How to serialize ExpandoObject using ServiceStack JsonSerializer?

Question

Is it possible to get ServiceStack JsonSerializer to serialize ExpandoObject as a flat object, not a dictionary? Something roughly approximate:

{"x":"xvalue","y":"\/Date(1313966045485)\/"} 

I am trying to compare JSON serialization of ExpandoObject using three different systems: .NET BCL JavaScriptSerializer, Newtonsoft JSON.NET and ServiceStack JSON.

I start with a fairly simple dynamic object.

 dynamic test = new ExpandoObject(); test.x = "xvalue"; test.y = DateTime.Now; 

It seems easier for the serializer to consider ExpandoObject as an IDictionary<string, object> . Both BCL and ServiceStack begin this way, although they go on different routes with the result.

 JavaScriptSerializer javaScriptSerializer = new JavaScriptSerializer(); Console.WriteLine(javaScriptSerializer.Serialize(test)); // [{"Key":"x","Value":"xvalue"},{"Key":"y","Value":"\/Date(1313966045485)\/"}] Console.WriteLine(ServiceStack.Text.JsonSerializer.SerializeToString(test)); // ["[x, xvalue]","[y, 8/21/2011 16:59:34 PM]"] 

I would prefer ExpandoObject to serialize more, since it is compiled in code, since a typical class will be serialized. You can add an overriding JavaScript serializer to the BCL system for IDictionary<string, object> . This works fine if there really is no IDictionary<string, object> that should remain that way (which I don't know yet).

 JavaScriptSerializer javaScriptSerializer = new JavaScriptSerializer(); javaScriptSerializer.RegisterConverters(new JavaScriptConverter[] { new ExpandoJsonConverter() }); Console.WriteLine(javaScriptSerializer.Serialize(test)); // {"x":"xvalue","y":"\/Date(1313966045485)\/"} 

Unfortunately, I still need a way to get the ServiceStack JsonSerializer to treat ExpandoObject in the same way. How to connect to a ServiceStack system to make this possible?

Update: While this is not an option for my purposes, it seems that ServiceStack does a great job with anonymous objects.

 Console.WriteLine(ServiceStack.Text.JsonSerializer.SerializeToString(new { x = "xvalue", y = DateTime.Now })); // {"x":"xvalue","y":"\/Date(1313980029620+0000)\/"} 

Answer 1

There are no hooks available in the ServiceStack JsonSerializer that you can hook to change this behavior, but I will gladly take a pull request that does this;)

The classes you need to change are:

• JsWriter.cs (line 223) - paste the code to detect the expando object and return the delegate that writes the expando object as you want it
• JsReader (line 42) - paste the code to find the expando object and return the delegate to read the contents of the line and deserialize it back to expando

I assume that the code for working with the expando object is like a dictionary, so you should be able to use dictionary implementation classes for guidance (i.e. WriteDictionary.cs and DeserializeDictionary.cs )

Feel free to use the ServiceStack forum if you have more questions / questions on this subject: https://groups.google.com/forum/#!forum/servicestack