Imported Upstream version 3.6.0

Former-commit-id: da6be194a6b1221998fc28233f2503bd61dd9d14

external/aspnetwebstack/src/System.Web.Helpers/Json.cs

@@ -0,0 +1,72 @@
+// Copyright (c) Microsoft Corporation. All rights reserved. See License.txt in the project root for license information.
+
+using System.Collections.Generic;
+using System.IO;
+using System.Web.Script.Serialization;
+
+namespace System.Web.Helpers
+{
+    public static class Json
+    {
+        private static readonly JavaScriptSerializer _serializer = CreateSerializer();
+
+        public static string Encode(object value)
+        {
+            // Serialize our dynamic array type as an array
+            DynamicJsonArray jsonArray = value as DynamicJsonArray;
+            if (jsonArray != null)
+            {
+                return _serializer.Serialize((object[])jsonArray);
+            }
+
+            return _serializer.Serialize(value);
+        }
+
+        public static void Write(object value, TextWriter writer)
+        {
+            writer.Write(_serializer.Serialize(value));
+        }
+
+        public static dynamic Decode(string value)
+        {
+            return WrapObject(_serializer.DeserializeObject(value));
+        }
+
+        public static dynamic Decode(string value, Type targetType)
+        {
+            return WrapObject(_serializer.Deserialize(value, targetType));
+        }
+
+        public static T Decode<T>(string value)
+        {
+            return _serializer.Deserialize<T>(value);
+        }
+
+        private static JavaScriptSerializer CreateSerializer()
+        {
+            JavaScriptSerializer serializer = new JavaScriptSerializer();
+            serializer.RegisterConverters(new[] { new DynamicJavaScriptConverter() });
+            return serializer;
+        }
+
+        internal static dynamic WrapObject(object value)
+        {
+            // The JavaScriptSerializer returns IDictionary<string, object> for objects
+            // and object[] for arrays, so we wrap those in different dynamic objects
+            // so we can access the object graph using dynamic
+            var dictionaryValues = value as IDictionary<string, object>;
+            if (dictionaryValues != null)
+            {
+                return new DynamicJsonObject(dictionaryValues);
+            }
+
+            var arrayValues = value as object[];
+            if (arrayValues != null)
+            {
+                return new DynamicJsonArray(arrayValues);
+            }
+
+            return value;
+        }
+    }
+}