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
flowchart LR
Bundle["Sample bundle"]
V1["FishTagCreator"]
V2["FishTagReader"]
Boundary["CoreNFC APIs"]
Bundle --> V1
V1 --> Boundary
Bundle --> V2
V2 --> Boundary
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
classDiagram
AppDelegate o-- UIWindow : window
CouponViewController o-- NFCTagReaderSession : readerSession
CouponViewController *-- String : couponCode
MainViewController o-- NFCNDEFReaderSession : readerSession
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
AppDelegateis 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 |