finish activity: Long running save/send data to server

[Rainer-Lang]

Do you have any suggestions for such a usecase with rxjava?

1. user: backpress/leaves activity
2. save/send data to server -> potentially long running task

[Mitchell Tilbrook]

An Intent service will work well for any one-off task that needs to outlive an activity. If you need a longer running task or more lifecycle control, then a service would be a better choice.

One use case I can think off is file transfers. Lot's of things that can go wrong, and can take a long time to finish.

[Rainer-Lang]

@marukami Could you point me to some samples?

[Mitchell Tilbrook]

A fire and forget example would look a bit like the code below.

If you need to be able to cancel the tasks, or handle more complex flows, then I don't know of any examples. In the next week or so I should have time to create some examples. If you need something now, just experiment with using Rx in Services.

@kaushikgopal Have you done anything along these lines?

public class CountIntentService extends IntentService {
    public CountIntentService() {
        super("CountIntentService");
    }

    public CountIntentService(String name) {
        super(name);
    }

    @Override protected void onHandleIntent(Intent intent) {
        // Some long running task
        Observable.timer(10, TimeUnit.SECONDS)
            .flatMap(new Func1<Long, Observable<Long>>() {
                @Override public Observable<Long> call(final Long aLong) {
                    // Some 2nd long running task
                    return Observable.timer(10, TimeUnit.SECONDS);
                }
            })
            .subscribe(new Subscriber<Long>() {
                @Override public void onCompleted() {
                    // Finished
                }

                @Override public void onError(final Throwable e) {
                    // Error
                }

                @Override public void onNext(final Long aLong) {
                    // Last unit of work finished
                }
            });
    }
}

[Rainer-Lang]

@marukami Thanks. I think Service will fit for me - hopefully. :)
The "send data to server" means sending a picture to the server. This I have to do later/retry in the app automatically if something goes wrong the first time. So "fire and forget" will do it for me.

I'm very interested in every example you could provide. 👍

[Rainer-Lang]

@marukami I use now an IntentService and it's working fine. Thanks!