Using dismissViewController on queue of multiple UIViewControllers with delegate - ios

Question

I'm presenting a tutorial of 4 UIViewController when my app starts the first time.
Every UIViewController has a Button with a segue presenting the next ViewController.
The last ViewController has a button "Let's start" which should dismiss the tutorial completely.
Problem:
It this dismiss all ViewControllers except the first. I don't understand why?!
What I expect:
On the last ViewController4 I'm calling the dismissIntroduction() function of the first ViewController, so I except ALL ViewControllers (ViewController1 included) should disappear.
When I put a button on the first ViewController and call the function "dismissIntroduction()" it disappears.
ViewController 1 (WelcomeViewController):
protocol WelcomeViewDelegate {
func dismissIntroduction()
}
class WelcomeViewController: UIViewController, WelcomeViewDelegate {
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
}
func dismissIntroduction() {
self.dismissViewControllerAnimated(true, completion: nil)
}
// MARK: - Navigation
// In a storyboard-based application, you will often want to do a little preparation before navigation
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
let destination = segue.destinationViewController as! ViewController2
destination.delegate = self
}
}
ViewController 2:
class ViewController2: UIViewController {
var delegate:WelcomeViewDelegate?
override func viewDidLoad() {
super.viewDidLoad()
}
// MARK: - Navigation
// In a storyboard-based application, you will often want to do a little preparation before navigation
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
let destination = segue.destinationViewController as! ViewController3
destination.delegate = self.delegate
}
}
ViewController 3:
class ViewController3: UIViewController {
var delegate:WelcomeViewDelegate?
override func viewDidLoad() {
super.viewDidLoad()
}
// MARK: - Navigation
// In a storyboard-based application, you will often want to do a little preparation before navigation
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
let destination = segue.destinationViewController as! ViewController4
destination.delegate = self.delegate
}
}
ViewController4 (the last one):
class ViewController4: UIViewController {
var delegate:WelcomeViewDelegate?
override func viewDidLoad() {
super.viewDidLoad()
}
#IBAction func pressLetsStart(sender: AnyObject) {
self.delegate!.dismissIntroduction()
}
}
EDIT:
I got it working, when I put the dismissViewControllerAnimated function TWO times!?
func dismissIntroduction() {
self.dismissViewControllerAnimated(true, completion: nil)
self.dismissViewControllerAnimated(true, completion: nil)
}
But why? I don't understand the logic behind...

Answer 1

You are looking at the wrong solution to your problem, what you need to do is look for Unwind Segues. Go through this tutorial: https://spin.atomicobject.com/2014/10/25/ios-unwind-segues/

Answer 2

I solved the problem now with following function in last ViewController:
#IBAction func pressLetsStart(sender: AnyObject) {
self.dismissModalStack()
}
private func dismissModalStack() {
var vc = self.presentingViewController! as UIViewController
while (vc.presentingViewController != nil) {
vc = vc.presentingViewController!;
}
vc.dismissViewControllerAnimated(true, completion: nil)
}