iOS/Swift: How to add one extension to multiple controllers? - swift

Question

In a file called Extensions, I'm trying to add one extension to 2 View Controllers so I don't have to write the whole code twice.
import UIKit
extension TempConvertViewController {
// code
}
I need to use the exact same code for LocationViewController.
Any help would be appreciated!
Edit:
Thank you all for responding.
What I am trying to achieve is reuse the same keyboard/view code in 2 controllers as both contain textFields. The reason I've extended TempConvertViewController is because I have a variable (activeTextField) which won't be recognizable if I were to implement this in UIViewController.
If I put the code in a function, the keyboardDidShow() and keyboardWillHide() functions won't be recognized in the controller itself. I get the error: Use of unresolved identifier 'keyboardDidShow(notification:), Use of unresolved identifier 'keyboardWillHide(notification:)'
See second part of the code below
Here is the extension of TempConvertViewController
extension TempConvertViewController: UITextFieldDelegate {
#objc func keyboardDidShow(notification: Notification) {
let notificationInfo: NSDictionary = notification.userInfo! as NSDictionary
let keyboardSize = (notificationInfo[UIKeyboardFrameEndUserInfoKey] as! NSValue).cgRectValue
let yKeyboard = view.frame.size.height - keyboardSize.height
let yTextFieldEditing: CGFloat! = activeTextField?.frame.origin.y
if view.frame.origin.y >= 0 {
//checking if textField is covered by keyboard
if yTextFieldEditing > yKeyboard - 60 {
UIView.animate(withDuration: 0.25, delay: 0.0, options: UIViewAnimationOptions.curveEaseIn, animations:{self.view.frame = CGRect(x: 0, y: self.view.frame.origin.y -
(yTextFieldEditing! - (yKeyboard - 60)), width: self.view.bounds.width, height: self.view.bounds.height)}, completion: nil)
}
}
}
#objc func keyboardWillHide(notification: Notification) {
UIView.animate(withDuration: 0.25, delay: 0.0, options: UIViewAnimationOptions.curveEaseIn, animations: { self.view.frame = CGRect(x: 0, y:0, width: self.view.bounds.width, height: self.view.bounds.height)}, completion: nil)
}
func textFieldDidBeginEditing(_ textField: UITextField) {
activeTextField = textField
}
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
self.view.endEditing(true)
}
}
TempConvertViewController:
override func viewDidLoad() {
super.viewDidLoad()
// Subscribe to Notifications
let center: NotificationCenter = NotificationCenter.default;
center.addObserver(self, selector: #selector(keyboardDidShow(notification:)), name: NSNotification.Name.UIKeyboardWillShow, object: nil)
center.addObserver(self, selector: #selector(keyboardWillHide(notification:)), name: NSNotification.Name.UIKeyboardWillHide, object: nil)
}
If I manage to include everything in one function, e.g. keyboardViewManagement(), can't I use a new extension for the other View Controller (LocationChangeViewController) like this:
extension LocationChangeViewController: UITextFieldDelegate {
// calling the function
func keyboardViewManagement()
}
Thank you all again!

Answer 1

Use power of protocols, we are in swift after all
protocol Extendable: class {
var editingTextField: UITextField? { get }
func someFunc()
}
extension Extendable where Self: UIViewController {
func someFunc() {
// yor implementation
}
}
class ViewController: UIViewController {
var editingTextField: UITextField? {
return activeTextField
}
}

Answer 2

Just write an extension of UIViewController:
extension UIViewController {
//anything can go here
func some() {
}
}
Then in your view controller:
class VC1: UIViewController {
some()
}