Adding ApiController.Validate : Fixes #1286

Author: harshgMSFT

src/Microsoft.AspNet.Mvc.WebApiCompatShim/ApiController.cs

@@ -5,6 +5,7 @@
 using Microsoft.AspNet.Http;
 using Microsoft.AspNet.Mvc;
 using Microsoft.AspNet.Mvc.ModelBinding;
+using Microsoft.Framework.DependencyInjection;
 
 namespace System.Web.Http
 {
@@ -27,7 +28,8 @@ public HttpContext Context
         }
 
         /// <summary>
-        /// Gets model state after the model binding process. This ModelState will be empty before model binding happens.
+        /// Gets model state after the model binding process. This ModelState will be empty before model binding 
+        ///  happens.
         /// </summary>
         public ModelStateDictionary ModelState
         {
@@ -58,6 +60,43 @@ public void Dispose()
             GC.SuppressFinalize(this);
         }
 
+        /// <summary>
+        /// Validates the given entity and adds the validation errors to the <see cref="ApiController.ModelState"/>
+        /// under the empty prefix, if any.
+        /// </summary>
+        /// <typeparam name="TEntity">The type of the entity to be validated.</typeparam>
+        /// <param name="entity">The entity being validated.</param>
+        public void Validate<TEntity>(TEntity entity)
+        {
+            Validate(entity, keyPrefix: String.Empty);
+        }
+
+        /// <summary>
+        /// Validates the given entity and adds the validation errors to the <see cref="ApiController.ModelState"/>,
+        /// if any.
+        /// </summary>
+        /// <typeparam name="TEntity">The type of the entity to be validated.</typeparam>
+        /// <param name="entity">The entity being validated.</param>
+        /// <param name="keyPrefix">
+        /// The key prefix under which the model state errors would be added in the <see cref="ApiController.ModelState"/>.
+        /// </param>
+        public void Validate<TEntity>(TEntity entity, string keyPrefix)
+        {
+            var validator = Context.RequestServices.GetService<IBodyModelValidator>();
+            if (validator != null)
+            {
+                var metadataProvider = Context.RequestServices.GetService<IModelMetadataProvider>();
+                var modelMetadata = metadataProvider.GetMetadataForType(() => entity, typeof(TEntity));
+                var validatorProvider = Context.RequestServices.GetService<ICompositeModelValidatorProvider>();
+                var modelValidationContext = new ModelValidationContext(metadataProvider,
+                                                                        validatorProvider,
+                                                                        ModelState,
+                                                                        modelMetadata,
+                                                                        containerMetadata: null);
+                validator.Validate(modelValidationContext, keyPrefix);
+            }
+        }
+
         protected virtual void Dispose(bool disposing)
         {
         }

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

@@ -10,6 +10,8 @@
 using Microsoft.AspNet.TestHost;
 using Newtonsoft.Json;
 using Xunit;
+using Newtonsoft.Json;
+using System.Collections.Generic;
 
 namespace Microsoft.AspNet.Mvc.FunctionalTests
 {
@@ -77,6 +79,75 @@ public async Task Options_SetsDefaultFormatters()
             // Assert
             Assert.Equal(HttpStatusCode.OK, response.StatusCode);
             Assert.Equal(expected, formatters);
+
+            // Assert
+            var json = JsonConvert.DeserializeObject<Dictionary<string, string>>(response);
+            Assert.Equal(1, json.Count);
+            Assert.Equal("The field ID must be between 0 and 100.", json["ID"]);
+        }
+
+        [Fact]
+        public async Task ApiController_CanValidateCustomObjectWithPrefix_Fails()
+        {
+            // Arrange
+            var server = TestServer.Create(_provider, _app);
+            var client = server.CreateClient();
+
+            // Act
+            var response = await client.GetStringAsync(
+                "http://localhost/BasicApi/ValidateObjectWithPrefixFails?prefix=prefix");
+
+            // Assert
+            var json = JsonConvert.DeserializeObject<Dictionary<string, string>>(response);
+            Assert.Equal(1, json.Count);
+            Assert.Equal("The field ID must be between 0 and 100.", json["prefix.ID"]);
+        }
+        
+        [Fact]
+        public async Task ApiController_CanValidateCustomObject_IsSuccessFul()
+        {
+            // Arrange
+            var server = TestServer.Create(_provider, _app);
+            var client = server.CreateClient();
+
+            // Act
+            var response = await client.GetStringAsync("http://localhost/BasicApi/ValidateObject_Passes");
+
+            // Assert
+            Assert.Equal("true", response);
+        }
+
+        [Fact]
+        public async Task ApiController_CanValidateCustomObject_Fails()
+        {
+            // Arrange
+            var server = TestServer.Create(_provider, _app);
+            var client = server.CreateClient();
+
+            // Act
+            var response = await client.GetStringAsync("http://localhost/BasicApi/ValidateObjectFails");
+
+            // Assert
+            var json = JsonConvert.DeserializeObject<Dictionary<string, string>>(response);
+            Assert.Equal(1, json.Count);
+            Assert.Equal("The field ID must be between 0 and 100.", json["ID"]);
+        }
+
+        [Fact]
+        public async Task ApiController_CanValidateCustomObjectWithPrefix_Fails()
+        {
+            // Arrange
+            var server = TestServer.Create(_provider, _app);
+            var client = server.CreateClient();
+
+            // Act
+            var response = await client.GetStringAsync(
+                "http://localhost/BasicApi/ValidateObjectWithPrefixFails?prefix=prefix");
+
+            // Assert
+            var json = JsonConvert.DeserializeObject<Dictionary<string, string>>(response);
+            Assert.Equal(1, json.Count);
+            Assert.Equal("The field ID must be between 0 and 100.", json["prefix.ID"]);
         }
     }
 }

test/WebSites/WebApiCompatShimWebSite/Controllers/BasicApiController.cs

@@ -1,6 +1,7 @@
 // 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 System.ComponentModel.DataAnnotations;
 using System.Linq;
 using System.Threading.Tasks;
 using System.Web.Http;
@@ -45,5 +46,49 @@ public string[] GetFormatters()
         {
             return OptionsAccessor.Options.Formatters.Select(f => f.GetType().FullName).ToArray();
         }
+        
+        public bool ValidateObject_Passes()
+        {
+            var entity = new TestEntity { ID = 42 };
+            Validate(entity);
+            return ModelState.IsValid;
+        }
+
+        public object ValidateObjectFails()
+        {
+            var entity = new TestEntity { ID = -1 };
+            Validate(entity);
+            return CreateValidationDictionary();
+        }
+
+        public object ValidateObjectWithPrefixFails(string prefix)
+        {
+            var entity = new TestEntity { ID = -1 };
+            Validate(entity, prefix);
+            return CreateValidationDictionary();
+        }
+
+        private class TestEntity
+        {
+            [Range(0, 100)]
+            public int ID { get; set; }
+        }
+
+        private Dictionary<string, string> CreateValidationDictionary()
+        {
+            var result = new Dictionary<string, string>();
+            foreach (var item in ModelState)
+            {
+                var error = item.Value.Errors.SingleOrDefault();
+                if (error != null)
+                {
+                    var value = error.Exception != null ? error.Exception.Message :
+                                                          error.ErrorMessage;
+                    result.Add(item.Key, value);
+                }
+            }
+
+            return result;
+        }
     }
 }