Set UIImageView From Modal To Another Controller - swift

Question

I have a form the user is filling out, and I present a modal with images for them to choose from. I am attempting to set a UIImage in the original controller from the modal, but the problem is it's nil.
What is the best way to set it? The viewDidLoad doesn't seem to trigger on dismissal of a modal, which is how I'm getting rid of it, and neither does the viewWillAppear. When can I set the image?
My Code right now:
//Collection view choosing deal background
#IBOutlet var collectionView: UICollectionView!
var chosenNumber: Int?
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(true)
if(self.restorationIdentifier == "NewDeal") {
if(chosenNumber != nil) {
newDealBackgroundImage.image = UIImage(named: "food_\(chosenNumber!)")
}
}
}
extension BusinessOwnerVC: UICollectionViewDelegate {
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
collectionView.deselectItem(at: indexPath, animated: true)
//self.newDealBackgroundImage.image = UIImage(named: "food_\(indexPath.row + 1)")!
chosenNumber = indexPath.row + 1
self.dismiss(animated: true, completion: nil)
}
}

Answer 1

If your presentation style is fullScreen … then your willAppear will be called
navigationController.modalPresentationStyle = .fullScreen
but if you dont want full screen presentation Make yourself the presentation controller's delegate and override presentationControllerDidDismiss(_:).
class ViewController: UIViewController {
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
print("viewWillAppear")
}
#IBAction func show(_ sender: Any) {
let newViewController = NewViewController()
//set delegate of UIAdaptivePresentationControllerDelegate to self
newViewController.presentationController?.delegate = self
present(newViewController, animated: true, completion: nil)
}
}
extension UIViewController: UIAdaptivePresentationControllerDelegate {
public func presentationControllerDidDismiss( _ presentationController: UIPresentationController) {
if #available(iOS 13, *) {
//Call viewWillAppear only in iOS 13
viewWillAppear(true)
}
}
}

Answer 2

After much experimentation, here's what I found works for me. All I wanted was to access and update a view controller (of the same kind) under a modal I am presenting. Turns out my previous VC was still active, so all I had to do was pass a reference to that VC into the modal, and then I could change its properties.
let modal = UIStoryboard.init(name: "BusinessOwner", bundle: nil).instantiateViewController(withIdentifier: "DealBackgroundSelection") as! BusinessOwnerVC
modal.newDealView = self // This is a weak var of BusinessOwnerVC? declared in the view controller itself
present(modal, animated: true, completion: nil)
And then when I was ready to dismiss that modal:
self.newDealView!.updateDealImage(number: indexPath.row + 1)
updateDealImage was just a function I created to handle all the update. And that works for me.