Swiftui Navigation Agent Skill

SwiftUI Navigation

Navigation patterns for SwiftUI apps targeting iOS 26+ with Swift 6.3. Covers push navigation, multi-column layouts, sheet presentation, tab architecture, and deep linking. Patterns are backward-compatible to iOS 17 unless noted.

Contents

• NavigationStack (Push Navigation)
• NavigationSplitView (Multi-Column)
• Sheet Presentation
• Tab-Based Navigation
• Deep Links
• Common Mistakes
• Review Checklist
• References

NavigationStack (Push Navigation)

Use NavigationStack with a typed [Route] binding for programmatic push navigation. Define routes as a Hashable enum and map them with .navigationDestination(for:); this keeps the path compile-time checked. Use NavigationPath only when one stack must hold heterogeneous route value types.

enum Route: Hashable {
    case item(id: Item.ID)
}

struct ContentView: View {
    @State private var path: [Route] = []
    let items: [Item]

    var body: some View {
        NavigationStack(path: $path) {
            List(items) { item in
                NavigationLink(value: Route.item(id: item.id)) {
                    ItemRow(item: item)
                }
            }
            .navigationDestination(for: Route.self) { route in
                switch route {
                case .item(let id):
                    DetailView(itemID: id)
                }
            }
            .navigationTitle("Items")
        }
    }
}

Programmatic navigation:

path.append(.item(id: item.id))  // Push
path.removeLast()                // Pop one
path = []                        // Pop to root

Router pattern: For apps with complex navigation, use a router object that owns the path and sheet state. Each tab gets its own router instance injected via .environment(). Centralize destination mapping with a single .navigationDestination(for:) block or a shared withAppRouter() modifier.

See references/navigationstack.md for full router examples including per-tab stacks, centralized destination mapping, and generic tab routing.

NavigationSplitView (Multi-Column)

Use NavigationSplitView for sidebar-detail layouts on iPad and Mac. Falls back to stack navigation on iPhone.

struct MasterDetailView: View {
    @State private var selectedItem: Item?

    var body: some View {
        NavigationSplitView {
            List(items, selection: $selectedItem) { item in
                NavigationLink(value: item) { ItemRow(item: item) }
            }
            .navigationTitle("Items")
        } detail: {
            if let item = selectedItem {
                ItemDetailView(item: item)
            } else {
                ContentUnavailableView("Select an Item", systemImage: "sidebar.leading")
            }
        }
    }
}

Custom Split Column (Manual HStack)

For custom multi-column layouts (e.g., a dedicated notification column independent of selection), use a manual HStack split with horizontalSizeClass checks:

@MainActor
struct AppView: View {
  @Environment(\.horizontalSizeClass) private var horizontalSizeClass
  @AppStorage("showSecondaryColumn") private var showSecondaryColumn = true

  var body: some View {
    HStack(spacing: 0) {
      primaryColumn
      if shouldShowSecondaryColumn {
        Divider().edgesIgnoringSafeArea(.all)
        secondaryColumn
      }
    }
  }

  private var shouldShowSecondaryColumn: Bool {
    horizontalSizeClass == .regular
      && showSecondaryColumn
  }

  private var primaryColumn: some View {
    TabView { /* tabs */ }
  }

  private var secondaryColumn: some View {
    NotificationsTab()
      .environment(\.isSecondaryColumn, true)
      .frame(maxWidth: .secondaryColumnWidth)
  }
}

Use the manual HStack split when you need full control or a non-standard secondary column. Use NavigationSplitView when you want a standard system layout with minimal customization.

Sheet Presentation

Prefer .sheet(item:) over .sheet(isPresented:) when state represents a selected model. Sheets should own their actions and call dismiss() internally.

@State private var selectedItem: Item?

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

Presentation sizing (iOS 18+): Control sheet dimensions with .presentationSizing:

.sheet(item: $selectedItem) { item in
    EditItemSheet(item: item)
        .presentationSizing(.form)  // .form, .page, .fitted, .automatic
}

PresentationSizing values:

• .automatic -- platform default
• .page -- roughly paper size, for informational content
• .form -- slightly narrower than page, for form-style UI
• .fitted -- sized by the content's ideal size

Fine-tuning: .fitted(horizontal:vertical:) constrains fitting axes; .sticky(horizontal:vertical:) grows but does not shrink in specified dimensions.

Dismissal protection: On iOS/iPadOS, use .interactiveDismissDisabled(hasUnsavedChanges) and provide explicit Save/Discard actions inside the sheet. On macOS 15+, use .dismissalConfirmationDialog("Discard?", shouldPresent: hasUnsavedChanges) for window dismissal confirmation.

Route every programmatic close through the same save/validate/discard gate;

interactiveDismissDisabled guards interactive dismissal only.

Enum-driven sheet routing: Define a SheetDestination enum that is Identifiable, store it on the router, and map it with a shared view modifier. This lets any child view present sheets without prop-drilling. See references/sheets.md for the full centralized sheet routing pattern.

Tab-Based Navigation

Use the Tab API with a selection binding for scalable tab architecture. Each tab should wrap its content in an independent NavigationStack.

struct MainTabView: View {
    @State private var selectedTab: AppTab = .home

    var body: some View {
        TabView(selection: $selectedTab) {
            Tab("Home", systemImage: "house", value: .home) {
                NavigationStack { HomeView() }
            }
            Tab("Search", systemImage: "magnifyingglass", value: .search) {
                NavigationStack { SearchView() }
            }
            Tab("Profile", systemImage: "person", value: .profile) {
                NavigationStack { ProfileView() }
            }
        }
    }
}

Custom binding with side effects: Route selection changes through a function to intercept special tabs (e.g., compose) that should trigger an action instead of changing selection.

iOS 26 Tab Additions

• Tab(value:role:) with .search -- marks a dedicated search tab with system default search title, icon, and pinning behavior
• .tabViewSearchActivation(_:) -- controls search tab activation and deactivation behavior
• .tabBarMinimizeBehavior(_:) -- .onScrollDown, .onScrollUp, .never (iPhone only)
• .tabViewSidebarHeader/Footer -- customize sidebar sections on iPadOS/macOS
• .tabViewBottomAccessory { } -- attach content below the tab bar (e.g., Now Playing bar)
• TabSection -- group tabs into sidebar sections with .tabPlacement(.sidebarOnly)

See references/tabview.md for full TabView patterns including custom bindings, dynamic tabs, and sidebar customization.

Deep Links

Use parse → validate → commit. Parse into a typed route without mutating

navigation; validate scheme/host/path, identifier shape, authorization, and

destination existence; then update tab/path atomically. Invalid links must leave

the current navigation unchanged.

Universal Links

Universal links let iOS open your app for standard HTTPS URLs. They require:

• An Apple App Site Association (AASA) file at /.well-known/apple-app-site-association
• An Associated Domains entitlement (applinks:example.com)

Handle Universal Links and custom URL schemes in SwiftUI with .onOpenURL:

@main
struct MyApp: App {
    @State private var router = Router()

    var body: some Scene {
        WindowGroup {
            ContentView()
                .environment(router)
                .onOpenURL { url in router.handle(url: url) }
        }
    }
}

Custom URL Schemes

Register schemes in Info.plist under CFBundleURLTypes. Handle with .onOpenURL. Prefer universal links over custom schemes for publicly shared links -- they provide web fallback and domain verification.

Handoff (NSUserActivity)

Advertise activities with .userActivity() and receive Handoff or other user activities with .onContinueUserActivity(). Declare activity types in Info.plist under NSUserActivityTypes. Set isEligibleForHandoff = true and provide a webpageURL as fallback.

See references/deeplinks.md for full examples of AASA configuration, router URL handling, custom URL schemes, and NSUserActivity continuation.

Common Mistakes

• Using deprecated NavigationView -- use NavigationStack or NavigationSplitView
• Sharing one navigation path or router across all tabs -- each tab needs its own path
• Using .sheet(isPresented:) when state represents a model -- use .sheet(item:) instead
• Storing view instances in navigation paths -- store lightweight Hashable route data
• Nesting @Observable router objects inside other @Observable objects
• Prefer Tab(value:) with TabView(selection:) over the older .tabItem { } API
• Assuming tabBarMinimizeBehavior works on iPad -- it is iPhone only
• Handling deep links in multiple places -- centralize URL parsing in the router
• Hard-coding sheet frame dimensions -- use .presentationSizing(.form) instead

10. Missing @MainActor on router classes -- required for Swift 6 concurrency safety

Review Checklist

• [ ] NavigationStack used (not NavigationView)
• [ ] Each tab has its own NavigationStack with independent path
• [ ] Route enum is Hashable with stable identifiers
• [ ] .navigationDestination(for:) maps all route types
• [ ] .sheet(item:) preferred over .sheet(isPresented:)
• [ ] Sheets own their dismiss logic internally
• [ ] Router object is @MainActor and @Observable
• [ ] Deep link URLs parsed and validated before navigation
• [ ] Universal links have AASA and Associated Domains configured
• [ ] Tab selection uses Tab(value:) with binding

References

• NavigationStack and router patterns: references/navigationstack.md
• Sheet presentation and routing: references/sheets.md
• TabView patterns and iOS 26 API: references/tabview.md
• Deep links, universal links, and Handoff: references/deeplinks.md
• Architecture and state management: see swiftui-patterns skill
• Layout and components: see swiftui-layout-components skill