Bind uitextfield value to viewModel using mvvm - swift

Question

I'm trying to bind a UITextField to a viewModel, however whatever i do i keep getting Cannot invoke 'bind' with an argument list of type '(to: EmailViewModel). What am i doing wrong?
SignUpViewModel
class SignUpViewModel {
let model: SignUpModel
private let disposeBag = DisposeBag()
let emailFieldViewModel = EmailViewModel()
init(model :SignUpModel) {
self.model = model
}
}
EmailViewModel
struct EmailViewModel : FieldViewModel {
var value: Variable<String> = Variable("")
var errorValue: Variable<String?> = Variable(nil)
let title = "Email"
let errorMessage = "Email is wrong"
func validate() -> Bool {
let emailPattern = "[A-Z0-9a-z._%+-]+#([A-Za-z0-9.-]{2,64})+\\.[A-Za-z]{2,64}"
guard validateString(value.value, pattern:emailPattern) else {
errorValue.value = errorMessage
return false
}
errorValue.value = nil
return true
}
}
viewcontroller
class SignUpViewController: UIViewController {
#IBOutlet var emailField: UITextField!
override func viewDidLoad() {
super.viewDidLoad()
configureBinding()
}
private func configureBinding() {
// binding
self.emailField.rx.text.bind(to: viewModel.emailFieldViewModel)
}
}

Answer 1

The bind function expects an object that conforms to the ObserverType protocol. Here, EmailViewModel does not conform to that type, hence the error.
Writing an extension to make EmailViewModel conform to the ObserverType protocol would solve the compilation error.
extension EmailViewModel: ObserverType {
func on(_ event: Event<String?>) {
switch event {
case .next(let newValue): value.value = newValue ?? ""
case .error(_), .completed: fatalError("Completion and error are not handled")
}
}
}