Adding UIView with data to the window - ios

Question

I need to add a UIView with size of tabbar but exactly above tabbar. This view allow user to come back to a started workout. My idea is holding data inside UIView and instantiate a View Controller with unfinished data when user clicks button. The problem is that when I want to instantiate VC my data in UIView become nil.
class BeforeRoutineClass {
// HERE I CREATE the UIView
func showWorkoutView(temporaryRoutine: Routine) {
guard let tabBar = navigationController.tabBarController else { return print("Tabbar is nil") }
let window = UIApplication.shared.keyWindow!
let height = tabBar.tabBar.frame.height
view2 = BackToWorkoutButton(frame: CGRect(x: 0, y: (tabBar.tabBar.frame.origin.y) - height, width: window.frame.width, height: height), routine: temporaryRoutine)
window.addSubview(view2!)
}
}
class BackToWorkoutButton: UIView {
var routine: Routine?
init(frame: CGRect, routine: Routine?, bobo: String?) {
self.routine = routine
super.init(frame: frame)
customInit()
}
required init?(coder: NSCoder) {
super.init(coder: coder)
}
private func customInit() {
let xibView = Bundle.main.loadNibNamed("BackToWorkoutButton", owner: self, options: nil)?.first as! UIView
xibView.frame = self.bounds
addSubview(xibView)
}
#IBAction func backButtonTapped(_ sender: UIButton) {
// THERE IS NIL ALWAYS
guard let routine = routine else { return print("Routine is nil") }
let routineVC = RoutineFactory.startWorkoutScene(routine: routine)
let navBarOnModal = UINavigationController(rootViewController: routineVC)
navBarOnModal.modalPresentationStyle = .fullScreen
guard let nav = UIApplication.shared.windows.last?.rootViewController else { return print("there is no nav")}
nav.present(navBarOnModal, animated: true, completion: nil)
self.removeFromSuperview()
}
}