専用のNavigatorを作って画面遷移を管理する

この記事そのままだけどなんかいいと思ったのでメモ。
複数の遷移先があるとき使ってみようかな・・・

.navigate(to: .signup)

みたいに画面遷移できる。

protocol Navigator {
    associatedtype Destination

    func navigate(to destination: Destination)
}



class LoginNavigator: Navigator {
    // Here we define a set of supported destinations using an
    // enum, and we can also use associated values to add support
    // for passing arguments from one screen to another.
    enum Destination {
        case loginCompleted
        case forgotPassword
        case signup
    }

    // In most cases it's totally safe to make this a strong
    // reference, but in some situations it could end up
    // causing a retain cycle, so better be safe than sorry :)
    private weak var navigationController: UINavigationController?

    // MARK: - Initializer

    init(navigationController: UINavigationController) {
        self.navigationController = navigationController
    }

    // MARK: - Navigator

    func navigate(to destination: Destination) {
        let viewController = makeViewController(for: destination)
        navigationController?.pushViewController(viewController, animated: true)
    }

    // MARK: - Private

    private func makeViewController(for destination: Destination) -> UIViewController {
        switch destination {
        case .loginCompleted:
            return WelcomeViewController()
        case .forgotPassword:
            return PasswordResetViewController()
        case .signup:
            return SignUpViewController()
        }
    }
}