Permission request flow in Android Kotlin - Build, Publish & Deploy

Build & Publish - Permission request flow

Performance Impact

Requesting permissions itself has minimal impact on frame rate or memory. However, improper handling can cause UI freezes if requests block the main thread. Frequent or repeated permission dialogs annoy users and may cause app abandonment, indirectly affecting perceived performance.

Battery usage is unaffected by permission requests, but granted permissions may enable features that consume more battery (e.g., location updates).

Optimization Tips

• Request permissions only when needed, not at app start, to avoid blocking UI.
• Use asynchronous callbacks to handle user responses without freezing the UI thread.
• Explain clearly why permissions are needed before requesting, reducing repeated denials.
• Cache granted permissions state to avoid unnecessary requests.
• Test on various Android versions to handle permission model differences smoothly.

App Size and Startup Time Impact

Permission request flow code adds negligible size to the app bundle. It mainly involves system dialogs and callbacks managed by Android OS.

Requesting permissions at startup can delay app readiness and increase perceived startup time. Request permissions contextually to keep startup fast.

iOS vs Android Differences

Android uses runtime permission requests starting from Android 6.0 (API 23). Permissions are requested individually or in groups, and users can deny or grant them anytime.

iOS also requires runtime permission requests but uses different APIs and permission types. iOS permissions are requested via system dialogs triggered by specific APIs (e.g., location, camera).

Android requires explicit permission checks and requests in code, while iOS permissions are often requested implicitly when accessing protected resources.

Store Review Guidelines

• Google Play: Must declare all requested permissions in the manifest. Avoid requesting unnecessary permissions. Provide clear user-facing explanations for sensitive permissions.
• Apple App Store: Provide usage descriptions in Info.plist for each permission. Explain why the app needs access to sensitive data.
• Both stores reject apps that request permissions without clear purpose or misuse sensitive permissions.
• Follow principle of least privilege: request only permissions essential for app functionality.

Self-Check Question

Your app takes 5 seconds to load this screen. What's likely wrong?

• Requesting multiple permissions at app start blocking UI thread.
• Not handling permission callbacks asynchronously, causing UI freeze.
• Requesting permissions repeatedly without caching granted state.
• Showing permission dialogs without user context, causing delays.

Key Result

Request permissions only when needed and handle user responses asynchronously to maintain smooth UI and fast startup. Declare permissions clearly for store compliance.

Practice

1. What is the first step before requesting a dangerous permission in Android Kotlin?

easy

A. Restart the app

B. Directly call requestPermissions without checking

C. Show a Toast message to the user

D. Check if the permission is already granted

Solution

1. Step 1: Understand permission checking

   Before asking for permission, the app must check if it already has it to avoid unnecessary requests.

2. Step 2: Use ContextCompat.checkSelfPermission

   This method returns if the permission is granted or denied, guiding the next action.

3. Final Answer:

   Check if the permission is already granted -> Option D

4. Quick Check:

   Check permission first = A [OK]

Hint: Always check permission status before requesting [OK]

Common Mistakes:

• Requesting permission without checking first
• Assuming permission is granted by default
• Ignoring permission status before action

2. Which Kotlin code snippet correctly requests a permission from an Activity?

easy

A. ActivityCompat.requestPermissions(this, arrayOf(Manifest.permission.CAMERA), 100)

B. requestPermissions(Manifest.permission.CAMERA, 100)

C. Activity.requestPermissions(this, Manifest.permission.CAMERA, 100)

D. requestPermission(Manifest.permission.CAMERA)

Solution

1. Step 1: Identify correct method signature

   ActivityCompat.requestPermissions requires context, array of permissions, and request code.

2. Step 2: Check syntax correctness

   ActivityCompat.requestPermissions(this, arrayOf(Manifest.permission.CAMERA), 100) matches the correct syntax with 'this' as context and arrayOf for permissions.

3. Final Answer:

   ActivityCompat.requestPermissions(this, arrayOf(Manifest.permission.CAMERA), 100) -> Option A

4. Quick Check:

   Correct requestPermissions syntax = D [OK]

Hint: Use ActivityCompat.requestPermissions with arrayOf permissions [OK]

Common Mistakes:

• Passing single permission string instead of array
• Using wrong method name or class
• Missing context parameter

3. Given this code snippet inside an Activity:

override fun onRequestPermissionsResult(requestCode: Int, permissions: Array<String>, grantResults: IntArray) {
  super.onRequestPermissionsResult(requestCode, permissions, grantResults)
  if (requestCode == 101 && grantResults.isNotEmpty() && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
    println("Permission granted")
  } else {
    println("Permission denied")
  }
}

What will be printed if the user denies the permission?

medium

A. Permission denied

B. Permission granted

C. No output

D. App crashes

Solution

1. Step 1: Analyze grantResults array

   If the user denies permission, grantResults[0] will not equal PERMISSION_GRANTED.

2. Step 2: Follow conditional logic

   The else branch executes, printing "Permission denied".

3. Final Answer:

   Permission denied -> Option A

4. Quick Check:

   User denies permission = "Permission denied" [OK]

Hint: Denied permission triggers else branch in onRequestPermissionsResult [OK]

Common Mistakes:

• Assuming grantResults[0] is always granted
• Not checking if grantResults is empty
• Ignoring requestCode check

4. What is wrong with this permission request code snippet?

ActivityCompat.requestPermissions(this, Manifest.permission.ACCESS_FINE_LOCATION, 200)

medium

A. Request code 200 is invalid

B. Missing arrayOf() around permission string

C. Should use ContextCompat instead of ActivityCompat

D. No need to request ACCESS_FINE_LOCATION permission

Solution

1. Step 1: Check method parameters

   requestPermissions expects an array of permissions, not a single string.

2. Step 2: Identify correct usage

   Permission string must be wrapped in arrayOf() to form an array.

3. Final Answer:

   Missing arrayOf() around permission string -> Option B

4. Quick Check:

   Permissions must be in arrayOf() [OK]

Hint: Wrap permissions in arrayOf() when requesting [OK]

Common Mistakes:

• Passing single permission string instead of array
• Confusing ContextCompat with ActivityCompat
• Using invalid request codes

5. You want to request both CAMERA and LOCATION permissions at once. Which code correctly handles the request and checks the result in Kotlin?

hard

A. requestPermissions(arrayOf(Manifest.permission.CAMERA, Manifest.permission.ACCESS_FINE_LOCATION), 300)
override fun onRequestPermissionsResult(requestCode: Int, permissions: Array<String>, grantResults: IntArray) {
println("Permissions handled")
}

B. ActivityCompat.requestPermissions(this, arrayOf(Manifest.permission.CAMERA), 300)
override fun onRequestPermissionsResult(requestCode: Int, permissions: Array<String>, grantResults: IntArray) {
if (requestCode == 300 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
println("All permissions granted")
} else {
println("Some permissions denied")
}
}

C. ActivityCompat.requestPermissions(this, arrayOf(Manifest.permission.CAMERA, Manifest.permission.ACCESS_FINE_LOCATION), 300)
override fun onRequestPermissionsResult(requestCode: Int, permissions: Array<String>, grantResults: IntArray) {
if (requestCode == 300 && grantResults.all { it == PackageManager.PERMISSION_GRANTED }) {
println("All permissions granted")
} else {
println("Some permissions denied")
}
}

D. ActivityCompat.requestPermissions(this, arrayOf(Manifest.permission.CAMERA, Manifest.permission.ACCESS_FINE_LOCATION), 300)
override fun onRequestPermissionsResult(requestCode: Int, permissions: Array<String>, grantResults: IntArray) {
if (requestCode == 300 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
println("All permissions granted")
} else {
println("Some permissions denied")
}
}

Solution

1. Step 1: Request multiple permissions correctly

   Use arrayOf with both permissions and a unique request code.

2. Step 2: Check all permissions granted in onRequestPermissionsResult

   Use grantResults.all { it == PackageManager.PERMISSION_GRANTED } to verify all permissions.

3. Final Answer:

   Request both permissions and check all granted with grantResults.all -> Option C

4. Quick Check:

   Multiple permissions need all granted check [OK]

Hint: Check all grantResults for multiple permissions [OK]

Common Mistakes:

• Checking only first permission result
• Not using arrayOf for multiple permissions
• Ignoring requestCode in result handler