Wishlist: Planning travel in a SwiftUI app

At a glance

Project structure

Source bundle/
├── WithSwiftData/
│   └── Wishlist/
│       ├── WishlistApp.swift
│       └── Views/
│           ├── Trips/
│           │   ├── AddTripView.swift
│           │   └── TripCollectionView.swift
│           ├── SearchView.swift
│           └── Goals/
│               └── GoalsView.swift
└── WithoutPersistence/
    └── Wishlist/
        ├── WishlistApp.swift
        ├── Views/
        │   ├── Trips/
        │   │   ├── AddTripView.swift
        │   │   └── TripCollectionView.swift
        │   ├── SearchView.swift
        │   └── Goals/
        │       └── GoalsView.swift
        └── Models/
            ├── DataSource.swift
            └── TripEditModel.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 84 source declaration(s).

Overall architecture

flowchart LR
    Bundle["Sample bundle"]
    V1["WithSwiftData"]
    V2["WithoutPersistence"]
    Boundary["SwiftUI APIs"]
    Bundle --> V1
    V1 --> Boundary
    Bundle --> V2
    V2 --> Boundary

Reference code

WithSwiftData/Wishlist/WishlistApp.swift:11 — architecture anchor

@main
struct WishlistApp: App {

    let container: ModelContainer = {
        do {
            let modelContainer = try ModelContainer(for: Trip.self, Activity.self, TripImage.self, Goal.self, TripGoal.self, ActivityGoal.self)
            try SampleData.seedIfNeeded(in: modelContainer.mainContext)
            return modelContainer
        } catch {
            fatalError("Could not create model container: \(error)")
        }
    }()

    var body: some Scene {
        WindowGroup {
            ContentView()
                .preferredColorScheme(.dark)
        }
        .modelContainer(container)
    }
}

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

classDiagram
    SearchResultsListView *-- Array : trips
    SearchResultsListView *-- Array : activities
    SearchResultsListView *-- String : searchText
    SearchResultsListView o-- ID : namespace

Ownership evidence

WithSwiftData/Wishlist/Views/SearchView.swift:52 — stored dependency or nearest verified ownership anchor

private struct SearchResultsListView: View {
    // ...
    @Query(sort: \Trip.name) private var trips: [Trip]
    // ...
}

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.

Concurrency, scheduling, and thread safety

Evidence limit: actor isolation, async/await, or Task creation does not by itself prove background-thread execution; Sendable conformance alone does not prove thread-safe mutation.

@MainActor/MainActor.run, DispatchQueue.main, and RunLoop.main are reported as distinct isolation, queue, and event-loop mechanisms. A plain Task is kept separate from Task.detached; neither is labeled as a background thread.

Reference code

WithSwiftData/Wishlist/Views/Trips/AddTripView.swift:113 — representative execution boundary

private struct TripImagePicker: View {
    // ...
                    selectedPhotoData = try await newPhoto.loadTransferable(type: Data.self)
    // ...
}

State propagation, frameworks, and dependencies

Evidence limit: an import proves a source-level compilation dependency at the cited line; it does not prove runtime use, architectural adoption, or whether a Swift package is a direct application dependency.

receive(on:) describes downstream delivery scheduling, while subscribe(on:) describes upstream subscription/request/cancel scheduling. An import Combine alone establishes neither behavior nor a Store, reducer, Redux, or other application architecture.

Class and protocol design

WithSwiftData/Wishlist/WishlistApp.swift:12 — representative type boundary

@main
struct WishlistApp: App {
    // ...
            let modelContainer = try ModelContainer(for: Trip.self, Activity.self, TripImage.self, Goal.self, TripGoal.self, ActivityGoal.self)
    // ...
}

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

Access control

Reference code

WithSwiftData/Wishlist/Models/Goal.swift:56 — representative boundary

    fileprivate var ordinalModifier: String {
        target == 1 ? "first" : "\(target.ordinal)"
    }

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

Design patterns

Naming conventions

• Types: App: WishlistApp; DataSource: DataSource; Model: Model, TripEditModel; View: ActivityItemView, ActivityProgressView, ActivitySearchSectionView, AddTripView, ContentView.
• Protocols: no local protocol declaration in the scanned source.
• Methods: saveImageToTemporaryDirectory, addTrip.
• Files: WithSwiftData/Wishlist/WishlistApp.swift, WithoutPersistence/Wishlist/WishlistApp.swift, WithSwiftData/Wishlist/Views/Trips/AddTripView.swift, WithoutPersistence/Wishlist/Views/Trips/AddTripView.swift, WithSwiftData/Wishlist/Views/SearchView.swift, WithoutPersistence/Wishlist/Views/SearchView.swift.

Architecture takeaways

• WishlistApp is the main source-visible entry or composition anchor for this sample.
• Framework work reaches SwiftUI, SwiftData, PhotosUI, UIKit 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

• Official Apple documentation