CODEWITHSUNDEEP
c#.netsystem.reactiveobservable
Dwight Matthys
Dwight Matthys

Reputation: 143

RX, retry and allow to handle exception

I'm trying to wrap my head around RX but somewhere my brain explodes :)

What I'm trying to do is invoke a WCF method in an async way through RX. Nothing special here, but when the WCF method throws an error I want to recreate the channel and give it another go (max 3 times).

What I have so far is:

var _sc = new Service.Service1Client();
var _observableFunc = Observable.FromAsyncPattern<int, string>(_sc.BeginGetData, _sc.EndGetData);
var _observable = _observableFunc(666);

var _defered = Observable.Defer(() => _observable);

// Here something should be done, but don't know what...

using (_retryable.Subscribe(x => Console.WriteLine("Async ==> '{0}'", x),
                            ex => Console.WriteLine("Oops ==> {0}", ex.Message)))
{
    Console.ReadLine();
}

I played around with Catch<TSource, TException>, which allowed me to trap the exception and continue with the same observable, hence giving me what I wanted. Only problem is that it runs forever, meaning if I keep on throwing exceptions the thing never stops!

Upvotes: 4

Views: 1380

Answers (1)

Enigmativity
Enigmativity

Reputation: 117175

Try doing this:

var retryable = Observable.Defer(() => _observableFunc(666).Retry(3));

The Retry extension method "Repeats the source observable sequence the specified number of times or until it successfully terminates."

Also, don't do this:

var _observable = _observableFunc(666);
var _defered = Observable.Defer(() => _observable);

There's no point deferring the observable after you've kicked it off.

You should do this instead:

var _defered = Observable.Defer(() => _observableFunc(666));

Then you're only one step away from my suggested solution at the top.

Upvotes: 3

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