Attempting to set up a delegate for a custom AlertControlView - ios

Question

My code for the alert is as follows:
struct AlertControlView: UIViewControllerRepresentable {
#Binding var textString: String
#Binding var showAlert: Bool
var title: String
var message: String
// Make sure that, this fuction returns UIViewController, instead of UIAlertController.
// Because UIAlertController gets presented on UIViewController
func makeUIViewController(context: UIViewControllerRepresentableContext<AlertControlView>) -> UIViewController {
return UIViewController() // Container on which UIAlertContoller presents
}
func updateUIViewController(_ uiViewController: UIViewController, context: UIViewControllerRepresentableContext<AlertControlView>) {
// Make sure that Alert instance exist after View's body get re-rendered
guard context.coordinator.alert == nil else { return }
if self.showAlert {
// Create UIAlertController instance that is gonna present on UIViewController
let alert = UIAlertController(title: title, message: message, preferredStyle: .alert)
context.coordinator.alert = alert
// Adds UITextField & make sure that coordinator is delegate to UITextField.
alert.addTextField { textField in
textField.placeholder = "Enter some text"
textField.text = self.textString // setting initial value
textField.delegate = context.coordinator // using coordinator as delegate
}
// As usual adding actions
alert.addAction(UIAlertAction(title: NSLocalizedString("Cancel", comment: "") , style: .destructive) { _ in
// On dismiss, SiwftUI view's two-way binding variable must be update (setting false) means, remove Alert's View from UI
alert.dismiss(animated: true) {
self.showAlert = false
}
})
alert.addAction(UIAlertAction(title: NSLocalizedString("Submit", comment: ""), style: .default) { _ in
// On submit action, get texts from TextField & set it on SwiftUI View's two-way binding varaible `textString` so that View receives enter response.
if let textField = alert.textFields?.first, let text = textField.text {
self.textString = text
}
alert.dismiss(animated: true) {
self.showAlert = false
}
})
// Most important, must be dispatched on Main thread,
// Curious? then remove `DispatchQueue.main.async` & find out yourself, Dont be lazy
DispatchQueue.main.async { // must be async !!
uiViewController.present(alert, animated: true, completion: {
self.showAlert = false // hide holder after alert dismiss
context.coordinator.alert = nil
})
}
}
}
func makeCoordinator() -> AlertControlView.Coordinator {
Coordinator(self)
}
class Coordinator: NSObject, UITextFieldDelegate {
// Holds reference of UIAlertController, so that when `body` of view gets re-rendered so that Alert should not disappear
var alert: UIAlertController?
// Holds back reference to SwiftUI's View
var control: AlertControlView
init(_ control: AlertControlView) {
self.control = control
}
func textFieldDidEndEditing(_ textField: UITextField) {
textField.text = textField.text!.replacingOccurrences(of: "^0+", with: "")
}
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
if let text = textField.text as NSString? {
self.control.textString = text.replacingCharacters(in: range, with: string)
} else {
self.control.textString = ""
}
return true
}
}
}
Its being called as such:
#State var changePassword = false
var body: some View {
ZStack {
HStack {
Text("Password")
Spacer()
Text(String(editingPool.password))
.foregroundColor(.gray)
.font(.callout)
Button(action: {
changePassword.toggle()
}) {
Text("Change")
}
}
if self.changePassword {
AlertControlView(textString: $editingPool.password,
showAlert: $changePassword,
title: "Change Pool Password",
message: "Enter the new pool password.")
}
}
}
I cant seem to get the shouldChangeCharactersIn function to get called, or any of the begin, end or onchange functions either?