Develop Reference

How to set TimeOut for complete Observer in RXjava - Android?

I have many request merged in Observable, and I need a Timeout Not for every emission but for complete observable in RXjava. Is it Possible??
Observable
.merge(listOfObservables).subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(new DisposableObserver<Response>() {
#Override
public void onNext(#io.reactivex.annotations.NonNull Response response) {
}
#Override
public void onError(#io.reactivex.annotations.NonNull Throwable e) {
}
#Override
public void onComplete() {
}
});

You could use takeUntil with a delayed error:
Observable
.merge(listOfObservables)
.subscribeOn(Schedulers.io())
.takeUntil(Observable.error(new TimeoutException()).delay(5, TimeUnit.MINUTES, true))
.observeOn(AndroidSchedulers.mainThread())

How to delay loading items by using RxJava?

While inflating Android view I load a bunch of stuff from the background thread and inflate some views based on network responses. So I am trying to defer some of that tasks using RxJava like this
Single.fromCallable(() -> savedInstanceState)
.delay(50,TimeUnit.MICROSECONDS,AndroidSchedulers.mainThread())
.flatMapCompletable(this::loadVideos)
.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(new CompletableObserver() {
#Override
public void onSubscribe(Disposable d) {
Timber.d("on Subscribe");
}
#Override
public void onComplete() {
Timber.d("on onComplete");
}
#Override
public void onError(Throwable e) {
Timber.d("on onError");
}
});
And the loadVideos method is like this:
private Completable loadVideos(Bundle savedInstanceState) {
return Completable.fromAction(() -> {
videoPresenter.loadVideos(savedInstance);
});
}
What I am finding is onSubscribe() certainly gets called, but method videoPresenter.loadVideos never gets called. Would appreciate if anyone can point out what I am doing wrong.
For my testing, I implemented following test that seems to work...
public class DelayTest {
public static void main(String[] args) throws InterruptedException {
Single.fromCallable(() -> "hello")
.delay(50, TimeUnit.MICROSECONDS)
.flatMapCompletable(new Function<String, CompletableSource>() {
#Override
public CompletableSource apply(String s) throws Exception {
return getFlatMapCompletable();
}
})
.subscribe(new CompletableObserver() {
#Override
public void onSubscribe(Disposable d) {
System.out.println("In onSubscribe");
}
#Override
public void onComplete() {
System.out.println("In onComplete");
}
#Override
public void onError(Throwable e) {
System.out.println("In onError");
}
});
Thread.sleep(200L);
}
private static Completable getFlatMapCompletable() {
return Completable.fromAction(new Action() {
#Override
public void run() throws Exception {
System.out.println("In flatmapCompletable");
}
});
}
}

Delay operator in RxJava is executed in another thread. So the rest of the execution does not wait for this one to be finished.
Take a look to some examples https://github.com/politrons/reactive/blob/master/src/test/java/rx/observables/utils/ObservableDelay.java

RxJava Immediate-like Scheduler

Activity.runOnUiThread() has this:
if (Thread.currentThread() != mUiThread) {
mHandler.post(action);
} else {
action.run();
}
It means, it runs action immediately if I am in UI thread and posts action to handler if I am not.
I am looking for RxJava Scheduler like this functionality. Does it exists?

Yes it's simple.
getSomeObservable().observeOn(AndroidSchedulers.mainThread())
after .observeOn(AndroidSchedulers.mainThread()) you can subscribe to your observable and callbacks will come into main thread.
.subscribe(new Subscriber<Object>() {
#Override
public void onCompleted() {
Log.i(TAG,Thread.currentThread().getName());
}
#Override
public void onError(Throwable e) {
Log.i(TAG,Thread.currentThread().getName());
}
#Override
public void onNext(Object o) {
Log.i(TAG,Thread.currentThread().getName());
}
});

onNext() onError() callbacks not executing on second subscribtion android

I've an Observable something like this:
#GET("endpoint")
Observable<Something> getSomething();
and Subscriber like this
Subscriber<Something> somethingSubscriber = new Subscriber<Something>() {
public void onCompleted() {
}
public void onError(Throwable e) {
//handle exceptions
}
public void onNext() {
//do something
}
In my OnClickListener associated with a button, i make a subscription
getSomething()
.subscribeOn(Schedulers.newThread())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(somethingSubscriber);
If i don't have an internet connection, onError is called and i do some exception handling. when I press the button again (assume i want to retry), the callback methods do not get called.
I want that onNext / onError callbacks get called everytime I press the button.

There is extention for RxJava. It has a lot of "cool tools", but for handling retrofit errors you can use ResponseOrError class.
So in you case it would looks like:
final PublishSubject<Object> clickSubject = PublishSubject.create();
final Observable<ResponseOrError<Something>> responseOrErrorObservable = clickSubject
.flatMap(new Func1<Object, Observable<ResponseOrError<Something>>>() {
#Override
public Observable<ResponseOrError<Something>> call(Object o) {
return getSomething()
.subscribeOn(Schedulers.newThread())
.observeOn(AndroidSchedulers.mainThread())
.compose(ResponseOrError.<Something>toResponseOrErrorObservable());
}
})
.replay(1)
.refCount();
final Observable<Throwable> error = responseOrErrorObservable
.compose(ResponseOrError.<Something>onlyError())
.subscribe(new Action1<Segment>() {
#Override
public void call(Throwable throwable) {
// what to do on error, some toast or what ever yu need
}
});
final Observable<UserInfoResponse> success = responseOrErrorObservable
.compose(ResponseOrError.<Something>onlySuccess())
.subscribe(new Action1<Something>() {
#Override
public void call(Something some) {
// code what to do on success
}
});
And now, into onClick you just need to put clickSubject.onNext(null)
.replay(1).refCount(); needed because there are 2 Observables that uses responseOrErrorObservable, so without it retrofit request will "happens" two times.

You are reusing the same Subscriber. Once you get the onError or a result (so it completes) the subscriber is unsubscribed. Try to pass every time a new subscriber.

use this code
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
getSomething()
.subscribeOn(Schedulers.newThread())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(new Action1<Something>() {
#Override
public void call(Something something) {
//do something
}
},
new Action1<Throwable>() {
#Override
public void call(Throwable throwable) {
//handle exceptions
}
},
new Action0() {
#Override
public void call() {
}
});
}
});
Addition
or
replace this
Subscriber<Something> somethingSubscriber = new Subscriber<Something>() {
public void onCompleted() {
}
public void onError(Throwable e) {
//handle exceptions
}
public void onNext() {
//do something
}
};
to
Subscriber<String> somethingSubscriber = new Subscriber<String>() {
#Override
public void onCompleted() {
}
#Override
public void onError(Throwable e) {
}
#Override
public void onNext(String s) {
}
};

In my Case onNext() and onError() methods are not getting called because of my model class wrong parsing, I was taking a double object as Integer so NumberFormatException was thrown and nothing was happening after getting the result from retrofit.

Continue next Observable onError

I have sequence of tasks to be completed, if any of them throws exception would like to continue with next task.
But with this implementation, if first REST calls fail it throws onError in subscriber.
Wondering what is best operator to use or I need to call some other function to make it resume on exception.
private void logout() {
// Observable from Retrofit to make logout service call
requestLogout()
.doOnNext(o -> {
clearNotifications();
})
.doOnNext(o -> {
unregisterGcm();
})
.doOnNext(o -> {
clearLocalData();
})
.doOnNext(o -> {
// clear all jobs
mJobManager.clear();
})
.subscribeOn(Schedulers.newThread())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(new Subscriber<Object>() {
#Override
public void onCompleted() {
// no op
}
#Override
public void onError(Throwable e) {
mView.navigateToLogin();
}
#Override
public void onNext(Object o) {
mView.navigateToLogin();
}
});
}

If you just want to re-subscribe use Observable.retry():
.observeOn(AndroidSchedulers.mainThread())
.retry().subscribe(new Subscriber<Object>() {
// rest of code

So I found way to execute all the Observables even if one of them have error. But this does not preserve order.
I am still looking for way where order is preserved and on error it should continue to next observable.
Observable.mergeDelayError(requestLogout(),
clearNotifications(),
unregisterGcm(),
clearLocalData(),
clearJobs())
.first()
.observeOn(AndroidSchedulers.mainThread())
.subscribe(new Subscriber<Object>() {
#Override
public void onCompleted() {
// no op
}
#Override
public void onError(Throwable e) {
mView.navigateToLogin();
}
#Override
public void onNext(Object o) {
mView.navigateToLogin();
}
}
);