JSON.Net - Change $type field to another name?

Question

When using Json.Net, I understand how to get the $type property into the rendered json, but is there a way to change that field name? I need to use "__type" instead of "$type".

Answer 1

http://json.codeplex.com/workitem/22429

"I would rather keep $type hard coded and consistent."

Consistent with what I wonder?

http://json.codeplex.com/workitem/21989

I would rather not - I think this is too specific to me and I don't want to go overboard with settings. At some point I will probably implement this - http://json.codeplex.com/workitem/21856 - allowing people to read/write there own meta properties in the JSON and you could reimplement type name handling with a new property name. The other option is just to modify the source code for yourself to have that property name.

And more recently, Issue #36: Customizable $type property name feature:

I'd rather not

This is my solution...

json.Replace("\"$type\": \"", "\"type\": \"");

Answer 2

Looks like this is hardcoded as public const string TypePropertyName = "$type"; in Newtonsoft.Json.Serialization.JsonTypeReflector which is internal static class unfortunately.

I needed this myself, and the only thing I can think of is having custom modified version of json.net itself. Which is of course is a major pita.

Answer 3

when serializing, there is a nice way to override the property name:

public class CustomJsonWriter : JsonTextWriter
{
    public CustomJsonWriter(TextWriter writer) : base(writer)
    {
    }

    public override void WritePropertyName(string name, bool escape)
    {
        if (name == "$type") name = "__type";
        base.WritePropertyName(name, escape);
    }
}

var serializer = new JsonSerializer();
var writer = new StreamWriter(stream) { AutoFlush = true };
serializer.Serialize(new CustomJsonWriter(writer), objectToSerialize);

I haven't tried deserialization yet, but in worst case I could use:

json.Replace("\"__type": \"", "\"type\": \"$type\");