Runtime Permissions - Kotlin Android

Introduction to Runtime Permissions in Kotlin Android

In Android, permissions are used to protect sensitive user data and device resources. Starting from Android 6.0 (API level 23), the way permissions are handled has changed. Instead of requesting all the required permissions at the time of installation, Android now uses a runtime permission model where permissions are requested at runtime when they are needed.

This tutorial will guide you through the process of handling runtime permissions in Kotlin Android. We will cover the basics of runtime permissions, their features, and show you how to implement them in your Android application.

Features of Runtime Permissions

Selective Permission Requests: With runtime permissions, you can request only the permissions that are required for a specific task, rather than asking for all the permissions upfront. This allows users to grant or deny permissions individually, giving them more control over their privacy.
Permission Status Checking: You can check the status of a permission at runtime to determine if it has been granted or denied by the user. This allows you to adapt your application's behavior based on the permission status.
Permission Request Handling: Runtime permissions provide a built-in mechanism to handle permission requests and responses. You can handle the user's decision to grant or deny a permission and take appropriate actions based on the result.

Usage of Runtime Permissions

Follow these steps to implement runtime permissions in your Kotlin Android application:

Step 1: Declare Permissions in the Manifest

Open your AndroidManifest.xml file and declare the permissions your app requires. This allows the system to check and enforce these permissions when needed. For example, if your app requires the CAMERA permission, add the following line inside the <manifest> tag:

<uses-permission android:name="android.permission.CAMERA" />

Step 2: Check Permission Status

Before requesting a permission, it's important to check if it has already been granted by the user. You can use the checkSelfPermission() method to check the status of a permission. For example, to check if the CAMERA permission is granted, use the following code:

val cameraPermission = Manifest.permission.CAMERA
val permissionStatus = ContextCompat.checkSelfPermission(this, cameraPermission)

if (permissionStatus == PackageManager.PERMISSION_GRANTED) {
    // Permission is already granted
    // Proceed with the task that requires this permission
} else {
    // Permission is not granted
    // Request the permission
}

Step 3: Request Permission

To request a runtime permission, use the requestPermissions() method. This method takes an array of permissions to request and a request code that will be used to identify the permission request callback. For example, to request the CAMERA permission, use the following code:

val cameraPermission = Manifest.permission.CAMERA
val requestCode = 1

requestPermissions(arrayOf(cameraPermission), requestCode)

Step 4: Handle Permission Request Result

After requesting a permission, the system will display a permission dialog to the user. The user can either grant or deny the permission. To handle the result of the permission request, override the onRequestPermissionsResult() method in your Activity or Fragment. This method will be called when the user responds to the permission request dialog. For example:

override fun onRequestPermissionsResult(requestCode: Int, permissions: Array<String>, grantResults: IntArray) {
    when (requestCode) {
        requestCode -> {
            if (grantResults.isNotEmpty() && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                // Permission is granted
                // Proceed with the task that requires this permission
            } else {
                // Permission is denied
                // Handle the denied permission case
            }
        }
    }
}

Step 5: Handle Denied Permission

If the user denies a permission, it's important to handle this case gracefully. You can show an explanation to the user about why the permission is required and ask them to grant the permission again. To handle the denied permission case, you can use the shouldShowRequestPermissionRationale() method to check if the user has previously denied the permission. For example:

if (shouldShowRequestPermissionRationale(cameraPermission)) {
    // Show an explanation to the user
    // Ask the user to grant the permission again
} else {
    // The user has permanently denied the permission
    // Show a dialog or navigate to app settings to enable the permission manually
}