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@magillus
Last active August 21, 2020 22:25
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RxJava2.0 Broadcast Receiver for getting intent broadcasts as Observable<Intent>
IntentFilter intentFilter = new IntentFilter();
intentFilter.addAction("com.example.mat.ACTION_START");
intentFilter.addAction("com.example.mat.ACTION_STOP");
Disposable disposable = RxBroadcastReceiver.create(this, intentFilter)
.share() // optional if you want do not want multiply broadcast receivers created
.map(SOMECLASS::someStaticMethod) // example mapping method for parsing data from Intent
.subscribe(data -> {......});
disposable.dispose(); // that or use CompositeDisposable
SOMECLASS:
public static Data someStaticMethod(Intent intent) {
// fetch data from intent EXTRAs
}
/**
* RxJava based broadcast reciever that registers its local BroadcastReceiver until end of subscription.
* Listens for update and passes Intent to the Stream (Subscriber).
*
* Copyright 2016 Mateusz Perlak - http://www.apache.org/licenses/LICENSE-2.0
* Created on 11/18/16.
*/
public class RxBroadcastReceiver implements ObservableOnSubscribe<Intent> {
protected final WeakReference<Context> contextWeakReference;
private IntentFilter intentFilter;
/**
* Creates Observable with intent filter for Broadcast receiver.
*
* @param context
* @param intentFilter
* @return
*/
public static Observable<Intent> create(Context context, IntentFilter intentFilter) {
return Observable.defer(() -> Observable.create(new RxBroadcastReceiver(context, intentFilter))
.subscribeOn(Schedulers.io())
);
}
/**
* @param context
* @param intentFilter
*/
private RxBroadcastReceiver(Context context, IntentFilter intentFilter) {
contextWeakReference = new WeakReference<Context>(context.getApplicationContext());
this.intentFilter = intentFilter;
}
@Override
public void subscribe(ObservableEmitter<Intent> emitter) throws Exception {
BroadcastReceiver broadcastReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
emitter.onNext(intent);
}
};
emitter.setDisposable(Disposables.fromRunnable(() -> { // thank you Jake W.
if (contextWeakReference != null && contextWeakReference.get() != null) {
contextWeakReference.get().unregisterReceiver(broadcastReceiver);
}
}));
if (contextWeakReference != null && contextWeakReference.get() != null) {
contextWeakReference.get().registerReceiver(broadcastReceiver, intentFilter);
}
}
}
@ultraon
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ultraon commented Jun 27, 2019

Hello, I'm curious, isn't better to use just this one:

    @NonNull
    public static Observable<Intent> create(@NonNull final Context context, @NonNull final IntentFilter intentFilter) {
        final Context appContext = context.getApplicationContext();
        return Observable.create(emitter -> {
            final BroadcastReceiver receiver = new BroadcastReceiver() {
                @Override
                public void onReceive(final Context context, final Intent intent) {
                    emitter.onNext(intent);
                }
            };
            appContext.registerReceiver(receiver, intentFilter);
            emitter.setCancellable(() -> appContext.unregisterReceiver(receiver));
        });
    }

Some notes here: we don't need WeakReference for Application Context, because dynamic receiver exists only in the scope of current Application instance (it is a Singleton for Android app process).

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