self.dismiss resets parent view controller's screen data - swift

Question

I am presenting a view controller inside the ParentViewController:
let item = getCurrentItem()
let presentViewController = viewController as! TestViewController
presentViewController.id = item.id
presentViewController.dismissController { // my custom delegate to inform the parent vc
self.dismiss(animated: true, completion: nil) // presenting view controller is closing then viewWillAppear will be triggered
}
self.present(presentViewController, animated: true, completion: nil)
But when dismiss is called, the ParentViewController's global arrays and variables are back to their initial values.
class ParentViewController {
// MARK: - Stored Properties
private let refreshControl = UIRefreshControl()
private var items = [String:[Item]]()
private var screenLoaded: Bool = false
// MARK: - Controller Lifecycle
override func viewDidLoad() {
super.viewDidLoad()
}
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
// after dismiss is called viewWillAppear gets hit but the "screenLoaded" is always false
if !screenLoaded {
screenLoaded = true
}
// items is initialised as well
}
private func openPopover() {
let item = getCurrentItem()
let presentViewController = viewController as! TestViewController
presentViewController.id = item.id
presentViewController.dismissController { // my custom delegate to inform the parent vc
self.dismiss(animated: true, completion: nil) // presenting view controller is closing then viewWillAppear will be triggered
}
self.present(presentViewController, animated: true, completion: nil)
}
}
How can I keep the parent view controller's original state after the dismiss is called?

Answer 1

After hours of digging Apple's documentations finally I found the following solution and it works for me. Hope it helps someone in the future.
[https://developer.apple.com/documentation/uikit/uimodalpresentationstyle/overcurrentcontext][1]
presentViewController.modalPresentationStyle = .overCurrentContext
Also, if there is a tabbar, the bottom of the child view controller will be under it if you set the presentation style to overCurrentContext. The workaround is to present the child view controller from the window's rootViewController.
sender.view.window?.rootViewController?.present(viewController, animated: true, completion: nil)
Now when the dismiss is called viewWillAppear is not triggered and I can keep the parent view controller's data and it's state.