Configure SwiftUI state, view lifecycle, and Property Wrappers correctly. Use when managing SwiftUI state, view lifecycle, or property wrappers like @State and @Binding.
---
name: swift-swiftui
description: Configure SwiftUI state, view lifecycle, and Property Wrappers correctly. Use when managing SwiftUI state, view lifecycle, or property wrappers like @State and @Binding.
metadata:
triggers:
files:
- '**/*.swift'
keywords:
- "@State"
- "@Binding"
- "@ObservedObject"
- View
- body
---
# SwiftUI Standards
## **Priority: P0 (CRITICAL)**
## Implementation Guidelines
### State Management
- **@State**: @State for data owned by view (e.g., toggle, text input). Private.
- **@Binding**: @Binding for data passed down from parent to child. Two-way.
- **@ObservedObject**: @ObservedObject when receiving instance from external source.
- **@StateObject**: `@StateObject` when the view is creating the object instance — view owns lifecycle.
- **@EnvironmentObject**: `@EnvironmentObject` to inject data into the view's hierarchy via `.environmentObject()`. Shared across view hierarchy.
### View Composition
- **Extract Subviews**: Views < 200 lines. Extract reusable components.
- **View Modifiers**: Chain modifiers for styling (`.font()`, `.padding()`).
- **Custom Modifiers**: Create `ViewModifier` for reusable styles.
### Performance
- **Avoid Heavy Computation**: Use `@State` + `.task()` for async work.
- **Equatable**: Conform views to `Equatable` to prevent unnecessary re-renders.
- **LazyStacks**: `LazyVStack`/`LazyHStack` when displaying large number of views in scrolling container to load them only as they appear.
## Anti-Patterns
- **No @ObservedObject for owned objects**: Use @StateObject.
- **No logic in body**: Move to computed properties or methods.
- **No ! in View**: Use if-let or nil coalescing.
## References
- [State & Binding](references/implementation.md)
## Canonical response anchors
When this skill applies, preserve the following domain terminology or equivalent concrete examples in the answer when relevant:
- @Binding for data passed down
- @ObservedObject when receiving
- @State for data owned
- inject data into the view's hierarchy
- large number of views
- load them only as they appear
---
name: swift-swiftui
description: Configure SwiftUI state, view lifecycle, and Property Wrappers correctly. Use when managing SwiftUI state, view lifecycle, or property wrappers like @State and @Binding.
metadata:
triggers:
files:
- '**/*.swift'
keywords:
- "@State"
- "@Binding"
- "@ObservedObject"
- View
- body
---
# SwiftUI Standards
## **Priority: P0 (CRITICAL)**
## Implementation Guidelines
### State Management
- **@State**: @State for data owned by view (e.g., toggle, text input). Private.
- **@Binding**: @Binding for data passed down from parent to child. Two-way.
- **@ObservedObject**: @ObservedObject when receiving instance from external source.
- **@StateObject**: `@StateObject` when the view is creating the object instance — view owns lifecycle.
- **@EnvironmentObject**: `@EnvironmentObject` to inject data into the view's hierarchy via `.environmentObject()`. Shared across view hierarchy.
### View Composition
- **Extract Subviews**: Views < 200 lines. Extract reusable components.
- **View Modifiers**: Chain modifiers for styling (`.font()`, `.padding()`).
- **Custom Modifiers**: Create `ViewModifier` for reusable styles.
### Performance
- **Avoid Heavy Computation**: Use `@State` + `.task()` for async work.
- **Equatable**: Conform views to `Equatable` to prevent unnecessary re-renders.
- **LazyStacks**: `LazyVStack`/`LazyHStack` when displaying large number of views in scrolling container to load them only as they appear.
## Anti-Patterns
- **No @ObservedObject for owned objects**: Use @StateObject.
- **No logic in body**: Move to computed properties or methods.
- **No ! in View**: Use if-let or nil coalescing.
## References
- [State & Binding](references/implementation.md)
## Canonical response anchors
When this skill applies, preserve the following domain terminology or equivalent concrete examples in the answer when relevant:
- @Binding for data passed down
- @ObservedObject when receiving
- @State for data owned
- inject data into the view's hierarchy
- large number of views
- load them only as they appear
Imported from the listed AgentSkill.sh category. Complete supplied package files and notices are retained. Required external tools and credentials are not installed. No bundled code was executed during import. Individual agent task behavior has not been tested.