Windows Store Apps – a simple HttpClient request & response debugger

Here’s the deal: Debugging is a pain. Sometimes a huge pain, other times it’s not that big of a deal. Regardless of the case at hand I often find myself digging into the requests and responses of the HttpClient, so therefore I wrote this little helper.
So, with that said, let me introduce you to InspectorHandler for Windows Store apps.
It’s simple really - InspectorHandler is a MessageProcessingHandler that you can add to your HttpClient definition that outputs the request & response from the HttpClient to the debug output window when you’re in debug configuration.
Usage is really straight forward:

1. Hook up the handler
2. Create the HttpClient
3. You’re set.

Continue using the HttpClient just as you normally would with await, ReadAsStringAsync() and all that.

        private async void btnGo_Click_1(object sender, RoutedEventArgs e)
        {
            // declare http handler
            HttpMessageHandler handler = new HttpClientHandler();
            // append the Inspector handler
            handler = new InspectorHandler(handler);
            // allocate a http client on the above handlers
            var client = new HttpClient(handler) { BaseAddress = new System.Uri("http://dev.virtualearth.net/REST/v1/Locations/") };

            // fire request
            var response = await client.GetAsync("Eiffel%20Tower?o=xml&key=BingMapsKey"); // insert a proper bing maps key here otherwise you'll just get the access denied view..
            // output result
            tbContent.Text = await response.Content.ReadAsStringAsync();
        }

      Below is a screenshot of a example app that once the button is pressed fires a GET request to the http://dev.virtualearth.net/REST/v1/Locations/Eiffel%20Tower?o=xml&key=BingMapsKey url and ouputs the result into a textbox.
  
And some basic interesting details from the request & response objects are now available in the ouput of the debugger:
  
There you have it. Simple, fairly effective and perhaps useful. Under the hood the InspectorHandler is far from a work of art, but it does the job quite well for being a simple debug tool. Here’s the complete source code:

    public class InspectorHandler : MessageProcessingHandler
    {
        public InspectorHandler(HttpMessageHandler innerHandler)
            : base(innerHandler)
        {
        }

        protected override HttpRequestMessage ProcessRequest(HttpRequestMessage request, CancellationToken cancellationToken)
        {
#if DEBUG
            if (request.Content!=null)
            {
                var content = request.Content.ReadAsStringAsync();
                content.Wait();
                Debug.WriteLine(string.Format("INSPECTOR: {0} REQUEST - {1} - {2}", request.Method, request.RequestUri.ToString(), content.Result));
            }
            else
            {
                Debug.WriteLine(string.Format("INSPECTOR: {0} REQUEST - {1}", request.Method, request.RequestUri.ToString()));
            }
#endif
            return request;
        }

        protected override HttpResponseMessage ProcessResponse(HttpResponseMessage response, CancellationToken cancellationToken)
        {
#if DEBUG
            if (response.Content!=null)
            {
                var content = response.Content.ReadAsStringAsync();
                content.Wait();
                Debug.WriteLine(string.Format("INSPECTOR: {0} RESPONSE - {1} - {2}", response.RequestMessage.Method, response.StatusCode, content.Result));
            }
            else
            {
                Debug.WriteLine(string.Format("INSPECTOR: {0} RESPONSE - {1} - {2}", response.RequestMessage.Method, response.StatusCode));
            }
#endif
            return response;
        }
    }

If you want it, you can grab it here as a zip containing the class library project ready to be compiled & referenced.