POST to WCF from Fiddler succeeds but passes null values

Question

I\'ve followed this video series on WCF and have the demo working. It involves building a WCF service that manages student evaluation forms, and implements CRUD operations

Answer 1

For POST you need to use BodyStyle = WebMessageBodyStyle.Bare NOT
WebMessageBodyStyle.Wrapped

    [OperationContract]
    [WebInvoke(RequestFormat = WebMessageFormat.Json,ResponseFormat = WebMessageFormat.Json,UriTemplate = "eval",BodyStyle = WebMessageBodyStyle.Bare)]
    void SubmitEval(Eval eval);

Answer 2

The default body style in the WebInvoke attribute is Bare, meaning that the object should be sent without a wrapper containing the object name:

{"Comment":"testComment222",
 "Id":"doesntMatter",
 "Submitter":"Tom",
 "TimeSubmitted":"11/10/2011 4:00 PM"}

Or you can set the request body style to Wrapped, and that would make the input require the wrapping {"eval"...} object:

[OperationContract]
[WebInvoke(RequestFormat=WebMessageFormat.Json,
   ResponseFormat=WebMessageFormat.Json,
   UriTemplate = "eval",
   BodyStyle = WebMessageBodyStyle.WrappedRequest)] // or .Wrapped
void SubmitEval(Eval eval);

Update: there's another problem in your code, since you're using DateTime, and the format expected by the WCF serializer for dates in JSON is something like \/Date(1234567890)\/. You can change your class to support the format you have by following the logic described at MSDN Link (fine-grained control of serialization format for primitives), and shown in the code below.

public class StackOverflow_8086483
{
    [DataContract]
    public class Eval //Models an evaluation
    {
        [DataMember]
        public string Id { get; set; }

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

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

        [DataMember(Name = "TimeSubmitted")]
        private string timeSubmitted;

        public DateTime TimeSubmitted { get; set; }

        public override string ToString()
        {
            return string.Format("Eval[Id={0},Submitter={1},Comment={2},TimeSubmitted={3}]", Id, Submitter, Comment, TimeSubmitted);
        }

        [OnSerializing]
        void OnSerializing(StreamingContext context)
        {
            this.timeSubmitted = this.TimeSubmitted.ToString("MM/dd/yyyy h:mm tt", CultureInfo.InvariantCulture);
        }

        [OnDeserialized]
        void OnDeserialized(StreamingContext context)
        {
            DateTime value;
            if (DateTime.TryParseExact(this.timeSubmitted, "MM/dd/yyyy h:mm tt", CultureInfo.InvariantCulture, DateTimeStyles.None, out value))
            {
                this.TimeSubmitted = value;
            }
        }
    }

    [ServiceContract]
    public interface IEvalService
    {
        [OperationContract]
        [WebInvoke(RequestFormat = WebMessageFormat.Json,
           ResponseFormat = WebMessageFormat.Json, UriTemplate = "eval",
           BodyStyle = WebMessageBodyStyle.Wrapped)]
        void SubmitEval(Eval eval);
    }

    [ServiceBehavior(InstanceContextMode = InstanceContextMode.Single)]
    class EvalService : IEvalService
    {
        public void SubmitEval(Eval eval)
        {
            Console.WriteLine("Received eval: {0}", eval);
        }
    }

    public static void Test()
    {
        string baseAddress = "http://" + Environment.MachineName + ":8000/Service";
        WebServiceHost host = new WebServiceHost(typeof(EvalService), new Uri(baseAddress));
        host.Open();
        Console.WriteLine("Host opened");

        string data = "{\"eval\":{\"Comment\":\"testComment222\",\"Id\":\"doesntMatter\", \"Submitter\":\"Tom\",\"TimeSubmitted\":\"11/10/2011 4:00 PM\"}}";
        WebClient c = new WebClient();
        c.Headers[HttpRequestHeader.ContentType] = "application/json; charset=utf-8";
        c.UploadData(baseAddress + "/eval", Encoding.UTF8.GetBytes(data));

        Console.Write("Press ENTER to close the host");
        Console.ReadLine();
        host.Close();
    }
}