Cannot add collection view to two view controllers - ios

Question

I am have added collection view to two of my view controllers and when I click on the cell in the first view controller (TabBar.swift) it should go to the second view controller and vice Versa, but for some reason, the app crashes when I launch.
Here is the code for the first view controller: TabBar.swift
struct OpenViewController {
var viewController: UIViewController
}
class TabBar: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = .white
addCollectionViewConstraints()
}
var viewControllerList = [
OpenViewController(viewController: FirstScreen())
]
// Setup the collection veiw
let collectionView: UICollectionView = {
let layout = UICollectionViewFlowLayout()
let cv = UICollectionView(frame: .zero, collectionViewLayout: layout)
cv.register(UICollectionViewCell.self, forCellWithReuseIdentifier: "cellID")
cv.translatesAutoresizingMaskIntoConstraints = false
return cv
}()
// Add constraints to the collection view
func addCollectionViewConstraints() {
view.addSubview(collectionView)
collectionView.backgroundColor = .blue
collectionView.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor, constant: 10).isActive = true
collectionView.leadingAnchor.constraint(equalTo: view.leadingAnchor).isActive = true
collectionView.trailingAnchor.constraint(equalTo: view.trailingAnchor).isActive = true
collectionView.heightAnchor.constraint(equalTo: collectionView.widthAnchor, multiplier: 0.3).isActive = true
collectionView.delegate = self
collectionView.dataSource = self
}
}
Here is the code for the second view controller:
FirstScreen.swift
struct OpenViewControllerTwo {
var viewController: UIViewController
}
class FirstScreen: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = .yellow
addCollectionViewConstraints()
}
var viewControllerList = [
OpenViewControllerTwo(viewController: FirstScreen())
]
let collectionView: UICollectionView = {
let layout = UICollectionViewFlowLayout()
let cv = UICollectionView(frame: .zero, collectionViewLayout: layout)
cv.register(UICollectionViewCell.self, forCellWithReuseIdentifier: "cellID")
cv.translatesAutoresizingMaskIntoConstraints = false
return cv
}()
// Add constraints to the collection view
func addCollectionViewConstraints() {
view.addSubview(collectionView)
collectionView.backgroundColor = .blue
collectionView.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor, constant: 10).isActive = true
collectionView.leadingAnchor.constraint(equalTo: view.leadingAnchor).isActive = true
collectionView.trailingAnchor.constraint(equalTo: view.trailingAnchor).isActive = true
collectionView.heightAnchor.constraint(equalTo: collectionView.widthAnchor, multiplier: 0.3).isActive = true
collectionView.delegate = self
collectionView.dataSource = self
}
}
extension FirstScreen: UICollectionViewDelegateFlowLayout, UICollectionViewDataSource {
// The number of elements inside the collection view
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 1
}
// Adding the cells
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "cellID", for: indexPath)
// Customize the cells
cell.backgroundColor = .black
cell.layer.cornerRadius = collectionView.contentSize.height / 2
cell.layer.borderWidth = 1
cell.layer.borderColor = UIColor.black.cgColor
return cell
}
// The witdth and the height of the cell
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
return CGSize(width: collectionView.frame.height, height: collectionView.frame.height)
}
// Padding to the cells
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAt section: Int) -> UIEdgeInsets {
return UIEdgeInsets(top: 0, left: 8, bottom: 0, right: 8)
}
// Selecting a cell and navigating to another view controller
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
let openViewController = self.viewControllerList[indexPath.row]
self.present(openViewController.viewController, animated: false)
}
}
Crash log:

Answer 1

Your are getting memory issue because of viewControllerList is initialised in loops.
Just declare variable like this
var viewControllerList = [OpenViewController]()
then assign value like this in viewDidLoad.
viewControllerList = [
OpenViewController(viewController: FirstScreen())
]

Answer 2

I found that code in FirstScreen
var viewControllerList = [
OpenViewControllerTwo(viewController: FirstScreen())
]
When FirstScreen init, viewControllerList will init all call FirstScreen.
It created recursive recursive. Please change above code, put another class, ex: In FirstClass
var viewControllerList = [
OpenViewControllerTwo(viewController: SecondClass())
]