Archives

• Jun 26 2006

  Json.NET - Simplifying .NET <-> JavaScript communication

  JSON (JavaScript Object Notation) is lightweight data interchange format. In recent times JSON has achieved widespread use due to the ease of which it can be parsed and then the data accessed from within JavaScript compared to alternatives like XML.

  While many JavaScript libraries exist for converting JSON text to and from a JavaScript object, working with JSON in .NET has been much more problematic. Correctly escaping strings and building up objects when writing JSON text can be difficult and error prone, while parsing values back out of JSON text is harder still.

  Json.NET

  Json.NET is a JSON .NET API for simply and safely reading and writing valid JSON text. At the core of Json.NET, similar to the .NET XML APIs, are two classes: JsonReader and JsonWriter. Also like XML in .NET, Json.NET includes a JsonSerializer class.

  Reading JSON

  JsonReader is a fast, forward only, readonly cursor. Like XmlTextReader it works over the top of a TextReader and maximizes performance while minimizing memory use.

  The following code is a brief example of how to read a JSON object.

  string jsonText = "['JSON!',1,true,{property:'value'}]";

  JsonReader reader = new JsonReader(new StringReader(jsonText));

  Console.WriteLine("TokenType\t\tValueType\t\tValue");

  while (reader.Read())

  {

      Console.WriteLine(reader.TokenType + "\t\t" + WriteValue(reader.ValueType) + "\t\t" + WriteValue(reader.Value))

  }

  Resulting in...

  TokenType	ValueType	Value
  StartArray	null	null
  String	System.String	JSON!
  Integer	System.Int32	1
  Boolean	System.Boolean	True
  StartObject	null	null
  PropertyName	System.String	property
  String	System.String	value
  EndObject	null	null
  EndArray	null	null

  Writing JSON

  JsonWriter is also forward only, and writes JSON text to a TextWriter. It handles formatting numbers, escaping strings and validating that the object is valid.

  The following code is a brief example of how to write a JSON object.

  StringWriter sw = new StringWriter();

  JsonWriter writer = new JsonWriter(sw);

  writer.WriteStartArray();

  writer.WriteValue("JSON!");

  writer.WriteValue(1);

  writer.WriteValue(true);

  writer.WriteStartObject();

  writer.WritePropertyName("property");

  writer.WriteValue("value");

  writer.WriteEndObject();

  writer.WriteEndArray();

  writer.Flush();

  string jsonText = sw.GetStringBuilder().ToString();

  Console.WriteLine(jsonText);

  // ['JSON!',1,true,{property:'value'}]

  Which prints out: ['JSON!',1,true,{property:'value'}].

  Serializing and deserializing JSON and .NET objects

  JsonSerializer, similar to XML serialization, provides a hassle free way to automatically convert .NET objects to and from JSON text.

  The following code is a brief example of how to serialize and deserialize JSON and .NET objects.

  string jsonText = "['JSON!',1,true,{property:'value'}]";

  JsonSerializer serializer = new JsonSerializer();

  JavaScriptArray jsArray = (JavaScriptArray) serializer.Deserialize(new JsonReader(new StringReader(jsonText)));

  Console.WriteLine(jsArray[0]);

  // JSON!

  JavaScriptObject jsObject = (JavaScriptObject)jsArray[3];

  Console.WriteLine(jsObject["property"]);

  // value

  StringWriter sw = new StringWriter();

  using (JsonWriter jsonWriter = new JsonWriter(sw))

  {

      serializer.Serialize(sw, jsArray);

  }

  Console.WriteLine(sw.GetStringBuilder().ToString());

  // ['JSON!',1,true,{property:'value'}]

  Json.NET - Json.NET Homepage

• Jun 17 2006

  Getting into WinFX... sorry .NET 3.0

  Beta 2 of WinFX was released a couple of weeks ago. Even though I've been quite excited about what Microsoft has been doing with WinFX, I've learn't to stear clear of Microsoft community previews and the beta 1 release. APIs are too volatile, there is little support out on the web for when you run into problems (which you will) and chances are that even when a more stable version does get released something from a previous version will cause problems. CTP Madness indeed.

  Strangely, even before I'd managed to install WinFX it ceased to exist. A name changed was announced, with WinFX now a part of .NET. Although there has been much nashing of teeth and rendering of clothing both from the usual suspects and some Microsoft developers, I believe the name change was a good move. One name are one download will be less confusing for users and to most developers. All they need to know is that to run or develop an application they need a specific version of .NET. Having to worry about X version of .NET, Y version of WinFX, plus whatever else comes out in the next couple of years is too much for most and really, 99% of the public don't need to know. One download, one name. KISS.

  Back on task; first .NET 3.0 impression:

  

  Hmmm, this may take a while.