Subclassing UITextField to include a picker and a toolbar - ios

Question

Problem
I have an application that has a user registration view. It has many UITextField, and many of these have a picker with a toolbar embedded to close the picker i.e:
myTextField.inputView = myPicker
myTextField.inputAccessoryView = myToolbar
Essentially I want to reuse these text fields in different parts of my application, so I thought of subclassing UITextField, something like PickerUITextField.
Attempt
I've tried something like this:
class PickerUITextField: UITextField {
let picker = UIPickerView()
let toolbar = UIToolbar()
override init(frame: CGRect) {
super.init(frame: frame)
setup()
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
setup()
}
private func setup() {
withToolbar()
self.inputView = self.picker
self.inputAccessoryView = self.toolbar
}
private func withToolbar() {
toolbar.barStyle = UIBarStyle.default
toolbar.isTranslucent = true
let space = UIBarButtonItem(barButtonSystemItem: .flexibleSpace,
target: nil, action: nil)
let doneButton = UIBarButtonItem(title: "Done", style: .done,
target: self, action: #selector(removeToolBar))
toolbar.setItems([space, doneButton], animated: false)
toolbar.isUserInteractionEnabled = true
toolbar.sizeToFit()
}
#objc func removeToolBar() {
self.resignFirstResponder()
}
}
Question
However, how can I detect in the view controller that the user has pressed the "Done" button of my PickerUITextField? In other words:
class UserRegistrationViewController: UIViewController {
#IBOutlet weak var country: PickerUITextField!
// I want this to be triggered whenever the country picker closes
func didSelectCountry() {
print("User selected \(country.text!)")
}
}
Thank you for the help.

Answer 1

You can create a closure in PickerUITextField to perform done button action.
class PickerUITextField: UITextField {
let picker = UIPickerView()
let toolbar = UIToolbar()
var doneBtnAction:(() -> Void)?
override init(frame: CGRect) {
super.init(frame: frame)
setup()
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
setup()
}
private func setup() {
withToolbar()
self.inputView = self.picker
self.inputAccessoryView = self.toolbar
}
private func withToolbar() {
toolbar.barStyle = UIBarStyle.default
toolbar.isTranslucent = true
let space = UIBarButtonItem(barButtonSystemItem: .flexibleSpace,
target: nil, action: nil)
let doneButton = UIBarButtonItem(title: "Done", style: .done,
target: self, action: #selector(removeToolBar))
toolbar.setItems([space, doneButton], animated: false)
toolbar.isUserInteractionEnabled = true
toolbar.sizeToFit()
}
#objc func removeToolBar() {
doneBtnAction?()
self.resignFirstResponder()
}
}
And in your view controller, you can assign a closure. It will be called when you tap the done button.
class UserRegistrationViewController: UIViewController {
#IBOutlet weak var country: PickerUITextField!
override func viewDidLoad() {
super.viewDidLoad()
country.doneBtnAction = { [weak self] in
print("User selected \(self?.country.text!)")
}
}
}

Answer 2

You can use a protocol/delegate:
protocol PickerUITextFieldDelegate: class {
func didSelectCountry()
}
class PickerUITextField: UITextField {
// UITextField already have a 'delegate' we need a different name
weak var pickerDelegate: PickerUITextFieldDelegate?
let picker = UIPickerView()
let toolbar = UIToolbar()
#objc func removeToolBar() {
self.resignFirstResponder()
self.pickerDelegate?.didSelectCountry()
}
}
// We need to implement the PickerUITextFieldDelegate delegate here:
class UserRegistrationViewController: UIViewController, PickerUITextFieldDelegate {
#IBOutlet weak var country: PickerUITextField!
// Don't forget to set the delegate!
override func viewDidLoad() {
super.viewDidLoad()
self.country.pickerDelegate = self
}
// This will now be triggered by the delegate
func didSelectCountry() {
print("User selected \(country.text!)")
}
}