swiftui-ui-patterns

SwiftUI UI Patterns

Quick start

When to Use

• When creating or refactoring SwiftUI screens, flows, or reusable UI components.
• When you need guidance on navigation, sheets, async state, previews, or component patterns.

Choose a track based on your goal:

Existing project

• Identify the feature or screen and the primary interaction model (list, detail, editor, settings, tabbed).
• Find a nearby example in the repo with rg "TabView\(" or similar, then read the closest SwiftUI view.
• Apply local conventions: prefer SwiftUI-native state, keep state local when possible, and use environment injection for shared dependencies.
• Choose the relevant component reference from references/components-index.md and follow its guidance.
• If the interaction reveals secondary content by dragging or scrolling the primary content away, read references/scroll-reveal.md before implementing gestures manually.
• Build the view with small, focused subviews and SwiftUI-native data flow.

New project scaffolding

• Start with references/app-wiring.md to wire TabView + NavigationStack + sheets.
• Add a minimal AppTab and RouterPath based on the provided skeletons.
• Choose the next component reference based on the UI you need first (TabView, NavigationStack, Sheets).
• Expand the route and sheet enums as new screens are added.

General rules to follow

• Use modern SwiftUI state (@State, @Binding, @Observable, @Environment) and avoid unnecessary view models.
• If the deployment target includes iOS 16 or earlier and cannot use the Observation API introduced in iOS 17, fall back to ObservableObject with @StateObject for root ownership, @ObservedObject for injected observation, and @EnvironmentObject only for truly shared app-level state.
• Prefer composition; keep views small and focused.
• Use async/await with .task and explicit loading/error states. For restart, cancellation, and debouncing guidance, read references/async-state.md.
• Keep shared app services in @Environment, but prefer explicit initializer injection for feature-local dependencies and models. For root wiring patterns, read references/app-wiring.md.
• Prefer the newest SwiftUI API that fits the deployment target and call out the minimum OS whenever a pattern depends on it.
• Maintain existing legacy patterns only when editing legacy files.
• Follow the project's formatter and style guide.
• Sheets: Prefer .sheet(item:) over .sheet(isPresented:) when state represents a selected model. Avoid if let inside a sheet body. Sheets should own their actions and call dismiss() internally instead of forwarding onCancel/onConfirm closures.
• Scroll-driven reveals: Prefer deriving a normalized progress value from scroll offset and driving the visual state from that single source of truth. Avoid parallel gesture state machines unless scroll alone cannot express the interaction.