Composing a Message in IClientMessageFormatter.SerializeRequest (HTTP GET)

Question

I'm working with WCF Extensibilty and I've created a IClientMessageFormatter that serialize requests via Json-RPC. The code is this one:

    public Message SerializeRequest(MessageVersion messageVersion, object[] parameters)
    {
        string jsonText = SerializeJsonRequestParameters(parameters);

        // Compose message
        Message message = Message.CreateMessage(messageVersion, _clientOperation.Action, new JsonRpcBodyWriter(Encoding.UTF8.GetBytes(jsonText)));
        message.Properties.Add(WebBodyFormatMessageProperty.Name, new WebBodyFormatMessageProperty(WebContentFormat.Raw));
        _address.ApplyTo(message);

        HttpRequestMessageProperty reqProp = new HttpRequestMessageProperty();
        reqProp.Headers[HttpRequestHeader.ContentType] = "application/json";
        message.Properties.Add(HttpRequestMessageProperty.Name, reqProp);

        UriBuilder builder = new UriBuilder(message.Headers.To);
        builder.Query = string.Format("jsonrpc={0}", HttpUtility.UrlEncode(jsonText));
        message.Headers.To = builder.Uri;
        message.Properties.Via = builder.Uri;

        return message;
    }

I was trying to use HttpRequestMessageProperty to force WCF to use GET http verb, but setting the following:

reqProp.Method = "GET";

cause WCF to throw a System.Net.ProtocolViolationException. Can anyone tell me what I'm doing wrong?

Answer 1

Found the answer myself! The GET verb requires the Message to contains no body:

    public Message SerializeRequest(MessageVersion messageVersion, object[] parameters)
    {
        string jsonText = SerializeJsonRequestParameters(parameters);

        // Compose message
        Message message = Message.CreateMessage(messageVersion, _clientOperation.Action);
        _address.ApplyTo(message);

        HttpRequestMessageProperty reqProp = new HttpRequestMessageProperty();
        reqProp.Headers[HttpRequestHeader.ContentType] = "application/json";
        reqProp.Method = "GET";
        message.Properties.Add(HttpRequestMessageProperty.Name, reqProp);


        UriBuilder builder = new UriBuilder(message.Headers.To);
        builder.Query = string.Format("jsonrpc={0}", HttpUtility.UrlEncode(jsonText));
        message.Headers.To = builder.Uri;
        message.Properties.Via = builder.Uri;

        return message;
    }