Is it possible to use RxJava/RxAndroid and Retrofit to perform periodic http requests to update data every x seconds?
Currently I am using an IntentService and Recursive Handler/Runnable that fires every x seconds. I'd like to know if I could remove all that and let RxJava handle the requests instead.
final RestClient client = new RestClient();
final ApiService service = client.getApiService();
public interface ApiService {
@GET("/athletes")
public Observable<List<Athlete>> getAthletes();
}
service.getAthletes()
.retry(3)
.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(new Action1<List<Athlete>>() {
@Override
public void call(List<Athlete> athletes) {
// Handle Success
}
}, new Action1<Throwable>() {
@Override
public void call(Throwable throwable) {
// Handle Error
}
});
EDIT
After all is done I ended up with the following code. Any updates are welcome.
final Scheduler scheduler = Schedulers.from(Executors.newSingleThreadExecutor());
obs = Observable.interval(30, TimeUnit.SECONDS, scheduler)
.flatMap(tick -> service.getAthletes(1, 0l))
// Performed on service.getAthletes() observable
.subscribeOn(scheduler)
.observeOn(AndroidSchedulers.mainThread())
.doOnError(err -> Log.d("APP", "Error retrieving athletes: " + err.toString()))
.retry()
.flatMap(Observable::from)
.filter(athlete -> {
// Process Athlete here in the filter
// Return true to always send messages but could filter them out too
return true;
});
public static void startUpdates() {
if (sub != null) {
sub = obs.subscribe(athlete -> {
Log.d("APP", "Done updating athletes! ");
});
}
}
public static void stopUpdates() {
sub.unsubscribe();
sub = null;
}
Use Observable.interval
and to prevent overlapping requests from service.getAthletes()
subscribe on a single threaded Scheduler
within the flatMap
:
Scheduler scheduler = Schedulers.from(Executors.newSingleThreadExecutor());
Observable.interval(x, TimeUnit.SECONDS)
.flatMap(n ->
service.getAthletes()
.retry(3)
.subscribeOn(scheduler))
.observeOn(AndroidSchedulers.mainThread())
.subscribe(new Action1<List<Athlete>>() {
@Override
public void call(List<Athlete> athletes) {
// Handle Success
}
}, new Action1<Throwable>() {
@Override
public void call(Throwable throwable) {
// Handle Error
}
});
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