CleanView.swift

protocol View: class {
    func show(data: String)
}
 
class ViewController: UIViewController, View {
    
    let presenter: Presenter
    var label: UILabel!
    
    init(presenter: Presenter) {
        self.presenter = presenter
        super.init(nibName: nil, bundle: nil)
    }
    
    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    func show(data: String) {
        label.text = data
    }
    
    override func viewDidLoad() {
        super.viewDidLoad()
        presenter.viewLoaded()
    }
}