Fix #298 - Added ModelMetadata.Container property and unit tests.

src/Microsoft.AspNet.Mvc.Core/Rendering/Expressions/ExpressionMetadataProvider.cs

@@ -2,7 +2,6 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
-using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
@@ -73,6 +72,7 @@ namespace Microsoft.AspNet.Mvc.Rendering.Expressions
                 modelAccessor,
                 typeof(TValue),
                 propertyName,
+                container,
                 containerType,
                 metadataProvider);
         }
@@ -92,12 +92,14 @@ namespace Microsoft.AspNet.Mvc.Rendering.Expressions
             Type modelType = null;
             Func<object> modelAccessor = null;
             string propertyName = null;
+            object container = null;
 
             if (viewDataInfo != null)
             {
                 if (viewDataInfo.Container != null)
                 {
                     containerType = viewDataInfo.Container.GetType();
+                    container = viewDataInfo.Container;
                 }
 
                 modelAccessor = () => viewDataInfo.Value;
@@ -124,8 +126,12 @@ namespace Microsoft.AspNet.Mvc.Rendering.Expressions
                 }
             }
 
-            return GetMetadataFromProvider(modelAccessor, modelType ?? typeof(string), propertyName, containerType,
+            return GetMetadataFromProvider(modelAccessor, 
-                metadataProvider);
+                                           modelType ?? typeof(string), 
+                                           propertyName, 
+                                           container, 
+                                           containerType,
+                                           metadataProvider);
         }
 
         private static ModelMetadata FromModel([NotNull] ViewDataDictionary viewData,
@@ -138,6 +144,7 @@ namespace Microsoft.AspNet.Mvc.Rendering.Expressions
                     modelAccessor: null,
                     modelType: typeof(string),
                     propertyName: null,
+                    container: null,
                     containerType: null,
                     metadataProvider: metadataProvider);
             }
@@ -149,12 +156,23 @@ namespace Microsoft.AspNet.Mvc.Rendering.Expressions
 
         // An IModelMetadataProvider is not required unless this method is called. Therefore other methods in this
         // class lack [NotNull] attributes for their corresponding parameter.
-        private static ModelMetadata GetMetadataFromProvider(Func<object> modelAccessor, Type modelType,
+        private static ModelMetadata GetMetadataFromProvider(Func<object> modelAccessor, 
-            string propertyName, Type containerType, [NotNull] IModelMetadataProvider metadataProvider)
+                                                             Type modelType,
+                                                             string propertyName, 
+                                                             object container, 
+                                                             Type containerType, 
+                                                             [NotNull] IModelMetadataProvider metadataProvider)
         {
             if (containerType != null && !string.IsNullOrEmpty(propertyName))
             {
-                return metadataProvider.GetMetadataForProperty(modelAccessor, containerType, propertyName);
+                var metadata =
+                    metadataProvider.GetMetadataForProperty(modelAccessor, containerType, propertyName);
+                if (metadata != null)
+                {
+                    metadata.Container = container;
+                }
+
+                return metadata;
             }
 
             return metadataProvider.GetMetadataForType(modelAccessor, modelType);

src/Microsoft.AspNet.Mvc.ModelBinding/Metadata/AssociatedMetadataProvider.cs

@@ -97,7 +97,13 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
                 {
                     modelAccessor = () => propertyInfo.PropertyHelper.GetValue(container);
                 }
-                yield return CreatePropertyMetadata(modelAccessor, propertyInfo);
+                var propertyMetadata = CreatePropertyMetadata(modelAccessor, propertyInfo);
+                if (propertyMetadata != null)
+                {
+                    propertyMetadata.Container = container;
+                }
+
+                yield return propertyMetadata;
             }
         }
 

src/Microsoft.AspNet.Mvc.ModelBinding/Metadata/ModelMetadata.cs

@@ -67,6 +67,12 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
         /// </summary>
         public IBinderMetadata BinderMetadata { get; set; }
 
+        /// <summary>
+        /// A reference to the model's container <see cref="object"/>. 
+        /// Will be non-<c>null</c> if the model represents a property.
+        /// </summary>
+        public object Container { get; set; }
+
         public Type ContainerType
         {
             get { return _containerType; }

test/Microsoft.AspNet.Mvc.Core.Test/Rendering/Expression/ExpressionMetadataProviderTest.cs

@@ -0,0 +1,59 @@
+// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using Microsoft.AspNet.Mvc.ModelBinding;
+using Xunit;
+
+namespace Microsoft.AspNet.Mvc.Rendering.Expressions
+{
+    public class ExpressionMetadataProviderTest
+    {
+        [Fact]
+        public void FromLambaExpression_SetsContainerAsExpected()
+        {
+            // Arrange
+            var myModel = new TestModel { SelectedCategory = new Category() };
+            var provider = new EmptyModelMetadataProvider();
+            var viewData = new ViewDataDictionary<TestModel>(provider);
+            viewData.Model = myModel;
+
+            // Act
+            var metadata = ExpressionMetadataProvider.FromLambdaExpression<TestModel,Category>(
+                model => model.SelectedCategory, 
+                viewData,
+                provider);
+
+            // Assert
+            Assert.Same(myModel, metadata.Container);
+        }
+
+        [Fact]
+        public void FromStringExpression_SetsContainerAsExpected()
+        {
+            // Arrange
+            var myModel = new TestModel { SelectedCategory = new Category() };
+            var provider = new EmptyModelMetadataProvider();
+            var viewData = new ViewDataDictionary<TestModel>(provider);
+            viewData["Object"] = myModel;
+
+            // Act
+            var metadata = ExpressionMetadataProvider.FromStringExpression("Object.SelectedCategory",
+                                                                           viewData, 
+                                                                           provider);
+
+            // Assert
+            Assert.Same(myModel, metadata.Container);
+        }
+
+        private class TestModel
+        {
+            public Category SelectedCategory { get; set; }
+        }
+
+        private class Category
+        {
+            public int CategoryId { get; set; }
+            public string CategoryName { get; set; }
+        }
+    }
+}

test/Microsoft.AspNet.Mvc.ModelBinding.Test/Metadata/AssociatedMetadataProviderTest.cs

@@ -199,6 +199,23 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
         }
 #endif
 
+        [Fact]
+        public void GetMetadataForProperties_SetsContainerAsExpected()
+        {
+            // Arrange
+            var model = new PropertyModel { LocalAttributes = 42, MetadataAttributes = "hello", MixedAttributes = 21.12 };
+            var provider = new EmptyModelMetadataProvider();
+
+            // Act
+            var metadata = provider.GetMetadataForProperties(model, typeof(PropertyModel)).ToList();
+
+            // Assert
+            Assert.Equal(3, metadata.Count);
+            Assert.Same(model, metadata[0].Container);
+            Assert.Same(model, metadata[1].Container);
+            Assert.Same(model, metadata[2].Container);
+        }
+
         // Helpers
 
         // TODO: This type used System.ComponentModel.MetadataType to separate attribute declaration from property

test/Microsoft.AspNet.Mvc.ModelBinding.Test/Metadata/ModelMetadataTest.cs

@@ -17,6 +17,10 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
         {
             get
             {
+                var emptycontainerModel = new DummyModelContainer();
+                var contactModel = new DummyContactModel { FirstName = "test" };
+                var nonEmptycontainerModel = new DummyModelContainer { Model = contactModel };
+
                 return new TheoryData<Action<ModelMetadata>, Func<ModelMetadata, object>, object>
                 {
                     { m => m.ConvertEmptyStringToNull = false, m => m.ConvertEmptyStringToNull, false },
@@ -38,6 +42,9 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
                     { m => m.TemplateHint = "New template hint", m => m.TemplateHint, "New template hint" },
 
                     { m => m.Order = 23, m => m.Order, 23 },
+                    { m => m.Container = null, m => m.Container, null },
+                    { m => m.Container = emptycontainerModel, m => m.Container, emptycontainerModel },
+                    { m => m.Container = nonEmptycontainerModel, m => m.Container, nonEmptycontainerModel },
                 };
             }
         }
@@ -56,6 +63,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
 
             // Assert
             Assert.Equal(typeof(Exception), metadata.ContainerType);
+            Assert.Null(metadata.Container);
 
             Assert.True(metadata.ConvertEmptyStringToNull);
             Assert.False(metadata.HasNonDefaultEditFormat);