RxPermissions

This library allows the usage of RxJava with the new Android M permission model.

Setup

To use this library your minSdkVersion must be >= 9.

In your build.gradle :

repositories {
    jcenter() // If not already there
}

dependencies {
    compile 'com.tbruyelle.rxpermissions:rxpermissions:0.9.1@aar'
}

Setup for RxJava2

Thanks to @vanniktech, RxPermissions now supports RxJava2, just change the package name to com.tbruyelle.rxpermissions2.

dependencies {
    compile 'com.tbruyelle.rxpermissions2:rxpermissions:0.8.2@aar'
}

Migration to 0.9

Version 0.9 now uses a retained fragment to trigger the permission request from the framework. As a result, the RxPermissions class is no more a singleton. To migrate from 0.8 or earlier, just replace the following :

RxPermissions.getInstance(this) -> new RxPermissions(this) // where this is an Activity instance

For the moment, branch 2.x doesn't reflect that change and is still in version 0.8.2. It will be updated later.

Usage

Create a RxPermissions instance :

RxPermissions rxPermissions = new RxPermissions(this); // where this is an Activity instance

Example : request the CAMERA permission (with Retrolambda for brevity, but not required)

// Must be done during an initialization phase like onCreate
rxPermissions
    .request(Manifest.permission.CAMERA)
    .subscribe(granted -> {
        if (granted) { // Always true pre-M
           // I can control the camera now
        } else {
           // Oups permission denied
        }
    });

If you need to trigger the permission request from a specific event, you need to setup your event as an observable inside an initialization phase.

You can use JakeWharton/RxBinding to turn your view to an observable (not included in the library).

Example :

// Must be done during an initialization phase like onCreate
RxView.clicks(findViewById(R.id.enableCamera))
    .compose(rxPermissions.ensure(Manifest.permission.CAMERA))
    .subscribe(granted -> {
        // R.id.enableCamera has been clicked
    });

If multiple permissions at the same time, the result is combined :

rxPermissions
    .request(Manifest.permission.CAMERA,
             Manifest.permission.READ_PHONE_STATE)
    .subscribe(granted -> {
        if (granted) {
           // All requested permissions are granted
        } else {
           // At least one permission is denied
        }
    });

You can also observe a detailed result with requestEach or ensureEach :

rxPermissions
    .requestEach(Manifest.permission.CAMERA,
             Manifest.permission.READ_PHONE_STATE)
    .subscribe(permission -> { // will emit 2 Permission objects
        if (permission.granted) {
           // `permission.name` is granted !
        } else if (permission.shouldShowRequestPermissionRationale)
           // Denied permission without ask never again
        } else {
           // Denied permission with ask never again
           // Need to go to the settings
        }
    });

Look at the sample app for more.

Important read

As mentioned above, because your app may be restarted during the permission request, the request must be done during an initialization phase. This may be Activity.onCreate, or View.onFinishInflate, but not pausing methods like onResume, because you'll potentially create an infinite request loop, as your requesting activity is paused by the framework during the permission request.

If not, and if your app is restarted during the permission request (because of a configuration change for instance), the user's answer will never be emitted to the subscriber.

You can find more details about that here.

Status

This library is still beta, so contributions are welcome. I'm currently using it in production since months without issue.

Benefits

Avoid worrying about the framework version. If the sdk is pre-M, the observer will automatically receive a granted result.
Prevents you to split your code between the permission request and the result handling. Currently without this library you have to request the permission in one place and handle the result in Activity.onRequestPermissionsResult().
All what RX provides about transformation, filter, chaining...

nhaarman/RxPermissions