RestSharp with Async Await

19 December 2013

RestSharp is an excellent open source project to use in a Windows Phone app if you want make http calls to a json api. However it doesn't have any inbuilt support for the async await syntax. Thankfully with C#'s extensions methods we can add this support in our app.

namespace RestSharpEx
{
  public static class RestClientExtensions
  {
    public static Task&lt;IRestResponse&gt; ExecuteTaskAsync(this RestClient @this, RestRequest request)
    {
      if (@this == null)
          throw new NullReferenceException();

      var tcs = new TaskCompletionSource&lt;IRestResponse&gt;();

      @this.ExecuteAsync(request, (response) =&gt;
      {
          if (response.ErrorException != null)
              tcs.TrySetException(response.ErrorException);
          else
              tcs.TrySetResult(response);
      });

      return tcs.Task;
    }
  }
}

This will add a new function to the RestSharp client type called ExecutreTaskAsync. Inside the method it will call the ExecuteAsync function as you normally would, but has also implemented returning a Task and setting it's results when its complete.

To use the function would be as follows

var client = new RestClient("http://www.YOUR SITE.com/api/");
var request = new RestRequest("Products", Method.GET);
var response = await client.ExecuteTaskAsync(request);