Removing creating ModelValidationNode by default in CompositeModelBinder.

This moves the responsibility of of MVN creation to individual model binders if they want the individual models to be validated.

src/Microsoft.AspNet.Mvc.Core/DefaultControllerActionArgumentBinder.cs

@@ -89,12 +89,16 @@ namespace Microsoft.AspNet.Mvc
                     metadata,
                     modelBindingResult.Model);
 
-                var validationContext = new ModelValidationContext(
-                    modelBindingContext.BindingSource,
-                    operationContext.ValidatorProvider,
-                    modelState,
-                    modelExplorer);
-                _validator.Validate(validationContext, modelBindingResult.ValidationNode);
+                if (modelBindingResult.ValidationNode != null)
+                {
+                    var validationContext = new ModelValidationContext(
+                        modelBindingContext.BindingSource,
+                        operationContext.ValidatorProvider,
+                        modelState,
+                        modelExplorer);
+
+                    _validator.Validate(validationContext, modelBindingResult.ValidationNode);
+                }
             }
 
             return modelBindingResult;

src/Microsoft.AspNet.Mvc.Core/ModelBinding/ByteArrayModelBinder.cs

@@ -39,12 +39,16 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
             try
             {
                 var model = Convert.FromBase64String(value);
+                var validationNode = new ModelValidationNode(
+                    bindingContext.ModelName,
+                    bindingContext.ModelMetadata,
+                    model);
 
-                // We do not need to set an explict ModelValidationNode since CompositeModelBinder does that automatically.
                 return new ModelBindingResult(
                     model,
                     bindingContext.ModelName,
-                    isModelSet: true);
+                    isModelSet: true,
+                    validationNode: validationNode);
             }
             catch (Exception ex)
             {

src/Microsoft.AspNet.Mvc.Core/ModelBinding/CancellationTokenModelBinder.cs

@@ -17,7 +17,13 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
             if (bindingContext.ModelType == typeof(CancellationToken))
             {
                 var model = bindingContext.OperationBindingContext.HttpContext.RequestAborted;
-                return Task.FromResult(new ModelBindingResult(model, bindingContext.ModelName, isModelSet: true));
+                var validationNode =
+                    new ModelValidationNode(bindingContext.ModelName, bindingContext.ModelMetadata, model);
+                return Task.FromResult(new ModelBindingResult(
+                    model,
+                    bindingContext.ModelName,
+                    isModelSet: true,
+                    validationNode: validationNode));
             }
 
             return Task.FromResult<ModelBindingResult>(null);

src/Microsoft.AspNet.Mvc.Core/ModelBinding/CompositeModelBinder.cs

@@ -83,24 +83,11 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
                 }
             }
 
-            // Update the model validation node if the model binding result was set but no validation node was provided.
-            // This would typically be the case where leaf level model binders, do not have to add a validation node
-            // for validation to take effect. The composite being the entry point for model binders, takes care or
-            // adding missing validation nodes.
-            var modelValidationNode = modelBindingResult.ValidationNode;
-            if (modelBindingResult.IsModelSet && modelValidationNode == null)
-            {
-                modelValidationNode = new ModelValidationNode(
-                    bindingKey,
-                    bindingContext.ModelMetadata,
-                    modelBindingResult.Model);
-            }
-
             return new ModelBindingResult(
                 modelBindingResult.Model,
                 bindingKey,
                 modelBindingResult.IsModelSet,
-                modelValidationNode);
+                modelBindingResult.ValidationNode);
         }
 
         private async Task<ModelBindingResult> TryBind(ModelBindingContext bindingContext)

src/Microsoft.AspNet.Mvc.Core/ModelBinding/FormCollectionModelBinder.cs

@@ -46,7 +46,13 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
                 model = new FormCollection(new Dictionary<string, string[]>());
             }
 
-            return new ModelBindingResult(model, bindingContext.ModelName, isModelSet: true);
+            var validationNode =
+                 new ModelValidationNode(bindingContext.ModelName, bindingContext.ModelMetadata, model);
+            return new ModelBindingResult(
+                model,
+                bindingContext.ModelName,
+                isModelSet: true,
+                validationNode: validationNode);
         }
     }
 }

src/Microsoft.AspNet.Mvc.Core/ModelBinding/FormFileModelBinder.cs

@@ -24,14 +24,26 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
             {
                 var postedFiles = await GetFormFilesAsync(bindingContext);
                 var value = postedFiles.FirstOrDefault();
-                return new ModelBindingResult(value, bindingContext.ModelName, isModelSet: value != null);
+                var validationNode =
+                    new ModelValidationNode(bindingContext.ModelName, bindingContext.ModelMetadata, value);
+                return new ModelBindingResult(
+                    value,
+                    bindingContext.ModelName,
+                    isModelSet: value != null,
+                    validationNode: validationNode);
             }
             else if (typeof(IEnumerable<IFormFile>).GetTypeInfo().IsAssignableFrom(
                     bindingContext.ModelType.GetTypeInfo()))
             {
                 var postedFiles = await GetFormFilesAsync(bindingContext);
                 var value = ModelBindingHelper.ConvertValuesToCollectionType(bindingContext.ModelType, postedFiles);
-                return new ModelBindingResult(value, bindingContext.ModelName, isModelSet: value != null);
+                var validationNode =
+                    new ModelValidationNode(bindingContext.ModelName, bindingContext.ModelMetadata, value);
+                return new ModelBindingResult(
+                    value,
+                    bindingContext.ModelName,
+                    isModelSet: value != null,
+                    validationNode: validationNode);
             }
 
             return null;

src/Microsoft.AspNet.Mvc.Core/ModelBinding/TypeConverterModelBinder.cs

@@ -30,12 +30,16 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
             {
                 newModel = valueProviderResult.ConvertTo(bindingContext.ModelType);
                 ModelBindingHelper.ReplaceEmptyStringWithNull(bindingContext.ModelMetadata, ref newModel);
+                var validationNode = new ModelValidationNode(
+                   bindingContext.ModelName,
+                   bindingContext.ModelMetadata,
+                   newModel);
 
-                // We do not need to set an explict ModelValidationNode since CompositeModelBinder does that automatically.
                 return new ModelBindingResult(
                     newModel,
                     bindingContext.ModelName,
-                    isModelSet: true);
+                    isModelSet: true,
+                    validationNode: validationNode);
             }
             catch (Exception ex)
             {

src/Microsoft.AspNet.Mvc.Core/ModelBinding/TypeMatchModelBinder.cs

@@ -19,12 +19,16 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
             bindingContext.ModelState.SetModelValue(bindingContext.ModelName, valueProviderResult);
             var model = valueProviderResult.RawValue;
             ModelBindingHelper.ReplaceEmptyStringWithNull(bindingContext.ModelMetadata, ref model);
+            var validationNode = new ModelValidationNode(
+                  bindingContext.ModelName,
+                  bindingContext.ModelMetadata,
+                  model);
 
-            // We do not need to set an explict ModelValidationNode since CompositeModelBinder does that automatically.
             return new ModelBindingResult(
                 model,
                 bindingContext.ModelName,
-                isModelSet: true);
+                isModelSet: true,
+                validationNode: validationNode);
         }
 
         internal static async Task<ValueProviderResult> GetCompatibleValueProviderResult(ModelBindingContext context)

src/Microsoft.AspNet.Mvc.Core/ModelBinding/Validation/DefaultObjectValidator.cs

@@ -247,8 +247,8 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Validation
                                 modelState.GetFieldValidationState(errorKey) == ModelValidationState.Unvalidated)
                             {
 
-                                // If we are not able to add a model error 
-                                // for instance when the max error count is reached, mark the model as skipped. 
+                                // If we are not able to add a model error
+                                // for instance when the max error count is reached, mark the model as skipped.
                                 modelState.MarkFieldSkipped(errorKey);
                             }
 

test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/KeyValuePairModelBinderTest.cs

@@ -309,7 +309,9 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Test
                 {
                     if (mbc.ModelType == typeof(int))
                     {
-                        return Task.FromResult(new ModelBindingResult(42, mbc.ModelName, true));
+                        var model = 42;
+                        var validationNode = new ModelValidationNode(mbc.ModelName, mbc.ModelMetadata, model);
+                        return Task.FromResult(new ModelBindingResult(model, mbc.ModelName, true, validationNode));
                     }
                     return Task.FromResult<ModelBindingResult>(null);
                 });
@@ -325,7 +327,9 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Test
                 {
                     if (mbc.ModelType == typeof(string))
                     {
-                        return Task.FromResult(new ModelBindingResult("some-value", mbc.ModelName, true));
+                        var model = "some-value";
+                        var validationNode = new ModelValidationNode(mbc.ModelName, mbc.ModelMetadata, model);
+                        return Task.FromResult(new ModelBindingResult(model, mbc.ModelName, true, validationNode));
                     }
                     return Task.FromResult<ModelBindingResult>(null);
                 });

test/Microsoft.AspNet.Mvc.Core.Test/ParameterBinding/ControllerActionArgumentBinderTests.cs

@@ -588,10 +588,14 @@ namespace Microsoft.AspNet.Mvc.Core.Test
         private static ActionBindingContext GetActionBindingContext(object model)
         {
             var binder = new Mock<IModelBinder>();
-            binder
-                .Setup(b => b.BindModelAsync(It.IsAny<ModelBindingContext>()))
-                .Returns(Task.FromResult(
-                    result: new ModelBindingResult(model: model, key: string.Empty, isModelSet: true)));
+            binder.Setup(b => b.BindModelAsync(It.IsAny<ModelBindingContext>()))
+                  .Returns<ModelBindingContext>(mbc =>
+                  {
+                      var validationNode = new ModelValidationNode(string.Empty, mbc.ModelMetadata, model);
+                      return Task.FromResult(
+                      result: new ModelBindingResult(model, string.Empty, isModelSet: true, validationNode: validationNode));
+                  });
+
             return new ActionBindingContext()
             {
                 ModelBinder = binder.Object,

test/Microsoft.AspNet.Mvc.FunctionalTests/ModelBindingTest.cs

@@ -1462,7 +1462,7 @@ namespace Microsoft.AspNet.Mvc.FunctionalTests
 
             };
             var url = "http://localhost/dealers/43/update-vehicle?dealer.name=TestCarDealer&dealer.location=NE";
-            
+
             // Act
             var response = await client.PostAsJsonAsync(url, postedContent);
 

test/WebSites/ModelBindingWebSite/Controllers/ModelBinderAttribute_ProductController.cs

@@ -74,7 +74,9 @@ namespace ModelBindingWebSite.Controllers
                     // by the type converter binder.
                     OrderStatus model;
                     var isModelSet = Enum.TryParse<OrderStatus>("Status" + request.Query.Get("status"), out model);
-                    return Task.FromResult(new ModelBindingResult(model, "status", isModelSet));
+                    var validationNode =
+                     new ModelValidationNode(bindingContext.ModelName, bindingContext.ModelMetadata, model);
+                    return Task.FromResult(new ModelBindingResult(model, "status", isModelSet, validationNode));
                 }
 
                 return Task.FromResult<ModelBindingResult>(null);
@@ -91,15 +93,17 @@ namespace ModelBindingWebSite.Controllers
 
                     model.BinderType = GetType();
 
-                    var key = 
-                        string.IsNullOrEmpty(bindingContext.ModelName) ? 
-                        "productId" : 
+                    var key =
+                        string.IsNullOrEmpty(bindingContext.ModelName) ?
+                        "productId" :
                         bindingContext.ModelName + "." + "productId";
 
                     var value = await bindingContext.ValueProvider.GetValueAsync(key);
                     model.ProductId = (int)value.ConvertTo(typeof(int));
 
-                    return new ModelBindingResult(model, key, true);
+                    var validationNode =
+                        new ModelValidationNode(bindingContext.ModelName, bindingContext.ModelMetadata, value);
+                    return new ModelBindingResult(model, key, true, validationNode);
                 }
 
                 return null;