Question

When this “quick one hour” project came up I never thought that 2 days later I would be on Stackoverflow asking this question. However, here we go…

I have a number of external client applications (java, perl, php, c#) that are currently calling GET methods on a WCF REST service that returns JSON. This is working fine and is implemented exactly as you would expect.

I now have a requirement for these same applications to POST JSON into an new method on the original service interface. The C# app uses WebClient, Perl and PHP are using CURL, Java is using some magic that I am not involved with. All of them generate the JSON as a string and then call basic HTTP functionality to POST the data to an endpoint.

The issue is that the JSON we are using does not have a C# class associated with it (for reasons that can’t be changed), as such we intend to use strings and json.net to parse/handle the incoming data. As an example, the endpoint could be:

https://magic.myserver.com/service/dataaggregator/

the external applications post a JSON string to this and in the underlying code we parse and handle as necessary.

So the question is a very simple one, how would this be implemented from a service interface perspective? I can handle serialisation/management of the JSON string within the service code without any problems the question is how do I get that string of JSON into the service code in the first place.

At the moment I am thinking that these can’t be done using a “normal” WCF REST interface, rather I will have to implement a lower level HTTP listener where I can access the incoming post data directly.

Answer 1

If you want to accept arbitrary JSON, look here:

http://social.msdn.microsoft.com/Forums/en-US/wcf/thread/071f73bb-e141-4a68-ae61-05635382934f

If that’s not what you want, then you may need to clarify your goals in the question.

See also, https://stackoverflow.com/a/7360619 and https://stackoverflow.com/a/2330219

The service interface is like this:

[OperationContract]
public Whatever  MyMethod(DataPacket rawJSON)
{ 
     ....
}

[DataContract]
public class DataPacket
{
  [DataMember]
  public JsonDictionary Registration { get; set; }
}

…where JsonDictionary is defined according to this answer.

You can also code the method to accept a stream, like this:

[OperationContract]
public Whatever  MyMethod(Stream rawJSON)
{ 
     ....
}

…and parse the JSON yourself, according to this answer.