Get back parentViewController - swift

Question

I have a PhoneViewController : UIViewController
let phonePage = storyboard.instantiateViewControllerWithIdentifier("phoneViewController") as! PhoneViewController
I am presenting it from 2 different controllers.
// UIViewController1
self.navigationController?.pushViewController(phonePage, animated: true)
// UIViewController2
self.presentViewController(phonePage.embedInNavController(), animated: true, completion: nil)
I would like to have a have to detect which controller was its parent. How would I be able to do that?

Answer 1

you can try this code:-
if let wd = self.window {
var vc = wd.rootViewController
if(vc is UINavigationController){
vc = (vc as UINavigationController).visibleViewController
}
if(vc is YourViewController){
//your code
}
}

Answer 2

The short answer is :
if let navController = self.navigationController {
return navController.viewControllers[navController.viewControllers.count - 1]
// take care if count <= 1
else {
return self.parent
}
But is this what you really looking for ? What behavior are you trying to implement based on who is his parent ?
I don't have the answer to this question but you should make your code readable. Let me explain by an example :
let phonePage = storyboard.instantiateViewControllerWithIdentifier("phoneViewController") as! PhoneViewController
// Option 1
self.navigationController?.pushViewController(phonePage, animated: true)
phonePage.mode = PhonePageMode.list
// Option 2
self.presentViewController(phonePage.embedInNavController(), animated: true, completion: nil)
phonePage.mode = PhonePageMode.grid
// In your PhoneViewController class
switch self.mode {
case .list: // present as a list
case .grid: // present as a grid
}
is more readable than :
let phonePage = storyboard.instantiateViewControllerWithIdentifier("phoneViewController") as! PhoneViewController
// Option 1
self.navigationController?.pushViewController(phonePage, animated: true)
// Option 2
self.presentViewController(phonePage.embedInNavController(), animated: true, completion: nil)
// In your PhoneViewController class
guard let parent = self.parentViewController else { return }
if parent is ThisClassWhichWantsAList {
// present as list
} else if parent is ThisOtherClassWhichWantsAGrid {
// present as grid
}
If you want to use its parent as a condition to do things differently, you'd rather use an additional attribute. Your futur self will be thankful.

Answer 3

if your'r view controller is pushed from navigationViewController than parent class in parentViewController available and if presented than in presentationController available.
You can check in this way:
if let parentVC = self.navigationController.parentViewController{
//parentVC.className
}
if let presentedVC = self.navigationController?.presentationController{
//presentedVC.className
}

Answer 4

So you basically have to check if the view controller in the navigation controller stack, at the index of count - 1 is the kind of view controller that you are looking for.
Short version:
if navigationController.viewControllers[navigationController.viewControllers.count - 1].isKind(of: TheVCYouAreLooking for.self) {
print("it is")
} else {
print("it is NOT")
}
Long version from a playground:
//These are your two view controllers
class FirstVCClass: UIViewController {}
class SecondVCClass: UIViewController {}
let vc = FirstVCClass()
let secondVC = SecondVCClass()
//Create a navigationcontroller and add the first VC in the stack
let navigationController = UINavigationController()
navigationController.setViewControllers([vc], animated: true)
//Now push the secondVC
vc.navigationController?.pushViewController(secondVC, animated: true)
//The last vc in the stack is the one you've just pushed
print(navigationController.viewControllers.last!)
// Now check
if navigationController.viewControllers[navigationController.viewControllers.count - 1].isKind(of: FirstVCClass.self) {
//The view controller that is before you current vc in the stack is of the class
print("it is")
} else {
print("it is NOT")
}