How does the client pass parameter to a RESTful WCF Service

Question

I am building a RESTful service as below with 2 methods (NOTE: I have the ASPNETCompatilibilityMode set to true):

[WebInvoke]
string TestMethodA()
{
        string test = HttpContext.Current.Request.Form["xml"];
}

[WebInvoke]
string TestMethodB(string res)
{
        string xml = res;
}

Now when building the client in order to pass parameter to MethodA i do the following:

request.AddParameter("xmlString", HttpUtility.HtmlEncode(requestBody));

And for sending message to MethodB i do the following:

request.AddParameter("text/xml",requestBody, ParameterType.RequestBody);

Now the question is:

How does the client know on how to pass the parameter? The client is not aware of the server implementation.

The client that sends the request is using RestSharp Api.

Your service has knowledge of the infrastructure (in this case HTTP to look in the request body) which generally is not ideal. Why not just make TestMethodA take a string and then always call your methods the same way? That way your service will work even when not hosted on an http binding and your client just has one way it needs to know how to call the service. — kmp, Dec 21 '11 at 15:48

score 0 · Answer 1 · answered Mar 16 '12 at 02:12

Since MethodB() take a string, WCF has no idea what it should look like. It could be XML, JSON, free text, whatever. In your implementation, you'll just have to document how to format the request and give that to whoever is implementing the client.

A better approach would be to create a C# object, mark it up with appropriate serialization attributes, and use that as the parameter to MethodB(). For example:

[DataContract]
public class MyDataContract{

    [DataMember]
    public string SomeString{get;set;}

    [DataMember]
    public int SomeNumber{get;set;}    
}

public void MethodB(MyDataContract arguments){
  //do stuff

}

This will allow the WCF infrastructure to automatically parse the arguments. You can also have WCF autogenerate help documentation from this.

How does the client pass parameter to a RESTful WCF Service

1 Answers1