How can I go back to the previous ViewController from UICollectionViewCell? - swift

Question

There are two pages(view controllers) in Main.storyboard: FirstViewController and SecondViewController. I have added a button into FirstViewController. Here is the button click scope:
let controller = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "MainPage") as! SecondViewController
controller.modalPresentationStyle = .fullScreen
show(controller, sender: nil)
I have added UICollectionView into SecondViewController. UICollectionViewCell is also added (with .xib file) I have added back button in to .xib file. And I wanted to write below code for back button action(please focus func btnBack)
import UIKit
class ViewCell: UICollectionViewCell {
#IBOutlet weak var lblOutlet: UILabel!
#IBOutlet weak var contentViewOutlet: UIView!
override func awakeFromNib() {
super.awakeFromNib()
// Initialization code
}
#IBAction func btnBack(_ sender: UIButton) {
present(controller, animated: true, completion: nil)
}
}
but as you known, ViewCell has no member dismiss. What i am trying to do is going back to the FirstViewController with this back button in UICollectionViewCell. And yes, app user see this back button in each ui collection records.

Answer 1

May be you can use protocol & delegate pattern to pop back from second view controller. You can add in your CollectionViewCell file a protocol like
protocol popBackDelegate {
func popBack()
}
then inject it in your CollectionViewCell
var popBackDelegate: popBackDelegate!
After that you can call it in your btnBack action
popBackDelegate.popBack()
Now you have to bind it your second view controller's collection view's cellforitem event
cell.popBackDelegate = self
Lastly you can conform this protocol func in your view controller and pop back in that.
Hopefully I helped you with that.

Answer 2

I would suggest add a callback in ViewCell for such small interaction as below,
class ViewCell: UICollectionViewCell {
#IBOutlet weak var lblOutlet: UILabel!
#IBOutlet weak var contentViewOutlet: UIView!
override func awakeFromNib() {
super.awakeFromNib()
// Initialization code
}
public var dismiss: (()-> Void)? = nil
#IBAction func btnBack(_ sender: UIButton) {
self.dismiss?()
}
}
Now, in your ViewController bind that callback inside cellForItemAt as,
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell: ViewCell = // Your code to dequeue cell
cell.dismiss = { [weak self] in
self?.dismiss(animated: true, completion: nil) // OR Pop whatever
}
}