Support user overrides of system-provided `ModelError` messages

- #2969
- add `ModelBindingMessages` for configuration and `IBindingMetadataProvider` overrides
  - use `interface` to avoid `new` oddities when adding a setter to an `abstract` property
- add `IModelBindingMessages` to `ModelMetadata` for use in rest of the product code
- plumb the various bits through the system
- add integration tests using a custom `IBindingMetadataProvider`s to override messages

nits:
- remove unused resources
- use `AttemptedValue` and not `model` in `SimpleTypeModelBinder`

src/Microsoft.AspNet.Mvc.Abstractions/ModelBinding/Metadata/IModelBindingMessageProvider.cs

@@ -0,0 +1,34 @@
+// 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.AspNet.Mvc.ModelBinding.Metadata
+{
+    /// <summary>
+    /// Provider for error messages the model binding system detects.
+    /// </summary>
+    public interface IModelBindingMessageProvider
+    {
+        /// <summary>
+        /// Error message the model binding system adds when a property with an associated
+        /// <c>BindRequiredAttribute</c> is not bound.
+        /// </summary>
+        /// <value>Default <see cref="string"/> is "A value for the '{0}' property was not provided.".</value>
+        Func<string, string> MissingBindRequiredValueAccessor { get; }
+
+        /// <summary>
+        /// Error message the model binding system adds when either the key or the value of a
+        /// <see cref="System.Collections.Generic.KeyValuePair{TKey, TValue}"/> is bound but not both.
+        /// </summary>
+        /// <value>Default <see cref="string"/> is "A value is required.".</value>
+        Func<string> MissingKeyOrValueAccessor { get; }
+
+        /// <summary>
+        /// Error message the model binding system adds when a <c>null</c> value is bound to a
+        /// non-<see cref="Nullable"/> property.
+        /// </summary>
+        /// <value>Default <see cref="string"/> is "The value '{0}' is invalid.".</value>
+        Func<string, string> ValueMustNotBeNullAccessor { get; }
+    }
+}

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

@@ -242,6 +242,11 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
         /// </remarks>
         public abstract bool IsRequired { get; }
 
+        /// <summary>
+        /// Gets the <see cref="IModelBindingMessageProvider"/> instance.
+        /// </summary>
+        public abstract IModelBindingMessageProvider ModelBindingMessageProvider { get; }
+
         /// <summary>
         /// Gets a value indicating where the current metadata should be ordered relative to other properties
         /// in its containing type.

src/Microsoft.AspNet.Mvc.Core/Internal/MvcCoreMvcOptionsSetup.cs

@@ -3,6 +3,7 @@
 
 using System;
 using Microsoft.AspNet.Http;
+using Microsoft.AspNet.Mvc.Core;
 using Microsoft.AspNet.Mvc.Formatters;
 using Microsoft.AspNet.Mvc.ModelBinding;
 using Microsoft.AspNet.Mvc.ModelBinding.Metadata;
@@ -23,6 +24,12 @@ namespace Microsoft.AspNet.Mvc.Internal
 
         public static void ConfigureMvc(MvcOptions options)
         {
+            // Set up default error messages
+            var messageProvider = options.ModelBindingMessageProvider;
+            messageProvider.MissingBindRequiredValueAccessor = Resources.FormatModelBinding_MissingBindRequiredMember;
+            messageProvider.MissingKeyOrValueAccessor = Resources.FormatKeyValuePair_BothKeyAndValueMustBePresent;
+            messageProvider.ValueMustNotBeNullAccessor = Resources.FormatModelBinding_NullValueNotValid;
+
             // Set up ModelBinding
             options.ModelBinders.Add(new BinderTypeBasedModelBinder());
             options.ModelBinders.Add(new ServicesModelBinder());
@@ -48,7 +55,7 @@ namespace Microsoft.AspNet.Mvc.Internal
             options.ValueProviderFactories.Add(new JQueryFormValueProviderFactory());
 
             // Set up metadata providers
-            options.ModelMetadataDetailsProviders.Add(new DefaultBindingMetadataProvider());
+            options.ModelMetadataDetailsProviders.Add(new DefaultBindingMetadataProvider(messageProvider));
             options.ModelMetadataDetailsProviders.Add(new DefaultValidationMetadataProvider());
 
             // Set up validators

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

@@ -1,5 +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 Microsoft.AspNet.Mvc.Core;
 using Microsoft.AspNet.Mvc.ModelBinding.Metadata;
 
 namespace Microsoft.AspNet.Mvc.ModelBinding
@@ -7,8 +9,33 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
     public class EmptyModelMetadataProvider : DefaultModelMetadataProvider
     {
         public EmptyModelMetadataProvider()
-            : base(new DefaultCompositeMetadataDetailsProvider(new IMetadataDetailsProvider[0]))
+            : base(new DefaultCompositeMetadataDetailsProvider(new IMetadataDetailsProvider[]
+            {
+                new MessageOnlyBindingProvider()
+            }))
         {
         }
+
+        private class MessageOnlyBindingProvider : IBindingMetadataProvider
+        {
+            private readonly ModelBindingMessageProvider _messageProvider = CreateMessageProvider();
+
+            public void GetBindingMetadata(BindingMetadataProviderContext context)
+            {
+                // Don't bother with ModelBindingMessageProvider copy constructor. No other provider can change the
+                // delegates.
+                context.BindingMetadata.ModelBindingMessageProvider = _messageProvider;
+            }
+
+            private static ModelBindingMessageProvider CreateMessageProvider()
+            {
+                return new ModelBindingMessageProvider
+                {
+                    MissingBindRequiredValueAccessor = Resources.FormatModelBinding_MissingBindRequiredMember,
+                    MissingKeyOrValueAccessor = Resources.FormatKeyValuePair_BothKeyAndValueMustBePresent,
+                    ValueMustNotBeNullAccessor = Resources.FormatModelBinding_NullValueNotValid,
+                };
+            }
+        }
     }
 }

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

@@ -3,7 +3,6 @@
 
 using System.Collections.Generic;
 using System.Threading.Tasks;
-using Microsoft.AspNet.Mvc.Core;
 
 namespace Microsoft.AspNet.Mvc.ModelBinding
 {
@@ -30,7 +29,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
             {
                 bindingContext.ModelState.TryAddModelError(
                     keyResult.Key,
-                    Resources.KeyValuePair_BothKeyAndValueMustBePresent);
+                    bindingContext.ModelMetadata.ModelBindingMessageProvider.MissingKeyOrValueAccessor());
 
                 // Were able to get some data for this model.
                 // Always tell the model binding system to skip other model binders.
@@ -40,7 +39,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
             {
                 bindingContext.ModelState.TryAddModelError(
                     valueResult.Key,
-                    Resources.KeyValuePair_BothKeyAndValueMustBePresent);
+                    bindingContext.ModelMetadata.ModelBindingMessageProvider.MissingKeyOrValueAccessor());
 
                 // Were able to get some data for this model.
                 // Always tell the model binding system to skip other model binders.

src/Microsoft.AspNet.Mvc.Core/ModelBinding/Metadata/BindingMetadata.cs

@@ -10,6 +10,8 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Metadata
     /// </summary>
     public class BindingMetadata
     {
+        private ModelBindingMessageProvider _messageProvider;
+
         /// <summary>
         /// Gets or sets the <see cref="ModelBinding.BindingSource"/>.
         /// See <see cref="ModelMetadata.BindingSource"/>.
@@ -50,6 +52,27 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Metadata
         /// </summary>
         public bool? IsReadOnly { get; set; }
 
+        /// <summary>
+        /// Gets the <see cref="Metadata.ModelBindingMessageProvider"/> instance. See
+        /// <see cref="ModelMetadata.ModelBindingMessageProvider"/>.
+        /// </summary>
+        public ModelBindingMessageProvider ModelBindingMessageProvider
+        {
+            get
+            {
+                return _messageProvider;
+            }
+            set
+            {
+                if (value == null)
+                {
+                    throw new ArgumentNullException(nameof(value));
+                }
+
+                _messageProvider = value;
+            }
+        }
+
         /// <summary>
         /// Gets or sets the <see cref="ModelBinding.IPropertyBindingPredicateProvider"/>.
         /// See <see cref="ModelMetadata.PropertyBindingPredicateProvider"/>.

src/Microsoft.AspNet.Mvc.Core/ModelBinding/Metadata/DefaultBindingMetadataProvider.cs

@@ -14,6 +14,18 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Metadata
     /// </summary>
     public class DefaultBindingMetadataProvider : IBindingMetadataProvider
     {
+        private readonly ModelBindingMessageProvider _messageProvider;
+
+        public DefaultBindingMetadataProvider(ModelBindingMessageProvider messageProvider)
+        {
+            if (messageProvider == null)
+            {
+                throw new ArgumentNullException(nameof(messageProvider));
+            }
+
+            _messageProvider = messageProvider;
+        }
+
         /// <inheritdoc />
         public void GetBindingMetadata([NotNull] BindingMetadataProviderContext context)
         {
@@ -47,6 +59,10 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Metadata
                 }
             }
 
+            // ModelBindingMessageProvider
+            // Provide a unique instance based on one passed to the constructor.
+            context.BindingMetadata.ModelBindingMessageProvider = new ModelBindingMessageProvider(_messageProvider);
+
             // PropertyBindingPredicateProvider
             var predicateProviders = context.Attributes.OfType<IPropertyBindingPredicateProvider>().ToArray();
             if (predicateProviders.Length > 0)
@@ -62,7 +78,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Metadata
                 var bindingBehavior = context.PropertyAttributes.OfType<BindingBehaviorAttribute>().FirstOrDefault();
                 if (bindingBehavior == null)
                 {
-                    bindingBehavior = 
+                    bindingBehavior =
                         context.Key.ContainerType.GetTypeInfo()
                         .GetCustomAttributes(typeof(BindingBehaviorAttribute), inherit: true)
                         .OfType<BindingBehaviorAttribute>()

src/Microsoft.AspNet.Mvc.Core/ModelBinding/Metadata/DefaultModelMetadata.cs

@@ -418,6 +418,15 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Metadata
             }
         }
 
+        /// <inheritdoc />
+        public override IModelBindingMessageProvider ModelBindingMessageProvider
+        {
+            get
+            {
+                return BindingMetadata.ModelBindingMessageProvider;
+            }
+        }
+
         /// <inheritdoc />
         public override string NullDisplayText
         {

src/Microsoft.AspNet.Mvc.Core/ModelBinding/Metadata/DefaultValidationMetadataProvider.cs

@@ -1,7 +1,6 @@
 // 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.Linq;
 using Microsoft.AspNet.Mvc.ModelBinding.Validation;
 using Microsoft.Framework.Internal;
 
@@ -19,8 +18,8 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Metadata
             {
                 if (attribute is IModelValidator || attribute is IClientModelValidator)
                 {
-                    // If another provider has already added this attribute, do not repeat it. 
+                    // If another provider has already added this attribute, do not repeat it.
-                    // This will prevent attributes like RemoteAttribute (which implement ValidationAttribute and 
+                    // This will prevent attributes like RemoteAttribute (which implement ValidationAttribute and
                     // IClientModelValidator) to be added to the ValidationMetadata twice.
                     // This is to ensure we do not end up with duplication validation rules on the client side.
                     if (!context.ValidationMetadata.ValidatorMetadata.Contains(attribute))

src/Microsoft.AspNet.Mvc.Core/ModelBinding/Metadata/ModelBindingMessageProvider.cs

@@ -0,0 +1,95 @@
+// 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.AspNet.Mvc.ModelBinding.Metadata
+{
+    /// <summary>
+    /// Read / write <see cref="IModelBindingMessageProvider"/> implementation.
+    /// </summary>
+    public class ModelBindingMessageProvider : IModelBindingMessageProvider
+    {
+        private Func<string, string> _missingBindRequiredValueAccessor;
+        private Func<string> _missingKeyOrValueAccessor;
+        private Func<string, string> _valueMustNotBeNullAccessor;
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="ModelBindingMessageProvider"/> class.
+        /// </summary>
+        public ModelBindingMessageProvider()
+        {
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="ModelBindingMessageProvider"/> class based on
+        /// <paramref name="originalProvider"/>.
+        /// </summary>
+        /// <param name="originalProvider">The <see cref="ModelBindingMessageProvider"/> to duplicate.</param>
+        public ModelBindingMessageProvider(ModelBindingMessageProvider originalProvider)
+        {
+            if (originalProvider == null)
+            {
+                throw new ArgumentNullException(nameof(originalProvider));
+            }
+
+            MissingBindRequiredValueAccessor = originalProvider.MissingBindRequiredValueAccessor;
+            MissingKeyOrValueAccessor = originalProvider.MissingKeyOrValueAccessor;
+            ValueMustNotBeNullAccessor = originalProvider.ValueMustNotBeNullAccessor;
+        }
+
+        /// <inheritdoc/>
+        public Func<string, string> MissingBindRequiredValueAccessor
+        {
+            get
+            {
+                return _missingBindRequiredValueAccessor;
+            }
+            set
+            {
+                if (value == null)
+                {
+                    throw new ArgumentNullException(nameof(value));
+                }
+
+                _missingBindRequiredValueAccessor = value;
+            }
+        }
+
+        /// <inheritdoc/>
+        public Func<string> MissingKeyOrValueAccessor
+        {
+            get
+            {
+                return _missingKeyOrValueAccessor;
+            }
+            set
+            {
+                if (value == null)
+                {
+                    throw new ArgumentNullException(nameof(value));
+                }
+
+                _missingKeyOrValueAccessor = value;
+            }
+        }
+
+        /// <inheritdoc/>
+        public Func<string, string> ValueMustNotBeNullAccessor
+        {
+            get
+            {
+                return _valueMustNotBeNullAccessor;
+            }
+            set
+            {
+                if (value == null)
+                {
+                    throw new ArgumentNullException(nameof(value));
+                }
+
+                _valueMustNotBeNullAccessor = value;
+            }
+        }
+    }
+}

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

@@ -6,8 +6,6 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Reflection;
 using System.Threading.Tasks;
-using Microsoft.AspNet.Mvc.Core;
-using Microsoft.AspNet.Mvc.ModelBinding.Validation;
 using Microsoft.Framework.Internal;
 
 namespace Microsoft.AspNet.Mvc.ModelBinding
@@ -414,7 +412,8 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
 
                 bindingContext.ModelState.TryAddModelError(
                     modelStateKey,
-                    Resources.FormatModelBinding_MissingBindRequiredMember(propertyName));
+                    bindingContext.ModelMetadata.ModelBindingMessageProvider.MissingBindRequiredValueAccessor(
+                        propertyName));
             }
 
             // For each property that BindPropertiesAsync() attempted to bind, call the setter, recording

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

@@ -3,7 +3,6 @@
 
 using System;
 using System.Threading.Tasks;
-using Microsoft.AspNet.Mvc.Core;
 
 namespace Microsoft.AspNet.Mvc.ModelBinding
 {
@@ -51,7 +50,8 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
                 {
                     bindingContext.ModelState.TryAddModelError(
                         bindingContext.ModelName,
-                        Resources.FormatCommon_ValueNotValidForProperty(model));
+                        bindingContext.ModelMetadata.ModelBindingMessageProvider.ValueMustNotBeNullAccessor(
+                            valueProviderResult.ToString()));
 
                     return ModelBindingResult.FailedAsync(bindingContext.ModelName);
                 }

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

@@ -28,6 +28,7 @@ namespace Microsoft.AspNet.Mvc
             InputFormatters = new FormatterCollection<IInputFormatter>();
             OutputFormatters = new FormatterCollection<IOutputFormatter>();
             ModelBinders = new List<IModelBinder>();
+            ModelBindingMessageProvider = new ModelBindingMessageProvider();
             ModelMetadataDetailsProviders = new List<IMetadataDetailsProvider>();
             ModelValidatorProviders = new List<IModelValidatorProvider>();
             ValidationExcludeFilters = new ExcludeTypeValidationFilterCollection();
@@ -87,7 +88,14 @@ namespace Microsoft.AspNet.Mvc
         public IList<IModelBinder> ModelBinders { get; }
 
         /// <summary>
-        /// Gets a list of <see cref="IMetadataDetailsProvider"/> instances that will be used to 
+        /// Gets the default <see cref="IModelBindingMessageProvider"/>. Changes here are copied to the
+        /// <see cref="ModelMetadata.ModelBindingMessageProvider"/> property of all <see cref="ModelMetadata"/>
+        /// instances unless overridden in a custom <see cref="IBindingMetadataProvider"/>.
+        /// </summary>
+        public ModelBindingMessageProvider ModelBindingMessageProvider { get; }
+
+        /// <summary>
+        /// Gets a list of <see cref="IMetadataDetailsProvider"/> instances that will be used to
         /// create <see cref="ModelMetadata"/> instances.
         /// </summary>
         /// <remarks>
@@ -112,7 +120,7 @@ namespace Microsoft.AspNet.Mvc
         public FormatterCollection<IOutputFormatter> OutputFormatters { get; }
 
         /// <summary>
-        /// Gets or sets the flag which causes content negotiation to ignore Accept header 
+        /// Gets or sets the flag which causes content negotiation to ignore Accept header
         /// when it contains the media type */*. <see langword="false"/> by default.
         /// </summary>
         public bool RespectBrowserAcceptHeader { get; set; }

src/Microsoft.AspNet.Mvc.Core/Properties/Resources.Designer.cs

@@ -74,22 +74,6 @@ namespace Microsoft.AspNet.Mvc.Core
             return string.Format(CultureInfo.CurrentCulture, GetString("ActionExecutor_UnexpectedTaskInstance"), p0, p1);
         }
 
-        /// <summary>
-        /// Replacing the action context is not supported.
-        /// </summary>
-        internal static string ActionContextAccessor_SetValueNotSupported
-        {
-            get { return GetString("ActionContextAccessor_SetValueNotSupported"); }
-        }
-
-        /// <summary>
-        /// Replacing the action context is not supported.
-        /// </summary>
-        internal static string FormatActionContextAccessor_SetValueNotSupported()
-        {
-            return GetString("ActionContextAccessor_SetValueNotSupported");
-        }
-
         /// <summary>
         /// An action invoker could not be created for action '{0}'.
         /// </summary>
@@ -171,51 +155,19 @@ namespace Microsoft.AspNet.Mvc.Core
         }
 
         /// <summary>
-        /// The supplied route values are ambiguous and can select multiple sets of actions.
+        /// The value '{0}' is invalid.
         /// </summary>
-        internal static string ActionSelector_GetCandidateActionsIsAmbiguous
+        internal static string ModelBinding_NullValueNotValid
         {
-            get { return GetString("ActionSelector_GetCandidateActionsIsAmbiguous"); }
+            get { return GetString("ModelBinding_NullValueNotValid"); }
-        }
-
-        /// <summary>
-        /// The supplied route values are ambiguous and can select multiple sets of actions.
-        /// </summary>
-        internal static string FormatActionSelector_GetCandidateActionsIsAmbiguous()
-        {
-            return GetString("ActionSelector_GetCandidateActionsIsAmbiguous");
-        }
-
-        /// <summary>
-        /// Property '{0}' is of type '{1}', but this method requires a value of type '{2}'.
-        /// </summary>
-        internal static string ArgumentPropertyUnexpectedType
-        {
-            get { return GetString("ArgumentPropertyUnexpectedType"); }
-        }
-
-        /// <summary>
-        /// Property '{0}' is of type '{1}', but this method requires a value of type '{2}'.
-        /// </summary>
-        internal static string FormatArgumentPropertyUnexpectedType(object p0, object p1, object p2)
-        {
-            return string.Format(CultureInfo.CurrentCulture, GetString("ArgumentPropertyUnexpectedType"), p0, p1, p2);
         }
 
         /// <summary>
         /// The value '{0}' is invalid.
         /// </summary>
-        internal static string Common_ValueNotValidForProperty
+        internal static string FormatModelBinding_NullValueNotValid(object p0)
         {
-            get { return GetString("Common_ValueNotValidForProperty"); }
+            return string.Format(CultureInfo.CurrentCulture, GetString("ModelBinding_NullValueNotValid"), p0);
-        }
-
-        /// <summary>
-        /// The value '{0}' is invalid.
-        /// </summary>
-        internal static string FormatCommon_ValueNotValidForProperty(object p0)
-        {
-            return string.Format(CultureInfo.CurrentCulture, GetString("Common_ValueNotValidForProperty"), p0);
         }
 
         /// <summary>
@@ -282,38 +234,6 @@ namespace Microsoft.AspNet.Mvc.Core
             return string.Format(CultureInfo.CurrentCulture, GetString("AsyncResultFilter_InvalidShortCircuit"), p0, p1, p2, p3);
         }
 
-        /// <summary>
-        /// Unable to locate an implementation of IAuthorizationService.
-        /// </summary>
-        internal static string AuthorizeAttribute_AuthorizationServiceMustBeDefined
-        {
-            get { return GetString("AuthorizeAttribute_AuthorizationServiceMustBeDefined"); }
-        }
-
-        /// <summary>
-        /// Unable to locate an implementation of IAuthorizationService.
-        /// </summary>
-        internal static string FormatAuthorizeAttribute_AuthorizationServiceMustBeDefined()
-        {
-            return GetString("AuthorizeAttribute_AuthorizationServiceMustBeDefined");
-        }
-
-        /// <summary>
-        /// OnAuthorization is not implemented by this filter, use OnAuthorizationAsync instead.
-        /// </summary>
-        internal static string AuthorizeAttribute_OnAuthorizationNotImplemented
-        {
-            get { return GetString("AuthorizeAttribute_OnAuthorizationNotImplemented"); }
-        }
-
-        /// <summary>
-        /// OnAuthorization is not implemented by this filter, use OnAuthorizationAsync instead.
-        /// </summary>
-        internal static string FormatAuthorizeAttribute_OnAuthorizationNotImplemented()
-        {
-            return GetString("AuthorizeAttribute_OnAuthorizationNotImplemented");
-        }
-
         /// <summary>
         /// The type provided to '{0}' must implement '{1}'.
         /// </summary>
@@ -826,22 +746,6 @@ namespace Microsoft.AspNet.Mvc.Core
             return string.Format(CultureInfo.CurrentCulture, GetString("Format_NotValid"), p0);
         }
 
-        /// <summary>
-        /// The property '{0}' on controller '{1}' cannot be activated.
-        /// </summary>
-        internal static string ControllerFactory_PropertyCannotBeActivated
-        {
-            get { return GetString("ControllerFactory_PropertyCannotBeActivated"); }
-        }
-
-        /// <summary>
-        /// The property '{0}' on controller '{1}' cannot be activated.
-        /// </summary>
-        internal static string FormatControllerFactory_PropertyCannotBeActivated(object p0, object p1)
-        {
-            return string.Format(CultureInfo.CurrentCulture, GetString("ControllerFactory_PropertyCannotBeActivated"), p0, p1);
-        }
-
         /// <summary>
         /// The '{0}' cache profile is not defined.
         /// </summary>
@@ -938,22 +842,6 @@ namespace Microsoft.AspNet.Mvc.Core
             return string.Format(CultureInfo.CurrentCulture, GetString("BindingSource_CannotBeGreedy"), p0, p1);
         }
 
-        /// <summary>
-        /// The provided binding source '{0}' is not a request-based binding source. '{1}' requires that the source must represent data from an HTTP request.
-        /// </summary>
-        internal static string BindingSource_MustBeFromRequest
-        {
-            get { return GetString("BindingSource_MustBeFromRequest"); }
-        }
-
-        /// <summary>
-        /// The provided binding source '{0}' is not a request-based binding source. '{1}' requires that the source must represent data from an HTTP request.
-        /// </summary>
-        internal static string FormatBindingSource_MustBeFromRequest(object p0, object p1)
-        {
-            return string.Format(CultureInfo.CurrentCulture, GetString("BindingSource_MustBeFromRequest"), p0, p1);
-        }
-
         /// <summary>
         /// The property {0}.{1} could not be found.
         /// </summary>
@@ -1082,38 +970,6 @@ namespace Microsoft.AspNet.Mvc.Core
             return string.Format(CultureInfo.CurrentCulture, GetString("ModelBinding_MissingBindRequiredMember"), p0);
         }
 
-        /// <summary>
-        /// A value is required.
-        /// </summary>
-        internal static string ModelBinding_ValueRequired
-        {
-            get { return GetString("ModelBinding_ValueRequired"); }
-        }
-
-        /// <summary>
-        /// A value is required.
-        /// </summary>
-        internal static string FormatModelBinding_ValueRequired()
-        {
-            return GetString("ModelBinding_ValueRequired");
-        }
-
-        /// <summary>
-        /// More than one parameter and/or property is bound to the HTTP request's content.
-        /// </summary>
-        internal static string MultipleBodyParametersOrPropertiesAreNotAllowed
-        {
-            get { return GetString("MultipleBodyParametersOrPropertiesAreNotAllowed"); }
-        }
-
-        /// <summary>
-        /// More than one parameter and/or property is bound to the HTTP request's content.
-        /// </summary>
-        internal static string FormatMultipleBodyParametersOrPropertiesAreNotAllowed()
-        {
-            return GetString("MultipleBodyParametersOrPropertiesAreNotAllowed");
-        }
-
         /// <summary>
         /// The type '{0}' does not implement the interface '{1}'.
         /// </summary>
@@ -1130,38 +986,6 @@ namespace Microsoft.AspNet.Mvc.Core
             return string.Format(CultureInfo.CurrentCulture, GetString("PropertyBindingPredicateProvider_WrongType"), p0, p1);
         }
 
-        /// <summary>
-        /// The model object inside the metadata claimed to be compatible with '{0}', but was actually '{1}'.
-        /// </summary>
-        internal static string ValidatableObjectAdapter_IncompatibleType
-        {
-            get { return GetString("ValidatableObjectAdapter_IncompatibleType"); }
-        }
-
-        /// <summary>
-        /// The model object inside the metadata claimed to be compatible with '{0}', but was actually '{1}'.
-        /// </summary>
-        internal static string FormatValidatableObjectAdapter_IncompatibleType(object p0, object p1)
-        {
-            return string.Format(CultureInfo.CurrentCulture, GetString("ValidatableObjectAdapter_IncompatibleType"), p0, p1);
-        }
-
-        /// <summary>
-        /// Cannot convert value '{0}' to enum type '{1}'.
-        /// </summary>
-        internal static string ValueProviderResult_CannotConvertEnum
-        {
-            get { return GetString("ValueProviderResult_CannotConvertEnum"); }
-        }
-
-        /// <summary>
-        /// Cannot convert value '{0}' to enum type '{1}'.
-        /// </summary>
-        internal static string FormatValueProviderResult_CannotConvertEnum(object p0, object p1)
-        {
-            return string.Format(CultureInfo.CurrentCulture, GetString("ValueProviderResult_CannotConvertEnum"), p0, p1);
-        }
-
         /// <summary>
         /// The parameter conversion from type '{0}' to type '{1}' failed because no type converter can convert between these types.
         /// </summary>

src/Microsoft.AspNet.Mvc.Core/Resources.resx

@@ -129,9 +129,6 @@
   <data name="ActionExecutor_UnexpectedTaskInstance" xml:space="preserve">
     <value>The method '{0}' on type '{1}' returned a Task instance even though it is not an asynchronous method.</value>
   </data>
-  <data name="ActionContextAccessor_SetValueNotSupported" xml:space="preserve">
-    <value>Replacing the action context is not supported.</value>
-  </data>
   <data name="ActionInvokerFactory_CouldNotCreateInvoker" xml:space="preserve">
     <value>An action invoker could not be created for action '{0}'.</value>
   </data>
@@ -147,13 +144,7 @@
   <data name="TypeMethodMustReturnNotNullValue" xml:space="preserve">
     <value>The '{0}' method of type '{1}' cannot return a null value.</value>
   </data>
-  <data name="ActionSelector_GetCandidateActionsIsAmbiguous" xml:space="preserve">
+  <data name="ModelBinding_NullValueNotValid" xml:space="preserve">
-    <value>The supplied route values are ambiguous and can select multiple sets of actions.</value>
-  </data>
-  <data name="ArgumentPropertyUnexpectedType" xml:space="preserve">
-    <value>Property '{0}' is of type '{1}', but this method requires a value of type '{2}'.</value>
-  </data>
-  <data name="Common_ValueNotValidForProperty" xml:space="preserve">
     <value>The value '{0}' is invalid.</value>
   </data>
   <data name="Invalid_IncludePropertyExpression" xml:space="preserve">
@@ -168,12 +159,6 @@
   <data name="AsyncResultFilter_InvalidShortCircuit" xml:space="preserve">
     <value>If an {0} cancels execution by setting the {1} property of {2} to 'true', then it cannot call the next filter by invoking {3}.</value>
   </data>
-  <data name="AuthorizeAttribute_AuthorizationServiceMustBeDefined" xml:space="preserve">
-    <value>Unable to locate an implementation of IAuthorizationService.</value>
-  </data>
-  <data name="AuthorizeAttribute_OnAuthorizationNotImplemented" xml:space="preserve">
-    <value>OnAuthorization is not implemented by this filter, use OnAuthorizationAsync instead.</value>
-  </data>
   <data name="FilterFactoryAttribute_TypeMustImplementIFilter" xml:space="preserve">
     <value>The type provided to '{0}' must implement '{1}'.</value>
   </data>
@@ -279,9 +264,6 @@
   <data name="Format_NotValid" xml:space="preserve">
     <value>The format provided is invalid '{0}'. A format must be a non-empty file-extension, optionally prefixed with a '.' character.</value>
   </data>
-  <data name="ControllerFactory_PropertyCannotBeActivated" xml:space="preserve">
-    <value>The property '{0}' on controller '{1}' cannot be activated.</value>
-  </data>
   <data name="CacheProfileNotFound" xml:space="preserve">
     <value>The '{0}' cache profile is not defined.</value>
   </data>
@@ -300,9 +282,6 @@
   <data name="BindingSource_CannotBeGreedy" xml:space="preserve">
     <value>The provided binding source '{0}' is a greedy data source. '{1}' does not support greedy data sources.</value>
   </data>
-  <data name="BindingSource_MustBeFromRequest" xml:space="preserve">
-    <value>The provided binding source '{0}' is not a request-based binding source. '{1}' requires that the source must represent data from an HTTP request.</value>
-  </data>
   <data name="Common_PropertyNotFound" xml:space="preserve">
     <value>The property {0}.{1} could not be found.</value>
   </data>
@@ -327,21 +306,9 @@
   <data name="ModelBinding_MissingBindRequiredMember" xml:space="preserve">
     <value>A value for the '{0}' property was not provided.</value>
   </data>
-  <data name="ModelBinding_ValueRequired" xml:space="preserve">
-    <value>A value is required.</value>
-  </data>
-  <data name="MultipleBodyParametersOrPropertiesAreNotAllowed" xml:space="preserve">
-    <value>More than one parameter and/or property is bound to the HTTP request's content.</value>
-  </data>
   <data name="PropertyBindingPredicateProvider_WrongType" xml:space="preserve">
     <value>The type '{0}' does not implement the interface '{1}'.</value>
   </data>
-  <data name="ValidatableObjectAdapter_IncompatibleType" xml:space="preserve">
-    <value>The model object inside the metadata claimed to be compatible with '{0}', but was actually '{1}'.</value>
-  </data>
-  <data name="ValueProviderResult_CannotConvertEnum" xml:space="preserve">
-    <value>Cannot convert value '{0}' to enum type '{1}'.</value>
-  </data>
   <data name="ValueProviderResult_NoConverterExists" xml:space="preserve">
     <value>The parameter conversion from type '{0}' to type '{1}' failed because no type converter can convert between these types.</value>
   </data>

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

@@ -457,6 +457,14 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
                 }
             }
 
+            public override IModelBindingMessageProvider ModelBindingMessageProvider
+            {
+                get
+                {
+                    throw new NotImplementedException();
+                }
+            }
+
             public override string NullDisplayText
             {
                 get

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

@@ -4,7 +4,6 @@
 #if DNX451
 using System;
 using System.Collections.Generic;
-using System.Linq;
 using System.Threading.Tasks;
 using Microsoft.AspNet.Http.Internal;
 using Microsoft.AspNet.Mvc.ModelBinding.Validation;
@@ -54,7 +53,10 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Test
             Assert.Null(result.Model);
             Assert.False(bindingContext.ModelState.IsValid);
             Assert.Equal("someName", bindingContext.ModelName);
-            Assert.Equal(bindingContext.ModelState["someName.Value"].Errors.First().ErrorMessage, "A value is required.");
+            var state = bindingContext.ModelState["someName.Value"];
+            Assert.NotNull(state);
+            var error = Assert.Single(state.Errors);
+            Assert.Equal("A value is required.", error.ErrorMessage);
         }
 
         [Fact]
@@ -117,7 +119,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Test
             {
                 innerResult = ModelBindingResult.Failed("somename.key");
             }
-            
+
             var innerBinder = new Mock<IModelBinder>();
             innerBinder
                 .Setup(o => o.BindModelAsync(It.IsAny<ModelBindingContext>()))
@@ -161,7 +163,8 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Test
             // Assert
             Assert.NotEqual(ModelBindingResult.NoResult, result);
 
-            Assert.Equal(default(KeyValuePair<string, string>), Assert.IsType<KeyValuePair<string, string>>(result.Model));
+            var model = Assert.IsType<KeyValuePair<string, string>>(result.Model);
+            Assert.Equal(default(KeyValuePair<string, string>), model);
             Assert.Equal("modelName", result.Key);
             Assert.True(result.IsModelSet);
         }

test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/Metadata/DefaultBindingMetadataProviderTest.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 Microsoft.AspNet.Mvc.Core;
 using Xunit;
 
 namespace Microsoft.AspNet.Mvc.ModelBinding.Metadata
@@ -21,7 +22,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Metadata
                 ModelMetadataIdentity.ForType(typeof(string)),
                 new ModelAttributes(attributes));
 
-            var provider = new DefaultBindingMetadataProvider();
+            var provider = new DefaultBindingMetadataProvider(CreateMessageProvider());
 
             // Act
             provider.GetBindingMetadata(context);
@@ -45,7 +46,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Metadata
                 ModelMetadataIdentity.ForType(typeof(string)),
                 new ModelAttributes(attributes));
 
-            var provider = new DefaultBindingMetadataProvider();
+            var provider = new DefaultBindingMetadataProvider(CreateMessageProvider());
 
             // Act
             provider.GetBindingMetadata(context);
@@ -68,7 +69,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Metadata
                 ModelMetadataIdentity.ForType(typeof(string)),
                 new ModelAttributes(attributes));
 
-            var provider = new DefaultBindingMetadataProvider();
+            var provider = new DefaultBindingMetadataProvider(CreateMessageProvider());
 
             // Act
             provider.GetBindingMetadata(context);
@@ -92,7 +93,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Metadata
                 ModelMetadataIdentity.ForType(typeof(string)),
                 new ModelAttributes(attributes));
 
-            var provider = new DefaultBindingMetadataProvider();
+            var provider = new DefaultBindingMetadataProvider(CreateMessageProvider());
 
             // Act
             provider.GetBindingMetadata(context);
@@ -115,7 +116,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Metadata
                 ModelMetadataIdentity.ForType(typeof(string)),
                 new ModelAttributes(attributes));
 
-            var provider = new DefaultBindingMetadataProvider();
+            var provider = new DefaultBindingMetadataProvider(CreateMessageProvider());
 
             // Act
             provider.GetBindingMetadata(context);
@@ -139,7 +140,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Metadata
                 ModelMetadataIdentity.ForType(typeof(string)),
                 new ModelAttributes(attributes));
 
-            var provider = new DefaultBindingMetadataProvider();
+            var provider = new DefaultBindingMetadataProvider(CreateMessageProvider());
 
             // Act
             provider.GetBindingMetadata(context);
@@ -161,7 +162,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Metadata
                 ModelMetadataIdentity.ForProperty(typeof(int), "Length", typeof(string)),
                 new ModelAttributes(propertyAttributes, typeAttributes: new object[0]));
 
-            var provider = new DefaultBindingMetadataProvider();
+            var provider = new DefaultBindingMetadataProvider(CreateMessageProvider());
 
             // Act
             provider.GetBindingMetadata(context);
@@ -184,7 +185,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Metadata
                 ModelMetadataIdentity.ForProperty(typeof(int), "Length", typeof(string)),
                 new ModelAttributes(propertyAttributes, typeAttributes: new object[0]));
 
-            var provider = new DefaultBindingMetadataProvider();
+            var provider = new DefaultBindingMetadataProvider(CreateMessageProvider());
 
             // Act
             provider.GetBindingMetadata(context);
@@ -207,7 +208,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Metadata
                 ModelMetadataIdentity.ForProperty(typeof(int), "Length", typeof(string)),
                 new ModelAttributes(propertyAttributes, typeAttributes: new object[0]));
 
-            var provider = new DefaultBindingMetadataProvider();
+            var provider = new DefaultBindingMetadataProvider(CreateMessageProvider());
 
             // Act
             provider.GetBindingMetadata(context);
@@ -230,7 +231,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Metadata
                 ModelMetadataIdentity.ForProperty(typeof(int), "Length", typeof(string)),
                 new ModelAttributes(propertyAttributes, typeAttributes: new object[0]));
 
-            var provider = new DefaultBindingMetadataProvider();
+            var provider = new DefaultBindingMetadataProvider(CreateMessageProvider());
 
             // Act
             provider.GetBindingMetadata(context);
@@ -253,7 +254,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Metadata
                 ModelMetadataIdentity.ForProperty(typeof(int), "Length", typeof(string)),
                 new ModelAttributes(propertyAttributes, typeAttributes: new object[0]));
 
-            var provider = new DefaultBindingMetadataProvider();
+            var provider = new DefaultBindingMetadataProvider(CreateMessageProvider());
 
             // Act
             provider.GetBindingMetadata(context);
@@ -279,7 +280,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Metadata
                 ModelMetadataIdentity.ForProperty(typeof(int), "Length", typeof(string)),
                 new ModelAttributes(propertyAttributes, typeAttributes: new object[0]));
 
-            var provider = new DefaultBindingMetadataProvider();
+            var provider = new DefaultBindingMetadataProvider(CreateMessageProvider());
 
             // Act
             provider.GetBindingMetadata(context);
@@ -297,7 +298,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Metadata
                 ModelMetadataIdentity.ForProperty(typeof(string), "Property", typeof(BindRequiredOnClass)),
                 new ModelAttributes(propertyAttributes: new object[0], typeAttributes: new object[0]));
 
-            var provider = new DefaultBindingMetadataProvider();
+            var provider = new DefaultBindingMetadataProvider(CreateMessageProvider());
 
             // Act
             provider.GetBindingMetadata(context);
@@ -315,7 +316,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Metadata
                 ModelMetadataIdentity.ForProperty(typeof(string), "Property", typeof(BindNeverOnClass)),
                 new ModelAttributes(propertyAttributes: new object[0], typeAttributes: new object[0]));
 
-            var provider = new DefaultBindingMetadataProvider();
+            var provider = new DefaultBindingMetadataProvider(CreateMessageProvider());
 
             // Act
             provider.GetBindingMetadata(context);
@@ -333,7 +334,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Metadata
                 ModelMetadataIdentity.ForProperty(typeof(string), "Property", typeof(InheritedBindNeverOnClass)),
                 new ModelAttributes(propertyAttributes: new object[0], typeAttributes: new object[0]));
 
-            var provider = new DefaultBindingMetadataProvider();
+            var provider = new DefaultBindingMetadataProvider(CreateMessageProvider());
 
             // Act
             provider.GetBindingMetadata(context);
@@ -356,7 +357,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Metadata
                 ModelMetadataIdentity.ForProperty(typeof(string), "Property", typeof(BindNeverOnClass)),
                 new ModelAttributes(propertyAttributes, typeAttributes: new object[0]));
 
-            var provider = new DefaultBindingMetadataProvider();
+            var provider = new DefaultBindingMetadataProvider(CreateMessageProvider());
 
             // Act
             provider.GetBindingMetadata(context);
@@ -379,7 +380,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Metadata
                 ModelMetadataIdentity.ForProperty(typeof(string), "Property", typeof(BindNeverOnClass)),
                 new ModelAttributes(propertyAttributes, typeAttributes: new object[0]));
 
-            var provider = new DefaultBindingMetadataProvider();
+            var provider = new DefaultBindingMetadataProvider(CreateMessageProvider());
 
             // Act
             provider.GetBindingMetadata(context);
@@ -402,7 +403,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Metadata
                 ModelMetadataIdentity.ForProperty(typeof(string), "Property", typeof(InheritedBindNeverOnClass)),
                 new ModelAttributes(propertyAttributes, typeAttributes: new object[0]));
 
-            var provider = new DefaultBindingMetadataProvider();
+            var provider = new DefaultBindingMetadataProvider(CreateMessageProvider());
 
             // Act
             provider.GetBindingMetadata(context);
@@ -425,7 +426,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Metadata
                 ModelMetadataIdentity.ForProperty(typeof(string), "Property", typeof(BindRequiredOnClass)),
                 new ModelAttributes(propertyAttributes, typeAttributes: new object[0]));
 
-            var provider = new DefaultBindingMetadataProvider();
+            var provider = new DefaultBindingMetadataProvider(CreateMessageProvider());
 
             // Act
             provider.GetBindingMetadata(context);
@@ -444,7 +445,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Metadata
                 ModelMetadataIdentity.ForProperty(typeof(string), "Property", typeof(BindRequiredOverridesInheritedBindNever)),
                 new ModelAttributes(propertyAttributes: new object[0], typeAttributes: new object[0]));
 
-            var provider = new DefaultBindingMetadataProvider();
+            var provider = new DefaultBindingMetadataProvider(CreateMessageProvider());
 
             // Act
             provider.GetBindingMetadata(context);
@@ -473,7 +474,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Metadata
             context.BindingMetadata.IsBindingAllowed = initialValue;
             context.BindingMetadata.IsBindingRequired = initialValue;
 
-            var provider = new DefaultBindingMetadataProvider();
+            var provider = new DefaultBindingMetadataProvider(CreateMessageProvider());
 
             // Act
             provider.GetBindingMetadata(context);
@@ -504,7 +505,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Metadata
             context.BindingMetadata.IsBindingAllowed = initialValue;
             context.BindingMetadata.IsBindingRequired = initialValue;
 
-            var provider = new DefaultBindingMetadataProvider();
+            var provider = new DefaultBindingMetadataProvider(CreateMessageProvider());
 
             // Act
             provider.GetBindingMetadata(context);
@@ -514,6 +515,16 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Metadata
             Assert.Equal(initialValue, context.BindingMetadata.IsBindingRequired);
         }
 
+        private static ModelBindingMessageProvider CreateMessageProvider()
+        {
+            return new ModelBindingMessageProvider
+            {
+                MissingBindRequiredValueAccessor = Resources.FormatModelBinding_MissingBindRequiredMember,
+                MissingKeyOrValueAccessor = Resources.FormatKeyValuePair_BothKeyAndValueMustBePresent,
+                ValueMustNotBeNullAccessor = Resources.FormatModelBinding_NullValueNotValid,
+            };
+        }
+
         [BindNever]
         private class BindNeverOnClass
         {

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

@@ -787,7 +787,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
                 property => ModelBindingResult.Failed(property.PropertyName));
             var nameProperty = containerMetadata.Properties[nameof(model.Name)];
             results[nameProperty] = ModelBindingResult.Success(string.Empty, "John Doe");
-            
+
             var testableBinder = new TestableMutableObjectModelBinder();
 
             // Act
@@ -1219,7 +1219,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
             results[lastNameProperty] = ModelBindingResult.Success(
                 nameof(model.LastName),
                 "Doe");
-            
+
             var testableBinder = new TestableMutableObjectModelBinder();
 
             // Act

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

@@ -105,7 +105,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Test
             Assert.Null(result.Model);
 
             var error = Assert.Single(bindingContext.ModelState["theModelName"].Errors);
-            Assert.Equal(error.ErrorMessage, "The value '' is invalid.", StringComparer.Ordinal);
+            Assert.Equal("The value '' is invalid.", error.ErrorMessage, StringComparer.Ordinal);
             Assert.Null(error.Exception);
         }
 

test/Microsoft.AspNet.Mvc.DataAnnotations.Test/ModelMetadataProviderTest.cs

@@ -1026,13 +1026,23 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Metadata
             public AttributeInjectModelMetadataProvider(object[] attributes)
                 : base(new DefaultCompositeMetadataDetailsProvider(new IMetadataDetailsProvider[]
                     {
-                        new DefaultBindingMetadataProvider(),
+                        new DefaultBindingMetadataProvider(CreateMessageProvider()),
                         new DataAnnotationsMetadataProvider(),
                     }))
             {
                 _attributes = attributes;
             }
 
+            private static ModelBindingMessageProvider CreateMessageProvider()
+            {
+                return new ModelBindingMessageProvider
+                {
+                    MissingBindRequiredValueAccessor = name => $"A value for the '{ name }' property was not provided.",
+                    MissingKeyOrValueAccessor = () => $"A value is required.",
+                    ValueMustNotBeNullAccessor = value => $"The value '{ value }' is invalid.",
+                };
+            }
+
             protected override DefaultMetadataDetails CreateTypeDetails(ModelMetadataIdentity key)
             {
                 var entry = base.CreateTypeDetails(key);

test/Microsoft.AspNet.Mvc.IntegrationTests/KeyValuePairModelBinderIntegrationTest.cs

@@ -5,6 +5,7 @@ using System.Collections.Generic;
 using System.Threading.Tasks;
 using Microsoft.AspNet.Http;
 using Microsoft.AspNet.Mvc.Abstractions;
+using Microsoft.AspNet.Mvc.Controllers;
 using Microsoft.AspNet.Mvc.ModelBinding;
 using Xunit;
 
@@ -46,13 +47,183 @@ namespace Microsoft.AspNet.Mvc.IntegrationTests
 
             var entry = Assert.Single(modelState, kvp => kvp.Key == "parameter.Key").Value;
             Assert.Equal("key0", entry.AttemptedValue);
-           Assert.Equal("key0", entry.RawValue);
+            Assert.Equal("key0", entry.RawValue);
 
             entry = Assert.Single(modelState, kvp => kvp.Key == "parameter.Value").Value;
             Assert.Equal("10", entry.AttemptedValue);
             Assert.Equal("10", entry.RawValue);
         }
 
+        [Fact]
+        public async Task KeyValuePairModelBinder_SimpleTypes_WithNoKey_AddsError()
+        {
+            // Arrange
+            var argumentBinder = ModelBindingTestHelper.GetArgumentBinder();
+            var parameter = new ParameterDescriptor
+            {
+                Name = "parameter",
+                ParameterType = typeof(KeyValuePair<string, int>)
+            };
+            var operationContext = ModelBindingTestHelper.GetOperationBindingContext(request =>
+            {
+                request.QueryString = new QueryString("?parameter.Value=10");
+            });
+            var modelState = new ModelStateDictionary();
+
+            // Act
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, modelState, operationContext);
+
+            // Assert
+            Assert.False(modelBindingResult.IsModelSet);
+            Assert.Equal(2, modelState.Count);
+
+            Assert.False(modelState.IsValid);
+            Assert.Equal(1, modelState.ErrorCount);
+
+            var entry = Assert.Single(modelState, kvp => kvp.Key == "parameter.Key").Value;
+            var error = Assert.Single(entry.Errors);
+            Assert.Null(error.Exception);
+            Assert.Equal("A value is required.", error.ErrorMessage);
+
+            entry = Assert.Single(modelState, kvp => kvp.Key == "parameter.Value").Value;
+            Assert.Empty(entry.Errors);
+            Assert.Equal("10", entry.AttemptedValue);
+            Assert.Equal("10", entry.RawValue);
+        }
+
+        [Fact]
+        public async Task KeyValuePairModelBinder_SimpleTypes_WithNoKey_AndCustomizedMessage_AddsGivenMessage()
+        {
+            // Arrange
+            var metadataProvider = new TestModelMetadataProvider();
+            metadataProvider
+                .ForType(typeof(KeyValuePair<string, int>))
+                .BindingDetails((System.Action<ModelBinding.Metadata.BindingMetadata>)(binding =>
+                {
+                    // A real details provider could customize message based on BindingMetadataProviderContext.
+                    binding.ModelBindingMessageProvider.MissingKeyOrValueAccessor = () => $"Hurts when nothing is provided.";
+                }));
+
+            var argumentBinder = new DefaultControllerActionArgumentBinder(
+                metadataProvider,
+                ModelBindingTestHelper.GetObjectValidator());
+            var parameter = new ParameterDescriptor
+            {
+                Name = "parameter",
+                ParameterType = typeof(KeyValuePair<string, int>)
+            };
+            var operationContext = ModelBindingTestHelper.GetOperationBindingContext(request =>
+            {
+                request.QueryString = new QueryString("?parameter.Value=10");
+            });
+            var modelState = new ModelStateDictionary();
+
+            // Act
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, modelState, operationContext);
+
+            // Assert
+            Assert.False(modelBindingResult.IsModelSet);
+            Assert.Equal(2, modelState.Count);
+
+            Assert.False(modelState.IsValid);
+            Assert.Equal(1, modelState.ErrorCount);
+
+            var entry = Assert.Single(modelState, kvp => kvp.Key == "parameter.Key").Value;
+            var error = Assert.Single(entry.Errors);
+            Assert.Null(error.Exception);
+            Assert.Equal("Hurts when nothing is provided.", error.ErrorMessage);
+
+            entry = Assert.Single(modelState, kvp => kvp.Key == "parameter.Value").Value;
+            Assert.Empty(entry.Errors);
+            Assert.Equal("10", entry.AttemptedValue);
+            Assert.Equal("10", entry.RawValue);
+        }
+
+        [Fact]
+        public async Task KeyValuePairModelBinder_SimpleTypes_WithNoValue_AddsError()
+        {
+            // Arrange
+            var argumentBinder = ModelBindingTestHelper.GetArgumentBinder();
+            var parameter = new ParameterDescriptor
+            {
+                Name = "parameter",
+                ParameterType = typeof(KeyValuePair<string, int>)
+            };
+            var operationContext = ModelBindingTestHelper.GetOperationBindingContext(request =>
+            {
+                request.QueryString = new QueryString("?parameter.Key=10");
+            });
+            var modelState = new ModelStateDictionary();
+
+            // Act
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, modelState, operationContext);
+
+            // Assert
+            Assert.False(modelBindingResult.IsModelSet);
+            Assert.Equal(2, modelState.Count);
+
+            Assert.False(modelState.IsValid);
+            Assert.Equal(1, modelState.ErrorCount);
+
+            var entry = Assert.Single(modelState, kvp => kvp.Key == "parameter.Key").Value;
+            Assert.Empty(entry.Errors);
+            Assert.Equal("10", entry.AttemptedValue);
+            Assert.Equal("10", entry.RawValue);
+
+            entry = Assert.Single(modelState, kvp => kvp.Key == "parameter.Value").Value;
+            var error = Assert.Single(entry.Errors);
+            Assert.Null(error.Exception);
+            Assert.Equal("A value is required.", error.ErrorMessage);
+        }
+
+        [Fact]
+        public async Task KeyValuePairModelBinder_SimpleTypes_WithNoValue_AndCustomizedMessage_AddsGivenMessage()
+        {
+            // Arrange
+            var metadataProvider = new TestModelMetadataProvider();
+            metadataProvider
+                .ForType(typeof(KeyValuePair<string, int>))
+                .BindingDetails((System.Action<ModelBinding.Metadata.BindingMetadata>)(binding =>
+                {
+                    // A real details provider could customize message based on BindingMetadataProviderContext.
+                    binding.ModelBindingMessageProvider.MissingKeyOrValueAccessor = () => $"Hurts when nothing is provided.";
+                }));
+            var argumentBinder = new DefaultControllerActionArgumentBinder(
+                metadataProvider,
+                ModelBindingTestHelper.GetObjectValidator());
+
+            var parameter = new ParameterDescriptor
+            {
+                Name = "parameter",
+                ParameterType = typeof(KeyValuePair<string, int>)
+            };
+            var operationContext = ModelBindingTestHelper.GetOperationBindingContext(request =>
+            {
+                request.QueryString = new QueryString("?parameter.Key=10");
+            });
+            var modelState = new ModelStateDictionary();
+
+            // Act
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, modelState, operationContext);
+
+            // Assert
+            Assert.False(modelBindingResult.IsModelSet);
+            Assert.Equal(2, modelState.Count);
+
+            Assert.False(modelState.IsValid);
+            Assert.Equal(1, modelState.ErrorCount);
+
+            var entry = Assert.Single(modelState, kvp => kvp.Key == "parameter.Key").Value;
+            Assert.Empty(entry.Errors);
+            Assert.Equal("10", entry.AttemptedValue);
+            Assert.Equal("10", entry.RawValue);
+
+            entry = Assert.Single(modelState, kvp => kvp.Key == "parameter.Value").Value;
+            var error = Assert.Single(entry.Errors);
+            Assert.Null(error.Exception);
+            Assert.Equal("Hurts when nothing is provided.", error.ErrorMessage);
+        }
+
         [Fact]
         public async Task KeyValuePairModelBinder_BindsKeyValuePairOfSimpleType_WithExplicitPrefix_Success()
         {
@@ -90,7 +261,7 @@ namespace Microsoft.AspNet.Mvc.IntegrationTests
 
             var entry = Assert.Single(modelState, kvp => kvp.Key == "prefix.Key").Value;
             Assert.Equal("key0", entry.AttemptedValue);
-           Assert.Equal("key0", entry.RawValue);
+            Assert.Equal("key0", entry.RawValue);
 
             entry = Assert.Single(modelState, kvp => kvp.Key == "prefix.Value").Value;
             Assert.Equal("10", entry.AttemptedValue);
@@ -130,7 +301,7 @@ namespace Microsoft.AspNet.Mvc.IntegrationTests
 
             var entry = Assert.Single(modelState, kvp => kvp.Key == "Key").Value;
             Assert.Equal("key0", entry.AttemptedValue);
-           Assert.Equal("key0", entry.RawValue);
+            Assert.Equal("key0", entry.RawValue);
 
             entry = Assert.Single(modelState, kvp => kvp.Key == "Value").Value;
             Assert.Equal("10", entry.AttemptedValue);
@@ -207,7 +378,7 @@ namespace Microsoft.AspNet.Mvc.IntegrationTests
 
             var entry = Assert.Single(modelState, kvp => kvp.Key == "parameter.Key").Value;
             Assert.Equal("key0", entry.AttemptedValue);
-           Assert.Equal("key0", entry.RawValue);
+            Assert.Equal("key0", entry.RawValue);
 
             entry = Assert.Single(modelState, kvp => kvp.Key == "parameter.Value.Id").Value;
             Assert.Equal("10", entry.AttemptedValue);
@@ -252,7 +423,7 @@ namespace Microsoft.AspNet.Mvc.IntegrationTests
 
             var entry = Assert.Single(modelState, kvp => kvp.Key == "prefix.Key").Value;
             Assert.Equal("key0", entry.AttemptedValue);
-           Assert.Equal("key0", entry.RawValue);
+            Assert.Equal("key0", entry.RawValue);
 
             entry = Assert.Single(modelState, kvp => kvp.Key == "prefix.Value.Id").Value;
             Assert.Equal("10", entry.AttemptedValue);
@@ -293,7 +464,7 @@ namespace Microsoft.AspNet.Mvc.IntegrationTests
 
             var entry = Assert.Single(modelState, kvp => kvp.Key == "Key").Value;
             Assert.Equal("key0", entry.AttemptedValue);
-           Assert.Equal("key0", entry.RawValue);
+            Assert.Equal("key0", entry.RawValue);
 
             entry = Assert.Single(modelState, kvp => kvp.Key == "Value.Id").Value;
             Assert.Equal("10", entry.AttemptedValue);

test/Microsoft.AspNet.Mvc.IntegrationTests/MutableObjectModelBinderIntegrationTest.cs

@@ -10,6 +10,7 @@ using Microsoft.AspNet.Http;
 using Microsoft.AspNet.Http.Features.Internal;
 using Microsoft.AspNet.Http.Internal;
 using Microsoft.AspNet.Mvc.Abstractions;
+using Microsoft.AspNet.Mvc.Controllers;
 using Microsoft.AspNet.Mvc.Infrastructure;
 using Microsoft.AspNet.Mvc.ModelBinding;
 using Microsoft.Framework.Primitives;
@@ -859,8 +860,7 @@ namespace Microsoft.AspNet.Mvc.IntegrationTests
             // Need to have a key here so that the MutableObjectModelBinder will recurse to bind elements.
             var operationContext = ModelBindingTestHelper.GetOperationBindingContext(request =>
             {
-                request.QueryString =
+                request.QueryString = new QueryString("?Name=bill&ProductIds[0]=10&ProductIds[1]=11");
-                    new QueryString("?Name=bill&ProductIds[0]=10&ProductIds[1]=11");
             });
 
             var modelState = new ModelStateDictionary();
@@ -1032,8 +1032,7 @@ namespace Microsoft.AspNet.Mvc.IntegrationTests
             // Need to have a key here so that the MutableObjectModelBinder will recurse to bind elements.
             var operationContext = ModelBindingTestHelper.GetOperationBindingContext(request =>
             {
-                request.QueryString =
+                request.QueryString = new QueryString("?Name=bill&ProductIds[0]=10&ProductIds[1]=11");
-                    new QueryString("?Name=bill&ProductIds[0]=10&ProductIds[1]=11");
             });
 
             var modelState = new ModelStateDictionary();
@@ -1205,8 +1204,7 @@ namespace Microsoft.AspNet.Mvc.IntegrationTests
             // Need to have a key here so that the MutableObjectModelBinder will recurse to bind elements.
             var operationContext = ModelBindingTestHelper.GetOperationBindingContext(request =>
             {
-                request.QueryString =
+                request.QueryString = new QueryString("?Name=bill&ProductIds[0].Key=key0&ProductIds[0].Value=10");
-                    new QueryString("?Name=bill&ProductIds[0].Key=key0&ProductIds[0].Value=10");
             });
 
             var modelState = new ModelStateDictionary();
@@ -1378,8 +1376,7 @@ namespace Microsoft.AspNet.Mvc.IntegrationTests
             // Need to have a key here so that the MutableObjectModelBinder will recurse to bind elements.
             var operationContext = ModelBindingTestHelper.GetOperationBindingContext(request =>
             {
-                request.QueryString =
+                request.QueryString = new QueryString("?Name=bill&ProductId.Key=key0&ProductId.Value=10");
-                    new QueryString("?Name=bill&ProductId.Key=key0&ProductId.Value=10");
             });
 
             var modelState = new ModelStateDictionary();
@@ -1563,9 +1560,7 @@ namespace Microsoft.AspNet.Mvc.IntegrationTests
             };
 
             // No Data
-            var operationContext = ModelBindingTestHelper.GetOperationBindingContext(request =>
+            var operationContext = ModelBindingTestHelper.GetOperationBindingContext();
-            {
-            });
 
             var modelState = new ModelStateDictionary();
 
@@ -1589,6 +1584,53 @@ namespace Microsoft.AspNet.Mvc.IntegrationTests
             Assert.Equal("A value for the 'Customer' property was not provided.", error.ErrorMessage);
         }
 
+        [Fact]
+        public async Task MutableObjectModelBinder_WithBindRequired_NoData_AndCustomizedMessage_AddsGivenMessage()
+        {
+            // Arrange
+            var metadataProvider = new TestModelMetadataProvider();
+            metadataProvider
+                .ForType(typeof(Order10))
+                .BindingDetails((Action<ModelBinding.Metadata.BindingMetadata>)(binding =>
+                {
+                    // A real details provider could customize message based on BindingMetadataProviderContext.
+                    binding.ModelBindingMessageProvider.MissingBindRequiredValueAccessor =
+                        name => $"Hurts when '{ name }' is not provided.";
+                }));
+            var argumentBinder = new DefaultControllerActionArgumentBinder(
+                metadataProvider,
+                ModelBindingTestHelper.GetObjectValidator());
+            var parameter = new ParameterDescriptor()
+            {
+                Name = "parameter",
+                ParameterType = typeof(Order10)
+            };
+
+            // No Data
+            var operationContext = ModelBindingTestHelper.GetOperationBindingContext();
+
+            var modelState = new ModelStateDictionary();
+
+            // Act
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, modelState, operationContext);
+
+            // Assert
+            Assert.True(modelBindingResult.IsModelSet);
+
+            var model = Assert.IsType<Order10>(modelBindingResult.Model);
+            Assert.Null(model.Customer);
+
+            Assert.Equal(1, modelState.Count);
+            Assert.Equal(1, modelState.ErrorCount);
+            Assert.False(modelState.IsValid);
+
+            var entry = Assert.Single(modelState, e => e.Key == "Customer").Value;
+            Assert.Null(entry.RawValue);
+            Assert.Null(entry.AttemptedValue);
+            var error = Assert.Single(modelState["Customer"].Errors);
+            Assert.Equal("Hurts when 'Customer' is not provided.", error.ErrorMessage);
+        }
+
         private class Order11
         {
             public Person11 Customer { get; set; }

test/Microsoft.AspNet.Mvc.IntegrationTests/SimpleTypeModelBinderIntegrationTest.cs

@@ -9,6 +9,7 @@ using System.Threading.Tasks;
 using Microsoft.AspNet.Http;
 using Microsoft.AspNet.Http.Internal;
 using Microsoft.AspNet.Mvc.Abstractions;
+using Microsoft.AspNet.Mvc.Controllers;
 using Microsoft.AspNet.Mvc.ModelBinding;
 using Microsoft.Framework.Primitives;
 using Xunit;
@@ -262,7 +263,7 @@ namespace Microsoft.AspNet.Mvc.IntegrationTests
             };
             var operationContext = ModelBindingTestHelper.GetOperationBindingContext(request =>
             {
-                request.QueryString = QueryString.Create("Parameter1", string.Empty);
+                request.QueryString = QueryString.Create("Parameter1", "  ");
             });
             var modelState = new ModelStateDictionary();
 
@@ -277,6 +278,58 @@ namespace Microsoft.AspNet.Mvc.IntegrationTests
             // Model
             Assert.Null(modelBindingResult.Model);
 
+            // ModelState
+            Assert.False(modelState.IsValid);
+            var key = Assert.Single(modelState.Keys);
+            Assert.Equal("Parameter1", key);
+            Assert.Equal("  ", modelState[key].AttemptedValue);
+            Assert.Equal("  ", modelState[key].RawValue);
+            var error = Assert.Single(modelState[key].Errors);
+            Assert.Equal("The value '  ' is invalid.", error.ErrorMessage, StringComparer.Ordinal);
+            Assert.Null(error.Exception);
+        }
+
+        [Theory]
+        [InlineData(typeof(int))]
+        [InlineData(typeof(bool))]
+        public async Task BindParameter_WithEmptyData_AndPerTypeMessage_AddsGivenMessage(Type parameterType)
+        {
+            // Arrange
+            var metadataProvider = new TestModelMetadataProvider();
+            metadataProvider
+                .ForType(parameterType)
+                .BindingDetails((Action<ModelBinding.Metadata.BindingMetadata>)(binding =>
+                {
+                    // A real details provider could customize message based on BindingMetadataProviderContext.
+                    binding.ModelBindingMessageProvider.ValueMustNotBeNullAccessor =
+                        value => $"Hurts when '{ value }' is provided.";
+                }));
+            var argumentBinder = new DefaultControllerActionArgumentBinder(
+                metadataProvider,
+                ModelBindingTestHelper.GetObjectValidator());
+            var parameter = new ParameterDescriptor
+            {
+                Name = "Parameter1",
+                BindingInfo = new BindingInfo(),
+
+                ParameterType = parameterType
+            };
+            var operationContext = ModelBindingTestHelper.GetOperationBindingContext(request =>
+            {
+                request.QueryString = QueryString.Create("Parameter1", string.Empty);
+            });
+            var modelState = new ModelStateDictionary();
+
+            // Act
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, modelState, operationContext);
+
+            // Assert
+            // ModelBindingResult
+            Assert.False(modelBindingResult.IsModelSet);
+
+            // Model
+            Assert.Null(modelBindingResult.Model);
+
             // ModelState
             Assert.False(modelState.IsValid);
             var key = Assert.Single(modelState.Keys);
@@ -284,7 +337,7 @@ namespace Microsoft.AspNet.Mvc.IntegrationTests
             Assert.Equal(string.Empty, modelState[key].AttemptedValue);
             Assert.Equal(string.Empty, modelState[key].RawValue);
             var error = Assert.Single(modelState[key].Errors);
-            Assert.Equal(error.ErrorMessage, "The value '' is invalid.", StringComparer.Ordinal);
+            Assert.Equal("Hurts when '' is provided.", error.ErrorMessage, StringComparer.Ordinal);
             Assert.Null(error.Exception);
         }
 

test/Microsoft.AspNet.Mvc.TestCommon/TestModelMetadataProvider.cs

@@ -16,7 +16,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
         {
             var detailsProviders = new IMetadataDetailsProvider[]
             {
-                new DefaultBindingMetadataProvider(),
+                new DefaultBindingMetadataProvider(CreateMessageProvider()),
                 new DefaultValidationMetadataProvider(),
                 new DataAnnotationsMetadataProvider(),
                 new DataMemberRequiredBindingMetadataProvider(),
@@ -36,7 +36,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
         private TestModelMetadataProvider(TestModelMetadataDetailsProvider detailsProvider)
             : base(new DefaultCompositeMetadataDetailsProvider(new IMetadataDetailsProvider[]
                 {
-                    new DefaultBindingMetadataProvider(),
+                    new DefaultBindingMetadataProvider(CreateMessageProvider()),
                     new DefaultValidationMetadataProvider(),
                     new DataAnnotationsMetadataProvider(),
                     detailsProvider
@@ -76,6 +76,16 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
             return ForProperty(typeof(TContainer), propertyName);
         }
 
+        private static ModelBindingMessageProvider CreateMessageProvider()
+        {
+            return new ModelBindingMessageProvider
+            {
+                MissingBindRequiredValueAccessor = name => $"A value for the '{ name }' property was not provided.",
+                MissingKeyOrValueAccessor = () => $"A value is required.",
+                ValueMustNotBeNullAccessor = value => $"The value '{ value }' is invalid.",
+            };
+        }
+
         private class TestModelMetadataDetailsProvider :
             IBindingMetadataProvider,
             IDisplayMetadataProvider,