Using suggested searches with a search controller

At a glance

Project structure

Source bundle/
├── SuggestedSearch/
│   ├── ResultsTableController.swift
│   ├── MainTableViewController.swift
│   ├── AppDelegate.swift
│   ├── DetailViewController.swift
│   ├── SceneDelegate.swift
│   ├── Product.swift
│   ├── MainTableViewController+ResultsUpdate.swift
│   ├── MainTableViewController+SuggestedSearch.swift
│   └── Base.lproj/
│       └── LaunchScreen.storyboard
├── Configuration/
│   └── SampleCode.xcconfig
└── SuggestedSearch.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 6 project/configuration file(s) and 10 source declaration(s).

Overall architecture

flowchart LR
    N1["AppDelegate"]
    N2["DetailViewController"]
    N3["UIKit APIs"]
    N1 --> N2
    N2 --> N3

Reference code

SuggestedSearch/AppDelegate.swift:20 — architecture anchor

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
        return true
    }

    func application(_ application: UIApplication,
                     configurationForConnecting connectingSceneSession: UISceneSession,
                     options: UIScene.ConnectionOptions) -> UISceneConfiguration {
        // Called when a new scene session is being created.
        // Use this method to select a configuration to create the new scene with.
        return UISceneConfiguration(name: "Default Configuration", sessionRole: connectingSceneSession.role)
    }

}

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 UIKit.

Ownership and state

classDiagram
    func o-- SuggestedSearch : suggestedSearchDelegate
    func *-- Bool : showSuggestedSearches
    MainTableViewController o-- UISearchController : searchController
    MainTableViewController o-- ResultsTableController : resultsTableController

Ownership evidence

SuggestedSearch/ResultsTableController.swift:50 — stored dependency or nearest verified ownership anchor

class ResultsTableController: UITableViewController {
    // ...
    weak var suggestedSearchDelegate: SuggestedSearch?
    // ...
}

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.

No source-visible execution, scheduling, or synchronization boundary was found in the indexed source.

@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.

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

SuggestedSearch/ResultsTableController.swift:11 — representative type boundary

protocol SuggestedSearch: AnyObject {
    // A suggested search was selected; inform our delegate that the selected search token was selected.
    func didSelectSuggestedSearch(token: UISearchToken)

    // A product was selected; inform our delgeate that a product was selected to view.
    func didSelectProduct(product: Product)
}

The source explicitly defines local protocol relationships: MainTableViewController → SuggestedSearch.

Access control

Reference code

SuggestedSearch/DetailViewController.swift:16 — representative boundary

class DetailViewController: UIViewController {
    // ...
    private static let restoredProductKey = "restoredProduct"

    // ...
}

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: DetailViewController, MainTableViewController, ResultsTableController; Delegate: AppDelegate, SceneDelegate.
• Protocols: SuggestedSearch.
• Methods: didSelectSuggestedSearch, didSelectProduct, suggestedColor, suggestedImage, suggestedTitle, tableView, prepare, colorKind.
• Files: SuggestedSearch/ResultsTableController.swift, SuggestedSearch/MainTableViewController.swift, SuggestedSearch/AppDelegate.swift, SuggestedSearch/DetailViewController.swift, SuggestedSearch/SceneDelegate.swift, SuggestedSearch/Product.swift.

Architecture takeaways

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

Source map

• Official Apple documentation