app-lifecycle

# App Lifecycle — Expert Decisions

Expert decision frameworks for app lifecycle choices. Claude knows scenePhase and SceneDelegate — this skill provides judgment calls for architecture decisions and background task trade-offs.

---

## Decision Trees

### Lifecycle API Selection

```
What's your project setup?
├─ Pure SwiftUI app (iOS 14+)
│  └─ @main App + scenePhase
│     Simplest approach, sufficient for most apps
│
├─ Need UIKit integration
│  └─ SceneDelegate + UIHostingController
│     Required for some third-party SDKs
│
├─ Need pre-launch setup
│  └─ AppDelegate + SceneDelegate
│     SDK initialization, remote notifications
│
└─ Legacy app (pre-iOS 13)
   └─ AppDelegate only
      window property on AppDelegate
```

**The trap**: Using SceneDelegate when pure SwiftUI suffices. scenePhase covers most use cases without the boilerplate.

### Background Task Strategy

```
What work needs to happen in background?
├─ Quick save (< 5 seconds)
│  └─ UIApplication.beginBackgroundTask
│     Request extra time in sceneDidEnterBackground
│
├─ Network sync (< 30 seconds)
│  └─ BGAppRefreshTask
│     System schedules, best-effort timing
│
├─ Large download/upload
│  └─ Background URL Session
│     Continues even after app termination
│
├─ Location tracking
│  └─ Location background mode
│     Significant change or continuous
│
└─ Long processing (> 30 seconds)
   └─ BGProcessingTask
      Runs during charging, overnight
```

### State Restoration Approach

```
What state needs restoration?
├─ Simple navigation state
│  └─ @SceneStorage
│     Per-scene, automatic, Codable types only
│
├─ Complex navigation + data
│  └─ @AppStorage + manual encoding
│     More control, cross-scene sharing
│
├─ UIKit-based navigation
│  └─ State restoration identifiers
│     encodeRestorableState/decodeRestorableState
│
└─ Don't need restoration
   └─ Start fresh each launch
      Some apps are better this way
```

### Launch Optimization Priority

```
What's blocking your launch time?
├─ S