Added support for jsv format output from the api

MediaBrowser.Common/Net/Handlers/BaseSerializationHandler.cs

@@ -0,0 +1,83 @@
+using System.IO;
+using System.Threading.Tasks;
+using MediaBrowser.Common.Serialization;
+using System;
+
+namespace MediaBrowser.Common.Net.Handlers
+{
+    public abstract class BaseJsonHandler<T> : BaseHandler
+    {
+        public SerializationFormat SerializationFormat
+        {
+            get
+            {
+                string format = QueryString["dataformat"];
+
+                if (string.IsNullOrEmpty(format))
+                {
+                    return Handlers.SerializationFormat.Json;
+                }
+
+                return (SerializationFormat)Enum.Parse(typeof(SerializationFormat), format, true);
+            }
+        }
+        
+        public override Task<string> GetContentType()
+        {
+            switch (SerializationFormat)
+            {
+                case Handlers.SerializationFormat.Jsv:
+                    return Task.FromResult<string>("text/plain");
+                default:
+                    return Task.FromResult<string>(MimeTypes.JsonMimeType);
+            }
+        }
+
+        private bool _ObjectToSerializeEnsured = false;
+        private T _ObjectToSerialize;
+     
+        private async Task EnsureObjectToSerialize()
+        {
+            if (!_ObjectToSerializeEnsured)
+            {
+                _ObjectToSerialize = await GetObjectToSerialize().ConfigureAwait(false);
+
+                if (_ObjectToSerialize == null)
+                {
+                    StatusCode = 404;
+                }
+
+                _ObjectToSerializeEnsured = true;
+            }
+        }
+
+        protected abstract Task<T> GetObjectToSerialize();
+
+        protected override Task PrepareResponse()
+        {
+            return EnsureObjectToSerialize();
+        }
+
+        protected async override Task WriteResponseToOutputStream(Stream stream)
+        {
+            await EnsureObjectToSerialize();
+
+            switch (SerializationFormat)
+            {
+                case Handlers.SerializationFormat.Jsv:
+                    JsvSerializer.SerializeToStream<T>(_ObjectToSerialize, stream);
+                    break;
+                default:
+                    JsonSerializer.SerializeToStream<T>(_ObjectToSerialize, stream);
+                    break;
+            }
+        }
+    }
+
+    public enum SerializationFormat
+    {
+        Json,
+        Jsv
+    }
+
+}