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

Interacting with App Clip Codes in AR

At a glance

Item Summary
Purpose Display content and provide services in an AR experience with App Clip Codes.
App architecture A Swift sample with the source-visible chain AppDelegateViewControllerCachingWebLoaderUIKit / ARKit APIs.
Main patterns View-controller organization, Delegate or data-source callbacks
Project style 8 scanned source file(s) across Swift, organized around ranked entry, type, and file boundaries.

Project structure

Source bundle/
└── ARKitAppClipCodesSample/
    ├── SharedAssets/
    │   ├── AppDelegate.swift
    │   ├── AppClipCodeCoachingOverlayView.swift
    │   ├── SceneDelegate.swift
    │   ├── ViewController.swift
    │   ├── CachingWebLoader.swift
    │   ├── Utilities.swift
    │   ├── ViewController+ProductKeyProcessing.swift
    │   └── OverlayLabel.swift
    ├── ARAppClip/
    │   ├── ARAppClip.entitlements
    │   └── Info.plist
    ├── ARParentApp/
    │   └── Info.plist
    └── ARSeedShop.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 6 project/configuration file(s) and 8 source declaration(s).

Overall architecture

Reference code

ARKitAppClipCodesSample/SharedAssets/AppDelegate.swift:10 — architecture anchor

@main
class AppDelegate: UIResponder, UIApplicationDelegate {
    // ...
}

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 App Clips.

Ownership and state

Ownership evidence

ARKitAppClipCodesSample/SharedAssets/SceneDelegate.swift:12 — stored dependency or nearest verified ownership anchor

class SceneDelegate: UIResponder, UIWindowSceneDelegate {
    // ...
    var window: UIWindow?
    // ...
}
Owner Object or state Relationship Mutation authority
SceneDelegate UIWindow (window) stores or receives App/module collaborators
SceneDelegate URL (appClipCodeURL) owns value state App/module collaborators
ViewController ARView (arView) creates and retains Initialized by the owner; the binding is immutable
ViewController AppClipCodeCoachingOverlayView (appClipCodeCoachingOverlay) stores or receives App/module collaborators

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

ARKitAppClipCodesSample/SharedAssets/AppDelegate.swift:11 — representative type boundary

class AppDelegate: UIResponder, UIApplicationDelegate {
    // ...
}
Type Responsibility Depends on or conforms to
AppDelegate Receives callback-driven events UIResponder, UIApplicationDelegate
AppClipCodeCoachingOverlayView User-interface presentation and input forwarding UILabel
SceneDelegate Receives callback-driven events UIResponder, UIWindowSceneDelegate
ViewController View lifecycle, callbacks, and feature coordination UIViewController, ARSessionDelegate, ARCoachingOverlayViewDelegate
CachingWebLoader Loads and prepares feature data or resources NSObject, URLSessionDelegate, URLSessionTaskDelegate, URLSessionDownloadDelegate
DownloadTaskHandlers Represents a feature value or composable behavior Concrete collaborators/imported frameworks
CachedWebLoad Owns feature behavior and collaborator lifecycle Concrete collaborators/imported frameworks
OverlayLabel Owns feature behavior and collaborator lifecycle UILabel

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
shared (ARKitAppClipCodesSample/SharedAssets/CachingWebLoader.swift:16) public The symbol is visible to importing modules. Inference: make the declaration available across a module or target boundary.
handlersFor (ARKitAppClipCodesSample/SharedAssets/CachingWebLoader.swift:18) fileprivate Use is restricted to this source file. Inference: share with same-file helpers or extensions without exposing the symbol module-wide.
loaderFor (ARKitAppClipCodesSample/SharedAssets/CachingWebLoader.swift:20) 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.
urlSession (ARKitAppClipCodesSample/SharedAssets/CachingWebLoader.swift:21) 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

ARKitAppClipCodesSample/SharedAssets/CachingWebLoader.swift:16 — representative boundary

    public static let shared = CachingWebLoader()
    
    fileprivate var handlersFor: [URLSessionDownloadTask: DownloadTaskHandlers] = [:]
    
    private var loaderFor: [URL: CachedWebLoad] = [:]
    private lazy var urlSession = URLSession(configuration: .default, delegate: self, delegateQueue: nil)

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
View lifecycle, callbacks, and feature coordination ViewController The source’s Controller suffix makes this role explicit.
Receives callback-driven events AppDelegate, SceneDelegate The source’s Delegate suffix makes this role explicit.
Loads and prepares feature data or resources CachingWebLoader The source’s Loader suffix makes this role explicit.
User-interface presentation and input forwarding AppClipCodeCoachingOverlayView The source’s View suffix makes this role explicit.

Design patterns

Pattern Source evidence Purpose or tradeoff
View-controller organization ARKitAppClipCodesSample/SharedAssets/ViewController.swift:13 A controller is the verified coordination boundary; this is MVC-style only where a separate model is present.
Delegate or data-source callbacks ARKitAppClipCodesSample/SharedAssets/AppDelegate.swift:11 Callback protocols invert event delivery back into the sample’s owner.

Naming conventions

  • Types: Controller: ViewController; Delegate: AppDelegate, SceneDelegate; Loader: CachingWebLoader; View: AppClipCodeCoachingOverlayView.
  • Protocols: no local protocol declaration in the scanned source.
  • Methods: application, setCoachingViewHidden, scene, viewDidLoad, session, displayUnsupportedDevicePrompt, initializeARView, runARSession.
  • Files: ARKitAppClipCodesSample/SharedAssets/AppDelegate.swift, ARKitAppClipCodesSample/SharedAssets/AppClipCodeCoachingOverlayView.swift, ARKitAppClipCodesSample/SharedAssets/SceneDelegate.swift, ARKitAppClipCodesSample/SharedAssets/ViewController.swift, ARKitAppClipCodesSample/SharedAssets/CachingWebLoader.swift, ARKitAppClipCodesSample/SharedAssets/OverlayLabel.swift.

Architecture takeaways

  • AppDelegate is the main source-visible entry or composition anchor for this sample.
  • Framework work reaches UIKit, ARKit, RealityKit 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
ARKitAppClipCodesSample/SharedAssets/AppDelegate.swift AppDelegate
ARKitAppClipCodesSample/SharedAssets/AppClipCodeCoachingOverlayView.swift AppClipCodeCoachingOverlayView
ARKitAppClipCodesSample/SharedAssets/SceneDelegate.swift SceneDelegate
ARKitAppClipCodesSample/SharedAssets/ViewController.swift ViewController
ARKitAppClipCodesSample/SharedAssets/CachingWebLoader.swift CachingWebLoader, DownloadTaskHandlers, CachedWebLoad
ARKitAppClipCodesSample/SharedAssets/Utilities.swift Feature implementation
ARKitAppClipCodesSample/SharedAssets/ViewController+ProductKeyProcessing.swift Feature implementation
ARKitAppClipCodesSample/SharedAssets/OverlayLabel.swift OverlayLabel