⚠️ Deprecated ⚠️

This library is no longer mantained. You should use the Android Navigation component with NavBackStackEntry for returning a result to the previous Destination.

RxActivityResult

The api which Android SDK exposes to retrieve the data from a ‘returning system call’ (camera, gallery, email…) just does not give a shit about Don’t break the chain leitmotiv. Indeed, the OnActivityResult approach will break entirely your observable chaining.

I did this library to not have to deal with this OnActivityResult pattern. Never. Ever.

RxActivityResult features:

• Launch the intent from any class, as long as you supply a valid Activity or Fragment instance.
• Get the Intent back with the data encapsulated in an observable and keep going crazy chaining operators.

Setup

Add the JitPack repository in your build.gradle (top level module):

allprojects {
    repositories {
        jcenter()
        maven { url "https://jitpack.io" }
    }
}

And add next dependencies in the build.gradle of the module:

dependencies {
    implementation 'com.github.VictorAlbertos:RxActivityResult:0.5.0-2.x'
    implementation 'io.reactivex.rxjava2:rxjava:2.2.3'
}

Usage

Call RxActivityResult.register in your Android Application class, supplying as parameter the current instance.

public class SampleApp extends Application {

    @Override public void onCreate() {
        super.onCreate();
        RxActivityResult.register(this);
    }
}

You can call RxActivityResult.on(this).startIntent(intent) supplying both, an Activity instance or a Fragment instance.
Observe the emitted Result item to know the resultCode and retrieve the associated data if appropriate.

Limitation: Your fragments need to extend from androidx.fragment.app.Fragment instead of android.app.Fragment, otherwise they won’t be notified.

Intent takePhoto = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);

RxActivityResult.on(this).startIntent(takePhoto)
        .subscribe(result -> {
            Intent data = result.data();
            int resultCode = result.resultCode();
            // the requestCode using which the activity is started can be received here.
            int requestCode = result.requestCode();

            if(requestCode == YourActivity.YOUR_REQUEST_CODE)
            {
                // Do Something
            }

            if (resultCode == RESULT_OK) {
                result.targetUI().showImage(data);
            } else {
                result.targetUI().printUserCanceled();
            }
        });

Please pay attention to the targetUI() method in the Result object emitted.

This method returns a safety instance of the current Activity/Fragment. Because the original one may be recreated (due to configuration changes or some other system events) it would be unsafe calling it.

Instead, you must call any method/variable of your Activity/Fragment from this instance encapsulated in the Result object.

StartIntentSenderForResult

RxActivityResult supports startIntentSenderForResult too, by calling RxActivityResult.on(this).startIntentSender and supplying the proper arguments. As follows:

RxActivityResult.on(this).startIntentSender(pendingIntent.getIntentSender(), new Intent(), 0, 0, 0)
        .subscribe(result -> {
            
        });

Examples

There is an example of RxActivityResult using both activity and fragment in the app module

Author

Víctor Albertos

• https://twitter.com/_victorAlbertos
• https://linkedin.com/in/victoralbertos
• https://github.com/VictorAlbertos

Another author’s libraries using RxJava:

• RxCache: Reactive caching library for Android and Java.
• RxPaparazzo: RxJava extension for Android to take images using camera and gallery.
• RxFcm: RxJava extension for Android Firebase Cloud Messaging (aka fcm).