gh-Dimillian-Skills/swiftui-ui-patterns/SKILL.md

name

description

swiftui-ui-patterns

Best practices and example-driven guidance for building SwiftUI views and components, including navigation hierarchies, custom view modifiers, and responsive layouts with stacks and grids. Use when creating or refactoring SwiftUI UI, designing tab architecture with TabView, composing screens with VStack/HStack, managing @State or @Binding, building declarative iOS interfaces, or needing component-specific patterns and examples.

SwiftUI UI Patterns

Quick start

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-scaffolding-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.
• Prefer composition; keep views small and focused.
• Use async/await with .task and explicit loading/error states.
• 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.

Workflow for a new SwiftUI view

1. Define the view's state and its ownership location.
2. Identify dependencies to inject via @Environment.
3. Sketch the view hierarchy and extract repeated parts into subviews. Build and verify no compiler errors before proceeding.
4. Implement async loading with .task and explicit state enum if needed.
5. Add accessibility labels or identifiers when the UI is interactive.
6. Validate with a build: confirm no compiler errors, check that previews render without crashing, and ensure state changes propagate correctly. For common SwiftUI compilation errors — missing @State annotations, ambiguous ViewBuilder closures, or mismatched generic types — resolve them before updating callsites. If the build fails: read the error message carefully, fix the identified issue, then rebuild before proceeding to the next step. If a preview crashes, isolate the offending subview, confirm its state initialisation is valid, and re-run the preview before continuing.

Component references

Use references/components-index.md as the entry point. Each component reference should include:

• Intent and best-fit scenarios.
• Minimal usage pattern with local conventions.
• Pitfalls and performance notes.
• Paths to existing examples in the current repo.

For detail surfaces that progressively reveal actions, metadata, or contextual panels, use references/scroll-reveal.md.

Sheet patterns

Item-driven sheet (preferred)

@State private var selectedItem: Item?

.sheet(item: $selectedItem) { item in
    EditItemSheet(item: item)
}

Sheet owns its actions

struct EditItemSheet: View {
    @Environment(\.dismiss) private var dismiss
    @Environment(Store.self) private var store

    let item: Item
    @State private var isSaving = false

    var body: some View {
        VStack {
            Button(isSaving ? "Saving…" : "Save") {
                Task { await save() }
            }
        }
    }

    private func save() async {
        isSaving = true
        await store.save(item)
        dismiss()
    }
}

Adding a new component reference

• Create references/<component>.md.
• Keep it short and actionable; link to concrete files in the current repo.
• Update references/components-index.md with the new entry.