Add ability to set up HttpWebRequest properties

Most of HttpWebRequest properties are not implemented on .NET Core,
but they are exist on other platforms such as Xamarin and .NET, so we can try to find the properties by Reflection and call setter on them, if property does not exists just do usual way

Author: xplicit

src/ServiceStack.Text/PclExport.Net40.cs

@@ -545,6 +545,26 @@ public override void Config(HttpWebRequest req,
             if (preAuthenticate.HasValue) req.PreAuthenticate = preAuthenticate.Value;
         }
 
+        public override void SetUserAgent(HttpWebRequest httpReq, string value)
+        {
+            httpReq.UserAgent = value;
+        }
+
+        public override void SetContentLength(HttpWebRequest httpReq, long value)
+        {
+            httpReq.ContentLength = value;
+        }
+
+        public override void SetAllowAutoRedirect(HttpWebRequest httpReq, bool value)
+        {
+            httpReq.AllowAutoRedirect = value;
+        }
+
+        public override void SetKeepAlive(HttpWebRequest httpReq, bool value)
+        {
+            httpReq.KeepAlive = value;
+        }
+
         public override string GetStackTrace()
         {
             return Environment.StackTrace;

src/ServiceStack.Text/PclExport.NetStandard.cs

@@ -13,10 +13,10 @@
 using System.Reflection;
 using System.Reflection.Emit;
 using System.Runtime.InteropServices;
+using System.Net;
 
 #if NETSTANDARD1_3
 using System.Collections.Specialized;
-using System.Net;
 using System.Linq.Expressions;
 #endif
 
@@ -54,6 +54,27 @@ public class NetStandardPclExport : PclExport
             "--MM--zzzzzz",
         };
 
+        static readonly Action<HttpWebRequest, string> SetUserAgentDelegate =
+            (Action<HttpWebRequest, string>)typeof(HttpWebRequest)
+                .GetProperty("UserAgent")
+                ?.SetMethod()?.CreateDelegate(typeof(Action<HttpWebRequest, string>));
+
+        static readonly Action<HttpWebRequest, bool> SetAllowAutoRedirectDelegate =
+            (Action<HttpWebRequest, bool>)typeof(HttpWebRequest)
+                .GetProperty("AllowAutoRedirect")
+                ?.SetMethod()?.CreateDelegate(typeof(Action<HttpWebRequest, bool>));
+
+        static readonly Action<HttpWebRequest, bool> SetKeepAliveDelegate =
+            (Action<HttpWebRequest, bool>)typeof(HttpWebRequest)
+                .GetProperty("KeepAlive")
+                ?.SetMethod()?.CreateDelegate(typeof(Action<HttpWebRequest, bool>));
+
+        static readonly Action<HttpWebRequest, long> SetContentLengthDelegate =
+            (Action<HttpWebRequest, long>)typeof(HttpWebRequest)
+                .GetProperty("ContentLength")
+                ?.SetMethod()?.CreateDelegate(typeof(Action<HttpWebRequest, long>));
+
+
         public NetStandardPclExport()
         {
             this.PlatformName = Platforms.NetStandard;
@@ -470,17 +491,48 @@ public override ParseStringDelegate GetJsReaderParseMethod<TSerializer>(Type typ
             return null;
         }
 
-#if NETSTANDARD1_3
+        public override void SetUserAgent(HttpWebRequest httpReq, string value)
+        {
+            if (SetUserAgentDelegate != null)
+            {
+                SetUserAgentDelegate(httpReq, value);
+            } else 
+            {
+                httpReq.Headers[HttpRequestHeader.UserAgent] = value;
+            }
+        }
+
+        public override void SetContentLength(HttpWebRequest httpReq, long value)
+        {
+            if (SetContentLengthDelegate != null)
+            {
+                SetContentLengthDelegate(httpReq, value);
+            } else 
+            {
+                httpReq.Headers[HttpRequestHeader.ContentLength] = value.ToString();
+            }
+        }
+
+        public override void SetAllowAutoRedirect(HttpWebRequest httpReq, bool value)
+        {
+            SetAllowAutoRedirectDelegate?.Invoke(httpReq, value);
+        }
+
+        public override void SetKeepAlive(HttpWebRequest httpReq, bool value)
+        {
+            SetKeepAliveDelegate?.Invoke(httpReq, value);
+        }
+
         public override void InitHttpWebRequest(HttpWebRequest httpReq,
             long? contentLength = null, bool allowAutoRedirect = true, bool keepAlive = true)
         {
-            httpReq.Headers[HttpRequestHeader.UserAgent] = Env.ServerUserAgent;
-            //httpReq.AllowAutoRedirect = allowAutoRedirect;
-            //httpReq.KeepAlive = keepAlive;
+            SetUserAgent(httpReq, Env.ServerUserAgent);
+            SetAllowAutoRedirect(httpReq, allowAutoRedirect);
+            SetKeepAlive(httpReq, keepAlive);
 
             if (contentLength != null)
             {
-                httpReq.Headers[HttpRequestHeader.ContentLength] = contentLength.Value.ToString();
+                SetContentLength(httpReq, contentLength.Value);
             }
         }
 
@@ -492,13 +544,14 @@ public override void Config(HttpWebRequest req,
             bool? preAuthenticate = null)
         {
             //req.MaximumResponseHeadersLength = int.MaxValue; //throws "The message length limit was exceeded" exception
-            //if (allowAutoRedirect.HasValue) req.AllowAutoRedirect = allowAutoRedirect.Value;
+            if (allowAutoRedirect.HasValue) SetAllowAutoRedirect(req, allowAutoRedirect.Value);
             //if (readWriteTimeout.HasValue) req.ReadWriteTimeout = (int)readWriteTimeout.Value.TotalMilliseconds;
             //if (timeout.HasValue) req.Timeout = (int)timeout.Value.TotalMilliseconds;
             if (userAgent != null) req.Headers[HttpRequestHeader.UserAgent] = userAgent;
             //if (preAuthenticate.HasValue) req.PreAuthenticate = preAuthenticate.Value;
         }
 
+#if NETSTANDARD1_3
         public override string GetStackTrace()
         {
             return Environment.StackTrace;

src/ServiceStack.Text/PclExport.cs

@@ -264,6 +264,24 @@ public virtual void AddHeader(WebRequest webReq, string name, string value)
             webReq.Headers[name] = value;
         }
 
+        public virtual void SetUserAgent(HttpWebRequest httpReq, string value)
+        {
+            httpReq.Headers[HttpRequestHeader.UserAgent] = value;
+        }
+
+        public virtual void SetContentLength(HttpWebRequest httpReq, long value)
+        {
+            httpReq.Headers[HttpRequestHeader.ContentLength] = value.ToString();
+        }
+
+        public virtual void SetAllowAutoRedirect(HttpWebRequest httpReq, bool value)
+        {
+        }
+
+        public virtual void SetKeepAlive(HttpWebRequest httpReq, bool value)
+        {
+        }
+
         public virtual Assembly[] GetAllAssemblies()
         {
             return new Assembly[0];

src/ServiceStack.Text/ReflectionExtensions.cs

@@ -88,19 +88,11 @@ internal static TypeInfo GetTypeInfo(this Type type)
 #endif
 
 #if NETSTANDARD1_1
-        private static readonly Func<Type, object> GetUninitializedObjectDelegate;
-
-        static ReflectionExtensions()
-        {
-            var formatterServices = typeof(string).GetTypeInfo().Assembly
-               .GetType("System.Runtime.Serialization.FormatterServices");
-            if (formatterServices != null)
-            {
-                var method = formatterServices.GetMethod("GetUninitializedObject");
-                if (method != null)
-                    GetUninitializedObjectDelegate = (Func<Type, object>)method.CreateDelegate(typeof(Func<Type, object>));
-            }
-        }
+        private static readonly Func<Type, object> GetUninitializedObjectDelegate = 
+            (Func<Type, object>) typeof(string).GetTypeInfo().Assembly
+               .GetType("System.Runtime.Serialization.FormatterServices")
+               ?.GetMethod("GetUninitializedObject")
+               ?.CreateDelegate(typeof(Func<Type, object>));
 #endif
 
         public static TypeCode GetTypeCode(this Type type)