Allow BindPropertyAttribute to be applied on PageModel

Fixes #6653

src/Microsoft.AspNetCore.Mvc.Core/BindPropertyAttribute.cs

@@ -6,7 +6,7 @@ using Microsoft.AspNetCore.Mvc.ModelBinding;
 
 namespace Microsoft.AspNetCore.Mvc
 {
-    [AttributeUsage(AttributeTargets.Property, AllowMultiple = false, Inherited = true)]
+    [AttributeUsage(AttributeTargets.Class | AttributeTargets.Property, AllowMultiple = false, Inherited = true)]
     public class BindPropertyAttribute : Attribute, IModelNameProvider, IBinderTypeProviderMetadata, IRequestPredicateProvider
     {
         private static readonly Func<ActionContext, bool> _supportsAllRequests = (c) => true;
@@ -31,22 +31,14 @@ namespace Microsoft.AspNetCore.Mvc
 
                 return _bindingSource;
             }
-            protected set
+            protected set => _bindingSource = value;
-            {
-                _bindingSource = value;
-            }
         }
 
         /// <inheritdoc />
         public string Name { get; set; }
 
         Func<ActionContext, bool> IRequestPredicateProvider.RequestPredicate
-        {
+            => SupportsGet ? _supportsAllRequests : _supportsNonGetRequests;
-            get
-            {
-                return SupportsGet ? _supportsAllRequests : _supportsNonGetRequests;
-            }
-        }
 
         private static bool IsNonGetRequest(ActionContext context)
         {

src/Microsoft.AspNetCore.Mvc.Core/Internal/DefaultApplicationModelProvider.cs

@@ -224,7 +224,6 @@ namespace Microsoft.AspNetCore.Mvc.Internal
             return propertyModel;
         }
 
-
         /// <summary>
         /// Creates the <see cref="ActionModel"/> instance for the given action <see cref="MethodInfo"/>.
         /// </summary>

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

@@ -220,10 +220,15 @@ namespace Microsoft.AspNetCore.Mvc.RazorPages.Internal
                 throw new ArgumentNullException(nameof(property));
             }
 
-            var attributes = property.GetCustomAttributes(inherit: true);
+            var propertyAttributes = property.GetCustomAttributes(inherit: true);
-            var bindingInfo = BindingInfo.GetBindingInfo(attributes);
+            var handlerAttributes = property.DeclaringType.GetCustomAttributes(inherit: true);
 
-            var model = new PagePropertyModel(property, property.GetCustomAttributes(inherit: true))
+            // Look for binding info on the handler if nothing is specified on the property.
+            // This allows BindProperty attributes on handlers to apply to properties.
+            var bindingInfo = BindingInfo.GetBindingInfo(propertyAttributes) ??
+                BindingInfo.GetBindingInfo(handlerAttributes);
+
+            var model = new PagePropertyModel(property, propertyAttributes)
             {
                 PropertyName = property.Name,
                 BindingInfo = bindingInfo,

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

@@ -1136,9 +1136,59 @@ Microsoft.AspNetCore.Mvc.ViewFeatures.ViewDataDictionary`1[AspNetCore._InjectedP
             // Act
             var response = await Client.GetStringAsync("/Pages/Localized/PageWithModel?culture=fr-FR");
 
+            // Assert
             Assert.Equal(expected, response.Trim());
         }
 
+        [Fact]
+        public async Task BindPropertyAttribute_CanBeAppliedToModelType()
+        {
+            // Arrange
+            var expected = "Property1 = 123, Property2 = 25,";
+            var request = new HttpRequestMessage(HttpMethod.Post, "/Pages/PropertyBinding/BindPropertyOnModel?Property1=123")
+            {
+                Content = new FormUrlEncodedContent(new[]
+                {
+                    new KeyValuePair<string, string>("Property2", "25"),
+                }),
+            };
+            await AddAntiforgeryHeaders(request);
+
+            // Act
+            var response = await Client.SendAsync(request);
+
+            // Assert
+            response.EnsureSuccessStatusCode();
+            var responseContent = await response.Content.ReadAsStringAsync();
+            Assert.StartsWith(expected, responseContent.Trim());
+        }
+
+        [Fact]
+        public async Task BindingInfoOnPropertiesIsPreferredToBindingInfoOnType()
+        {
+            // Arrange
+            var expected = "Property1 = 123, Property2 = 25,";
+            var request = new HttpRequestMessage(HttpMethod.Post, "/Pages/PropertyBinding/BindPropertyOnModel?Property1=123")
+            {
+                Content = new FormUrlEncodedContent(new[]
+                {
+                    // FormValueProvider appears before QueryStringValueProvider. However, the FromQuery explicitly listed
+                    // on the property should cause it to use the latter.
+                    new KeyValuePair<string, string>("Property1", "345"),
+                    new KeyValuePair<string, string>("Property2", "25"),
+                }),
+            };
+            await AddAntiforgeryHeaders(request);
+
+            // Act
+            var response = await Client.SendAsync(request);
+
+            // Assert
+            response.EnsureSuccessStatusCode();
+            var responseContent = await response.Content.ReadAsStringAsync();
+            Assert.StartsWith(expected, responseContent.Trim());
+        }
+
         private async Task AddAntiforgeryHeaders(HttpRequestMessage request)
         {
             var getResponse = await Client.GetAsync(request.RequestUri);

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

@@ -10,7 +10,6 @@ using Microsoft.AspNetCore.Mvc.ApplicationModels;
 using Microsoft.AspNetCore.Mvc.ModelBinding;
 using Microsoft.AspNetCore.Mvc.Razor;
 using Microsoft.AspNetCore.Mvc.RazorPages.Infrastructure;
-using Microsoft.Extensions.Options;
 using Xunit;
 
 namespace Microsoft.AspNetCore.Mvc.RazorPages.Internal
@@ -229,6 +228,60 @@ namespace Microsoft.AspNetCore.Mvc.RazorPages.Internal
             public string Property { get; set; }
         }
 
+        [Fact]
+        public void OnProvidersExecuting_DiscoversProperties_FromAllSubTypesThatDeclaresBindProperty()
+        {
+            // Arrange
+            var provider = new DefaultPageApplicationModelProvider();
+            var typeInfo = typeof(BindPropertyAttributeOnBaseModelPage).GetTypeInfo();
+            var descriptor = new PageActionDescriptor();
+            var context = new PageApplicationModelProviderContext(descriptor, typeInfo);
+
+            // Act
+            provider.OnProvidersExecuting(context);
+
+            // Assert
+            Assert.NotNull(context.PageApplicationModel);
+            Assert.Collection(
+                context.PageApplicationModel.HandlerProperties.OrderBy(p => p.PropertyName).Where(p => p.BindingInfo != null),
+                property =>
+                {
+                    var name = nameof(ModelLevel3.Property2);
+                    Assert.Equal(typeof(ModelLevel3).GetProperty(name), property.PropertyInfo);
+                    Assert.Equal(name, property.PropertyName);
+                    Assert.NotNull(property.BindingInfo);
+                },
+                property =>
+                {
+                    var name = nameof(ModelLevel3.Property3);
+                    Assert.Equal(typeof(ModelLevel3).GetProperty(name), property.PropertyInfo);
+                    Assert.Equal(name, property.PropertyName);
+                    Assert.NotNull(property.BindingInfo);
+                });
+        }
+
+        private class BindPropertyAttributeOnBaseModelPage : Page
+        {
+            public ModelLevel3 Model => null;
+            public override Task ExecuteAsync() => throw new NotImplementedException();
+        }
+
+        private class ModelLevel1 : PageModel
+        {
+            public string Property1 { get; set; }
+        }
+
+        [BindProperty]
+        private class ModelLevel2 : ModelLevel1
+        {
+            public string Property2 { get; set; }
+        }
+
+        private class ModelLevel3 : ModelLevel2
+        {
+            public string Property3 { get; set; }
+        }
+
         [Fact]
         public void OnProvidersExecuting_DiscoversHandlersFromPage()
         {
@@ -305,6 +358,53 @@ namespace Microsoft.AspNetCore.Mvc.RazorPages.Internal
                 });
         }
 
+        [Fact]
+        public void OnProvidersExecuting_DiscoversBindingInfoFromHandler()
+        {
+            // Arrange
+            var provider = new DefaultPageApplicationModelProvider();
+            var typeInfo = typeof(PageWithBindPropertyModel).GetTypeInfo();
+            var modelType = typeof(ModelWithBindProperty);
+            var descriptor = new PageActionDescriptor();
+            var context = new PageApplicationModelProviderContext(descriptor, typeInfo);
+
+            // Act
+            provider.OnProvidersExecuting(context);
+
+            // Assert
+            Assert.NotNull(context.PageApplicationModel);
+            Assert.Collection(
+                context.PageApplicationModel.HandlerProperties.OrderBy(p => p.PropertyName),
+                property =>
+                {
+                    Assert.Equal(nameof(ModelWithBindProperty.Property1), property.PropertyName);
+                    Assert.NotNull(property.BindingInfo);
+                },
+                property =>
+                {
+                    Assert.Equal(nameof(ModelWithBindProperty.Property2), property.PropertyName);
+                    Assert.NotNull(property.BindingInfo);
+                    Assert.Equal(BindingSource.Path, property.BindingInfo.BindingSource);
+                });
+        }
+
+        private class PageWithBindPropertyModel : PageBase
+        {
+            public ModelWithBindProperty Model => null;
+
+            public override Task ExecuteAsync() => null;
+        }
+
+        [BindProperty]
+        [PageModel]
+        private class ModelWithBindProperty
+        {
+            public string Property1 { get; set; }
+
+            [FromRoute]
+            public string Property2 { get; set; }
+        }
+
         [Fact]
         public void OnProvidersExecuting_DiscoversHandlersFromModel()
         {

test/WebSites/RazorPagesWebSite/Pages/PropertyBinding/BindPropertyOnModel.cs

@@ -0,0 +1,18 @@
+// 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;
+using Microsoft.AspNetCore.Mvc.ModelBinding;
+using Microsoft.AspNetCore.Mvc.RazorPages;
+
+namespace RazorPagesWebSite
+{
+    [BindProperty]
+    public class BindPropertyOnModel : PageModel
+    {
+        [FromQuery]
+        public string Property1 { get; set; }
+
+        public string Property2 { get; set; }
+    }
+}

test/WebSites/RazorPagesWebSite/Pages/PropertyBinding/BindPropertyOnModel.cshtml

@@ -0,0 +1,8 @@
+@page
+@model BindPropertyOnModel
+
+Property1 = @Model.Property1, Property2 = @Model.Property2,
+
+<form action="">
+    @Html.AntiForgeryToken()
+</form>