Adding refreshControl to collectionView inside a collectionViewCell - ios

Question

I have a UICollectionViewController (HomeViewController) with 3 cells.
Each cell is as big as the screen's size.
In the last cell I have another UICollectionView (collectionView) to display data.
This data should be refreshed every time I pull to refresh.
But that does not work.
This is the code so far:
HomeViewController
class HomeViewController: UICollectionViewController, UICollectionViewDelegateFlowLayout {
let thirdCellId = "thirdCell"
override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let thirdCell = collectionView.dequeueReusableCell(withReuseIdentifier: thirdCellId, for: indexPath) as! ThirdCell
thirdCell.refreshControl.addTarget(self, action: #selector(refreshData), for: UIControlEvents.valueChanged)
return thirdCell
}
#objc func refreshData(sender: UIRefreshControl) {
let cell = sender.superview as! ThirdCell <--- gives error: Could not cast value of type 'UICollectionView' to 'ExploreCell'
cell.loadData()
cell.refreshControl.endRefreshing()
print("Did work")
}
}
ThirdCell code:
class ThirdCell: UICollectionViewCell, UICollectionViewDataSource, UICollectionViewDelegate, UICollectionViewDelegateFlowLayout {
override init(frame: CGRect) {
super .init(frame: frame)
setupCollectionView()
loadData()
setupRefreshControl()
}
// --- CollectionView ---
lazy var collectionView: UICollectionView = {
let layout = UICollectionViewFlowLayout()
let cv = UICollectionView(frame: .zero, collectionViewLayout: layout)
cv.delegate = self
cv.dataSource = self
return cv
}()
func setupCollectionView() {
self.addSubview(collectionView)
// Setup constraints
}
// --- RefreshControl ---
var refreshControl: UIRefreshControl = {
let rfs = UIRefreshControl()
// Handle action in HomeViewController
return rfs
}()
func setupRefreshControl() {
if #available(iOS 10.0, *) {
collectionView.refreshControl = refreshControl
} else {
collectionView.addSubview(refreshControl)
}
refreshControl.centerXAnchor.constraint(equalTo: self.centerXAnchor).isActive = true
refreshControl.bottomAnchor.constraint(equalTo: self.topAnchor, constant: 30).isActive = true
refreshControl.translatesAutoresizingMaskIntoConstraints = false
}
func loadData() {
// Load data
self.collectionView.reloadData()
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}