Mobile Engineering Agents

Appearance

Template: UIKit MVP Screen ​

A programmatic UIKit screen built on the four-file MVP convention — Contract, View, View Controller, Presenter — plus a complete presenter test file. This is the corrected pattern: every dependency is injected through an initializer, and no work happens in init. See ../../../skills/architecture/ios/mvp.md.

Folder Structure ​

text
uikit_mvp_screen/
├── ArticleListContract.swift        // view + presenter protocols, and the coordinator delegate
├── ArticleListView.swift            // UIView subclass owning all layout and subviews
├── ArticleListViewController.swift  // lifecycle, presenter wiring, navigation triggers
├── ArticleListPresenter.swift       // all presentation logic and state; no `import UIKit`
└── ArticleListPresenterTests.swift  // presenter tests: spy view + stub repository

The files use a sample Article / ArticleList feature. Rename Article/ArticleList to your real domain entity and screen name when you copy this bundle into your codebase.

How the pieces connect ​

text
ArticleListCoordinator → ArticleListViewController.make(articles:delegate:)
                              │
                    ArticleListView (layout)   ArticleListPresenter (logic)
                              │                          │
                              └──── ArticleListViewProtocol / ArticleListPresenterProtocol ────┘
                                                          │
                                                  ArticleRepository (protocol)

ArticleListViewController.make(articles:delegate:) is the only supported construction path: it builds the view controller, then builds the presenter with a reference to that view controller, then returns the fully wired screen. A coordinator is the only caller of make and the only conformer of ArticleListCoordinatorDelegate — see ../../../skills/architecture/ios/coordinator_navigation.md.

Conventions Demonstrated ​

  • Contract declares ArticleListViewProtocol, ArticleListPresenterProtocol, and ArticleListCoordinatorDelegate — protocols only, no implementation.
  • View (ArticleListView) owns every subview and every constraint, built once with UIKit's own layout anchors (no third-party layout library) — see ../../../skills/ui/ios/uikit_view_layer.md.
  • View Controller owns lifecycle, presenter wiring, and navigation triggers only, and uses a plain UITableViewDataSource conformance: the contract's reloadList() is an imperative "reload everything" command, not a diffable snapshot, so this screen has nothing to key a diff on. Article is already Identifiable, so a screen whose contract instead exposes diff-friendly state can adopt UITableViewDiffableDataSource<Section, Article.ID> — see the diffable example in ../../../skills/ui/ios/uikit_view_layer.md.
  • Presenter is @MainActor final, holds the view weak, takes every dependency through init as a protocol, and does no work in init — loading starts from the explicit onViewDidLoad() entry point, and refresh() is a behaviorally distinct entry point that forwards refresh: true to the repository.
  • Tests cover the success path, the failure path, and the refresh()/onViewDidLoad() distinction, using a spy view and a stub repository — no real network, no UIApplication.shared.

Assumptions ​

  • ApiProtocol (showLoading(), hideLoading(), handleApiError(error:)) and PresenterProtocol (empty, @MainActor) are assumed to already exist in the host app and are shared across every MVP screen — this bundle references them but does not declare them.
  • ArticleRepository (func latest(refresh: Bool) async throws -> [Article]) is the Domain protocol defined in ../../../skills/architecture/ios/repository_pattern.md — it is referenced here, never redeclared.
  • Article.fixture() in the test file is expected from the host app's own test helpers.

Usage ​

  1. Copy the five files into your feature module.
  2. Rename Article/ArticleList throughout to your real domain entity and screen name.
  3. Point the injected ArticleRepository at your real Data-layer implementation.
  4. Wire a coordinator that conforms to ArticleListCoordinatorDelegate and calls ArticleListViewController.make(articles:delegate:) — see ../../../skills/architecture/ios/coordinator_navigation.md.
  5. Run ArticleListPresenterTests.swift as-is once Article.fixture() resolves in your test target, and extend it with coverage for your screen's own presentation rules.

These .swift files are illustrative, not part of a compiled package — this folder is not an Xcode/SwiftPM target. Cross-file symbols (Article, ApiProtocol, PresenterProtocol, Article.fixture()) will not resolve if you try to build this folder in isolation; they resolve once the files are copied into a host app that already supplies those types.

See also ​