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

1. ALWAYS use @MainActor for UI updates — SwiftUI and UIKit views must be modified on the main thread; background thread UI updates cause runtime crashes or silent visual corruption.
2. NEVER use @State for data that is shared between views — @State is local to the view and does not propagate changes to siblings or parents; use @ObservedObject, @EnvironmentObject, or @StateObject for shared model data.
3. ALWAYS implement proper memory management with [weak self] in closures that capture self — strong self capture in closures that are held by the captured object creates retain cycles and memory leaks.
4. 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.
5. ALWAYS use const constructors and mark SwiftUI views as struct — 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.md

After completing: Record any new patterns or exceptions discovered.

ASSUME INTERRUPTION: Your context may reset. If it's not in memory, it didn't happen.