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

Displaying searchable content by using a search controller

At a glance

Item Summary
Purpose Create a user interface with searchable content in a table view.
App architecture A Swift sample with the source-visible chain AppDelegateDetailViewControllerUIKit 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.
Execution model No structured execution marker indexed; callback threading requires source review.
State/event model No structured observation or publisher-scheduling marker indexed.
Key frameworks/packages UIKit, Foundation; these are source dependencies, not architecture labels.

Project structure

Source bundle/
├── TableSearch/
│   ├── AppDelegate.swift
│   ├── DetailViewController.swift
│   ├── Product.swift
│   ├── MainTableViewController+DataSource.swift
│   ├── MainTableViewController.swift
│   ├── ResultsTableController.swift
│   ├── MainTableViewController+Restore.swift
│   ├── MainTableViewController+Updating.swift
│   └── Base.lproj/
│       └── LaunchScreen.storyboard
├── Configuration/
│   └── SampleCode.xcconfig
└── TableSearch.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

Reference code

TableSearch/AppDelegate.swift:10 — architecture anchor

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

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

Ownership evidence

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

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
    // ...
    var window: UIWindow?
    // ...
}
Owner Object or state Relationship Mutation authority
AppDelegate UIWindow (window) stores or receives App/module collaborators
DetailViewController Product (product) stores or receives App/module collaborators
DetailViewController UILabel (yearLabel) holds a non-owning reference The referenced object’s lifecycle is owned elsewhere
DetailViewController UILabel (priceLabel) holds a non-owning reference The referenced object’s lifecycle is owned elsewhere

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.

Category Mechanism or module Verified role Evidence
Source import UIKit The cited file imports this module; runtime use and architectural role are not inferred. TableSearch/AppDelegate.swift:8
Source import Foundation The cited file imports this module; runtime use and architectural role are not inferred. TableSearch/Product.swift:8

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

TableSearch/AppDelegate.swift:11 — representative type boundary

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
    // ...
    var window: UIWindow?
    // ...
}
Type Responsibility Depends on or conforms to
AppDelegate Receives callback-driven events UIResponder, UIApplicationDelegate
DetailViewController View lifecycle, callbacks, and feature coordination UIViewController
MainTableViewController View lifecycle, callbacks, and feature coordination UITableViewController
ResultsTableController View lifecycle, callbacks, and feature coordination UITableViewController
Product Owns feature behavior and collaborator lifecycle NSObject, Codable
ExpressionKeys Defines a closed set of feature states or choices String
ProductType Defines a closed set of feature states or choices Int
Localization Defines a closed set of feature states or choices String
RestorationKeys Defines a closed set of feature states or choices String
SearchControllerRestorableState Represents mutable feature state Concrete collaborators/imported frameworks

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
restoreProduct (TableSearch/DetailViewController.swift:13) 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.
yearLabel (TableSearch/DetailViewController.swift:19) 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.
priceLabel (TableSearch/DetailViewController.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.
findMatches (TableSearch/MainTableViewController+Updating.swift:12) private Use is restricted to the lexical declaration and same-file extensions allowed by Swift. Inference: hide an implementation step that is not part of the collaboration surface.

Reference code

TableSearch/DetailViewController.swift:13 — representative boundary

class DetailViewController: UIViewController {
    // ...
    private static let restoreProduct = "restoreProductKey"

    // ...
}

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 DetailViewController, MainTableViewController, ResultsTableController The source’s Controller suffix makes this role explicit.
Receives callback-driven events AppDelegate The source’s Delegate suffix makes this role explicit.

Design patterns

Pattern Source evidence Purpose or tradeoff
View-controller organization TableSearch/DetailViewController.swift:10 A controller is the verified coordination boundary; this is MVC-style only where a separate model is present.
Delegate or data-source callbacks TableSearch/AppDelegate.swift:11 Callback protocols invert event delivery back into the sample’s owner.

Naming conventions

  • Types: Controller: DetailViewController, MainTableViewController, ResultsTableController; Delegate: AppDelegate.
  • Protocols: no local protocol declaration in the scanned source.
  • Methods: application, detailViewControllerForProduct, viewWillAppear, encodeRestorableState, decodeRestorableState, productTypeName, formattedIntroPrice, encode.
  • Files: TableSearch/AppDelegate.swift, TableSearch/DetailViewController.swift, TableSearch/Product.swift, TableSearch/MainTableViewController.swift, TableSearch/ResultsTableController.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.
  • The source does not justify labeling the design protocol-oriented.

Source map

Source file Relevant symbols
TableSearch/AppDelegate.swift Cited implementation, AppDelegate, UIKit
TableSearch/DetailViewController.swift Cited implementation, DetailViewController, func
TableSearch/MainTableViewController+Updating.swift Cited implementation, Feature implementation
TableSearch/Product.swift Foundation, Product, CodingKeys, ExpressionKeys, ProductType, func
TableSearch/MainTableViewController+DataSource.swift Localization
TableSearch/MainTableViewController.swift MainTableViewController
TableSearch/ResultsTableController.swift ResultsTableController
TableSearch/MainTableViewController+Restore.swift RestorationKeys, SearchControllerRestorableState