ios

Purpose

This skill handles core iOS development tasks using Apple's SDK, focusing on app lifecycle management (scene-based), permissions via NSUsageDescription in Info.plist, and adherence to Human Interface Guidelines (HIG) for UI/UX consistency.

When to Use

• Building native iOS apps with Swift or Objective-C.
• Managing app states in scene-based architectures (e.g., iOS 13+).
• Requesting user permissions like camera or location.
• Ensuring apps follow HIG for accessibility and design standards.
• Integrating iOS-specific features in cross-platform projects.

Key Capabilities

• Access iOS SDK components like UIKit and SwiftUI for UI building.
• Handle scene-based lifecycle events (e.g., sceneDidBecomeActive).
• Manage permissions by adding keys to Info.plist (e.g., NSCameraUsageDescription).
• Enforce HIG through practices like adaptive layouts and voiceover support.
• Support for Xcode tools and Apple ecosystem integration.

Usage Patterns

• Start by setting up an Xcode project: Use xcodegen or create via Xcode UI, then add dependencies via Swift Package Manager.
• For app lifecycle, implement UISceneDelegate methods in your scene manifest.
• To handle permissions, edit Info.plist directly or via Xcode's property list editor, adding strings for each usage description.
• Follow HIG by using Auto Layout constraints and testing with Accessibility Inspector.
• Test apps on simulators or devices using Xcode's build scheme: Select device, then run xcodebuild -scheme MyApp -destination 'platform=iOS Simulator,name=iPhone 14' build.

Common Commands/API

• CLI Commands: Use xcodebuild for building: xcodebuild -workspace MyApp.xcworkspace -scheme MyApp clean build. For archiving: xcodebuild -scheme MyApp -configuration Release archive.
• API Endpoints: Not applicable for direct endpoints; use iOS APIs like AVCaptureDevice.requestAccess(for: .video) for camera permission.
• Code Snippets:
  • Request camera permission:

    import AVFoundation
    AVCaptureDevice.requestAccess(for: .video) { granted in
        if granted { print("Access granted") } else { print("Denied") }
    }
    

  • Handle scene lifecycle in SceneDelegate.swift:

    func sceneDidBecomeActive(_ scene: UIScene) {
        // Resume tasks, e.g., start timers
    }
    func sceneWillResignActive(_ scene: UIScene) {
        // Pause tasks
    }
    

  • Add permission to Info.plist (XML format):

    <key>NSCameraUsageDescription</key>
    <string>This app uses the camera for photo capture.</string>
    

• Config Formats: Use Info.plist for permissions (key-value pairs) or entitlements files for capabilities like iCloud (e.g., <key>com.apple.security.application-groups</key><string>group.com.example</string>).

Integration Notes

• Integrate with other tools by linking via Xcode: Add pods with CocoaPods (pod install) or packages in Package.swift.
• For Apple services like App Store Connect, use environment variables for API keys: Set $APPLE_API_KEY and reference in scripts (e.g., xcrun altool --upload-app --file MyApp.ipa --username $APPLE_USERNAME --password $APPLE_API_KEY).
• When combining with Android (via mobile cluster), use shared configs but handle iOS-specific code in conditional blocks (e.g., #if os(iOS) in Swift).
• For CI/CD, integrate with GitHub Actions: Use actions/checkout then run xcodebuild in a macOS runner.
• If using third-party SDKs, add them via Swift Package Manager: Edit Package.swift and resolve with swift package resolve.

Error Handling

• For permission denials, check status with AVAuthorizationStatus.authorized and prompt users via UIAlertController if needed.
• Handle build errors from xcodebuild by parsing output: Look for "Command PhaseScriptExecution failed" and fix scripts; use xcodebuild -verbose for details.
• For lifecycle issues, add logging in delegate methods (e.g., print("Scene error: \(error)") in sceneWillEnterForeground).
• Common fixes: If Info.plist keys are missing, Xcode will error on build; add them via the project editor. For HIG violations, use Xcode's accessibility audit tool and resolve warnings.
• Use try-catch for API calls: e.g., do { try AVAudioSession.sharedInstance().setCategory(.playAndRecord) } catch { print(error.localizedDescription) }.

Usage Examples

• Example 1: Basic App with Camera Permission Create a new Xcode project, add NSCameraUsageDescription to Info.plist, and implement permission request in ViewController.swift:

  import UIKit
  import AVFoundation
  class ViewController: UIViewController {
      override func viewDidLoad() { super.viewDidLoad(); requestCamera() }
      func requestCamera() { AVCaptureDevice.requestAccess(for: .video) { granted in if granted { /* Proceed */ } } }
  }
  

  Build and run with xcodebuild -scheme MyApp build to test on simulator.

• Example 2: Managing App Lifecycle In a scene-based app, handle state changes in SceneDelegate.swift:

  import UIKit
  class SceneDelegate: UIResponder, UIWindowSceneDelegate {
      func sceneDidBecomeActive(_ scene: UIScene) { print("App active") }
      func sceneWillEnterForeground(_ scene: UIScene) { /* Reload data */ }
  }
  

  Use xcodebuild test to verify lifecycle events during app testing.

Graph Relationships

• Related to: mobile (cluster), as it shares mobile development patterns.
• Connected to: android (skill), via cross-platform mobile integration.
• Links with: apple-ecosystem (tag), for broader Apple services.
• Associated with: sdk-tools (implied), for shared SDK usage in iOS context.