Sample CodetvOSReviewed 2026-07-21View on Apple Developer

Implementing a Hybrid TV App with TVMLKit

At a glance

Item Summary
Purpose Display content options with document view controllers and fetch and populate content with TVMLKit JS.
App architecture A JavaScript, Swift sample with the source-visible chain AppDelegateHostControllerDocumentLoaderTVMLKit APIs.
Main patterns View-controller organization, Delegate or data-source callbacks
Project style 2 scanned source file(s) across JavaScript, Swift, organized around ranked entry, type, and file boundaries.

Project structure

Source bundle/
├── Server/
│   └── js/
│       └── application.js
├── DocumentService/
│   ├── DocumentService/
│   │   ├── AppDelegate.swift
│   │   └── Info.plist
│   └── DocumentService.xcodeproj/
│       ├── .xcodesamplecode.plist
│       └── project.pbxproj
└── Configuration/
    └── SampleCode.xcconfig

Structure observations

  • Architecturally prominent files are ranked from entry points and role-named declarations; resource-only paths are omitted.
  • Primary languages: JavaScript, Swift.
  • The verified tree contains 4 project/configuration file(s) and 3 source declaration(s).

Overall architecture

Reference code

DocumentService/DocumentService/AppDelegate.swift:10 — architecture anchor

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
    // ...
}

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 TVMLKit.

Ownership and state

Ownership evidence

Server/js/application.js:29 — stored dependency or nearest verified ownership anchor

class DocumentLoader 
{
    // ...
        let xhr = new XMLHttpRequest();
    // ...
}
Owner Object or state Relationship Mutation authority
DocumentLoader XMLHttpRequest (xhr) creates and retains Initialized by the owner; the binding is immutable
AppDelegate UIWindow (window) stores or receives App/module collaborators
AppDelegate TVApplicationController (appController) 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

DocumentService/DocumentService/AppDelegate.swift:11 — representative type boundary

class AppDelegate: UIResponder, UIApplicationDelegate {
    // ...
}
Type Responsibility Depends on or conforms to
AppDelegate Receives callback-driven events UIResponder, UIApplicationDelegate
HostController View lifecycle, callbacks, and feature coordination Concrete collaborators/imported frameworks
DocumentLoader Loads and prepares feature data or resources 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
AppDelegate (DocumentService/DocumentService/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.

Reference code

DocumentService/DocumentService/AppDelegate.swift:11 — representative boundary

class AppDelegate: UIResponder, UIApplicationDelegate {
    // ...
}

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 HostController The source’s Controller suffix makes this role explicit.
Receives callback-driven events AppDelegate The source’s Delegate suffix makes this role explicit.
Loads and prepares feature data or resources DocumentLoader The source’s Loader suffix makes this role explicit.

Design patterns

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

Naming conventions

  • Types: Controller: HostController; Delegate: AppDelegate; Loader: DocumentLoader.
  • Protocols: no local protocol declaration in the scanned source.
  • Methods: application, appController, documentViewController, navigationController, browserViewController.
  • Files: DocumentService/DocumentService/AppDelegate.swift.

Architecture takeaways

  • AppDelegate is the main source-visible entry or composition anchor for this sample.
  • Framework work reaches TVMLKit, 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
Server/js/application.js HostController, DocumentLoader
DocumentService/DocumentService/AppDelegate.swift AppDelegate