Permissions handling in Flutter - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ ui_behavior

intermediate

What happens when permission is denied in this Flutter code?

Consider this Flutter snippet that requests camera permission. What will the app do if the user denies the permission?

Flutter

import 'package:permission_handler/permission_handler.dart';

Future<void> checkCameraPermission() async {
  var status = await Permission.camera.status;
  if (!status.isGranted) {
    var result = await Permission.camera.request();
    if (result.isDenied) {
      print('Permission denied');
    } else if (result.isGranted) {
      print('Permission granted');
    }
  } else {
    print('Permission already granted');
  }
}

A The app prints 'Permission granted' even if denied.

B The app prints 'Permission denied' and does not access the camera.

C The app automatically retries requesting permission until granted.

D The app crashes because permission denial is not handled.

💡 Hint

Think about what the code does when result.isDenied is true.

The code checks if permission is denied and prints 'Permission denied'. It does not crash or retry automatically.

🧠 Conceptual

intermediate

Which permission status indicates the user permanently denied permission?

In Flutter's permission_handler package, which status means the user denied permission and selected 'Don't ask again'?

A PermissionStatus.denied

B PermissionStatus.limited

C PermissionStatus.restricted

D PermissionStatus.permanentlyDenied

💡 Hint

This status means the app cannot request permission again without user action in settings.

PermissionStatus.permanentlyDenied means the user denied permission and chose not to be asked again.

❓ lifecycle

advanced

When should you check permissions in a Flutter app lifecycle?

You want to check and request location permission in your Flutter app. When is the best lifecycle moment to do this to ensure permission is up to date?

A Only once in main() before runApp()

B Only when the user taps a button to use location

C Every time the app resumes from background

D Only after the app has been running for 5 minutes

💡 Hint

Permissions can change while app is in background.

Checking permissions on app resume ensures you catch changes made outside the app.

🔧 Debug

advanced

Why does this Flutter permission request code never print 'Permission granted'?

Review this code snippet. It requests microphone permission but never prints 'Permission granted' even when permission is granted.

Flutter

import 'package:permission_handler/permission_handler.dart';

Future<void> requestMic() async {
  var status = await Permission.microphone.request();
  if (status == PermissionStatus.granted) {
    print('Permission granted');
  } else if (status == PermissionStatus.denied) {
    print('Permission denied');
  }
}

A The function is not marked async, so await does not work.

B Permission.microphone.request() returns a Future<PermissionStatus?>, so await is missing.

C PermissionStatus.granted is not the correct enum value for granted permission.

D The code uses '==' to compare enums instead of '.isGranted' property.

💡 Hint

Check the function signature and usage of await.

The function is not async, so await does not pause execution and status is a Future, not PermissionStatus.

❓ navigation

expert

How to navigate user to app settings when permission is permanently denied?

In Flutter, if a user permanently denies camera permission, how can you open the app settings screen so they can manually enable it?

A Use openAppSettings() from permission_handler package.

B Use Navigator.pushNamed(context, '/settings') to open settings.

C Call SystemNavigator.pop() to close app and ask user to reopen.

D Use launchUrl('app-settings:') from url_launcher package.

💡 Hint

permission_handler provides a built-in method for this.

openAppSettings() opens the device app settings screen for your app.