AccessAppExercise

An app showing GitHub user list and user detail.

Feature

• Display Github user list by table view, showing avatar, login name and STAFF badge.

• Enable pagination by parsing next link in response header, and trigger load more in UITableViewDelegate willDisplayCell method.

• Display detailed user page by navigation controller.

• Custom UI component for STAFF badge.

Architecture

MVVM + RxSwift

HTTP Request

• RequestProtocol defines default implementation for sending a network request.

• UserInteractor is responsible for fetching user data from the GitHub API, and return Observable type for ViewModel.

• GitHubAPI use enum and its associate type to construct HTTP method, URL path, headers and parameters for each API case.

Model

• Structure GitHubUser represents a GitHub user in List users API.

• Structure DetailUser represents a detailed user information in Get a user API.

View

• ListViewController use UITableView to display user list.

• DetailViewController consists of UILabel, UIImageView, UIStackView, displaying detailed information of user.

• BadgeView is a custom UI component written in programming UI. Seperating this view from UITableViewCell or UIViewController enhances reusability.

• Use auto layout and XIB files to set UI constraints, which is beneficial for understanding the layout of the interface.

• Other UI settings, like font and text color, are written in code, providing a better way to rebranding or debug.

ViewModel

• Each view model has Inputs and Outputs type.

  protocol ListUserViewModelType {
      var inputs: ListUserViewModelInputs { get }
      var outputs: ListUserViewModelOutputs { get }
  }

• View model is responsible for translate inputs from view controller into outputs as observable.

  /// Inputs for the `ListUserViewModel`.
  protocol ListUserViewModelInputs {
      /// Called when the view controller is loaded.
      func viewDidLoad()
      /// Called when more users need to be loaded.
      func loadMore()
  }

  /// Outputs for the `ListUserViewModel`.
  protocol ListUserViewModelOutputs {
      /// A relay for the list of GitHub users.
      var userListRelay: BehaviorRelay<[GitHubUser]> { get }
      /// A relay for errorMessage.
      var errorRelay: PublishRelay<String> { get }
  }

• Each view model has interactor(s) to perform HTTP request. The interactor defined by protocol is injected when initiation. In this way, we can use mock interactor in unit test.

  init(interactor: UserInteractorProtocol) {
      self.interactor = interactor
  }

Data Flow

Client (Mobile) → view → view model inputs → trigger interactor method → call GitHub REST API → response parsed to custom model → view model outputs → update UI

Unit Tests

These tests cover various aspects of the application, including extensions and view model functionality.

• ListViewModelTest.swift validates ListViewModel's behavior when fetching user list and loading more users from the GitHub API. It also tests the extraction of next link from API response headers.

• DetailViewModelTest.swift validates DetailViewModel's behavior when retrieving and handling user details from the GitHub API.

• StringExtensionTests.swift verifies the functionality of the String extension used to extract the next link from a GitHub API link header.

• GitHubAPITest.swift verifies that the endpoint paths and parameters for fetching user lists and user details are correctly set.

Library

• RxSwfit for data flow and data binding.

• RxDataSources as table view data source.

• RxAlamofire as HTTP networking library.

• Kingfisher for downloading and caching images from the web.

License

This project is licensed under the terms of the MIT license.

See the LICENSE file for more info.