RxLifecycle

The utilities provided here allow for automatic unsubscription from sequences based on Activity or Fragment lifecycle events. This capability is useful in Android, where incomplete subscriptions can cause memory leaks.

Usage

You must provide an Observable<ActivityEvent> or Observable<FragmentEvent> that gives RxLifecycle the information needed to unsubscribe at the correct time.

You can then unsubscribe explicitly when an event occurs:

myObservable
    .compose(RxLifecycle.bindUntilActivityEvent(lifecycle, ActivityEvent.DESTROY))
    .subscribe();

Alternatively, you can let RxLifecycle determine the appropriate time to unsubscribe:

myObservable
    .compose(RxLifecycle.bindActivity(lifecycle))
    .subscribe();

It assumes you want to unsubscribe in the opposing lifecycle event - e.g., if subscribing during START, it will unsubscribe on STOP. If you subscribe after PAUSE, it will unsubscribe at the next destruction event (e.g., PAUSE will unsubscribe in STOP).

Warning: Due to the way the unsubscription works, it is only 100% safe if you call RxLifecycle immediately before calling subscribe(). Otherwise, some operators may ignore the unsubscription requests.

Components

Where do the sequences of ActivityEvent or FragmentEvent come from? You can either write it yourself, or you can include rxlifecycle-components, which comes with pre-built Activity and Fragment implementations with lifecycles.

If you use rxlifecycle-components, just extend the appropriate class, then use the built-in bindToLifecycle() (or bindUntilEvent()) methods:

public class MyActivity extends RxActivity {
    @Override
    public void onResume() {
        super.onResume();
        myObservable
            .compose(bindToLifecycle())
            .subscribe();
    }
}

In addition, these components come with lifecycle(), which allows you to do your own logic based on the Activity or Fragment lifecycle.

Installation

compile 'com.trello:rxlifecycle:0.2.0'
compile 'com.trello:rxlifecycle-components:0.2.0'

License

Copyright (C) 2015 Trello

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.