Support native platform Http handlers for Xamarin.iOS and Xamarin.Android

Microsoft.Graph.Core.sln

@@ -10,6 +10,8 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Microsoft.Graph.Core", "src
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Microsoft.Graph.DotnetCore.Core.Test", "tests\Microsoft.Graph.DotnetCore.Core.Test\Microsoft.Graph.DotnetCore.Core.Test.csproj", "{A337BD4B-5C76-4BC5-8EC2-2EE7B834D030}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Microsoft.Graph.Core.XamarinAndroid.Test", "tests\Microsoft.Graph.Core.XamarinAndroid.Test\Microsoft.Graph.Core.XamarinAndroid.Test.csproj", "{41E25C28-021A-4CFB-B02D-DB901021E720}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -54,13 +56,38 @@ Global
 		{A337BD4B-5C76-4BC5-8EC2-2EE7B834D030}.Release|x64.Build.0 = Release|Any CPU
 		{A337BD4B-5C76-4BC5-8EC2-2EE7B834D030}.Release|x86.ActiveCfg = Release|Any CPU
 		{A337BD4B-5C76-4BC5-8EC2-2EE7B834D030}.Release|x86.Build.0 = Release|Any CPU
+		{41E25C28-021A-4CFB-B02D-DB901021E720}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{41E25C28-021A-4CFB-B02D-DB901021E720}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{41E25C28-021A-4CFB-B02D-DB901021E720}.Debug|Any CPU.Deploy.0 = Debug|Any CPU
+		{41E25C28-021A-4CFB-B02D-DB901021E720}.Debug|ARM.ActiveCfg = Debug|Any CPU
+		{41E25C28-021A-4CFB-B02D-DB901021E720}.Debug|ARM.Build.0 = Debug|Any CPU
+		{41E25C28-021A-4CFB-B02D-DB901021E720}.Debug|ARM.Deploy.0 = Debug|Any CPU
+		{41E25C28-021A-4CFB-B02D-DB901021E720}.Debug|x64.ActiveCfg = Debug|Any CPU
+		{41E25C28-021A-4CFB-B02D-DB901021E720}.Debug|x64.Build.0 = Debug|Any CPU
+		{41E25C28-021A-4CFB-B02D-DB901021E720}.Debug|x64.Deploy.0 = Debug|Any CPU
+		{41E25C28-021A-4CFB-B02D-DB901021E720}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{41E25C28-021A-4CFB-B02D-DB901021E720}.Debug|x86.Build.0 = Debug|Any CPU
+		{41E25C28-021A-4CFB-B02D-DB901021E720}.Debug|x86.Deploy.0 = Debug|Any CPU
+		{41E25C28-021A-4CFB-B02D-DB901021E720}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{41E25C28-021A-4CFB-B02D-DB901021E720}.Release|Any CPU.Build.0 = Release|Any CPU
+		{41E25C28-021A-4CFB-B02D-DB901021E720}.Release|Any CPU.Deploy.0 = Release|Any CPU
+		{41E25C28-021A-4CFB-B02D-DB901021E720}.Release|ARM.ActiveCfg = Release|Any CPU
+		{41E25C28-021A-4CFB-B02D-DB901021E720}.Release|ARM.Build.0 = Release|Any CPU
+		{41E25C28-021A-4CFB-B02D-DB901021E720}.Release|ARM.Deploy.0 = Release|Any CPU
+		{41E25C28-021A-4CFB-B02D-DB901021E720}.Release|x64.ActiveCfg = Release|Any CPU
+		{41E25C28-021A-4CFB-B02D-DB901021E720}.Release|x64.Build.0 = Release|Any CPU
+		{41E25C28-021A-4CFB-B02D-DB901021E720}.Release|x64.Deploy.0 = Release|Any CPU
+		{41E25C28-021A-4CFB-B02D-DB901021E720}.Release|x86.ActiveCfg = Release|Any CPU
+		{41E25C28-021A-4CFB-B02D-DB901021E720}.Release|x86.Build.0 = Release|Any CPU
+		{41E25C28-021A-4CFB-B02D-DB901021E720}.Release|x86.Deploy.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
 	EndGlobalSection
 	GlobalSection(NestedProjects) = preSolution
 		{9F04608C-D845-4445-83B1-E6D4EEE38CBC} = {5E0B65FC-67B7-41F8-87BF-96D6A342C438}
 		{A337BD4B-5C76-4BC5-8EC2-2EE7B834D030} = {6496B661-8321-4D07-ACC2-B6602649293C}
+		{41E25C28-021A-4CFB-B02D-DB901021E720} = {6496B661-8321-4D07-ACC2-B6602649293C}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {0DB06E6E-58F0-497F-9ECC-00DD03BA9357}

src/Microsoft.Graph.Core/CoreConstants.cs

@@ -49,6 +49,9 @@ public static class Headers
         /// </summary>
         public static class MimeTypeNames
         {
+            /// <summary>
+            /// MimeTypeNames.Application constants.
+            /// </summary>
             public static class Application
             {
                 /// JSON content type value

src/Microsoft.Graph.Core/Extensions/BaseRequestExtensions.cs

@@ -62,13 +62,13 @@ public static T WithPerRequestAuthProvider<T>(this T baseRequest) where T : IBas
         }
 
         /// <summary>
-        /// Sets a ShouldRetry <see cref="Func{HttpResponseMessage httpResponseMessage, Boolean}"/> delegate to the default Retry Middleware Handler for this request.
+        /// Sets a ShouldRetry delegate to the default Retry Middleware Handler for this request.
         /// This only works with the default Retry Middleware Handler.
         /// If you use a custom Retry Middleware Handler, you have to handle it's retreival in your implementation.
         /// </summary>
         /// <typeparam name="T"></typeparam>
         /// <param name="baseRequest">The <see cref="BaseRequest"/> for the request.</param>
-        /// <param name="shouldRetry">A <see cref="Func{HttpResponseMessage, Boolean}"/> for the request.</param>
+        /// <param name="shouldRetry">A <see cref="Func{Int32, Int32, HttpResponseMessage, Boolean}"/> for the request.</param>
         /// <returns></returns>
         public static T WithShouldRetry<T>(this T baseRequest, Func<int, int, HttpResponseMessage, bool> shouldRetry) where T : IBaseRequest
         {

src/Microsoft.Graph.Core/Microsoft.Graph.Core.csproj

@@ -4,7 +4,7 @@
     <Copyright>&#169; Microsoft Corporation. All rights reserved.</Copyright>
     <AssemblyTitle>Microsoft Graph Core Client Library</AssemblyTitle>
     <Authors>Microsoft</Authors>
-    <TargetFrameworks>netstandard1.1;net45</TargetFrameworks>
+    <TargetFrameworks>netstandard1.1;net45;Xamarin.iOS10;MonoAndroid70</TargetFrameworks>
     <PreserveCompilationContext>false</PreserveCompilationContext>
     <AssemblyName>Microsoft.Graph.Core</AssemblyName>
     <PackageId>Microsoft.Graph.Core</PackageId>
@@ -21,10 +21,28 @@
     <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
     <VersionPrefix>1.16.0</VersionPrefix>
     <VersionSuffix></VersionSuffix>
-    <PackageReleaseNotes>- Retry handler handles 504.
-  - Fix #470. Keep StreamWriter open for NetCore 2.x.
+    <PackageReleaseNotes>
+      - Fix #481. Use native HTTP client handlers for Xamarin.iOS and Xamarin.Android.
+      - Fix #482. Skip CompressionHandler when NSUrlSessionHandler is used.
     </PackageReleaseNotes>
   </PropertyGroup>
+  <!--We manually configure LanguageTargets for Xamarin due to .Net SDK TFMs limitation https://github.com/dotnet/sdk/issues/491 -->
+  <PropertyGroup Condition="'$(TargetFramework)' == 'Xamarin.iOS10'">
+    <TargetFrameworkIdentifier>Xamarin.iOS</TargetFrameworkIdentifier>
+    <TargetFrameworkVersion>v1.0</TargetFrameworkVersion>
+    <DefineConstants>$(DefineConstants);iOS</DefineConstants>
+    <DebugType>full</DebugType>
+    <LanguageTargets>$(MSBuildExtensionsPath)\Xamarin\iOS\Xamarin.iOS.CSharp.targets</LanguageTargets>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(TargetFramework)' == 'MonoAndroid70'">
+    <TargetFrameworkIdentifier>MonoAndroid</TargetFrameworkIdentifier>
+    <TargetFrameworkVersion>v7.0</TargetFrameworkVersion>
+    <AndroidUseLatestPlatformSdk>False</AndroidUseLatestPlatformSdk>
+    <DebugType>full</DebugType>
+    <DefineConstants>$(DefineConstants);ANDROID</DefineConstants>
+	<LanguageTargets>$(MSBuildExtensionsPath)\Xamarin\Android\Xamarin.Android.CSharp.targets</LanguageTargets>
+  </PropertyGroup>
+
   <PropertyGroup Condition="'$(Configuration)|$(TargetFramework)|$(Platform)'=='Debug|netstandard1.1|AnyCPU'">
     <DocumentationFile>bin\Release\netstandard1.1\Microsoft.Graph.Core.xml</DocumentationFile>
     <NoWarn>1701;1702;1705;1591</NoWarn>
@@ -38,23 +56,42 @@
   <PropertyGroup Condition="'$(Configuration)|$(TargetFramework)|$(Platform)'=='Debug|net45|AnyCPU'">
     <DocumentationFile>bin\Debug\net45\Microsoft.Graph.xml</DocumentationFile>
   </PropertyGroup>
+
   <ItemGroup Condition=" '$(TargetFramework)' == 'net45' ">
     <Reference Include="System.Net.Http" />
     <Reference Include="System" />
     <Reference Include="Microsoft.CSharp" />
     <PackageReference Include="Newtonsoft.Json" Version="6.0.1" />
+	<PackageReference Include="System.ValueTuple" Version="4.3.0" />
   </ItemGroup>
   <ItemGroup Condition=" '$(TargetFramework)' == 'netstandard1.1' ">
     <PackageReference Include="Newtonsoft.Json" Version="9.0.1" />
     <PackageReference Include="System.Net.Http" Version="4.3.3" />
+	<PackageReference Include="System.ValueTuple" Version="4.3.0" />
   </ItemGroup>
-  <ItemGroup>
-    <None Include="..\..\LICENSE.txt">
-      <Pack>True</Pack>
-      <PackagePath></PackagePath>
-    </None>
+  <ItemGroup Condition=" '$(TargetFramework)' == 'Xamarin.iOS10' ">
+	<Reference Include="Xamarin.iOS" />
+	<Reference Include="System" />
+	<Reference Include="System.Core" />
+	<Reference Include="System.Xml" />
+	<Reference Include="Microsoft.CSharp" />
+	<PackageReference Include="Newtonsoft.Json" Version="11.0.1" />
+	<PackageReference Include="System.Net.Http" Version="4.3.3" />
+  </ItemGroup>
+  <ItemGroup Condition=" '$(TargetFramework)' == 'MonoAndroid70' ">
+	<Reference Include="Mono.Android" />
+	<Reference Include="System" />
+	<Reference Include="System.Core" />
+	<Reference Include="System.Xml" />
+	<Reference Include="Microsoft.CSharp" />
+	<PackageReference Include="Newtonsoft.Json" Version="11.0.1" />
+	<PackageReference Include="System.Net.Http" Version="4.3.3" />
+	<PackageReference Include="System.ValueTuple" Version="4.3.0" />
   </ItemGroup>
   <ItemGroup>
-    <PackageReference Include="System.ValueTuple" Version="4.3.0" />
+	<None Include="..\..\LICENSE.txt">
+	  <Pack>True</Pack>
+	  <PackagePath></PackagePath>
+	</None>
   </ItemGroup>
 </Project>

src/Microsoft.Graph.Core/Requests/Content/BatchRequestContent.cs

@@ -208,6 +208,12 @@ private string GetRelativeUrl(Uri requestUri)
             return requestUri.AbsoluteUri.Substring(requestUri.AbsoluteUri.IndexOf(version) + version.ToCharArray().Count());
         }
 
+        /// <summary>
+        /// Serialize the HTTP content to a stream as an asynchronous operation.
+        /// </summary>
+        /// <param name="stream">The target stream.</param>
+        /// <param name="context">Information about the transport (channel binding token, for example). This parameter may be null.</param>
+        /// <returns></returns>
         protected override async Task SerializeToStreamAsync(Stream stream, TransportContext context)
         {
             using (StreamWriter streamWritter = new StreamWriter(stream, new UTF8Encoding(), 1024, true))
@@ -218,6 +224,11 @@ protected override async Task SerializeToStreamAsync(Stream stream, TransportCon
             }
         }
 
+        /// <summary>
+        /// Determines whether the HTTP content has a valid length in bytes.
+        /// </summary>
+        /// <param name="length">The length in bytes of the HHTP content.</param>
+        /// <returns></returns>
         protected override bool TryComputeLength(out long length)
         {
             length = -1;

src/Microsoft.Graph.Core/Requests/FeatureFlag.cs

@@ -10,25 +10,25 @@ namespace Microsoft.Graph
     [Flags]
     public enum FeatureFlag
     {
-        // None set
+        /// None set
         None = 0x00000000,
-        // Redirect Handler
+        /// Redirect Handler
         RedirectHandler = 0x00000001,
-        // Retry Handler
+        /// Retry Handler
         RetryHandler = 0x00000002,
-        // Auth Handler
+        /// Auth Handler
         AuthHandler = 0x00000004,
-        // Default Handler
+        /// Default Handler
         DefaultHttpProvider = 0x00000008,
-        // Logging Handler
+        /// Logging Handler
         LoggingHandler = 0x00000010,
-        // Service Discovery Handler
+        /// Service Discovery Handler
         ServiceDiscoveryHandler = 0x00000020,
-        // Compression Handler
+        /// Compression Handler
         CompressionHandler = 0x00000040,
-        // Connection Pool Manager
+        /// Connection Pool Manager
         ConnectionPoolManager = 0x00000080,
-        // Long Running Operation Handler 
-        LongRunnungOperationHandler = 0x00000100
+        /// Long Running Operation Handler 
+        LongRunningOperationHandler = 0x00000100
     }
 }

src/Microsoft.Graph.Core/Requests/GraphClientFactory.cs

@@ -10,7 +10,6 @@ namespace Microsoft.Graph
     using System.Net.Http;
     using System.Reflection;
     using System.Net.Http.Headers;
-
     /// <summary>
     /// GraphClientFactory class to create the HTTP client
     /// </summary>
@@ -93,11 +92,17 @@ public static HttpClient Create(
             HttpMessageHandler finalHandler = null)
         {
             if (finalHandler == null)
-                finalHandler = new HttpClientHandler { Proxy = proxy, AllowAutoRedirect = false };
+            {
+                finalHandler = GetNativePlatformHttpHandler(proxy);
+            }
             else if ((finalHandler is HttpClientHandler) && (finalHandler as HttpClientHandler).Proxy == null && proxy != null)
+            {
                 (finalHandler as HttpClientHandler).Proxy = proxy;
+            }
             else if ((finalHandler is HttpClientHandler) && (finalHandler as HttpClientHandler).Proxy != null && proxy != null)
+            {
                 throw new ArgumentException(ErrorConstants.Messages.InvalidProxyArgument);
+            }
 
             var pipelineWithFlags = CreatePipelineWithFeatureFlags(handlers, finalHandler);
             HttpClient client = new HttpClient(pipelineWithFlags.Pipeline);
@@ -156,14 +161,21 @@ internal static (HttpMessageHandler Pipeline, FeatureFlag FeatureFlags) CreatePi
             FeatureFlag handlerFlags = FeatureFlag.None;
             if (finalHandler == null)
             {
-                finalHandler = new HttpClientHandler { AllowAutoRedirect = false };
+                finalHandler = GetNativePlatformHttpHandler();
             }
 
             if (handlers == null)
             {
                 return (Pipeline: finalHandler, FeatureFlags: handlerFlags);
             }
-
+#if iOS
+            // Remove CompressionHandler because NSUrlSessionHandler automatically handles decompression and it can't be turned off.
+            // See issue https://github.com/microsoftgraph/msgraph-sdk-dotnet/issues/481 for more details.
+            if (finalHandler.GetType() == typeof(NSUrlSessionHandler))
+            {
+                RemoveHandler(handlers.ToList(), typeof(CompressionHandler));
+            }
+#endif
             HttpMessageHandler httpPipeline = finalHandler;
             IEnumerable<DelegatingHandler> reversedHandlers = handlers.Reverse();
             HashSet<Type> existingHandlerTypes = new HashSet<Type>();
@@ -179,7 +191,7 @@ internal static (HttpMessageHandler Pipeline, FeatureFlag FeatureFlags) CreatePi
                     throw new ArgumentException(String.Format("DelegatingHandler array has unexpected InnerHandler. {0} has unexpected InnerHandler.", handler, "handler"));
                 }
 
-                // Add duplicate check based on handler type.
+                // Check for duplicate handler by type.
                 if (!existingHandlerTypes.Add(handler.GetType()))
                     throw new ArgumentException($"DelegatingHandler array has a duplicate handler. {handler} has a duplicate handler.", "handlers");
 
@@ -193,6 +205,42 @@ internal static (HttpMessageHandler Pipeline, FeatureFlag FeatureFlags) CreatePi
             return (Pipeline: httpPipeline, FeatureFlags: handlerFlags);
         }
 
+        /// <summary>
+        /// Gets a platform's native http handler i.e. NSUrlSessionHandler for Xamarin.iOS, AndroidClientHandler for Xamarin.Android and HttpClientHandler for others.
+        /// </summary>
+        /// <param name="proxy">The proxy to be used with created client.</param>
+        /// <returns>
+        /// 1. NSUrlSessionHandler for Xamarin.iOS 
+        /// 2. AndroidClientHandler for Xamarin.Android.
+        /// 3. HttpClientHandler for other platforms.
+        /// </returns>
+        internal static HttpMessageHandler GetNativePlatformHttpHandler(IWebProxy proxy = null)
+        {
+#if iOS
+            return new NSUrlSessionHandler { AllowAutoRedirect = false };
+#elif ANDROID
+            return new Xamarin.Android.Net.AndroidClientHandler { Proxy = proxy, AllowAutoRedirect = false, AutomaticDecompression = DecompressionMethods.None };
+#else
+            return new HttpClientHandler { Proxy = proxy, AllowAutoRedirect = false, AutomaticDecompression = DecompressionMethods.None };
+#endif
+        }
+
+        /// <summary>
+        /// Removes the specified targetHandlerType from the provided list of delegatingHandlers.
+        /// </summary>
+        /// <param name="delegatingHandlers">The list of <see cref="DelegatingHandler"/> to remove a <see cref="DelegatingHandler"/> type from.</param>
+        /// <param name="targetHandlerType">The <see cref="DelegatingHandler"/> type to remove.</param>
+        /// <returns></returns>
+        internal static bool RemoveHandler(IList<DelegatingHandler> delegatingHandlers, Type targetHandlerType)
+        {
+            if (delegatingHandlers == null)
+            {
+                throw new ArgumentNullException(nameof(delegatingHandlers), "DelegatingHandler list is null.");
+            }
+
+            return delegatingHandlers.Remove(delegatingHandlers.FirstOrDefault((h) => h.GetType().Equals(targetHandlerType)));
+        }
+
         /// <summary>
         /// Gets feature flag for the specified handler.
         /// </summary>

src/Microsoft.Graph.Core/Requests/HttpProvider.cs

@@ -65,8 +65,8 @@ public HttpProvider(HttpMessageHandler httpMessageHandler, bool disposeHandler,
             // This check won't be needed once we re-write the HttpProvider to work with GraphClientFactory.
             if (this.httpMessageHandler == null)
             {
-                this.httpMessageHandler = new HttpClientHandler { AllowAutoRedirect = false };
-                this.httpClient = GraphClientFactory.Create(authenticationProvider: null, version: "v1.0", nationalCloud: GraphClientFactory.Global_Cloud, finalHandler: httpMessageHandler);
+                this.httpMessageHandler = GraphClientFactory.GetNativePlatformHttpHandler();
+                this.httpClient = GraphClientFactory.Create(authenticationProvider: null, version: "v1.0", nationalCloud: GraphClientFactory.Global_Cloud, finalHandler: this.httpMessageHandler);
             }
             else
             {

src/Microsoft.Graph.Core/Requests/Middleware/RetryHandler.cs

@@ -13,7 +13,7 @@ namespace Microsoft.Graph
     using System.Net.Http.Headers;
 
     /// <summary>
-    /// An <see cref="DelegatingHandler"/> implementation using standard .NET libraries.
+    /// A <see cref="DelegatingHandler"/> implementation using standard .NET libraries.
     /// </summary>
     public class RetryHandler : DelegatingHandler
     {

src/Microsoft.Graph.Core/Requests/ResponseHandler.cs

@@ -9,10 +9,16 @@ namespace Microsoft.Graph
     using System.Net.Http;
     using System.Threading.Tasks;
 
+    /// <summary>
+    /// Provides method(s) to deserialize raw HTTP responses into strong types.
+    /// </summary>
     public class ResponseHandler
     {
         private readonly ISerializer serializer;
-
+        /// <summary>
+        /// Constructs a new <see cref="ResponseHandler"/>.
+        /// </summary>
+        /// <param name="serializer"></param>
         public ResponseHandler(ISerializer serializer)
         {
             this.serializer = serializer;

src/Microsoft.Graph.Core/Tasks/PageIterator.cs

@@ -3,11 +3,11 @@
 using System.Threading;
 using System.Threading.Tasks;
 
-/**
+/*
 
 Spec
     https://github.com/microsoftgraph/msgraph-sdk-design/blob/master/tasks/PageIteratorTask.md
-**/
+*/
 
 namespace Microsoft.Graph
 {