Hands-On Design Patterns with Swift

View controllers

Let's begin the refactoring of our view controller, as follows:

protocol ComposeViewControllerDelegate: AnyObject {    func composeViewController(_ controller: ComposeViewController,                                attemptToSend message: String)}class ComposeViewController: UIViewController {    enum State {    case `default`    case error(Error)    case sending    }    private var textView = UITextView()    private var sendButton = UIButton()    weak var delegate: ComposeViewControllerDelegate?    var state: State = .default {        didSet { /* todo handle state */ }    }    func sendTapped(sender: UIButton) {        delegate?.composeViewController(self, attemptToSend: textView.text)    }}

The view controller is now completely focused on managing views. It is easier to extend and to manage. If we have ...