Permissions handling in React Native - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of permissions in a mobile app?

Permissions let the app ask for access to sensitive device features like camera, location, or contacts. This protects user privacy and device security.

beginner

How do you request a permission in React Native?

You use the PermissionsAndroid API on Android or the react-native-permissions library for both platforms to ask the user to allow access.

intermediate

What should you do if a user denies a permission request?

You should explain why the permission is needed and offer a way to try again or open app settings to enable it manually.

intermediate

Why is it important to check permission status before accessing a feature?

Checking permission status prevents app crashes and improves user experience by handling denied or restricted permissions gracefully.

beginner

Name a popular React Native library to handle permissions on both iOS and Android.

react-native-permissions is a popular library that simplifies checking and requesting permissions across platforms.

Which React Native API is used to request permissions on Android?

A PermissionsAndroid

B Camera

C LocationManager

D AppRegistry

PermissionsAndroid is the built-in API to request permissions on Android in React Native.

What should you do before accessing the camera in your app?

A Directly open the camera

B Request camera permission from the user

C Restart the app

D Clear app cache

You must request camera permission to respect user privacy and avoid app crashes.

If a user denies a permission, what is a good practice?

A Delete user data

B Force the app to close

C Ignore the denial and continue

D Explain why the permission is needed and offer to retry

Explaining the need and offering retry improves user trust and app usability.

Which library helps manage permissions on both iOS and Android in React Native?

A react-navigation

B react-native-camera

C react-native-permissions

D redux

react-native-permissions simplifies permission handling across platforms.

Why is checking permission status important before feature use?

A To avoid app crashes and handle denied permissions

B To speed up the app launch

C To reduce app size

D To increase battery usage

Checking permission status prevents errors and improves user experience.

Describe the steps to request and handle a permission in a React Native app.

Think about how you ask the user and what you do based on their answer.

Explain why respecting user permissions is important in mobile apps.

Consider what happens if you ignore permissions.

Practice

1. What is the main purpose of requesting permissions in a React Native app?

easy

A. To get user approval before accessing sensitive device features

B. To speed up the app loading time

C. To change the app's theme colors

D. To increase the app's storage space

Solution

1. Step 1: Understand app permissions

   Permissions are needed to access sensitive features like camera or location.

2. Step 2: Recognize user control

   Requesting permissions asks users for approval to protect their privacy.

3. Final Answer:

   To get user approval before accessing sensitive device features -> Option A

4. Quick Check:

   Permissions = user approval [OK]

Hint: Permissions protect user privacy by asking approval [OK]

Common Mistakes:

• Thinking permissions speed up app loading
• Confusing permissions with UI settings
• Assuming permissions increase storage

2. Which of the following is the correct way to import the PermissionsAndroid module in React Native?

easy

A. import PermissionsAndroid from 'react-native-permissions';

B. import Permissions from 'PermissionsAndroid';

C. import { PermissionsAndroid } from 'react-native';

D. import { Permissions } from 'react-native';

Solution

1. Step 1: Identify correct import source

   PermissionsAndroid is part of the core 'react-native' package.

2. Step 2: Check import syntax

   Correct syntax uses curly braces for named imports: import { PermissionsAndroid } from 'react-native';

3. Final Answer:

   import { PermissionsAndroid } from 'react-native'; -> Option C

4. Quick Check:

   Correct import = import { PermissionsAndroid } from 'react-native'; [OK]

Hint: Use curly braces for named imports from 'react-native' [OK]

Common Mistakes:

• Importing from wrong package
• Missing curly braces for named imports
• Using incorrect module names

3. What will the following React Native code output if the user denies the camera permission?

async function requestCamera() {
  const granted = await PermissionsAndroid.request(
    PermissionsAndroid.PERMISSIONS.CAMERA
  );
  if (granted === PermissionsAndroid.RESULTS.GRANTED) {
    console.log('Camera permission granted');
  } else {
    console.log('Camera permission denied');
  }
}
requestCamera();

medium

A. Camera permission denied

B. Camera permission granted

C. Syntax error

D. No output

Solution

1. Step 1: Understand permission request result

   If user denies, the result is not 'GRANTED'.

2. Step 2: Check conditional output

   Code logs 'Camera permission denied' when permission is denied.

3. Final Answer:

   Camera permission denied -> Option A

4. Quick Check:

   Denied permission logs denial message [OK]

Hint: Denied permission triggers else block console log [OK]

Common Mistakes:

• Assuming permission is always granted
• Confusing async function behavior
• Ignoring else condition

4. Identify the error in this React Native permission request code:

async function requestLocation() {
  const granted = await PermissionsAndroid.request(
    PermissionsAndroid.PERMISSIONS.LOCATION
  );
  if (granted === PermissionsAndroid.RESULTS.GRANTED) {
    console.log('Location permission granted');
  }
}

medium

A. Async function cannot use await

B. Missing else block to handle denied permission

C. Console.log syntax is wrong

D. PermissionsAndroid.PERMISSIONS.LOCATION is incorrect permission name

Solution

1. Step 1: Check permission constant name

   There is no 'LOCATION' permission; correct names are 'ACCESS_FINE_LOCATION' or 'ACCESS_COARSE_LOCATION'.

2. Step 2: Understand impact of wrong permission name

   Using wrong permission name causes runtime error or unexpected behavior.

3. Final Answer:

   PermissionsAndroid.PERMISSIONS.LOCATION is incorrect permission name -> Option D

4. Quick Check:

   Permission name must be exact [OK]

Hint: Use exact permission constants from docs [OK]

Common Mistakes:

• Using generic or incorrect permission strings
• Forgetting to handle denied permissions
• Misusing async/await syntax

5. You want to request both camera and microphone permissions in a React Native app before starting a video call. Which approach correctly handles both permissions and proceeds only if both are granted?

hard

A. Request microphone permission twice to ensure access

B. Request camera and microphone permissions separately and check each result before proceeding

C. Request permissions without awaiting results and start video call immediately

D. Request only camera permission and assume microphone is granted

Solution

1. Step 1: Understand multiple permission requests

   Each permission must be requested and checked individually to ensure access.

2. Step 2: Combine results before proceeding

   Proceed only if both camera and microphone permissions are granted to avoid errors.

3. Final Answer:

   Request camera and microphone permissions separately and check each result before proceeding -> Option B

4. Quick Check:

   Check all permissions granted before action [OK]

Hint: Check each permission result before proceeding [OK]

Common Mistakes:

• Assuming one permission covers both features
• Not awaiting permission results
• Requesting same permission multiple times