Is there any way to get class name of parent VC in present (child) UIViewController? My 'child' VC (push) has two 'parent'UIViewControllers, so I would like to know which one is current parent?
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7 Answers
Here's one approach:
if let parentVC = parent as? SomeViewController {
// parentVC is someViewController
} else if let parentVC = parent as? AnotherViewController {
// parentVC is anotherViewController
}
This will conditionally assign and unwrap parent (the parent view controller) to its appropriate type. Within the condition blocks, parentVC will be the correct class.
That said, this is a code smell - child view controllers should typically have no idea who their parent view controllers are. Whatever problem you're solving, you should probably solve it with tell, don't ask and delegation instead.
4 Comments
Marko
It seems like good and right way to do that, but for some reason value of parentViewController in my pushed child-VC is always nil. So I did that on a dumb way: had to make Int variable parentIndicator in child-VC, and I'm passing some value to it from parent controllers (using delegation and prepareForSegue).
Shahen Kosyan
Update answer to swift 4! In swift for you should use parentVC is someViewController instead of your code!!!
Aaron Brager
If we used
is then we wouldn’t get the type binding inside the conditional bracket
iPhoneDeveloper
Note: 'parentViewController' has been renamed to 'parent'
UPDATED TO SWIFT 5
In your child view controller, you could try something like:
guard let parent = self.presentingViewController else{
// ...some code
return
}
//presented by parent view controller 1
if parent.isKind(of: Parent1.self){
// do something
}else{
//presented by parent view controller 2
}
I recommend you to place this logic in your viewWillAppear method because when viewDidLoad is called, there is no guarantee that the view controller hierarchy is loaded in the navigation tree and like a consequence of this, the presentingViewController property of your child view controller might be nil
2 Comments
Aaron Brager
Why not use
as? or is? Also, this will cause a crash if presentingViewController is nil.
mauricioconde
i just tried to show another way to approach, and you're right, everything could be inside the
if(self.presentingViewController != nil) statement. Thanks for the feedback!First add extension in view controller
extension UIView {
var parentViewController: UIViewController? {
var parentResponder: UIResponder? = self
while parentResponder != nil {
parentResponder = parentResponder!.next
if let viewController = parentResponder as? UIViewController {
return viewController
}
}
return nil
}
}
Now Use it Like this
let vc = self.parentViewController
or
if let parentVC = self.parentViewController {
if let parentVC = parentVC as? someViewController {
// parentVC is someViewController
} else if let parentVC = parentVC as? anotherViewController {
// parentVC is anotherViewController
}
}
Comments
try to pick the child from the children array as following
if let parentVC = self.parent {
if let parentVC = parentVC.children[0] as? someViewController {}}
1 Comment
Sujananth
Never know there exist a property named Children. This was usefull when we assign one viewcontroller view to another viecontroller
Simply use view.parentViewController and eventually its title property.
4 Comments
Aaron Brager
The OP asked for its class, not its title.
qwerty_so
Ah yes. But one could use the title to distinguish both ;-)
Priest
This is quite unreliable (since the
title property is purely optional for UIViewControllers), and a flat out wrong answer to this particular question since the title property will NEVER return the class name (unless you're explicitly assigning it, which is also quite pointless most of the time...)qwerty_so
@Priest Just see it as an alternative to distinguish things, not more. I posted this a bit before the accepted answer which is getting more to the point (
parentController).Add this extension and find parent view by it's type.
extension UIResponder {
func next<T: UIResponder>(_ type: T.Type) -> T? {
return next as? T ?? next?.next(type)
}
}
How to use
self.next(UIViewController.self)
Comments
Updated to Swift 4
Swift 4:
if let parentVC = self.parent {
if parentVC is someViewControllerr {
// parentVC is someViewController
} else if parentVC is anotherViewController {
// parentVC is anotherViewController
}
}
Swift 3:
if let parentVC = self.parentViewController {
if let parentVC = parentVC as? someViewController {
// parentVC is someViewController
} else if let parentVC = parentVC as? anotherViewController {
// parentVC is anotherViewController
}
}
Comments
