Failed dismiss 2 view controller - ios

Question

I have 3 ViewController : LoginViewController, CheckinViewController, & ProfileViewController
The flow is :
LoginVC --> CheckinVC --> ProfileVC
What i need is:
I want to dismiss "ProfileVC" & "CheckinVC" when click logout button in "ProfileVC" then go back to the "LoginVC"
LoginVC.swift
let checkinViewController = self.storyboard?.instantiateViewController(withIdentifier: "CheckinViewController") as! CheckinViewController
self.navigationController?.pushViewController(checkinViewController, animated: true)
JustHUD.shared.hide()
self.dismiss(animated: false, completion: nil)
CheckinVC.swift
if let profileView = self.storyboard?.instantiateViewController(withIdentifier: "ProfileViewController") {
profileView.providesPresentationContextTransitionStyle = true
profileView.definesPresentationContext = true
profileView.modalPresentationStyle = UIModalPresentationStyle.overCurrentContext;
// profileView.view.backgroundColor = UIColor.init(white: 0.4, alpha: 0.8)
profileView.view.backgroundColor = UIColor.clear
profileView.view.isOpaque = false
self.present(profileView, animated: true, completion: nil)
Here is i'm trying to do
ProfileVC.swift
#IBAction func clickLogout(_ sender: Any) {
UserDefaults.standard.removePersistentDomain(forName: Bundle.main.bundleIdentifier!)
UserDefaults.standard.synchronize()
self.dismiss(animated: false, completion: {
print("ProfileView : dismiss completed")
let loginViewController = self.storyboard?.instantiateViewController(withIdentifier: "LoginViewController") as! LoginViewController
self.navigationController?.pushViewController(loginViewController, animated: true)
self.dismiss(animated: false, completion: {
print("SUCCESS")
})
})
}

Answer 1

Well you need to do an Unwind Segue so you can go back in your LoginVC.
Follow these simple four steps to create Unwind segues:
In the view controller you are trying to go back to, LoginVC in your example, write this code:
#IBAction func unwindToVC1(segue:UIStoryboardSegue) { }
( Remember: It’s important to insert this method in the view
controller you are trying to go back TO! )
In the Storyboard, go to the screen you’re trying to unwind from ( ProfileVC in our case ), and control + drag the viewController icon to the Exit icon located on top.
3. Go to the document outline of the selected viewController in the Storyboard, select the unwind segue as shown below.
Now, go to the Attributes Inspector in the Utilities Pane and name the identifier of the unwind segue.
Finally, write this code where you want the unwind segue action to be triggered, ProfileVC in our case.
#IBAction func clickLogout(_ sender: Any) {
UserDefaults.standard.removePersistentDomain(forName: Bundle.main.bundleIdentifier!)
UserDefaults.standard.synchronize()
performSegue(withIdentifier: "unwindSegueToVC1", sender: self)
}
For more information check Create Unwind Segues

Answer 2

While Enea Dume's solution is correct if you want to use storyboards, here is the explanation of the problem, and the solution if you want to do it in code like you have been so far.
The Issue
If we focus on the self.dismiss calls in the logoutFunction in ProfileVC, this is what happens.
The first time you call self.dismiss, ProfileVC will dismiss itself and be removed from the view stack.
In the completion delegate, you are pushing a new LoginVC to a navigation controller. However, the CheckIN VC is presented over the navigation controller so you can't see anything happen.
The second call to self.dismiss does nothing as ProfileVC is not presenting any other view controllers and it is not in the stack any longer.
The Solution
You need to keep a reference to LoginVC that presented the CheckInVC. If you call "reference to LoginVC".dismiss, it will dismiss the view controllers above it in the stack and take you back to the login view controller.

Answer 3

In the class CheckinVC.swift, in the function viewDidAppear, check if the user is still active or not based on the session that you are maintaining and the pop to login view controller accordingly. If user status is logged out, then it will go to login view controller. Else it will work as usual.

Answer 4

Problem is that you are trying to dismiss twice ProfileVC but what you actually need is to dismiss it and then pop CheckinVC.
Also after dismissing a view controller it no longer has a reference to the NavigationController so you need a reference to it in a temporal variable.
Change ProfileVC like this:
#IBAction func clickLogout(_ sender: Any) {
UserDefaults.standard.removePersistentDomain(forName: Bundle.main.bundleIdentifier!)
UserDefaults.standard.synchronize()
let navigationController = self.navigationController
let loginViewController = storyboard?.instantiateViewController(withIdentifier: "LoginViewController") as! LoginViewController
self.dismiss(animated: false, completion: {
print("ProfileView : dismiss completed")
navigationController?.pushViewController(loginViewController, animated: true)
navigationController?.popViewController(animated: false)
})
}