderTest.cs

@@ -7,6 +7,7 @@ using Microsoft.AspNetCore.Mvc.ApplicationModels;
 using Microsoft.AspNetCore.Mvc.Filters;
 using Microsoft.AspNetCore.Mvc.Razor;
 using Microsoft.AspNetCore.Mvc.Razor.Internal;
+using Microsoft.AspNetCore.Mvc.ViewFeatures.Internal;
 using Microsoft.AspNetCore.Razor.Evolution;
 using Microsoft.Extensions.Options;
 using Moq;
@@ -193,6 +194,44 @@ namespace Microsoft.AspNetCore.Mvc.RazorPages.Infrastructure
                 });
         }
 
+        [Fact]
+        public void GetDescriptors_ImplicitFilters()
+        {
+            // Arrange
+            var options = new MvcOptions();
+            var razorProject = new Mock<RazorProject>();
+            razorProject.Setup(p => p.EnumerateItems("/"))
+                .Returns(new[]
+                {
+                    GetProjectItem("/", "/Home.cshtml", $"@page {Environment.NewLine}"),
+                });
+            var provider = new PageActionDescriptorProvider(
+                razorProject.Object,
+                GetAccessor(options),
+                GetAccessor<RazorPagesOptions>());
+            var context = new ActionDescriptorProviderContext();
+
+            // Act
+            provider.OnProvidersExecuting(context);
+
+            // Assert
+            var result = Assert.Single(context.Results);
+            var descriptor = Assert.IsType<PageActionDescriptor>(result);
+            Assert.Collection(
+                descriptor.FilterDescriptors,
+                filterDescriptor =>
+                {
+                    Assert.Equal(FilterScope.Action, filterDescriptor.Scope);
+                    Assert.IsType<SaveTempDataPropertyFilter>(filterDescriptor.Filter);
+                },
+                filterDescriptor =>
+                {
+                    Assert.Equal(FilterScope.Action, filterDescriptor.Scope);
+                    Assert.IsType<AutoValidateAntiforgeryTokenAttribute>(filterDescriptor.Filter);
+                });
+        }
+
+
         [Fact]
         public void GetDescriptors_AddsGlobalFilters()
         {
@@ -220,7 +259,8 @@ namespace Microsoft.AspNetCore.Mvc.RazorPages.Infrastructure
             // Assert
             var result = Assert.Single(context.Results);
             var descriptor = Assert.IsType<PageActionDescriptor>(result);
-            Assert.Collection(descriptor.FilterDescriptors,
+            Assert.Collection(
+                descriptor.FilterDescriptors,
                 filterDescriptor =>
                 {
                     Assert.Equal(FilterScope.Global, filterDescriptor.Scope);
@@ -230,6 +270,16 @@ namespace Microsoft.AspNetCore.Mvc.RazorPages.Infrastructure
                 {
                     Assert.Equal(FilterScope.Global, filterDescriptor.Scope);
                     Assert.Same(filter2, filterDescriptor.Filter);
+                },
+                filterDescriptor =>
+                {
+                    Assert.Equal(FilterScope.Action, filterDescriptor.Scope);
+                    Assert.IsType<SaveTempDataPropertyFilter>(filterDescriptor.Filter);
+                },
+                filterDescriptor =>
+                {
+                    Assert.Equal(FilterScope.Action, filterDescriptor.Scope);
+                    Assert.IsType<AutoValidateAntiforgeryTokenAttribute>(filterDescriptor.Filter);
                 });
         }
 
@@ -275,6 +325,16 @@ namespace Microsoft.AspNetCore.Mvc.RazorPages.Infrastructure
                     Assert.Same(globalFilter, filterDescriptor.Filter);
                 },
                 filterDescriptor =>
+                {
+                    Assert.Equal(FilterScope.Action, filterDescriptor.Scope);
+                    Assert.IsType<SaveTempDataPropertyFilter>(filterDescriptor.Filter);
+                },
+                filterDescriptor =>
+                {
+                    Assert.Equal(FilterScope.Action, filterDescriptor.Scope);
+                    Assert.IsType<AutoValidateAntiforgeryTokenAttribute>(filterDescriptor.Filter);
+                },
+                filterDescriptor =>
                 {
                     Assert.Equal(FilterScope.Action, filterDescriptor.Scope);
                     Assert.Same(localFilter, filterDescriptor.Filter);

test/Microsoft.AspNetCore.Mvc.RazorPages.Test/Internal/PageActionInvokerProviderTest.cs

@@ -283,6 +283,7 @@ namespace Microsoft.AspNetCore.Mvc.RazorPages.Internal
                 new TestOptionsManager<MvcOptions>(),
                 new TestOptionsManager<HtmlHelperOptions>(),
                 Mock.Of<IPageHandlerMethodSelector>(),
+                new TempDataPropertyProvider(),
                 razorProject,
                 new DiagnosticListener("Microsoft.AspNetCore"),
                 NullLoggerFactory.Instance);

test/Microsoft.AspNetCore.Mvc.RazorPages.Test/Internal/PageActionInvokerTest.cs

@@ -607,6 +607,7 @@ namespace Microsoft.AspNetCore.Mvc.RazorPages.Internal
 
             var invoker = new PageActionInvoker(
                 selector,
+                new TempDataPropertyProvider(),
                 diagnosticSource,
                 logger,
                 pageContext,