Pause and Resume Subscription on cold IObservable

Question

Using Rx, I desire pause and resume functionality in the following code:

How to implement Pause() and Resume() ?

    static IDisposable _subscripti         


        

Answer 1

Here it is as an application of IConnectableObservable that I corrected slightly for the newer api (original here):

public static class ObservableHelper {
    public static IConnectableObservable WhileResumable(Func condition, IObservable source) {
        var buffer = new Queue();
        var subscriptionsCount = 0;
        var isRunning = System.Reactive.Disposables.Disposable.Create(() => {
            lock (buffer)
            {
                subscriptionsCount--;
            }
        });
        var raw = Observable.Create(subscriber => {
            lock (buffer)
            {
                subscriptionsCount++;
                if (subscriptionsCount == 1)
                {
                    while (buffer.Count > 0) {
                        subscriber.OnNext(buffer.Dequeue());
                    }
                    Observable.While(() => subscriptionsCount > 0 && condition(), source)
                        .Subscribe(
                            v => { if (subscriptionsCount == 0) buffer.Enqueue(v); else subscriber.OnNext(v); },
                            e => subscriber.OnError(e),
                            () => { if (subscriptionsCount > 0) subscriber.OnCompleted(); }
                        );
                }
            }
            return isRunning;
        });
        return raw.Publish();
    }
}