Gestión de permisos en Android para localización, cámara y notificaciones

When developing Android applications that use sensitive data, such as the user's location or access to important hardware such as the camera, it is essential to correctly manage the required permissions. Android requires two main steps: register the permissions in the manifest file beforehand and enable them or request them from the user during execution.

What types of permissions are there and how are they added to the manifest?

The essential permissions to include in the manifest cover a variety of basic functions within an Android application. Some of the most common and relevant permissions are:

• ACCESS_COARSE_LOCATION: provides location via cellular networks.
• ACCESS_FINE_LOCATION: provides precise location via GPS.

Both permissions must be explicitly included in the Android manifest; however, the ACCESS_FINE_LOCATION permission additionally requires direct authorization from the user in real time.

How to implement useful functions to verify permissions in code?

To optimize permission validation throughout the application, it is convenient to develop reusable functions in the form of extensions. The creation of a package called utils and within it a permissions utils file optimizes this programming practice by using functions that check if certain permissions are approved:

Checking a specific permission.

First a basic function is used for any permission:

private fun Context.hasPermission(permission: String): Boolean  {    return ContextCompat.checkSelfPermission(        this,        permission     )  == PackageManager.PERMISSION_GRANTED}

It is then reused for specific permissions, such as fine location:

fun Context.hasLocationPermission(): Boolean  =    hasPermission(android.Manifest.permission.ACCESS_FINE_LOCATION)

Backward-compatible permission handling

For recent version-specific permissions, such as notifications in Android Tiramisu, conditional handling is implemented according to the SDK:

fun Context.hasNotificationPermission(): Boolean  {    return if (Build.VERSION.SDK_INT  >= Build.VERSION_CODES.TIRAMISU)  {        hasPermission(android.Manifest.permission.POST_NOTIFICATIONS)     } else true}

And the requirement for camera access is also provided:

fun Context.hasCameraPermission(): Boolean  =    hasPermission(android.Manifest.permission.CAMERA)

What to do when a user rejects certain permissions?

When the user rejects some permissions, Android provides an option called Rationale, a valuable tool to improve the user experience. This feature displays a dialog that explains in detail the importance and specific use of the requested permission.

Implementing 'Rationale' for permissions

The function to display an explanation of the need for the permission takes the following structure:

fun ComponentActivity.shouldShowLocationRationalePermission(): Boolean  {    return shouldShowRequestPermissionRationale(        android.Manifest.permission.ACCESS_FINE_LOCATION     )}fun ComponentActivity.shouldShowPostNotificationRationale(): Boolean  =    Build.VERSION.SDK_INT  >= Build.VERSION_CODES.TIRAMISU  &&            shouldShowRequestPermissionRationale(android.Manifest.permission.POST_NOTIFICATIONS)fun ComponentActivity.shouldShowCameraPermissionRationale(): Boolean  =    shouldShowRequestPermissionRationale(android.Manifest.permission.CAMERA)

These functions allow to verify if it is necessary to show the explanatory dialog, following good practices that recommend requesting permissions just at the moment required by the application functionality.