Frequently Asked Questions (FAQ) about RxPermissions

Q: What is RxPermissions? A: RxPermissions is a library that allows the usage of RxJava2 with the new Android M (Marshmallow) permission model. It simplifies requesting and handling runtime permissions in Android applications using a reactive approach.

Q: What are the minimum requirements to use RxPermissions? A: The minSdkVersion of your Android project must be >= 14 to use RxPermissions.

Q: How do I add RxPermissions to my Android project? A: Add the JitPack repository to your allprojects block in your build.gradle file, and then add the RxPermissions dependency. The configuration steps are provided in the Setup section.

Q: Can I use RxPermissions within a Fragment? A: Yes, you can use RxPermissions within a Fragment. When creating an instance of RxPermissions, pass the Fragment instance (new RxPermissions(this)) as the constructor parameter, rather than new RxPermissions(fragment.getActivity()).

Q: What happens if I request permissions on a pre-M device (Android 5.1 or lower)? A: On pre-M devices, the observer will automatically receive a granted result, as all permissions are granted at install time.

Q: What is the difference between request() and requestEach() methods? A: The request() method requests one or more permissions and emits a single boolean value indicating whether all permissions were granted. The requestEach() method requests one or more permissions and emits a Permission object for each requested permission, providing more detailed information about each permission’s status.

Q: What does shouldShowRequestPermissionRationale mean in the Permission object? A: shouldShowRequestPermissionRationale is true if the user has previously denied the permission request and the system thinks that the user should be shown a rationale for requesting the permission again. This allows you to explain why your app needs the permission before requesting it again.

Q: What does it mean if the user denies a permission with “Never ask again”? A: If the user denies a permission with “Never ask again”, your app will not be able to request the permission again unless the user manually grants it in the system settings. In this case, you may need to direct the user to the settings screen.

Q: Why is it important to request permissions during an initialization phase like onCreate()? A: Because your app may be restarted during the permission request, the request must be done during an initialization phase. This avoids potential issues where the user’s answer is never emitted to the subscriber if the app is restarted during the permission request.

Q: Can I use RxPermissions with RxBinding? A: Yes, RxPermissions provides methods like ensure() and ensureEach() that are designed to be used with RxBinding to trigger permission requests based on UI events. These methods automatically handle the subscription and unsubscription to the RxBinding observable.

Q: Where can I find more examples of using RxPermissions? A: Look at the sample app in the RxPermissions repository for more examples.