Swift 4 Alert with Input - ios

Question

I'm trying to create an alert with two input fields which contain a master password for this app. It's my first app. I saw a function online and wanted to see if it still works but it doesn't seem to pop up with the alert when the function is called. Has this been changed in Swift 4?
func showInputDialog() {
//Creating UIAlertController and
//Setting title and message for the alert dialog
let alertController = UIAlertController(title: "Choose Master Password", message: "Enter your Master and confirm it!", preferredStyle: .alert)
//the confirm action taking the inputs
let confirmAction = UIAlertAction(title: "Enter", style: .default) { (_) in
//getting the input values from user
let master = alertController.textFields?[0].text
let confirm = alertController.textFields?[1].text
if master == confirm {
self.labelCorrect.isHidden = true
self.labelCorrect.text = master
}
}
//the cancel action doing nothing
let cancelAction = UIAlertAction(title: "Cancel", style: .cancel) { (_) in }
//adding textfields to our dialog box
alertController.addTextField { (textField) in
textField.placeholder = "Enter Master"
}
alertController.addTextField { (textField) in
textField.placeholder = "Confirm Password"
}
//adding the action to dialogbox
alertController.addAction(confirmAction)
alertController.addAction(cancelAction)
//finally presenting the dialog box
self.present(alertController, animated: true, completion: nil)
}

Answer 1

//1. Create the alert controller.
let alert = UIAlertController(title: "Title", message: "Description", preferredStyle: .alert)
//2. Add the text field. You can configure it however you need.
alert.addTextField { (textField) in
textField.placeholder = "User"
}
alert.addTextField { (textFieldPass) in
textFieldPass.placeholder = "Password"
textFieldPass.isSecureTextEntry = true
}
// 3. Grab the value from the text field, and print it when the user clicks OK.
alert.addAction(UIAlertAction(title: "Cancelar", style: .default, handler: { [weak alert] (_) in
print("cerrar")
}))
alert.addAction(UIAlertAction(title: "Aceptar", style: .default, handler: { [weak alert] (_) in
let textField = alert?.textFields![0]
let textFieldPass = alert?.textFields![1]
print("Text field: \(textField!.text)")
print("Text field: \(textFieldPass!.text)")
self.Autentificacion(usuario: textField!.text!, clave: textFieldPass!.text!)
}))
// 4. Present the alert.
self.present(alert, animated: true, completion: nil)

Answer 2

Going off as a reference to your question and daniel fernando muñoz melendez answer, I have written some code below.
//Create the alert controller.
let alert = UIAlertController(title: "Login", message: "For User", preferredStyle: .alert)
//Add the text field. You can configure it however you need.
alert.addTextField { (userField) in
userField.placeholder = "User"
}
alert.addTextField { (passWordField) in
passWordField.placeholder = "Password"
passWordField.isSecureTextEntry = true
}
//the cancel action doing nothing
let cancelAction = UIAlertAction(title: "Cancel", style: .destructive)
//the confirm action taking the inputs
let acceptAction = UIAlertAction(title: "Enter", style: .default, handler: { [weak alert] (_) in
guard let userField = alert?.textFields?[0], let passWordField = alert?.textFields?[1] else {
print("Issue with Alert TextFields")
return
}
guard let userName = userField.text, let passWord = passWordField.text else {
print("Issue with TextFields Text")
return
}
print("Text field: \(userName)")
print("Text field: \(passWord)")
// Condition Logic
})
//adding the actions to alertController
alert.addAction(acceptAction)
alert.addAction(cancelAction)
// Presenting the alert
self.present(alert, animated: true, completion: nil)
The guard statement for the alert.textFields act as a check to make sure the text fields are in fact created and are not nil.
The guard statement for the userField.text is to make sure that the text in them can be cast to a String. It should be noted that even if the user does not enter anything into the text fields it will still run properly. Since you want them to enter in credentials, I would assume you don't want this to happen and recommend putting your condition logic there. Or have it like daniel fernando muñoz melendez did it and have it in a separate function.
Let me know if you need any clarification.