Updating an App to Use Swift Concurrency

At a glance

Project structure

Source bundle/
├── Starting Point/
│   └── Coffee Tracker WatchKit Extension/
│       ├── CoffeeTrackerApp.swift
│       ├── ExtensionDelegate.swift
│       ├── CoffeeTrackerView.swift
│       ├── ContentView.swift
│       ├── DrinkListView.swift
│       ├── ComplicationController.swift
│       └── HealthKitController.swift
└── Updated/
    └── Coffee Tracker WatchKit Extension/
        ├── CoffeeTrackerApp.swift
        ├── ExtensionDelegate.swift
        ├── CoffeeTrackerView.swift
        ├── ContentView.swift
        └── DrinkListView.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 11 project/configuration file(s) and 23 source declaration(s).

Overall architecture

flowchart LR
    Bundle["Sample bundle"]
    V1["Starting Point"]
    V2["Updated"]
    Boundary["SwiftUI APIs"]
    Bundle --> V1
    V1 --> Boundary
    Bundle --> V2
    V2 --> Boundary

Reference code

Starting Point/Coffee Tracker WatchKit Extension/CoffeeTrackerApp.swift:10 — architecture anchor

@main
struct CoffeeTrackerApp: 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

classDiagram
    CoffeeTrackerApp o-- ExtensionDelegate : appDelegate
    ExtensionDelegate *-- Logger : logger
    ExtensionDelegate *-- Logger : scheduleLogger
    CoffeeTrackerView o-- CoffeeData : coffeeData

Ownership evidence

Starting Point/Coffee Tracker WatchKit Extension/CoffeeTrackerApp.swift:13 — stored dependency or nearest verified ownership anchor

@main
struct CoffeeTrackerApp: App {
    // ...
    @WKExtensionDelegateAdaptor private var appDelegate: ExtensionDelegate
    // ...
}

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

Starting Point/Coffee Tracker WatchKit Extension/CoffeeTrackerApp.swift:11 — representative type boundary

struct CoffeeTrackerApp: App {
    // ...
}

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

Access control

Reference code

Starting Point/Coffee Tracker WatchKit Extension/CoffeeData.swift:12 — representative boundary

private let floatFormatter = FloatingPointFormatStyle<Double>().precision(.significantDigits(1...3))

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: CoffeeTrackerApp; Controller: ComplicationController, HealthKitController, HostingController; Delegate: ExtensionDelegate; Store: CoffeeDataStore; View: CoffeeTrackerView, ContentView, DrinkListView.
• Protocols: no local protocol declaration in the scanned source.
• Methods: handle, scheduleBackgroundRefreshTasks, colorForCaffeineDose, colorForDailyDrinkCount, addDrink.
• Files: Starting Point/Coffee Tracker WatchKit Extension/CoffeeTrackerApp.swift, Updated/Coffee Tracker WatchKit Extension/CoffeeTrackerApp.swift, Starting Point/Coffee Tracker WatchKit Extension/ExtensionDelegate.swift, Updated/Coffee Tracker WatchKit Extension/ExtensionDelegate.swift, Starting Point/Coffee Tracker WatchKit Extension/CoffeeTrackerView.swift, Starting Point/Coffee Tracker WatchKit Extension/ContentView.swift.

Architecture takeaways

• CoffeeTrackerApp is the main source-visible entry or composition anchor for this sample.
• Framework work reaches SwiftUI, ClockKit, HealthKit, WatchKit 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