iOS Swift Navigation unwind with redirection

Question

I would like to implement the following: (I am using navigation controllers)

View A has several options which determine which path to take. The first displays view B which will then display View C using navigation controllers. The tool bar's first item performs a unwind to View A. Which works. The second item in the tool bar, I would like to unwind not only to A but redirect to View E.

The code in A view controller looks like this:

@IBAction func unwindToHomeController(segue: UIStoryboardSegue) {
    self.performSegue(withIdentifier: "toPerson", sender: self)
}

When I click on the second item in the tool bar, View E is displayed but view A is immediately displayed after a brief delay.

How do I stop the display of View A?

Perhaps there is a better way.

Answer 1

You need to wait the animation finish to performSegue to E:

class ViewController: UIViewController {

    @IBAction func unwindToA(segue: UIStoryboardSegue) {
    }

    @IBAction func unwindToE(segue: UIStoryboardSegue) {
        CATransaction.begin()
        CATransaction.setCompletionBlock { 
            self.performSegue(withIdentifier: "E", sender: nil)
        }
        CATransaction.commit()
    }

}

UPDATED To avoid the flashing showing A while pushing E

1) Remove the unwindToE function:

extension ViewController {

    @IBAction func unwindToA(segue: UIStoryboardSegue) {
    }

//  @IBAction func unwindToE(segue: UIStoryboardSegue) {
//      CATransaction.begin()
//      CATransaction.setCompletionBlock { 
//          self.performSegue(withIdentifier: "E", sender: nil)
//      }
//      CATransaction.commit()
//  }

}

2) Create a custom segue:

class MyUnwindSegue: UIStoryboardSegue {

    override func perform() {

        guard let nav = source.navigationController else { return }
        guard let root = nav.viewControllers.first else { return }
        let viewControllers = [root, destination]
        nav.setViewControllers(viewControllers, animated: true)

    }

}

3) Update the segue to MyUnwindSegue in storyboard (make sure the Module is selected to your project module rather than empty):