WCF ResponseFormat For WebGet

Question

WCF offers two options for ResponseFormat attribute in WebGet annotation in ServiceContract.

[ServiceContract]
public interface IService1
{
    [OperationContract]
    [WebGet(UriTemplate = "greet/{value}", BodyStyle = WebMessageBodyStyle.Bare)]
    string GetData(string value);

    [OperationContract]
    [WebGet(UriTemplate = "foo", BodyStyle = WebMessageBodyStyle.Bare, ResponseFormat = WebMessageFormat.Json)]
    string Foo();

The options for ResponseFormat are WebMessageFormat.Json and WebMessageFormat.Xml. Is it possible to write my own web message format? I would like that when client calls foo() method he gets raw string - without json or xml wrappers.

Answer 1

WebGetAttribute is shipped by Microsoft, and I don't think you can extend WebMessageFormat. However you could probably extend the WebHttpBinding that uses WebGetAttribute. You could add your own attribute like

[WebGet2(UriTemplate = "foo", ResponseFormat = WebMessageFormat2.PlainText)]
string Foo();

In general, customizing the message layout in WCF is called custom message encoder/encoding. Microsoft provides an example: Custom Message Encoder: Compression Encoder. Also another common extension people do is to extend behavior to add custom error handling, so you could look for some example in that direction.