From within a view controller in a container view, how do you access the view controller containing the container?

Question

This is tricky to word but I have a view controller (vc1) that contains a container view (I\'m using storyboards). Within that container view is a navigation controller and

Answer 1

Swift - An alternative is to create a reference in parent UIViewController (vc1) to child/subview UIViewController (vc2) and in vc2 to vc1. Assign the references in parent(vc1) viewDidLoad() example below.

Parent UIViewController vc1:

      class vc1: UIViewController {

          @IBOutlet weak var parentLabel: UILabel!
          var childVc2: vc2?;

           overide func viewDidLoad() {
               super.viewDidLoad();
               // Use childViewControllers[0] without type/class verification only 
               // when adding a single child UIViewController 
               childVc2 = self.childViewControllers[0] as? vc2;
               childVc2?.parentVc1 = self
           }
      }

Child UIViewController vc2:

      class vc2: UIViewCortoller {
          var parentVc1: vc1?;

          // At this point child and parent UIViewControllers are loaded and 
          // child views can be accessed
          override func viewWillAppear(_ animated: Bool) {
             parentVc1?.parentLabel.text = "Parent label can be edited from child";
          }
      } 

In the Storyboard remember to set in Identity Inspector the parent UIViewContoller class to vc1 and child UIViewContoller class to vc2. Ctrl+drag from Container View in vc1 UIViewController to vc2 UIViewController and select Embed.