Creating turn-based games

At a glance

Project structure

Source bundle/
├── TurnBasedGameSample/
│   ├── TurnBasedGameSampleApp.swift
│   ├── GameView.swift
│   ├── ChatView.swift
│   ├── ContentView.swift
│   ├── MessageView.swift
│   ├── TurnBasedGame+GKTurnBasedMatchmakerViewControllerDelegate.swift
│   ├── TurnBasedGame+MatchData.swift
│   ├── TurnBasedGame.swift
│   └── TurnBasedGame+GKTurnBasedEventListener.swift
├── Configuration/
│   └── SampleCode.xcconfig
├── Turn-Based Game Sample.entitlements
└── Turn-Based Game Sample.xcodeproj/
    └── .xcodesamplecode.plist

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 4 project/configuration file(s) and 10 source declaration(s).

Overall architecture

flowchart LR
    N1["TurnBasedGameSampleApp"]
    N2["ContentView"]
    N3["GameKit APIs"]
    N1 --> N2
    N2 --> N3

Reference code

TurnBasedGameSample/TurnBasedGameSampleApp.swift:10 — architecture anchor

@main
struct TurnBasedGameSampleApp: App {

    var body: some Scene {
        WindowGroup {
            ContentView()
        }
    }
}

Interpretation

The arrows summarize the source-visible entry, role-named types or folders, and framework direction; when nodes come from structural folders, the sequence is a high-level interpretation rather than proof that every adjacent node calls the next. Ownership is claimed only where the next section cites a stored property or assignment. The diagram is intentionally limited to the dominant path into GameKit.

Ownership and state

classDiagram
    GameView o-- TurnBasedGame : game
    GameView *-- Bool : showMessages
    ChatView o-- TurnBasedGame : game
    ChatView *-- String : typingMessage

Ownership evidence

TurnBasedGameSample/GameView.swift:12 — stored dependency or nearest verified ownership anchor

struct GameView: View {
    // ...
    @ObservedObject var game: TurnBasedGame
    // ...
}

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

TurnBasedGameSample/ChatView.swift:42 — representative execution boundary

                        Task {
                            await game.sendMessage(content: typingMessage)
                            typingMessage = ""
                        }

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

TurnBasedGameSample/TurnBasedGameSampleApp.swift:11 — representative type boundary

@main
struct TurnBasedGameSampleApp: App {
    // ...
            ContentView()
    // ...
}

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

Access control

Reference code

TurnBasedGameSample/ChatView.swift:13 — representative boundary

struct ChatView: View {
    // ...
    @State private var typingMessage: String = ""

    // ...
}

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: TurnBasedGameSampleApp; View: ChatView, ContentView, GameView, MessageView.
• Protocols: no local protocol declaration in the scanned source.
• Methods: makeBody, turnBasedMatchmakerViewControllerWasCancelled, turnBasedMatchmakerViewController, encodeGameData, encode, decodeGameData, resetGame, authenticatePlayer.
• Files: TurnBasedGameSample/TurnBasedGameSampleApp.swift, TurnBasedGameSample/GameView.swift, TurnBasedGameSample/ChatView.swift, TurnBasedGameSample/ContentView.swift, TurnBasedGameSample/MessageView.swift, TurnBasedGameSample/TurnBasedGame.swift.

Architecture takeaways

• TurnBasedGameSampleApp is the main source-visible entry or composition anchor for this sample.
• Framework work reaches SwiftUI, GameKit 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