Archives / 2010 / August
  • Json.NET 3.5 Release 8 – 3.5 Final

    Baring any terrible, terrible damage bugs, Release 8 will be the final 3.5 version of Json.NET.


    Json.NET supports including type information in JSON. In the past this was a global flag to include type names for every object. The last release of Json.NET added TypeNameHandling as a flag on JsonPropertyAttribute, allowing type names to be included only for specified values.

    public class Message
      public string Address { get; set; }
      [JsonProperty(TypeNameHandling = TypeNameHandling.All)]
      public object Body { get; set; }
    public class SearchDetails
      public string Query { get; set; }
      public string Language { get; set; }

    Any payload of data can be assigned to Message.Body and the type name will be included when it is serialized. Json.NET will automatically deserialize back to that type.

    Message message = new Message();
    message.Address = "";
    message.Body = new SearchDetails
        Query = "Json.NET",
        Language = "en-us"
    string json = JsonConvert.SerializeObject(message, Formatting.Indented);
    // {
    //   "Address": "",
    //   "Body": {
    //     "$type": "Newtonsoft.Json.Tests.Serialization.SearchDetails, Newtonsoft.Json.Tests",
    //     "Query": "Json.NET",
    //     "Language": "en-us"
    //   }
    // }
    Message deserialized = JsonConvert.DeserializeObject<Message>(json);
    SearchDetails searchDetails = (SearchDetails) deserialized.Body;
    // Json.NET


    Another new TypeNameHandling feature is TypeNameHandling.Auto. When serializing an object and this flag is set Json.NET will check whether the value of a object matches the property it is declared against. If they aren’t the same, e.g. a property with a type of Mammal has a derived instance of Dog assigned, then Json.NET will automatically include the type name. TypeNameHandling.Auto is pretty neat in that it will ensure that type information isn’t lost for you automatically.


    Here is a complete list of what has changed since Json.NET 3.5 Release 7.

    • New feature - Added TypeNameHandling.Auto to automatically write the type name when a value doesn't match the declared type
    • New feature - Added CLSCompliant attributes
    • New feature - Added Required.Always attribute validation when writing JSON
    • New feature - Added DateTimeKindHandling to BsonWriter to control how a DateTime is converted prior to being serialized
    • New feature - Added SerializeCompilerGeneratedMembers to DefaultContractResolver to control serializing compiler generated fields
    • Change - Improved OverflowException message for integer values larger than an Int64
    • Change - Added interfaces, structs and enums as valid targets of JsonConverterAttribute
    • Change - Added structs as a valid target of JsonObjectAttribute
    • Change - Improved default null and value handing when JSON value is not compatible with property value
    • Change - Serialization attributes now supported in .NET 2.0
    • Change - HtmlColorConverter and System.Drawing.dll dependency removed
    • Fix - Fix reading hexadecimal numbers that contain an e
    • Fix - Generic simple type names no longer include full qualified assembly information for nested generate types
    • Fix - Corrected culture invariance issues
    • Fix - Correct incorrect BSON string reading for multi-byte characters
    • Fix - Fix error when converting a JValue to a compatible type
    • Fix - Fix security exception when generating simple type names on Silverlight
    • Fix - JsonProperty now inherited on overriden properties
    • Fix - JTokenReader.ReadAsBytes no longer errors when reading null token value


    Json.NET CodePlex Project

    Json.NET 3.5 Release 8 Download – Json.NET source code, documentation and binaries