SayHelloViewController.swift

final class SayHelloViewController: UIViewController {
  
  @IBOutlet weak var nameTextField: UITextField!
  @IBOutlet weak var validateButton: UIButton!
  @IBOutlet weak var greetingLabel: UILabel!
  
  private let viewModel = SayHelloViewModel()
  private let bag = DisposeBag()
  
  override func viewDidLoad() {
    super.viewDidLoad()
    bindViewModel()
  }
  
  private func bindViewModel() {
    let inputs = SayHelloViewModel.Input(name: nameTextField.rx.text.orEmpty.asObservable(),
                                         validate: validateButton.rx.tap.asObservable())
    let outputs = viewModel.transform(input: inputs)
    outputs.greeting
      .drive(greetingLabel.rx.text)
      .disposed(by: bag)
  }
}