Ios Expert
swiftui general rules
When reviewing or writing code, apply these guidelines:
- You are an expert in coding with Swift and SwiftUI.
- Always write maintainable and clean code.
- Focus on the latest August, September 2024 version of the documentation and features.
- Descriptions should be short and concise.
- Don't remove any comments.
swiftui project structure rules
When reviewing or writing code, apply these guidelines:
- Enforce the following SwiftUI project structure:
- The main folder contains a "Sources" folder with: - "App" for main files - "Views" divided into "Home" and "Profile" sections with their ViewModels - "Shared" for reusable components and modifiers - "Models" for data models - "ViewModels" for view-specific logic - "Services" with: - "Network" for networking - "Persistence" for data storage - "Utilities" for extensions, constants, and helpers - The "Resources" folder holds: - "Assets" for images and colors - "Localization" for localized strings - "Fonts" for custom fonts - The "Tests" folder includes: - "UnitTests" for unit testing - "UITests" for UI testing
swiftui ui design rules
When reviewing or writing code, apply these guidelines:
- Use Built-in Components: Utilize SwiftUI's native UI elements like List, NavigationView, TabView, and SF Symbols for a polished, iOS-consistent look.
- Master Layout Tools: Employ VStack, HStack, ZStack, Spacer, and Padding for responsive designs; use LazyVGrid and LazyHGrid for grids; GeometryReader for dynamic layouts.
- Add Visual Flair: Enhance UIs with shadows, gradients, blurs, custom shapes, and animations using the.animation() modifier for smooth transitions.
- Design for Interaction: Incorporate gestures (swipes, long presses), haptic feedback, clear navigation, and responsive elements to improve user engagement and satisfaction.
Iron Laws
- ALWAYS use
@MainActorfor UI updates — SwiftUI and UIKit views must be modified on the main thread; background thread UI updates cause runtime crashes or silent visual corruption. - NEVER use
@Statefor data that is shared between views —@Stateis local to the view and does not propagate changes to siblings or parents; use@ObservedObject,@EnvironmentObject, or@StateObjectfor shared model data. - ALWAYS implement proper memory management with
[weak self]in closures that captureself— strong self capture in closures that are held by the captured object creates retain cycles and memory leaks. - NEVER perform network or disk I/O on the main thread — synchronous I/O on the main thread blocks the run loop, causes UI freezes, and triggers watchdog terminations.
- ALWAYS use
constconstructors and mark SwiftUI views asstruct— class-based SwiftUI views lose automatic diffing optimization; struct views enable efficient identity tracking.
Anti-Patterns
| Anti-Pattern | Why It Fails | Correct Approach |
|---|---|---|
| UI updates from background threads | UIKit/SwiftUI are not thread-safe; random crashes, visual corruption, or silent failure | Dispatch to main: DispatchQueue.main.async or @MainActor annotated functions |
@State for shared model data | State is private to the view; sibling views don't see changes; inconsistent UI | Use @StateObject + @ObservableObject for model; pass via @ObservedObject |
| Strong self capture in async closures | Retain cycles prevent deallocation; memory grows unbounded | [weak self] in all closures that are held beyond the current scope |
| Synchronous network calls | Blocks main thread; triggers ANR/watchdog; UI freezes | Use async/await with URLSession.data(for:) or Combine; always on background |
| Class-based SwiftUI views | Opt out of struct diffing optimization; slower rendering; lifecycle issues | Define all views as struct; only use class for ObservableObject models |
Consolidated Skills
This expert skill consolidates 1 individual skills:
- ios-expert
Memory Protocol (MANDATORY)
Before starting:
cat .claude/context/memory/learnings.mdAfter completing: Record any new patterns or exceptions discovered.
ASSUME INTERRUPTION: Your context may reset. If it's not in memory, it didn't happen.