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

Creating NFC Tags from Your iPhone

At a glance

Item Summary
Purpose Save data to tags, and interact with them using native tag protocols.
App architecture A Swift sample bundle with entry-bearing project variants FishTagCreator, FishTagReader, each leading to CoreNFC APIs.
Main patterns View-controller organization, Delegate or data-source callbacks
Project style 7 scanned source file(s) across Swift, organized around ranked entry, type, and file boundaries.

Project structure

Source bundle/
├── FishTagCreator/
│   ├── AppDelegate.swift
│   ├── CouponViewController.swift
│   ├── MainViewController.swift
│   ├── MainViewController+DataSource.swift
│   ├── Base.lproj/
│   │   ├── LaunchScreen.storyboard
│   │   └── Main.storyboard
│   ├── FishTagCreator.entitlements
│   └── Info.plist
├── FishTagReader/
│   ├── AppDelegate.swift
│   ├── LoyaltyViewController.swift
│   └── ScanViewController.swift
└── Configuration/
    └── SampleCode.xcconfig

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 6 source declaration(s).

Overall architecture

Reference code

FishTagCreator/AppDelegate.swift:10 — architecture anchor

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?

}

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

Ownership evidence

FishTagCreator/AppDelegate.swift:13 — 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
CouponViewController NFCTagReaderSession (readerSession) stores or receives App/module collaborators
CouponViewController String (couponCode) owns value state App/module collaborators
MainViewController NFCNDEFReaderSession (readerSession) 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

FishTagCreator/AppDelegate.swift:11 — representative type boundary

class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?

}
Type Responsibility Depends on or conforms to
AppDelegate Receives callback-driven events UIResponder, UIApplicationDelegate
AppDelegate Receives callback-driven events UIResponder, UIApplicationDelegate
CouponViewController View lifecycle, callbacks, and feature coordination UITableViewController, NFCTagReaderSessionDelegate
MainViewController View lifecycle, callbacks, and feature coordination UITableViewController, UINavigationControllerDelegate, NFCNDEFReaderSessionDelegate
LoyaltyViewController View lifecycle, callbacks, and feature coordination UITableViewController, NFCTagReaderSessionDelegate
ScanViewController View lifecycle, callbacks, and feature coordination UITableViewController, NFCTagReaderSessionDelegate

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
AppDelegate (FishTagCreator/AppDelegate.swift:11) implicit internal No explicit modifier means the Swift declaration is internal to the module. Inference: app-target collaboration needs no exported library surface.
AppDelegate (FishTagReader/AppDelegate.swift:12) implicit internal No explicit modifier means the Swift declaration is internal to the module. Inference: app-target collaboration needs no exported library surface.
CouponViewController (FishTagCreator/CouponViewController.swift:11) implicit internal No explicit modifier means the Swift declaration is internal to the module. Inference: app-target collaboration needs no exported library surface.

Reference code

FishTagCreator/AppDelegate.swift:11 — representative boundary

class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?

}

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 CouponViewController, LoyaltyViewController, MainViewController, ScanViewController 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 FishTagCreator/CouponViewController.swift:11 A controller is the verified coordination boundary; this is MVC-style only where a separate model is present.
Delegate or data-source callbacks FishTagCreator/AppDelegate.swift:11 Callback protocols invert event delivery back into the sample’s owner.

Naming conventions

  • Types: Controller: CouponViewController, LoyaltyViewController, MainViewController, ScanViewController; Delegate: AppDelegate.
  • Protocols: no local protocol declaration in the scanned source.
  • Methods: application, createCoupon, write, writeCouponCode, tagReaderSessionDidBecomeActive, tagReaderSession, writeTag, createURLPayload.
  • Files: FishTagCreator/AppDelegate.swift, FishTagReader/AppDelegate.swift, FishTagCreator/CouponViewController.swift, FishTagCreator/MainViewController.swift, FishTagReader/LoyaltyViewController.swift, FishTagReader/ScanViewController.swift.

Architecture takeaways

  • AppDelegate is the main source-visible entry or composition anchor for this sample.
  • Framework work reaches UIKit, CoreNFC 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
FishTagCreator/AppDelegate.swift AppDelegate
FishTagReader/AppDelegate.swift AppDelegate
FishTagCreator/CouponViewController.swift CouponViewController
FishTagCreator/MainViewController.swift MainViewController
FishTagReader/LoyaltyViewController.swift LoyaltyViewController
FishTagReader/ScanViewController.swift ScanViewController
FishTagCreator/MainViewController+DataSource.swift Feature implementation