| name | ios-swift-patterns |
| description | SwiftUI, UIKit, MVVM, Combine, async/await, Core Data, and App Store submission patterns Use when this capability is needed. |
| metadata | {"author":"cosmicstack-labs"} |
iOS Swift Patterns
Production-grade iOS development with Swift, SwiftUI, and UIKit.
Architecture
MVVM + Coordinator Pattern
View (SwiftUI/UIViewController)
↕ binds to
ViewModel (ObservableObject)
↕ calls
Service Layer (Networking, DB)
↕
Core Data / API
Key Principles
- Views are dumb: They render state and forward actions — no business logic
- ViewModels own state:
@Published properties, @State only for local UI
- Services are stateless: Network calls, DB operations, analytics
- Coordinators handle navigation: Removing navigation from views makes them reusable
SwiftUI Best Practices
Performance
- Use
LazyVStack/LazyHStack for large lists, not VStack
- Mark views with
@MainActor explicitly
- Use
equatable() on complex views to prevent unnecessary re-renders
- Prefer
@State for local, @StateObject for owned, @ObservedObject for passed-in
State Management
@MainActor
class UserViewModel: ObservableObject {
@Published var users: [User] = []
@Published var isLoading = false
func loadUsers() async {
isLoading = true
users = await userService.fetchUsers()
isLoading = false
}
}
App Store Submission Checklist
Source: cosmicstack-labs/mercury-agent-skills — distributed by TomeVault.
