Logo Questions Linux Laravel Mysql Ubuntu Git Menu
 

If the onComplete call is made for a RxJava Subject, do i have to manually unsubscribe again?

I'm using an RxJava ReplaySubject in my Fragment.

I'm attempting to use the ReplaySubject in a way, where I would like the Subject to execute a process until completion (possibly beyond the life of the fragment).

On completion of the process, I would like to release the resources which -as i understand- is done by unsubscribing the subscription at the time of registering the observer (which in my case, is the subject itself).

In this github issue thread @benjchristensen says:

If it is an Observable then it should emit an onCompleted and be done.

If it is an Observer then it should unsubscribe from the Subscription it received when it called Observable.subscribe and it will give the Observable a chance to shutdown and clean up.

If it's a Subject -which is both an Observer and an Observable- what is the behavior? If i call onComplete on the subject, does that basically mean the subscription is stopped, and I am therefore relieved of needing to manually unsubscribe the subscription i get by registering the observer?

like image 928
Kaushik Gopal Avatar asked Sep 02 '14 07:09

Kaushik Gopal


People also ask

How do I unsubscribe from observable Rxjava?

You need to cancel your job properly via Observable::create and Observable::flatMap. And set your cancalable in Observable::create.

Should I unsubscribe from completed observable?

Yes you are correct. After a stream is terminated ( onComplete / onError has been called ), subscriber unsubscribes automatically. You should be able to test these behaviors using isUnsubscribed() method on the Subscription object.


1 Answers

Subjects are a relatively thin layer on top of an Observable that allow you to feed onNext(), onCompleted() and onError() calls from a source external to the Observable. Their unsubscribe behavior is the same as an Observable. If onCompleted() or onError() are called on the Subject, the subscribers will be unsubscribed. No need to call unsubscribe() on the subscription returned from Observable.subscribe().

For a ReplaySubject, note that resources will not be cleaned up until it is garbage collected. Even after onCompleted() has been called on a ReplaySubject, a subscriber can still subscribe and it will receive all of the original onNext(), onCompleted() or onError() calls that were made previous to subscribing.

like image 116
kjones Avatar answered Sep 23 '22 02:09

kjones