Providing Hands-Free App Control with Intents

At a glance

Project structure

Source bundle/
├── RecipeAssistant/
│   ├── App/
│   │   ├── AppDelegate.swift
│   │   └── SceneDelegate.swift
│   ├── Intent Handler/
│   │   ├── IntentHandler.swift
│   │   └── AppIntentHandler.swift
│   ├── View Controllers/
│   │   ├── RecipeDetailViewController.swift
│   │   ├── RecipeDirectionsViewController.swift
│   │   └── RecipesTableViewController.swift
│   ├── Model/
│   │   └── RecipeBook.swift
│   └── Base.lproj/
│       └── LaunchScreen.storyboard
├── Configuration/
│   └── SampleCode.xcconfig
└── RecipeAssistant.xcodeproj/
    ├── .xcodesamplecode.plist
    └── project.pbxproj

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 10 source declaration(s).

Overall architecture

flowchart LR
    N1["AppDelegate"]
    N2["RecipeDetailViewController"]
    N3["AppIntentHandler"]
    N4["Intents / IntentsUI APIs"]
    N1 --> N2
    N2 --> N3
    N3 --> N4

Reference code

RecipeAssistant/App/AppDelegate.swift:11 — architecture anchor

@UIApplicationMain
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 Intents.

Ownership and state

classDiagram
    AppDelegate o-- UIWindow : window
    IntentHandler o-- Recipe : currentRecipe
    IntentHandler o-- NextStepProviding : nextStepProvider
    RecipeDetailViewController o-- Recipe : recipe

Ownership evidence

RecipeAssistant/App/AppDelegate.swift:14 — stored dependency or nearest verified ownership anchor

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
    // ...
    var window: UIWindow?
    // ...
}

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

RecipeAssistant/Intent Handler/IntentHandler.swift:60 — representative type boundary

protocol NextStepProviding: NSObject {
    // ...
}

The source explicitly defines local protocol relationships: RecipeDetailViewController → NextStepProviding, RecipeDirectionsViewController → NextStepProviding, RecipesTableViewController → NextStepProviding.

Access control

Reference code

RecipeAssistant/Intent Handler/IntentHandler.swift:53 — representative boundary

    private func recipe(for intent: ShowDirectionsIntent) -> Recipe? {
        return currentRecipe != nil ? currentRecipe : intent.recipe
    }

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: Controller: RecipeDetailViewController, RecipeDirectionsViewController, RecipesTableViewController; Delegate: AppDelegate, SceneDelegate; Handler: AppIntentHandler, IntentHandler.
• Protocols: NextStepProviding.
• Methods: application, provideRecipeOptionsCollection, resolveRecipe, handle, recipe, nextStep, viewDidLoad, viewDidAppear.
• Files: RecipeAssistant/App/AppDelegate.swift, RecipeAssistant/Intent Handler/IntentHandler.swift, RecipeAssistant/View Controllers/RecipeDetailViewController.swift, RecipeAssistant/View Controllers/RecipeDirectionsViewController.swift, RecipeAssistant/App/SceneDelegate.swift, RecipeAssistant/Intent Handler/AppIntentHandler.swift.

Architecture takeaways

• AppDelegate is the main source-visible entry or composition anchor for this sample.
• Framework work reaches Intents, UIKit, IntentsUI 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.
• Local protocol relationships provide an explicit substitution boundary.

Source map

• Official Apple documentation