I have build a UICollectionViewController programmatically which returns 4 cells. HomeCell, TrendingCell, SubscriptionCell and AccountCell. All 4 cells should be different and you can scroll them horizontally. <--->.
class HomeController: UICollectionViewController, UICollectionViewDelegateFlowLayout{
override func viewDidLoad() {
super.viewDidLoad()
collectionView?.register(HomeCell.self, forCellWithReuseIdentifier: homeCellId)
collectionView?.register(TrendingCell.self, forCellWithReuseIdentifier: trendingCellId)
collectionView?.register(SubscriptionCell.self, forCellWithReuseIdentifier: subscriptionCellId)
collectionView?.register(AccountCell.self, forCellWithReuseIdentifier: accountCellId)
}
}Lets take the first cell of the HomeController called HomeCell to illustrate my problem. Homecell has three custom cells called VideoCell, CategoryCell and UserSearchCell.
class HomeCell: UICollectionViewCell, UICollectionViewDataSource, UICollectionViewDelegate, UICollectionViewDelegateFlowLayout {
let cellId = "cellId"
let searchId = "sarchId"
let scrollId = "scrollId"
lazy var collectionView: UICollectionView = {
let layout = UICollectionViewFlowLayout()
let cv = UICollectionView(frame: .zero, collectionViewLayout: layout)
cv.backgroundColor = UIColor.white
cv.dataSource = self
cv.delegate = self
return cv
}()
override func setupViews() {
super.setupViews()
.....
// register three different cells within HomeCell
collectionView.register(VideoCell.self, forCellWithReuseIdentifier: cellId)
collectionView.register(CategoryCell.self, forCellWithReuseIdentifier: scrollId)
collectionView.register(UserSearchCell.self, forCellWithReuseIdentifier: searchId) //
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
In HomeCell I register the UserSearchCell as third cell.
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
if indexPath.item == 0 {
cell = collectionView.dequeueReusableCell(withReuseIdentifier: "videoId", for: indexPath)
} else if indexPath.item == 1{
cell = collectionView.dequeueReusableCell(withReuseIdentifier: categoryId, for: indexPath)
}else {
cell = collectionView.dequeueReusableCell(withReuseIdentifier: searchId, for: indexPath)
}
return cell
}If I click on that element my goal is to push a new ViewController to the navigationController. But I have no access and don't know how to change the view within that nested structure. I tried the didSelectItem method within HomeCell class and was able to print something the console when clicking the third cell but couldn't change the view.
class HomeCell: UICollectionViewCell, UICollectionViewDataSource, UICollectionViewDelegate, UICollectionViewDelegateFlowLayout {
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
if indexPath.item == 2 {
print(123)
}
....
}Please help. Is there a way to change the View within the didSelectItem method of HomeCell ??
You need to write a protocol to refer back to your HomeController.
protocol HomeCellProtocol {
func pushNavigation(_ vc: UIViewController)
}
add write delegate property to HomeCell class with
class HomeCell: ..... {
var delegate: HomeCellProtocol?
}
and make HomeController confirm to HomeCellProtocol with
extention HomeController: HomeCellProtocol {
func pushNavigation(_ vc: UIViewController) {
self.navigationController?.pushViewController(vc, animated: true)
}
}
and when you setup your HomeCell you need to set your delegate in HomeController
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
cell = collectionView.dequeueReusableCell(withReuseIdentifier: homeCellId, for: indexPath) as HomeCell;
cell.delegate = self // Set the delegate
return cell
}
finally, you can call push function within HomeCell with
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
if indexPath.item == 2 {
let vc = UIViewController();
self.delegate?.pushNavigation(vc);
}
}