how to use parameter inside the selector Tapgesture - swift

Question

Currently I am making pickerDate to interact with TextField.
class ViewController: UIViewController {
#IBOutlet weak var fromDateFilterTextField: UITextField!
#IBOutlet weak var toDateFilterTextField: UITextField!
override func viewDidLoad() {
super.viewDidLoad()
setupUI()
}
private func setupUI(){
fromDateFilterTextField.setInputViewDatePicker(target: self, selector: #selector(tapDone(_:)))
toDateFilterTextField.setInputViewDatePicker(target: self, selector: #selector(tapDone(_:)))
}
#objc func tapDone(textField : UITextField) {
}
}
extension UITextField{
func setInputViewDatePicker(target : Any , selector : Selector){
//create a UIDatePicker object and assign to inputView
let screenWidth = UIScreen.main.bounds.width
let datePicker = UIDatePicker(frame: CGRect(x: 0, y: 0, width: screenWidth, height: 200))
datePicker.datePickerMode = .date
self.inputView = datePicker
//create a toolbar and assign it to inputAccesoryView
let toolBar = UIToolbar(frame: CGRect(x: 0.0, y: 0.0, width: screenWidth, height: 44.0))
toolBar.barTintColor = .red
datePicker.setValue(UIColor.black, forKeyPath: "textColor")
datePicker.setValue(false, forKeyPath: "highlightsToday")
datePicker.backgroundColor = .white
let flexible = UIBarButtonItem(barButtonSystemItem: .flexibleSpace, target: nil, action: nil)
let cancel = UIBarButtonItem(title: "Cancel", style: .plain, target: nil, action: #selector(tapCancel))
cancel.tintColor = .white
let barButton = UIBarButtonItem(title: "Done", style: .plain, target: target, action: selector) //7
barButton.tintColor = .white
toolBar.setItems([cancel, flexible, barButton], animated: false)
self.inputAccessoryView = toolBar
}
#objc func tapCancel() {
self.resignFirstResponder()
}
}
I'd like to pass textfield as parameter of tapDone for reuse the code, because I'd like to update the date of differents textfield using only change the parameters of tapDone.

Answer 1

OK, I understand (generally) what you are trying to do. The short answer is that you can't pass your UITextField as an argument for the Selector executed by your UIBarButtonItem. That said, there are other options.
The simplest solution I can think of would be to use the tag attribute of your UITextFields and UIBarButtonItems. To set this up you would need to update the tag of each UITextField so that they are all unique. For example, your fromDateFilterTextField could have a tag of 0, the toDateFilterTextField could be 1. Just make sure they are all different from each other if you have more.
Once you have updated the tags on your textFields you can make sure the UIBarButtonItem has the same tag by modifying your setInputViewDatePicker method like so:
func setInputViewDatePicker(target : Any , selector : Selector){
...
let barButton = UIBarButtonItem(title: "Done", style: .plain, target: target, action: selector) //7
barButton.tintColor = .white
//Make the barButton tag match the associated textField's tag
barButton.tag = self.tag
...
}
Even though you can't pass the UITextField as an argument, you can pass the UIBarButton executing the Selector by changing your selector method like this:
#objc func tapDone(_ sender: UIBarButtonItem) {
}
Then you can determine which textField is associated with the tapDone by looking for that matching tag:
#objc func tapDone(_ sender: UIBarButtonItem) {
switch sender.tag {
case 0:
print("This is fromDateFilterTextField")
case 1:
print("This is toDateFilterTextField")
default:
print("This is a different textField")
}
}
You can also look into viewWithTag in the docs for possible improvements, though sometimes being really explicit makes your code more readable and less prone to bugs.