do something after first view controller appears - swift

Question

I have a View Controller with a button..
This button calls a "Present as Popover Seague" to a second view controller.
The second view controller has a close button with this function:
#IBAction func exit(_ sender: UIButton) {
self.dismiss(animated: true, completion: nil)
}
Now I would like to do something in the first controller, after the second Controller is dismissed.
In the first view controller I tried this functions:
override func viewDidAppear(_ animated: Bool) {
print("viewDidAppear")
}
override func viewWillAppear(_ animated: Bool) {
print("viewWillAppear")
}
but no console log will shown.
Where is my mistake?
FirstViewContorller
import UIKit
class firstVC: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
//ERROR
secondVC.dismissCompletion = {
print("dismissCompletion")
}
}
}
SecondVC (popover)
import UIKit
class secondVC: UIViewController {
var dismissCompletion: (() -> Void)?
// EXIT POPOVER
#IBAction func exit(_ sender: UIButton) {
self.dismiss(animated: true, completion: dismissCompletion)
}
}

Answer 1

The viewDidAppear() method of the main view controller won't be called because of the popover presentation style you use. If you choose to present the second view controller full screen - those methods will fire.
If we're sticking with the popover, the first thing you need to do is in your second view controller, the one that's being presented, add a property for a closure that will be executed upon its dismiss:
class PopoverViewController: UIViewContoller {
var dismissCompletion: (() -> Void)?
#IBAction func exit(_ sender: UIButton) {
self.dismiss(animated: true, completion: dismissCompletion)
}
}
And in your main view controller you define what needs to be done upon the popover's dismiss:
popoverViewContoller.dismissCompletion = {
// do stuff
}
UPDATE:
I assume you've setup the segue in your storyboard. I also assume that in your storyboard you've given the view controllers their respective class names:
This is what your code should look like:
class FirstViewController: UIViewController {
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
guard let secondVC = segue.destination as? SecondViewController else {
return
}
secondVC.dismissCompletion = {
print("Popover dismissed")
}
}
}
class SecondViewController: UIViewController {
var dismissCompletion: (() -> Void)?
#IBAction func exit(_ sender: Any) {
dismiss(animated: true, completion: dismissCompletion)
}
}
Please note the classes naming and the way I got the secondVC instance.