NullReferenceException with AddBody method

[anatolykryzhanovsky]

good day!
i try to use your library but have confused when need send json request to server:

var request = new RestRequest("/api/some_method", HttpMethod.Post);
request.AddBody(new MethodRequest
    {
        Parameter = "Parameter",
    });

var response = _client.Execute<MethodResponse>(request);

in runtime i have exception:
Object reference not set to an instance of an object. at
   at Microsoft.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at Microsoft.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccess(Task task)
   at Microsoft.Runtime.CompilerServices.TaskAwaiter.ValidateEnd(Task task)
   at Microsoft.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
   at RestSharp.Portable.RestClient.<Execute>d__7`1.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
   at App1.MainPage.<ButtonBase_OnClick>d__0.MoveNext()

other method (without request body) work fine
then i try to set up body with AddParameter:

request.AddParameter("text/html", new MethodRequest
    {
        Parameter= "Parameter",
    }, ParameterType.RequestBody);

and this work perfectly

[fubar-coder]

I created a small unit test, but I cannot reproduce the error. Maybe you can provide a small test case?

[anatolykryzhanovsky]

ok, i create simple app - one button, one method, problem reproduce on my computer:
Response object

class Response
{
    public string Code { get; set; }
}

Request object

class Request
{
    public string Parameter { get; set; }
}

Service wrapper

class Service
{
    private readonly RestClient _client;

    public Service()
    {
        _client = new RestClient("http://localhost");
    }

    public Task<IRestResponse<Response>> TestMethod()
    {
        var request = new RestRequest("/method", HttpMethod.Post);
        request.AddBody(new Request
            {
                Parameter = "parameter"
            });

        var response = _client.Execute<Response>(request);

        return response;
    }
}

button handler - initiate request

private async void ButtonBase_OnClick(object sender, RoutedEventArgs e)
{
    var service = new Service.Service();
    var result = await service.TestMethod(); // exception there

   Debug.WriteLine(result.Data.Code);
}

test solution - https://dl.dropboxusercontent.com/u/75125692/WPTest.7z

[fubar-coder]

I just took a look at the sample application, and the only place where I get a NullReferenceExceptionis the line Debug.WriteLine(result.Data.Code); when the returned content type is unrecognized and the Data member is NULL. I tested it both in an emulator and with a hardware device (Lumia 720).

[anatolykryzhanovsky]

hm, thats strange, becouse i have exception on await.. ok i'll test on another pc

[fubar-coder]

Closed, because the problem is not reproducible.

[piotrek1231]

I have the same problem. When my API return string all is ok, but if I want to obtain object from json, still get this error.

[fubar-coder]

Can you provide a test case and a stack trace, because I'm unable to reproduce the error.

[fubar-coder]

Closed, because I cannot reproduce this problem.

[GeirGrusom]

It may be caused by this line.

So it happens if you have a HttpBasicAuthenticator on the client. A workaround is to call client.Authenticator.Authenticate before AddBody, since there at that point will be no parameters without a name (which is what causes the NullReferenceException).

You should be able to reproduce it with this:

var client = new RestClient("http://www.google.com");
client.Authenticator = new HttpBasicAuthenticator("foo", "bar");
var request = new RestRequest("Foo").AddBody("foo");
await client.Execute(request);

It will fail on the Execute.

[fubar-coder]

Thank you, I'll update it soon,