Enable UIAlertAction of UIAlertController only after input

Question

I am using a UIAlertController to present a dialog with a UITextField and one UIAlertAction button labeled \"Ok\". How do I disable th

Answer 1

Swift 3 implementation based on soulshined's answer:

var someAlert: UIAlertController {
    let alert = UIAlertController(title: "Some Alert", message: nil, preferredStyle: .alert)

    alert.addTextField {
        $0.placeholder = "Write something"
        $0.addTarget(self, action: #selector(self.textFieldTextDidChange(_:)), for: .editingChanged)
    }

    alert.addAction(UIAlertAction(title: "Cancel", style: .cancel))

    let submitAction = UIAlertAction(title: "Submit", style: .default) { _ in
        // Do something...
    }

    submitAction.isEnabled = false
    alert.addAction(submitAction)
    return alert
}

func textFieldTextDidChange(_ textField: UITextField) {
    if let alert = presentedViewController as? UIAlertController,
        let action = alert.actions.last,
        let text = textField.text {
        action.isEnabled = text.characters.count > 0
    }
}