tl;dr: I don’t. I grab the top view controller from the stack of the navigation controller.

From my DetailView, I wanted to push to a new ViewController for adding a comment. The “link” to add a new comment was in an action sheet (UIAlertController), so I had to call the segue from the code. To create the segue in the StoryBoard, I had to connect the NavigationController (not the UITableViewController) with the new ViewController.

This means, that when I call

self.navigationController?.performSegue(withIdentifier: "downtimeSegue", sender: self)

the segue will be perform correctly. BUT. The method

override func prepare(for segue: UIStoryboardSegue, sender: Any?)

will not be called since it is implemented in my DetailViewController, not in the NavigationController.

So I am not able to pass any data in that method.

Solution: I just grabbed the DetailViewController via the NavigationController and so I can access all properties.

override func viewDidLoad() {
    for controller in navigationController!.viewControllers {
        if controller is DetailViewController {
            self.delegate = controller as? DetailViewController
        }
    }
}