-Added JsonWriter.SetWriteState to support inheriting and override JsonWriters

Src/Newtonsoft.Json.Tests/JsonTextWriterTest.cs

@@ -26,6 +26,11 @@
 using System;
 using System.Collections.Generic;
 using System.Globalization;
+#if NET20
+using Newtonsoft.Json.Utilities.LinqBridge;
+#else
+using System.Linq;
+#endif
 using System.Runtime.Serialization;
 using System.Text;
 using System.Xml;
@@ -1312,6 +1317,83 @@ _____'propertyName': NaN
       if (appendDelimiters)
         writer.Write(delimiter);
     }
+
+    [Test]
+    public void CustomJsonTextWriterTests()
+    {
+      StringWriter sw = new StringWriter();
+      CustomJsonTextWriter writer = new CustomJsonTextWriter(sw) { Formatting = Formatting.Indented };
+      writer.WriteStartObject();
+      Assert.AreEqual(WriteState.Object, writer.WriteState);
+      writer.WritePropertyName("Property1");
+      Assert.AreEqual(WriteState.Property, writer.WriteState);
+      Assert.AreEqual("Property1", writer.Path);
+      writer.WriteNull();
+      Assert.AreEqual(WriteState.Object, writer.WriteState);
+      writer.WriteEndObject();
+      Assert.AreEqual(WriteState.Start, writer.WriteState);
+
+      Assert.AreEqual(@"{{{
+  ""1ytreporP"": NULL!!!
+}}}", sw.ToString());
+    }
+  }
+
+  public class CustomJsonTextWriter : JsonTextWriter
+  {
+    private readonly TextWriter _writer;
+
+    public CustomJsonTextWriter(TextWriter textWriter) : base(textWriter)
+    {
+      _writer = textWriter;
+    }
+
+    public override void WritePropertyName(string name)
+    {
+      WritePropertyName(name, true);
+    }
+
+    public override void WritePropertyName(string name, bool escape)
+    {
+      SetWriteState(JsonToken.PropertyName, name);
+
+      if (QuoteName)
+        _writer.Write(QuoteChar);
+
+      _writer.Write(new string(name.Reverse().ToArray()));
+
+      if (QuoteName)
+        _writer.Write(QuoteChar);
+
+      _writer.Write(':');
+    }
+
+    public override void WriteNull()
+    {
+      SetWriteState(JsonToken.Null, null);
+
+      _writer.Write("NULL!!!");
+    }
+
+    public override void WriteStartObject()
+    {
+      SetWriteState(JsonToken.StartObject, null);
+
+      _writer.Write("{{{");
+    }
+
+    public override void WriteEndObject()
+    {
+      SetWriteState(JsonToken.EndObject, null);
+    }
+
+    protected override void WriteEnd(JsonToken token)
+    {
+      if (token == JsonToken.EndObject)
+        _writer.Write("}}}");
+      else
+        base.WriteEnd(token);
+    }
   }
 
 #if !(PORTABLE || NETFX_CORE)

Src/Newtonsoft.Json/JsonTextWriter.cs

@@ -329,7 +329,7 @@ namespace Newtonsoft.Json
     /// </summary>
     public override void WriteNull()
     {
-      InternalWriteNull();
+      InternalWriteValue(JsonToken.Null);
       WriteValueInternal(JsonConvert.Null, JsonToken.Null);
     }
 
@@ -338,7 +338,7 @@ namespace Newtonsoft.Json
     /// </summary>
     public override void WriteUndefined()
     {
-      InternalWriteUndefined();
+      InternalWriteValue(JsonToken.Undefined);
       WriteValueInternal(JsonConvert.Undefined, JsonToken.Undefined);
     }
 

Src/Newtonsoft.Json/JsonWriter.cs

@@ -358,13 +358,6 @@ namespace Newtonsoft.Json
       InternalWriteStart(JsonToken.StartObject, JsonContainerType.Object);
     }
 
-    internal void InternalWriteStart(JsonToken token, JsonContainerType container)
-    {
-      UpdateScopeWithFinishedValue();
-      AutoComplete(token);
-      Push(container);
-    }
-
     /// <summary>
     /// Writes the end of a Json object.
     /// </summary>
@@ -406,11 +399,6 @@ namespace Newtonsoft.Json
       InternalWriteEnd(JsonContainerType.Constructor);
     }
 
-    internal void InternalWriteEnd(JsonContainerType container)
-    {
-      AutoCompleteClose(container);
-    }
-
     /// <summary>
     /// Writes the property name of a name/value pair on a JSON object.
     /// </summary>
@@ -430,12 +418,6 @@ namespace Newtonsoft.Json
       WritePropertyName(name);
     }
 
-    internal void InternalWritePropertyName(string name)
-    {
-      _currentPosition.PropertyName = name;
-      AutoComplete(JsonToken.PropertyName);
-    }
-
     /// <summary>
     /// Writes the end of the current Json object or array.
     /// </summary>
@@ -775,13 +757,7 @@ namespace Newtonsoft.Json
     /// </summary>
     public virtual void WriteNull()
     {
-      InternalWriteNull();
-    }
-
-    internal void InternalWriteNull()
-    {
-      UpdateScopeWithFinishedValue();
-      AutoComplete(JsonToken.Null);
+      InternalWriteValue(JsonToken.Null);
     }
 
     /// <summary>
@@ -789,13 +765,7 @@ namespace Newtonsoft.Json
     /// </summary>
     public virtual void WriteUndefined()
     {
-      InternalWriteUndefined();
-    }
-
-    internal void InternalWriteUndefined()
-    {
-      UpdateScopeWithFinishedValue();
-      AutoComplete(JsonToken.Undefined);
+      InternalWriteValue(JsonToken.Undefined);
     }
 
     /// <summary>
@@ -807,10 +777,6 @@ namespace Newtonsoft.Json
       InternalWriteRaw();
     }
 
-    internal void InternalWriteRaw()
-    {
-    }
-
     /// <summary>
     /// Writes raw JSON where a value is expected and updates the writer's state.
     /// </summary>
@@ -832,12 +798,6 @@ namespace Newtonsoft.Json
       InternalWriteValue(JsonToken.String);
     }
 
-    internal void InternalWriteValue(JsonToken token)
-    {
-      UpdateScopeWithFinishedValue();
-      AutoComplete(token);
-    }
-
     /// <summary>
     /// Writes a <see cref="Int32"/> value.
     /// </summary>
@@ -1265,11 +1225,6 @@ namespace Newtonsoft.Json
       InternalWriteComment();
     }
 
-    internal void InternalWriteComment()
-    {
-      AutoComplete(JsonToken.Comment);
-    }
-
     /// <summary>
     /// Writes out the given white space.
     /// </summary>
@@ -1279,15 +1234,6 @@ namespace Newtonsoft.Json
       InternalWriteWhitespace(ws);
     }
 
-    internal void InternalWriteWhitespace(string ws)
-    {
-      if (ws != null)
-      {
-        if (!StringUtils.IsWhiteSpace(ws))
-          throw JsonWriterException.Create(this, "Only white space characters should be used.", null);
-      }
-    }
-
     void IDisposable.Dispose()
     {
       Dispose(true);
@@ -1456,5 +1402,101 @@ namespace Newtonsoft.Json
     {
       return JsonWriterException.Create(writer, "Unsupported type: {0}. Use the JsonSerializer class to get the object's JSON representation.".FormatWith(CultureInfo.InvariantCulture, value.GetType()), null);
     }
+
+    /// <summary>
+    /// Sets the state of the JsonWriter,
+    /// </summary>
+    /// <param name="token">The JsonToken being written.</param>
+    /// <param name="value">The value being written.</param>
+    protected void SetWriteState(JsonToken token, object value)
+    {
+      switch (token)
+      {
+        case JsonToken.StartObject:
+          InternalWriteStart(token, JsonContainerType.Object);
+          break;
+        case JsonToken.StartArray:
+          InternalWriteStart(token, JsonContainerType.Array);
+          break;
+        case JsonToken.StartConstructor:
+          InternalWriteStart(token, JsonContainerType.Constructor);
+          break;
+        case JsonToken.PropertyName:
+          if (!(value is string))
+            throw new ArgumentException("A name is required when setting property name state.", "value");
+
+          InternalWritePropertyName((string)value);
+          break;
+        case JsonToken.Comment:
+          InternalWriteComment();
+          break;
+        case JsonToken.Raw:
+          InternalWriteRaw();
+          break;
+        case JsonToken.Integer:
+        case JsonToken.Float:
+        case JsonToken.String:
+        case JsonToken.Boolean:
+        case JsonToken.Date:
+        case JsonToken.Bytes:
+        case JsonToken.Null:
+        case JsonToken.Undefined:
+          InternalWriteValue(token);
+          break;
+        case JsonToken.EndObject:
+          InternalWriteEnd(JsonContainerType.Object);
+          break;
+        case JsonToken.EndArray:
+          InternalWriteEnd(JsonContainerType.Array);
+          break;
+        case JsonToken.EndConstructor:
+          InternalWriteEnd(JsonContainerType.Constructor);
+          break;
+        default:
+          throw new ArgumentOutOfRangeException("token");
+      }
+    }
+
+    internal void InternalWriteEnd(JsonContainerType container)
+    {
+      AutoCompleteClose(container);
+    }
+
+    internal void InternalWritePropertyName(string name)
+    {
+      _currentPosition.PropertyName = name;
+      AutoComplete(JsonToken.PropertyName);
+    }
+
+    internal void InternalWriteRaw()
+    {
+    }
+
+    internal void InternalWriteStart(JsonToken token, JsonContainerType container)
+    {
+      UpdateScopeWithFinishedValue();
+      AutoComplete(token);
+      Push(container);
+    }
+
+    internal void InternalWriteValue(JsonToken token)
+    {
+      UpdateScopeWithFinishedValue();
+      AutoComplete(token);
+    }
+
+    internal void InternalWriteWhitespace(string ws)
+    {
+      if (ws != null)
+      {
+        if (!StringUtils.IsWhiteSpace(ws))
+          throw JsonWriterException.Create(this, "Only white space characters should be used.", null);
+      }
+    }
+
+    internal void InternalWriteComment()
+    {
+      AutoComplete(JsonToken.Comment);
+    }
   }
 }