Android Kotlin registerForActivityResult no callback-CodePudding

In Android 13, I need a basic flow to get permission for push notifications:

class MainActivity : ComponentActivity(), LocationListener {
    val notificationPermissionLauncher = registerForActivityResult(ActivityResultContracts.RequestPermission()) { isGranted: Boolean ->
        if (isGranted) {
            // Permission is granted. Continue the action or workflow in your
            // app.
        } else {
            // Explain to the user that the feature is unavailable because the
            // feature requires a permission that the user has denied. At the
            // same time, respect the user's decision. Don't link to system
            // settings in an effort to convince the user to change their
            // decision.
        }
    }

    private fun requestPushNotificationPermissions(){
        if ((ContextCompat.checkSelfPermission(this, Manifest.permission.POST_NOTIFICATIONS) == PackageManager.PERMISSION_GRANTED)) {
            // granted
        }else {
            // not granted, ask for permission
            notificationPermissionLauncher.launch(Manifest.permission.POST_NOTIFICATIONS)
        }
    }
}

This is what happened:

when user first installed the app, checkSelfPermission returns not granted, and we then lauch permission launcher
user sees the permission dialog in Android 13
user selects Allow
Expected: registerForActivityResult callback will be fired with isGranted true
Actual: registerForActivityResult callback is not fired.

Same if user selects Not Allow. callback is never fired. Why?

This is my dependencies:

implementation 'androidx.activity:activity-ktx:1.2.0-alpha07'
implementation 'androidx.fragment:fragment-ktx:1.3.0-alpha07'

CodePudding user response：

sadly can't help why it doesn't work. But I used EasyPermission for handling the permissons request and it works fine. https://github.com/googlesamples/easypermissions

CodePudding user response：

Turns out, the registerForActivityResult callback never fires, because somewhere in the Activity, there is this piece of old function "onRequestPermissionsResult" that is accidentally catching all permissions callback:

override fun onRequestPermissionsResult(requestCode: Int, permissions: Array<out String>, grantResults: IntArray) {        
    if (requestCode == locationPermissionCode) {
        if (grantResults.isNotEmpty() && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
            //Location permission granted
        }
        else {
            //Location permission denied
        }
    }else{
        //Notification permission callback accidentally landed here silently        
    }
}

Hope this helps someone.