iOS Privacy & Permissions skill

iOS Privacy & Permissions

Best practices for permission requests, privacy UI, and building user trust.

Table of Contents

1. Permission Request Philosophy
2. Permission Request Timing
3. Permission Types & Best Practices
4. Handling Denied Permissions
5. Privacy UI Patterns
6. App Privacy Labels
7. Usage String Best Practices
8. Testing Permissions

---

Permission Request Philosophy

Core principle: Request permissions only when needed, explain why, and respect "no."

Users are increasingly permission-fatigued. Every unnecessary or poorly-timed request damages trust and increases denial rates.

---

Permission Request Timing

Just-In-Time Requests

Request permissions when the user takes an action that requires them, not at app launch.

Bad: Request camera permission on first launch Good: Request camera permission when user taps "Take Photo"

The Pre-Permission Pattern

Before the system dialog, show a custom screen explaining the value.

┌─────────────────────────────────────────┐
│                                         │
│         [Camera icon]                   │
│                                         │
│    Take photos of your receipts         │
│                                         │
│    We use your camera to quickly        │
│    scan and organize your expenses.     │
│    Photos are stored only on your       │
│    device.                              │
│                                         │
│    ┌─────────────────────────────────┐  │
│    │        Allow Camera             │  │
│    └─────────────────────────────────┘  │
│                                         │
│            Maybe Later                  │
│                                         │
└─────────────────────────────────────────┘

Benefits:

• Explains value before system dialog
• "Maybe Later" doesn't trigger system denial
• Higher acceptance rates
• Better user understanding

System Permission Dialog

// Camera
AVCaptureDevice.requestAccess(for: .video) { granted in
    // Handle response
}

// Photos
PHPhotoLibrary.requestAuthorization(for: .readWrite) { status in
    // Handle status
}

// Location
locationManager.requestWhenInUseAuthorization()
// or
locationManager.requestAlwaysAuthorization()

// Notifications
UNUserNotificationCenter.current().requestAuthorization(
    options: [.alert, .badge, .sound]
) { granted, error in
    // Handle response
}

---

Permission Types & Best Practices

Camera

When to request: When user initiates camera action

Usage string example: "[App] needs camera access to scan documents and take photos for your projects."

Best practices:

• Only request when camera feature is used
• Offer photo library as alternative
• Handle denial gracefully (show library option)

Photo Library

Access levels (iOS 14+):

• .addOnly - Can add photos, can't read (for saving)
• .readWrite - Full access
• Limited selection - User picks specific photos

When to request: When user wants to access photos

Usage string example: "[App] accesses your photos to let you add images to your posts."

Best practices:

• Request .addOnly if you only need to save
• Support limited photo selection (don't require full access)
• Use PHPicker for one-time selection (no permission needed)

// PHPicker - no permission required
var config = PHPickerConfiguration()
config.selectionLimit = 1
config.filter = .images

let picker = PHPickerViewController(configuration: config)

Location

Authorization levels:

• .whenInUse - Only while app is active
• .always - Background location access

When to request: When location feature is needed

Usage strings needed:

• NSLocationWhenInUseUsageDescription
• NSLocationAlwaysAndWhenInUseUsageDescription (for always)

Best practices:

• Start with "When In Use" before requesting "Always"
• Explain why background location is needed
• Provide value even without location
• Use significant location changes if precise tracking unnecessary

// Request when in use first
locationManager.requestWhenInUseAuthorization()

// Later, if needed, escalate to always
// (triggers new system prompt explaining upgrade)
locationManager.requestAlwaysAuthorization()

Notifications

When to request: After user has experienced app value

Usage string example: "[App] sends notifications for messages from your team and important updates."

Best practices:

• Don't request on first launch
• Wait until user has seen value
• Explain what notifications they'll receive
• Provide in-app notification preferences
• Respect system settings

Provisional notifications (iOS 12+):

// Quietly delivered to Notification Center
// User can choose to keep or turn off
UNUserNotificationCenter.current().requestAuthorization(
    options: [.provisional, .alert, .sound]
) { granted, error in }

Contacts

When to request: When user initiates contact-related feature

Usage string example: "[App] accesses your contacts to help you invite friends and find people you know."

Best practices:

• Use CNContactPickerViewController when possible (no permission)
• Only request full access when truly needed
• Never sync contacts without explicit permission

Microphone

When to request: When user initiates audio recording

Usage string example: "[App] uses your microphone to record voice messages and audio notes."

Best practices:

• Clear indicator when recording
• Option to preview before sending
• Explain storage/transmission of audio

Health Data

When to request: When user enables health features

Best practices:

• Request only specific data types needed
• Explain how data will be used
• Provide value without health access
• Handle partial authorization

Tracking (ATT)

When to request: Before tracking user across apps

Required prompt:

ATTrackingManager.requestTrackingAuthorization { status in
    switch status {
    case .authorized:
        // Enable tracking
    case .denied, .restricted:
        // Disable tracking
    case .notDetermined:
        // Request hasn't been shown yet
    }
}

Best practices:

• Explain value of personalized ads first
• Don't punish users who decline
• App must function without tracking

---

Handling Denied Permissions

Graceful Degradation

Always provide alternative paths when permission is denied.

Permission Denied	Alternative
Camera	Photo library option
Location	Manual address entry
Notifications	In-app message center
Contacts	Manual contact entry
Photos	Camera-only option

Re-Requesting After Denial

Once denied, system won't show prompt again. Guide users to Settings.

func openAppSettings() {
    guard let settingsUrl = URL(string: UIApplication.openSettingsURLString),
          UIApplication.shared.canOpenURL(settingsUrl) else {
        return
    }
    UIApplication.shared.open(settingsUrl)
}

UI pattern:

┌─────────────────────────────────────────┐
│                                         │
│         Camera Access Needed            │
│                                         │
│    To scan documents, allow camera      │
│    access in Settings.                  │
│                                         │
│    ┌─────────────────────────────────┐  │
│    │       Open Settings             │  │
│    └─────────────────────────────────┘  │
│                                         │
│           Not Now                       │
│                                         │
└─────────────────────────────────────────┘

Don't Ask Again (Within Session)

If user taps "Maybe Later" on pre-permission screen, don't immediately ask again.

// Track dismissal
UserDefaults.standard.set(Date(), forKey: "camera_prompt_dismissed")

// Wait before showing again
func shouldShowCameraPrompt() -> Bool {
    guard let lastDismissed = UserDefaults.standard.object(
        forKey: "camera_prompt_dismissed"
    ) as? Date else {
        return true
    }
    // Wait at least 3 days
    return Date().timeIntervalSince(lastDismissed) > 3 * 24 * 60 * 60
}

---

Privacy UI Patterns

Permission Status Indicators

Show current permission state in settings:

┌─────────────────────────────────────────┐
│ Permissions                             │
├─────────────────────────────────────────┤
│ 📷 Camera                  Allowed    ▶ │
│ 📍 Location                While Using▶ │
│ 🔔 Notifications           Off        ▶ │
│ 📱 Contacts                Not Asked  ▶ │
└─────────────────────────────────────────┘

Data Usage Transparency

Explain what data is collected and why:

┌─────────────────────────────────────────┐
│ Privacy                                 │
├─────────────────────────────────────────┤
│                                         │
│ Data We Collect                         │
│                                         │
│ • Usage analytics                       │
│   To improve app performance            │
│                                         │
│ • Crash reports                         │
│   To fix bugs and issues                │
│                                         │
│ • Photos you upload                     │
│   Stored securely on our servers        │
│                                         │
│ [View Privacy Policy]                   │
│                                         │
└─────────────────────────────────────────┘

Data Deletion Options

Provide clear data management:

┌─────────────────────────────────────────┐
│ Your Data                               │
├─────────────────────────────────────────┤
│ Download My Data                      ▶ │
│ Delete My Account                     ▶ │
└─────────────────────────────────────────┘

---

App Privacy Labels

Required Categories

Your App Store listing must declare:

Data Used to Track You

• Data used for advertising across apps

Data Linked to You

• Identifiable data (name, email, etc.)

Data Not Linked to You

• Anonymous analytics, crash data

Best Practices

• Be accurate—Apple verifies
• Minimize collection to reduce label size
• Simpler labels build trust
• Update when collection changes

---

Usage String Best Practices

Structure

"[App name] [action] to [user benefit]."

Examples by Permission

Permission	Good Example
Camera	"MyApp uses the camera to scan barcodes for quick product lookup."
Photos	"MyApp saves photos you create to your photo library."
Location	"MyApp uses your location to show nearby restaurants and estimated delivery times."
Microphone	"MyApp uses the microphone to record voice notes for your journal entries."
Contacts	"MyApp accesses contacts to help you split bills with friends."

What to Avoid

• Generic explanations ("to improve your experience")
• Technical jargon
• Mentioning advertising without explaining value
• Being vague about data use

---

Testing Permissions

Reset Permissions

# Reset all permissions for specific app
xcrun simctl privacy booted reset all com.yourapp.bundleid

# Reset specific permission
xcrun simctl privacy booted reset camera com.yourapp.bundleid

Test All States

For each permission:

1. Never requested (first launch)
2. Authorized
3. Denied
4. Restricted (parental controls)
5. Limited (Photos)
6. Provisional (Notifications)

Automated Testing

func testCameraPermissionDenied() {
    // Set up mock authorization status
    mockCameraAuthorization = .denied

    // Trigger camera feature
    app.buttons["Take Photo"].tap()

    // Verify fallback UI appears
    XCTAssertTrue(app.staticTexts["Camera access needed"].exists)
    XCTAssertTrue(app.buttons["Open Settings"].exists)
}