UIViewControllerRepresentable UIAlertController not able to enable/disable action? - ios

Question

I want to use an alert with textField in my swiftUI app so I made following wrapper for UIAlertController. I want to disable my save button when there is no text in textField and enable it the moment user enters some text, but for some reason it is not happening, the button is stuck to the initial state.
code
struct UIAlertControllerWrapper: UIViewControllerRepresentable {
#Binding var text: String
#Binding var showAlert: Bool
var title: String
var message: String
var placeholder: String
var action: () -> Void
func makeUIViewController(context: Context) -> some UIViewController {
return UIViewController()
}
func updateUIViewController(_ uiViewController: UIViewControllerType, context: Context) {
if showAlert {
let alert = createAlert(context)
context.coordinator.alert = alert
alert.actions[1].isEnabled = false
DispatchQueue.main.async {
uiViewController.present(alert, animated: true) {
showAlert = false
}
}
}
}
class Coordinator: NSObject, UITextFieldDelegate {
var parent: UIAlertControllerWrapper
var alert: UIAlertController?
init(_ parent: UIAlertControllerWrapper) {
self.parent = parent
}
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
if let text = textField.text as? NSString {
parent.text = text.replacingCharacters(in: range, with: string)
} else {
parent.text = ""
}
guard let alert = alert else {
return true
}
if parent.text.trimmingCharacters(in: .whitespaces).isEmpty {
alert.actions[1].isEnabled = false
} else {
alert.actions[1].isEnabled = true
}
return true
}
}
func makeCoordinator() -> Coordinator {
Coordinator(self)
}
func createAlert(_ context: Context) -> UIAlertController {
let alert = UIAlertController(
title: title,
message: message,
preferredStyle: .alert
)
alert.addTextField { textField in
textField.placeholder = placeholder
textField.text = text
textField.delegate = context.coordinator
}
let cancel = UIAlertAction(title: "Cancel", style: .cancel) { _ in
alert.dismiss(animated: true) {
showAlert = false
}
text = ""
}
let save = UIAlertAction(title: "Save", style: .default) { _ in
action()
alert.dismiss(animated: true) {
showAlert = false
}
text = ""
}
alert.addAction(cancel)
alert.addAction(save)
return alert
}
}