Sample CodeiOS, iPadOS, Mac Catalyst, macOSReviewed 2026-07-21View on Apple Developer

Localizing Landmarks

At a glance

Item Summary
Purpose Add localizations to the Landmarks sample code project.
App architecture A Swift sample bundle with entry-bearing project variants End, Start, each leading to SwiftUI / MapKit APIs.
Main patterns Delegate or data-source callbacks, Actor-isolated state
Project style 75 scanned source file(s) across Swift, organized around ranked entry, type, and file boundaries.

Project structure

Source bundle/
├── End/
│   └── Landmarks/
│       ├── LandmarksApp.swift
│       └── Views/
│           ├── Landmarks/
│           │   ├── Landmark Detail/
│           │   │   ├── LandmarkDetailInspectorView.swift
│           │   │   └── LandmarkDetailView.swift
│           │   └── Landmarks View/
│           │       └── LandmarksView.swift
│           ├── Badges/
│           │   └── BadgesView.swift
│           └── Collections/
│               └── Collections/
│                   └── CollectionsView.swift
└── Start/
    └── Landmarks/
        ├── LandmarksApp.swift
        └── Views/
            ├── Landmarks/
            │   ├── Landmark Detail/
            │   │   ├── LandmarkDetailInspectorView.swift
            │   │   └── LandmarkDetailView.swift
            │   └── Landmarks View/
            │       └── LandmarksView.swift
            ├── Badges/
            │   └── BadgesView.swift
            └── Collections/
                └── Collections/
                    └── CollectionsView.swift

Structure observations

  • Architecturally prominent files are ranked from entry points and role-named declarations; resource-only paths are omitted.
  • Primary languages: Swift.
  • The verified tree contains 7 project/configuration file(s) and 102 source declaration(s).

Overall architecture

Reference code

End/Landmarks/LandmarksApp.swift:11 — architecture anchor

@main
struct LandmarksApp: App {
    // ...
}

Interpretation

The branches represent separate entry-bearing project variants in the downloaded bundle, not runtime calls between those variants. Each branch is intentionally collapsed at the documented framework boundary; the detailed target-local flow remains in the cited files. Ownership is claimed only where the next section cites a stored property or assignment.

Ownership and state

Ownership evidence

End/Landmarks/LandmarksApp.swift:14 — stored dependency or nearest verified ownership anchor

@main
struct LandmarksApp: App {
    // ...
    @State private var modelData = ModelData()
    // ...
}
Owner Object or state Relationship Mutation authority
LandmarksApp ModelData (modelData) owns wrapper-managed state Owning lexical scope
Constants CGFloat (cornerRadius) owns value state Initialized by the owner; the binding is immutable
Constants CGFloat (leadingContentInset) owns value state Initialized by the owner; the binding is immutable
Constants CGFloat (standardPadding) owns value state Initialized by the owner; the binding is immutable

Composition arrows indicate a source-visible construction expression or locally owned value state; aggregation means the owner stores or receives a dependency without proving exclusive lifetime ownership.

Class and protocol design

End/Landmarks/LandmarksApp.swift:12 — representative type boundary

struct LandmarksApp: App {
    // ...
}
Type Responsibility Depends on or conforms to
LandmarksApp Application entry and top-level composition App
LandmarksApp Application entry and top-level composition App
LandmarkDetailInspectorView User-interface presentation and input forwarding View
LandmarkInspectorFormView User-interface presentation and input forwarding View
LandmarkInspectorBadgeView User-interface presentation and input forwarding View
EarnedBadgeView User-interface presentation and input forwarding View
BadgeProgressView User-interface presentation and input forwarding View
LandmarkDetailInspectorView User-interface presentation and input forwarding View
LandmarkInspectorFormView User-interface presentation and input forwarding View
LandmarkInspectorBadgeView User-interface presentation and input forwarding View

No local protocol conformance is claimed as protocol-oriented design; external framework conformances are listed only as dependencies.

Access control

Symbol Access Verified effect Likely rationale
localizedTitle (End/DiscoverKit/DiscoverKit.swift:30) public The symbol is visible to importing modules. Inference: make the declaration available across a module or target boundary.
modelData (End/Landmarks/LandmarksApp.swift:14) private Use is restricted to the lexical declaration and same-file extensions allowed by Swift. Inference: keep state mutation or dependency lifetime inside the owning implementation.
progress (End/Landmarks/Model/BadgeProgress.swift:14) private Use is restricted to the lexical declaration and same-file extensions allowed by Swift. Inference: keep state mutation or dependency lifetime inside the owning implementation.
currentLocationManager (End/Landmarks/Model/LocationFinder.swift:15) private Use is restricted to the lexical declaration and same-file extensions allowed by Swift. Inference: keep state mutation or dependency lifetime inside the owning implementation.

Reference code

End/DiscoverKit/DiscoverKit.swift:30 — representative boundary

    public var localizedTitle: String {
        switch self {
        case .friend: String(localized: .Discover.sharedByFriends)
        case .curated: String(localized: .Discover.curatedCollection)
        }
    }

Swift declarations without a modifier are internal; explicit private, fileprivate, private(set), public, or open entries above are interpreted by language semantics. Objective-C/C samples instead rely on header and implementation boundaries, which are not equivalent to Swift lexical privacy.

Logic ownership and placement

Logic Owning type or file Placement rationale
Application entry and top-level composition LandmarksApp The source’s App suffix makes this role explicit.
User-interface presentation and input forwarding BadgeProgressView, BadgesView, CollectionDetailDisplayView, CollectionDetailEditingView The source’s View suffix makes this role explicit.

Design patterns

Pattern Source evidence Purpose or tradeoff
Delegate or data-source callbacks End/Landmarks/Model/LocationFinder.swift:13 Callback protocols invert event delivery back into the sample’s owner.
Actor-isolated state End/Landmarks/Model/BadgeProgress.swift:11 Actor annotations make the concurrency ownership boundary explicit.

Naming conventions

  • Types: App: LandmarksApp; View: BadgeProgressView, BadgesView, CollectionDetailDisplayView, CollectionDetailEditingView, CollectionDetailView.
  • Protocols: no local protocol declaration in the scanned source.
  • Methods: body, showsBadges.
  • Files: End/Landmarks/LandmarksApp.swift, Start/Landmarks/LandmarksApp.swift, End/Landmarks/Views/Landmarks/Landmark Detail/LandmarkDetailInspectorView.swift, Start/Landmarks/Views/Landmarks/Landmark Detail/LandmarkDetailInspectorView.swift, End/Landmarks/Views/Badges/BadgesView.swift, Start/Landmarks/Views/Badges/BadgesView.swift.

Architecture takeaways

  • LandmarksApp is the main source-visible entry or composition anchor for this sample.
  • Framework work reaches SwiftUI, MapKit, CoreLocation, CoreTransferable through a deliberately small high-level chain; the detailed API graph remains inside the cited implementation files.
  • Stored-property evidence identifies lifecycle collaboration; it does not by itself prove exclusive object ownership.
  • Access-control conclusions separate verified language visibility from the likely design rationale.
  • The source does not justify labeling the design protocol-oriented.

Source map

Source file Relevant symbols
End/Landmarks/LandmarksApp.swift LandmarksApp
Start/Landmarks/LandmarksApp.swift LandmarksApp
End/Landmarks/Views/Landmarks/Landmark Detail/LandmarkDetailInspectorView.swift LandmarkDetailInspectorView, Segment, LandmarkInspectorFormView, LandmarkInspectorBadgeView, EarnedBadgeView, BadgeProgressView
Start/Landmarks/Views/Landmarks/Landmark Detail/LandmarkDetailInspectorView.swift LandmarkDetailInspectorView, Segment, LandmarkInspectorFormView, LandmarkInspectorBadgeView, EarnedBadgeView, BadgeProgressView
End/Landmarks/Views/Badges/BadgesView.swift BadgesView, BadgeLabel, ToggleBadgesLabel, ShowsBadgesViewModifier
Start/Landmarks/Views/Badges/BadgesView.swift BadgesView, BadgeLabel, ToggleBadgesLabel, ShowsBadgesViewModifier
End/Landmarks/Views/Collections/Collections/CollectionsView.swift CollectionsView, CollectionTitleView
End/Landmarks/Views/Landmarks/Landmark Detail/LandmarkDetailView.swift LandmarkDetailView, FavoriteButtonLabel
End/Landmarks/Views/Landmarks/Landmarks View/LandmarksView.swift LandmarksView, ContinentTitleView
Start/Landmarks/Views/Collections/Collections/CollectionsView.swift CollectionsView, CollectionTitleView