[Fixes #1841] Change XML DCS and XmlSerializer output formatters to not derive from the base XmlOutputFormatter

src/Microsoft.AspNet.Mvc.Core/Formatters/FormattingUtilities.cs

@@ -34,5 +34,19 @@ namespace Microsoft.AspNet.Mvc
                 MaxStringContentLength = int.MaxValue
             };
         }
+
+        /// <summary>
+        /// Gets the default XmlWriterSettings.
+        /// </summary>
+        /// <returns>Default <see cref="XmlWriterSettings"/></returns>
+        public static XmlWriterSettings GetDefaultXmlWriterSettings()
+        {
+            return new XmlWriterSettings
+            {
+                OmitXmlDeclaration = true,
+                CloseOutput = false,
+                CheckCharacters = false
+            };
+        }
     }
 }

src/Microsoft.AspNet.Mvc.Core/Formatters/XmlDataContractSerializerOutputFormatter.cs

@@ -2,9 +2,11 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
+using System.IO;
 using System.Runtime.Serialization;
 using System.Threading.Tasks;
 using System.Xml;
+using Microsoft.Net.Http.Headers;
 
 namespace Microsoft.AspNet.Mvc
 {
@@ -12,14 +14,14 @@ namespace Microsoft.AspNet.Mvc
     /// This class handles serialization of objects
     /// to XML using <see cref="DataContractSerializer"/>
     /// </summary>
-    public class XmlDataContractSerializerOutputFormatter : XmlOutputFormatter
+    public class XmlDataContractSerializerOutputFormatter : OutputFormatter
     {
         /// <summary>
         /// Initializes a new instance of <see cref="XmlDataContractSerializerOutputFormatter"/>
         /// with default XmlWriterSettings
         /// </summary>
-        public XmlDataContractSerializerOutputFormatter()
+        public XmlDataContractSerializerOutputFormatter() :
-            : this(GetDefaultXmlWriterSettings())
+            this(FormattingUtilities.GetDefaultXmlWriterSettings())
         {
         }
 
@@ -28,8 +30,39 @@ namespace Microsoft.AspNet.Mvc
         /// </summary>
         /// <param name="writerSettings">The settings to be used by the <see cref="DataContractSerializer"/>.</param>
         public XmlDataContractSerializerOutputFormatter([NotNull] XmlWriterSettings writerSettings)
-            : base(writerSettings)
         {
+            SupportedEncodings.Add(Encodings.UTF8EncodingWithoutBOM);
+            SupportedEncodings.Add(Encodings.UTF16EncodingLittleEndian);
+
+            SupportedMediaTypes.Add(MediaTypeHeaderValue.Parse("application/xml"));
+            SupportedMediaTypes.Add(MediaTypeHeaderValue.Parse("text/xml"));
+
+            WriterSettings = writerSettings;
+        }
+
+        /// <summary>
+        /// Gets the settings to be used by the XmlWriter.
+        /// </summary>
+        public XmlWriterSettings WriterSettings { get; }
+
+        /// <summary>
+        /// Gets the type of the object to be serialized.
+        /// </summary>
+        /// <param name="declaredType">The declared type.</param>
+        /// <param name="runtimeType">The runtime type.</param>
+        /// <returns>The type of the object to be serialized.</returns>
+        protected virtual Type GetSerializableType(Type declaredType, Type runtimeType)
+        {
+            if (declaredType == null ||
+                declaredType == typeof(object))
+            {
+                if (runtimeType != null)
+                {
+                    return runtimeType;
+                }
+            }
+
+            return declaredType;
         }
 
         /// <inheritdoc />
@@ -62,6 +95,17 @@ namespace Microsoft.AspNet.Mvc
             }
         }
 
+        /// <summary>
+        /// Creates a new instance of <see cref="XmlWriter"/> using the given stream and the <see cref="WriterSettings"/>.
+        /// </summary>
+        /// <param name="writeStream">The stream on which the XmlWriter should operate on.</param>
+        /// <returns>A new instance of <see cref="XmlWriter"/></returns>
+        public virtual XmlWriter CreateXmlWriter([NotNull] Stream writeStream,
+                                                 [NotNull] XmlWriterSettings xmlWriterSettings)
+        {
+            return XmlWriter.Create(writeStream, xmlWriterSettings);
+        }
+
         /// <inheritdoc />
         public override Task WriteResponseBodyAsync([NotNull] OutputFormatterContext context)
         {

src/Microsoft.AspNet.Mvc.Core/Formatters/XmlOutputFormatter.cs

@@ -1,77 +0,0 @@
-// 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;
-using System.IO;
-using System.Xml;
-using Microsoft.Net.Http.Headers;
-
-namespace Microsoft.AspNet.Mvc
-{
-    /// <summary>
-    /// Abstract base class from which all XML Output Formatters derive from.
-    /// </summary>
-    public abstract class XmlOutputFormatter : OutputFormatter
-    {
-        public XmlOutputFormatter([NotNull] XmlWriterSettings xmlWriterSettings)
-        {
-            SupportedEncodings.Add(Encodings.UTF8EncodingWithoutBOM);
-            SupportedEncodings.Add(Encodings.UTF16EncodingLittleEndian);
-
-            SupportedMediaTypes.Add(MediaTypeHeaderValue.Parse("application/xml"));
-            SupportedMediaTypes.Add(MediaTypeHeaderValue.Parse("text/xml"));
-
-            WriterSettings = xmlWriterSettings;
-        }
-
-        /// <summary>
-        /// Gets or sets the settings to be used by the XmlWriter.
-        /// </summary>
-        public XmlWriterSettings WriterSettings { get; private set; }
-
-        /// <summary>
-        /// Gets the type of the object to be serialized.
-        /// </summary>
-        /// <param name="declaredType">The declared type.</param>
-        /// <param name="runtimeType">The runtime type.</param>
-        /// <returns>The type of the object to be serialized.</returns>
-        protected virtual Type GetSerializableType(Type declaredType, Type runtimeType)
-        {
-            if (declaredType == null ||
-                declaredType == typeof(object))
-            {
-                if (runtimeType != null)
-                {
-                    return runtimeType;
-                }
-            }
-
-            return declaredType;
-        }
-
-        /// <summary>
-        /// Gets the default XmlWriterSettings.
-        /// </summary>
-        /// <returns>Default <see cref="XmlWriterSettings"/></returns>
-        public static XmlWriterSettings GetDefaultXmlWriterSettings()
-        {
-            return new XmlWriterSettings
-            {
-                OmitXmlDeclaration = true,
-                CloseOutput = false,
-                CheckCharacters = false
-            };
-        }
-
-        /// <summary>
-        /// Creates a new instance of <see cref="XmlWriter"/> using the given stream and the WriterSettings.
-        /// </summary>
-        /// <param name="writeStream">The stream on which the XmlWriter should operate on.</param>
-        /// <returns>A new instance of <see cref="XmlWriter"/></returns>
-        public virtual XmlWriter CreateXmlWriter([NotNull] Stream writeStream,
-                                                 [NotNull] XmlWriterSettings xmlWriterSettings)
-        {
-            return XmlWriter.Create(writeStream, xmlWriterSettings);
-        }
-    }
-}

src/Microsoft.AspNet.Mvc.Core/Formatters/XmlSerializerOutputFormatter.cs

@@ -2,9 +2,11 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
+using System.IO;
 using System.Threading.Tasks;
 using System.Xml;
 using System.Xml.Serialization;
+using Microsoft.Net.Http.Headers;
 
 namespace Microsoft.AspNet.Mvc
 {
@@ -12,14 +14,14 @@ namespace Microsoft.AspNet.Mvc
     /// This class handles serialization of objects
     /// to XML using <see cref="XmlSerializer"/>
     /// </summary>
-    public class XmlSerializerOutputFormatter : XmlOutputFormatter
+    public class XmlSerializerOutputFormatter : OutputFormatter
     {
         /// <summary>
         /// Initializes a new instance of <see cref="XmlSerializerOutputFormatter"/>
         /// with default XmlWriterSettings.
         /// </summary>
-        public XmlSerializerOutputFormatter()
+        public XmlSerializerOutputFormatter() :
-            : this(GetDefaultXmlWriterSettings())
+            this(FormattingUtilities.GetDefaultXmlWriterSettings())
         {
         }
 
@@ -28,8 +30,39 @@ namespace Microsoft.AspNet.Mvc
         /// </summary>
         /// <param name="writerSettings">The settings to be used by the <see cref="XmlSerializer"/>.</param>
         public XmlSerializerOutputFormatter([NotNull] XmlWriterSettings writerSettings)
-            : base(writerSettings)
         {
+            SupportedEncodings.Add(Encodings.UTF8EncodingWithoutBOM);
+            SupportedEncodings.Add(Encodings.UTF16EncodingLittleEndian);
+
+            SupportedMediaTypes.Add(MediaTypeHeaderValue.Parse("application/xml"));
+            SupportedMediaTypes.Add(MediaTypeHeaderValue.Parse("text/xml"));
+
+            WriterSettings = writerSettings;
+        }
+
+        /// <summary>
+        /// Gets the settings to be used by the XmlWriter.
+        /// </summary>
+        public XmlWriterSettings WriterSettings { get; }
+
+        /// <summary>
+        /// Gets the type of the object to be serialized.
+        /// </summary>
+        /// <param name="declaredType">The declared type.</param>
+        /// <param name="runtimeType">The runtime type.</param>
+        /// <returns>The type of the object to be serialized.</returns>
+        protected virtual Type GetSerializableType(Type declaredType, Type runtimeType)
+        {
+            if (declaredType == null ||
+                declaredType == typeof(object))
+            {
+                if (runtimeType != null)
+                {
+                    return runtimeType;
+                }
+            }
+
+            return declaredType;
         }
 
         /// <inheritdoc />
@@ -58,6 +91,17 @@ namespace Microsoft.AspNet.Mvc
             }
         }
 
+        /// <summary>
+        /// Creates a new instance of <see cref="XmlWriter"/> using the given stream and the <see cref="WriterSettings"/>.
+        /// </summary>
+        /// <param name="writeStream">The stream on which the XmlWriter should operate on.</param>
+        /// <returns>A new instance of <see cref="XmlWriter"/></returns>
+        public virtual XmlWriter CreateXmlWriter([NotNull] Stream writeStream,
+                                                 [NotNull] XmlWriterSettings xmlWriterSettings)
+        {
+            return XmlWriter.Create(writeStream, xmlWriterSettings);
+        }
+
         /// <inheritdoc />
         public override Task WriteResponseBodyAsync([NotNull] OutputFormatterContext context)
         {

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

@@ -13,8 +13,7 @@ namespace Microsoft.AspNet.Mvc
         /// <param name="options">The MvcOptions</param>
         public static void AddXmlDataContractSerializerFormatter([NotNull] this MvcOptions options)
         {
-            options.OutputFormatters.Add(
+            options.OutputFormatters.Add(new XmlDataContractSerializerOutputFormatter());
-                new XmlDataContractSerializerOutputFormatter(XmlOutputFormatter.GetDefaultXmlWriterSettings()));
 
             options.InputFormatters.Add(new XmlDataContractSerializerInputFormatter());
         }

test/Microsoft.AspNet.Mvc.Core.Test/ActionResults/ObjectResultTests.cs

@@ -492,7 +492,7 @@ namespace Microsoft.AspNet.Mvc.Core.Test.ActionResults
                 new HttpNoContentOutputFormatter(),
                 new StringOutputFormatter(),
                 new JsonOutputFormatter(),
-                new XmlDataContractSerializerOutputFormatter(XmlSerializerOutputFormatter.GetDefaultXmlWriterSettings())
+                new XmlDataContractSerializerOutputFormatter()
             };
             var response = GetMockHttpResponse();
 
@@ -533,7 +533,7 @@ namespace Microsoft.AspNet.Mvc.Core.Test.ActionResults
                 new HttpNoContentOutputFormatter(),
                 new StringOutputFormatter(),
                 new JsonOutputFormatter(),
-                new XmlDataContractSerializerOutputFormatter(XmlSerializerOutputFormatter.GetDefaultXmlWriterSettings())
+                new XmlDataContractSerializerOutputFormatter()
             };
             var response = GetMockHttpResponse();
 
@@ -568,7 +568,7 @@ namespace Microsoft.AspNet.Mvc.Core.Test.ActionResults
                 new HttpNoContentOutputFormatter(),
                 new StringOutputFormatter(),
                 new JsonOutputFormatter(),
-                new XmlDataContractSerializerOutputFormatter(XmlSerializerOutputFormatter.GetDefaultXmlWriterSettings())
+                new XmlDataContractSerializerOutputFormatter()
             };
             var response = GetMockHttpResponse();
 

test/Microsoft.AspNet.Mvc.Core.Test/Formatters/XmlDataContractSerializerOutputFormatterTests.cs

@@ -84,13 +84,51 @@ namespace Microsoft.AspNet.Mvc.Core
             Assert.True(outputFormatterContext.ActionContext.HttpContext.Response.Body.CanRead);
         }
 
+        [Fact]
+        public void DefaultConstructor_ExpectedWriterSettings_Created()
+        {
+            // Arrange and Act
+            var formatter = new XmlDataContractSerializerOutputFormatter();
+
+            // Assert
+            var writerSettings = formatter.WriterSettings;
+            Assert.NotNull(writerSettings);
+            Assert.True(writerSettings.OmitXmlDeclaration);
+            Assert.False(writerSettings.CloseOutput);
+            Assert.False(writerSettings.CheckCharacters);
+        }
+
+        [Fact]
+        public async Task SuppliedWriterSettings_TakeAffect()
+        {
+            // Arrange
+            var writerSettings = FormattingUtilities.GetDefaultXmlWriterSettings();
+            writerSettings.OmitXmlDeclaration = false;
+            var sampleInput = new DummyClass { SampleInt = 10 };
+            var formatterContext = GetOutputFormatterContext(sampleInput, sampleInput.GetType());
+            var formatter = new XmlDataContractSerializerOutputFormatter(writerSettings);
+            var expectedOutput = "<?xml version=\"1.0\" encoding=\"utf-8\"?>"+
+                                "<DummyClass xmlns:i=\"http://www.w3.org/2001/XMLSchema-instance\">" +
+                                "<SampleInt>10</SampleInt></DummyClass>";
+
+            // Act
+            await formatter.WriteAsync(formatterContext);
+
+            // Assert
+            Assert.Same(writerSettings, formatter.WriterSettings);
+            var responseStream = formatterContext.ActionContext.HttpContext.Response.Body;
+            Assert.NotNull(responseStream);
+            responseStream.Position = 0;
+            var actualOutput = new StreamReader(responseStream, Encoding.UTF8).ReadToEnd();
+            Assert.Equal(expectedOutput, actualOutput);
+        }
+
         [Fact]
         public async Task XmlDataContractSerializerOutputFormatterWritesSimpleTypes()
         {
             // Arrange
             var sampleInput = new DummyClass { SampleInt = 10 };
-            var formatter = new XmlDataContractSerializerOutputFormatter(
+            var formatter = new XmlDataContractSerializerOutputFormatter();
-                XmlOutputFormatter.GetDefaultXmlWriterSettings());
             var outputFormatterContext = GetOutputFormatterContext(sampleInput, sampleInput.GetType());
 
             // Act
@@ -118,8 +156,7 @@ namespace Microsoft.AspNet.Mvc.Core
                     sampleString = "TestLevelOne string"
                 }
             };
-            var formatter = new XmlDataContractSerializerOutputFormatter(
+            var formatter = new XmlDataContractSerializerOutputFormatter();
-                XmlOutputFormatter.GetDefaultXmlWriterSettings());
             var outputFormatterContext = GetOutputFormatterContext(sampleInput, sampleInput.GetType());
 
             // Act
@@ -168,8 +205,7 @@ namespace Microsoft.AspNet.Mvc.Core
             var sampleInput = new DummyClass { SampleInt = 10 };
             var outputFormatterContext = GetOutputFormatterContext(sampleInput, sampleInput.GetType(),
                 "application/xml; charset=utf-16");
-            var formatter = new XmlDataContractSerializerOutputFormatter(
+            var formatter = new XmlDataContractSerializerOutputFormatter();
-                XmlOutputFormatter.GetDefaultXmlWriterSettings());
             formatter.WriterSettings.OmitXmlDeclaration = false;
 
             // Act
@@ -190,8 +226,7 @@ namespace Microsoft.AspNet.Mvc.Core
         {
             // Arrange
             var sampleInput = new DummyClass { SampleInt = 10 };
-            var formatter = new XmlDataContractSerializerOutputFormatter(
+            var formatter = new XmlDataContractSerializerOutputFormatter();
-                XmlOutputFormatter.GetDefaultXmlWriterSettings());
             formatter.WriterSettings.Indent = true;
             var outputFormatterContext = GetOutputFormatterContext(sampleInput, sampleInput.GetType());
 
@@ -213,8 +248,7 @@ namespace Microsoft.AspNet.Mvc.Core
         {
             // Arrange
             var sampleInput = new DummyClass { SampleInt = 10 };
-            var formatter = new XmlDataContractSerializerOutputFormatter(
+            var formatter = new XmlDataContractSerializerOutputFormatter();
-                XmlOutputFormatter.GetDefaultXmlWriterSettings());
             var outputFormatterContext = GetOutputFormatterContext(sampleInput, sampleInput.GetType());
 
             // Act

test/Microsoft.AspNet.Mvc.Core.Test/Formatters/XmlSerializerOutputFormatterTests.cs

@@ -66,13 +66,51 @@ namespace Microsoft.AspNet.Mvc.Core
             Assert.True(outputFormatterContext.ActionContext.HttpContext.Response.Body.CanRead);
         }
 
+        [Fact]
+        public void DefaultConstructor_ExpectedWriterSettings_Created()
+        {
+            // Arrange and Act
+            var formatter = new XmlSerializerOutputFormatter();
+
+            // Assert
+            var writerSettings = formatter.WriterSettings;
+            Assert.NotNull(writerSettings);
+            Assert.True(writerSettings.OmitXmlDeclaration);
+            Assert.False(writerSettings.CloseOutput);
+            Assert.False(writerSettings.CheckCharacters);
+        }
+
+        [Fact]
+        public async Task SuppliedWriterSettings_TakeAffect()
+        {
+            // Arrange
+            var writerSettings = FormattingUtilities.GetDefaultXmlWriterSettings();
+            writerSettings.OmitXmlDeclaration = false;
+            var sampleInput = new DummyClass { SampleInt = 10 };
+            var formatterContext = GetOutputFormatterContext(sampleInput, sampleInput.GetType());
+            var formatter = new XmlSerializerOutputFormatter(writerSettings);
+            var expectedOutput = "<?xml version=\"1.0\" encoding=\"utf-8\"?>" +
+                                "<DummyClass xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" " +
+                                "xmlns:xsd=\"http://www.w3.org/2001/XMLSchema\"><SampleInt>10</SampleInt></DummyClass>";
+
+            // Act
+            await formatter.WriteAsync(formatterContext);
+
+            // Assert
+            Assert.Same(writerSettings, formatter.WriterSettings);
+            var responseStream = formatterContext.ActionContext.HttpContext.Response.Body;
+            Assert.NotNull(responseStream);
+            responseStream.Position = 0;
+            var actualOutput = new StreamReader(responseStream, Encoding.UTF8).ReadToEnd();
+            Assert.Equal(expectedOutput, actualOutput);
+        }
+
         [Fact]
         public async Task XmlSerializerOutputFormatterWritesSimpleTypes()
         {
             // Arrange
             var sampleInput = new DummyClass { SampleInt = 10 };
-            var formatter = new XmlSerializerOutputFormatter(
+            var formatter = new XmlSerializerOutputFormatter();
-                XmlOutputFormatter.GetDefaultXmlWriterSettings());
             var outputFormatterContext = GetOutputFormatterContext(sampleInput, sampleInput.GetType());
 
             // Act
@@ -101,8 +139,7 @@ namespace Microsoft.AspNet.Mvc.Core
                     sampleString = "TestLevelOne string"
                 }
             };
-            var formatter = new XmlSerializerOutputFormatter(
+            var formatter = new XmlSerializerOutputFormatter();
-                XmlOutputFormatter.GetDefaultXmlWriterSettings());
             var outputFormatterContext = GetOutputFormatterContext(sampleInput, sampleInput.GetType());
 
             // Act
@@ -152,8 +189,7 @@ namespace Microsoft.AspNet.Mvc.Core
             var sampleInput = new DummyClass { SampleInt = 10 };
             var outputFormatterContext =
                 GetOutputFormatterContext(sampleInput, sampleInput.GetType(), "application/xml; charset=utf-16");
-            var formatter = new XmlSerializerOutputFormatter(
+            var formatter = new XmlSerializerOutputFormatter();
-                XmlOutputFormatter.GetDefaultXmlWriterSettings());
             formatter.WriterSettings.OmitXmlDeclaration = false;
 
             // Act
@@ -174,8 +210,7 @@ namespace Microsoft.AspNet.Mvc.Core
         {
             // Arrange
             var sampleInput = new DummyClass { SampleInt = 10 };
-            var formatter = new XmlSerializerOutputFormatter(
+            var formatter = new XmlSerializerOutputFormatter();
-                XmlOutputFormatter.GetDefaultXmlWriterSettings());
             formatter.WriterSettings.Indent = true;
             var outputFormatterContext = GetOutputFormatterContext(sampleInput, sampleInput.GetType());
 
@@ -197,8 +232,7 @@ namespace Microsoft.AspNet.Mvc.Core
         {
             // Arrange
             var sampleInput = new DummyClass { SampleInt = 10 };
-            var formatter = new XmlSerializerOutputFormatter(
+            var formatter = new XmlSerializerOutputFormatter();
-                XmlOutputFormatter.GetDefaultXmlWriterSettings());
             var outputFormatterContext = GetOutputFormatterContext(sampleInput, sampleInput.GetType());
 
             // Act