Question

Im trying to get WebFaultException to be returns as json and xml depending on what the client asks for as described in

http://blogs.msdn.com/b/endpoint/archive/2010/01/21/error-handling-in-wcf-webhttp-services-with-webfaultexception.aspx

My service interface looks like this

    [OperationContract]
    [WebInvoke(Method = "POST", UriTemplate = "session_record?id={id}&command={command}")]
    void SessionRecord(Guid id, String command);

The exception

throw new WebFaultException<string>("Session not started", HttpStatusCode.Conflict);

Web.config service setup

<system.serviceModel>
<serviceHostingEnvironment aspNetCompatibilityEnabled="true" multipleSiteBindingsEnabled="true" />
<behaviors>
  <serviceBehaviors>
    <behavior>
      <serviceMetadata httpGetEnabled="true" />
      <serviceDebug includeExceptionDetailInFaults="true" />
    </behavior>
  </serviceBehaviors>
</behaviors>
<standardEndpoints>
  <webHttpEndpoint>
    <standardEndpoint name="" helpEnabled="true" faultExceptionEnabled="true" automaticFormatSelectionEnabled="true"  />
  </webHttpEndpoint>
</standardEndpoints>

My client call to the service

$.ajax({
            url: "Webservice/session_record?id={id}&command={command}".format({ id: $("#sessionGuid").val(), command : "start" }),
            type: "POST",
            dataType: "json",
            contentType: "application/json; charset=utf-8",
            success: function (data) {
                alert("Started");
            }
        });

I would except to receive json from the server, but i get xml

And as i read it in the link i have posted i should be possible

With the WebFaultException, the detail of the exception that is serialized in the body of >the response message will always be in the format (XML or JSON) that the client would have >received had there not been an error. If the client was expecting XML, the client will >get the exception detail serialized as XML. Likewise, if the client was expecting JSON, >the client will get the exception detail serialized as JSON.

Answer 1

I found the solution; faultExceptionEnabled needed to be false. Now I get the exception in json.