Training a Create ML Model to Classify Flowers
At a glance
| Item | Summary |
|---|---|
| Purpose | Train a flower classifier using Create ML in Swift Playgrounds, and apply the resulting model to real-time image classification using Vision. |
| App architecture | A Swift sample with the source-visible chain AppDelegate → ProductViewController → Vision APIs. |
| Main patterns | View-controller organization, Delegate or data-source callbacks |
| Project style | 5 scanned source file(s) across Swift, organized around ranked entry, type, and file boundaries. |
Project structure
Source bundle/
├── FlowerShop/
│ ├── AppDelegate.swift
│ ├── ProductViewController.swift
│ ├── ViewController.swift
│ ├── VisionViewController.swift
│ ├── Base.lproj/
│ │ ├── LaunchScreen.storyboard
│ │ └── Main.storyboard
│ ├── Info.plist
│ └── Product Resources/
│ └── ProductCatalog.plist
├── Training/
│ └── ImageClassifierPlayground.playground/
│ └── Contents.swift
├── Configuration/
│ └── SampleCode.xcconfig
└── FlowerShop.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 4 source declaration(s).
Overall architecture
flowchart LR
N1["AppDelegate"]
N2["ProductViewController"]
N3["Vision APIs"]
N1 --> N2
N2 --> N3
Reference code
FlowerShop/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 Vision.
Ownership and state
classDiagram
AppDelegate o-- UIWindow : window
ProductViewController o-- UIView : productView
ProductViewController o-- UILabel : label
ProductViewController o-- UIImageView : productPhoto
Ownership evidence
FlowerShop/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 |
ProductViewController |
UIView (productView) |
stores or receives | App/module collaborators |
ProductViewController |
UILabel (label) |
holds a non-owning reference | The referenced object’s lifecycle is owned elsewhere |
ProductViewController |
UIImageView (productPhoto) |
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.
Class and protocol design
FlowerShop/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 |
ProductViewController |
View lifecycle, callbacks, and feature coordination | UIViewController |
ViewController |
View lifecycle, callbacks, and feature coordination | UIViewController, AVCaptureVideoDataOutputSampleBufferDelegate |
VisionViewController |
View lifecycle, callbacks, and feature coordination | ViewController |
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 |
|---|---|---|---|
session (FlowerShop/ViewController.swift:18) |
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. |
previewLayer (FlowerShop/ViewController.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. |
videoDataOutput (FlowerShop/ViewController.swift:21) |
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. |
videoDataOutputQueue (FlowerShop/ViewController.swift:23) |
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. |
Reference code
FlowerShop/ViewController.swift:18 — representative boundary
private let session = AVCaptureSession()
private var previewLayer: AVCaptureVideoPreviewLayer! = nil
private let videoDataOutput = AVCaptureVideoDataOutput()
private let videoDataOutputQueue = DispatchQueue(label: "VideoDataOutput", qos: .userInitiated, attributes: [], autoreleaseFrequency: .workItem)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 | ProductViewController, ViewController, VisionViewController |
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 | FlowerShop/ProductViewController.swift:12 |
A controller is the verified coordination boundary; this is MVC-style only where a separate model is present. |
| Delegate or data-source callbacks | FlowerShop/AppDelegate.swift:11 |
Callback protocols invert event delivery back into the sample’s owner. |
Naming conventions
- Types: Controller: ProductViewController, ViewController, VisionViewController; Delegate: AppDelegate.
- Protocols: no local protocol declaration in the scanned source.
- Methods:
dismissProductView,awakeFromNib,viewDidLoad,captureOutput,didReceiveMemoryWarning,setupAVCapture,startCaptureSession,teardownAVCapture. - Files:
FlowerShop/AppDelegate.swift,FlowerShop/ProductViewController.swift,FlowerShop/ViewController.swift,FlowerShop/VisionViewController.swift.
Architecture takeaways
AppDelegateis the main source-visible entry or composition anchor for this sample.- Framework work reaches UIKit, AVFoundation, Vision, CreateMLUI 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 |
|---|---|
FlowerShop/AppDelegate.swift |
AppDelegate |
FlowerShop/ProductViewController.swift |
ProductViewController |
FlowerShop/ViewController.swift |
ViewController |
FlowerShop/VisionViewController.swift |
VisionViewController |
Training/ImageClassifierPlayground.playground/Contents.swift |
Feature implementation |