how to do Rx Observable on Silverlight Webclient - silverlight

Question

I would like to use Rx in my SL app. I want to set up an observable on my REST requests to my webserver. I dont see how to wire up Observable.FromEvent or Observable.FromAsync. My best guess is to make Webclient completion fire an event and then do Observable.FromEvent. IS there a better way?

Answer 1

Here you go, this is the best way to make a web request in Rx.
public IObservable<WebResponse> MakeWebRequest(
Uri uri,
Dictionary<string, string> headers = null,
string content = null,
int retries = 3,
TimeSpan? timeout = null)
{
var request = Observable.Defer(() =>
{
var hwr = WebRequest.Create(uri);
if (headers != null)
{
headers.ForEach(x => hwr.Headers[x.Key] = x.Value);
}
if (content == null)
{
return Observable.FromAsyncPattern<WebResponse>(hwr.BeginGetResponse, hwr.EndGetResponse)();
}
var buf = Encoding.UTF8.GetBytes(content);
return Observable.FromAsyncPattern<Stream>(hwr.BeginGetRequestStream, hwr.EndGetRequestStream)()
.SelectMany(x => Observable.FromAsyncPattern<byte[], int, int>(x.BeginWrite, x.EndWrite)(buf, 0, buf.Length))
.SelectMany(_ => Observable.FromAsyncPattern<WebResponse>(hwr.BeginGetResponse, hwr.EndGetResponse)());
});
return request.Timeout(timeout ?? TimeSpan.FromSeconds(15)).Retry(retries);
}
Here's how to use it:
MakeWebRequest(new Uri("http://www.google.com"))
.Subscribe(
x => Console.WriteLine("Response is {0}", x),
ex => Console.WriteLine("Someone Set Us Up The Bomb: {0}", ex.Message));