Add VIPER Arch as example

[specktro]

Summary

The VIPER pattern is a solution with steroids for this simple example but you can review the different layers an their function and this is thanks to the protocols or module skeleton.

// MARK: MessageViewProtocol
protocol MessageViewProtocol: UIViewController {
  var presenter: MessagePresenterProtocol? { get set }
  
  // Output
  func show(_ message: String)
}

// MARK: MessagePresenterProtocol protocol
protocol MessagePresenterProtocol: AnyObject {
  var view: MessageViewProtocol? { get set }
  var interactor: MessageInteractorProtocol? { get set }
  
  // Input
  func askMessage()
  
  // Output
  func retrieve(message: String)
}

// MARK: MessageInteractorProtocol protocol
protocol MessageInteractorProtocol: AnyObject {
  var presenter: MessagePresenterProtocol? { get set }
  var person: Person? { get set }
  
  // Input
  func prepareMessage()
}

And with the SharedViewController class our view was pretty simple:

// MARK: MessageView class
final class MessageView: SharedViewController, MessageViewProtocol {
  // MARK: - Properties
  var presenter: MessagePresenterProtocol?
  
  // MARK: - SharedViewController method
  override func didTapButton(_ button: UIButton) { ... }
  
  // MARK: - MessageViewProtocol
  func show(_ message: String) { ... }
}

and this ir our final module's implementation

// MARK: - VIPER Architecture
let view: MessageViewProtocol = MessageView()
let presenter: MessagePresenterProtocol = MessagePresenter()
let interactor: MessageInteractorProtocol = MessageInteractor()
view.presenter = presenter
presenter.view = view
presenter.interactor = interactor
interactor.presenter = presenter
interactor.person = model