How to present a ViewController modally from the presentingViewController? - ios

Question

I have 3 view controllers.
let's name them as A, B & C.
A presents B and then C should be present from A after dismissing B.
A <=> B
A -> C
How can I achieve this?
If the question is unclear then do let me know, I would be happy to edit it.

Answer 1

Well, I achieved it this way.
Note: I am inside B.
let cViewController = // getting a handle of this view controller from Storyboard
let aViewController = self.navigationController?.presentingViewController
self.dismiss(animated: true) {
aViewController?.present(cViewController, animated: true)
}

Answer 2

You can use custom notification observer like below:
In Controller A:
override func viewDidLoad() {
super.viewDidLoad()
// Register to custom notification
NotificationCenter.default.addObserver(self, selector: #selector(presentC), name: NSNotification.Name(rawValue: "BDismissed"), object: nil)
// Rest of your code
}
func presentC {
// Controller C presentation code goes here
}
In Controller B:
override func viewDidDisappear(_ animated: Bool) {
super.viewDidDisappear(animated)
NotificationCenter.default.post(name: NSNotification.Name(rawValue: "BDismissed"), object: nil, userInfo: nil)
}

Answer 3

Inside B try this
self.dismiss(animated: true) {
let aVC = UIApplication.shared.keyWindow?.rootViewController as! AVC
let cVC = ///
aVC.present(cVC, animated: true, completion: nil)
}

Answer 4

Write a protocol in B like:
protocol VCBDelegate {
func VCBDismissed()
}
Class VCB: UIViewController {
weak var delegate: VCBDelegate?
....
}
Now where you are dismissing B, call the delegate method in completion.
func dismissB() {
self.dismiss(animated: true) {
self.delegate.VCBDismissed()
}
}
Now conform this protocol in A.
extension VCA: VCBDelegate {
func VCBDismissed() {
//Here you present C
.....
}
}
Don't forget to make the delegate self where you are presenting B.
Hope this helps, for any queries please feel free to leave a comment.

Answer 5

You can use closures, it's better and simple.
Your A will present B and give it a closure to call when it dismiss, this closure will present C.
Here is an example :
class ViewControllerA : UIViewController{
func showViewControllerB(){
let vc = ViewControllerB()
vc.callOnDismiss = { [weak self] in
self?.showViewControllerC()
}
self.present(vc, animated: true, completion: nil);
}
func showViewControllerC(){
let vc = ViewControllerC()
self.present(vc, animated: true, completion: nil);
}
}
class ViewControllerB : UIViewController{
var callOnDismiss : () -> () = {}
func actionOnDismiss(){
self.dismiss(animated: true, completion: nil)
self.callOnDismiss()
}
}
class ViewControllerC : UIViewController{
}