how to reference a UICollectionView when its inside a UITableViewCell - ios

Question

I have a UITableView which has 2 sections. In section 1 is a static cell which has a horizontal collectionView inside it.
My question is how do I reference the collectionView in the Controller to reload the collectionView...
Here is my code:
TableView Controller
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
if indexPath.section == 0 {
let cell = tableView.dequeueReusableCell(withIdentifier: "collectionCellID", for: indexPath) as! CollectionTableViewCell
return cell
} else {
let cell = tableView.dequeueReusableCell(withIdentifier: "tableCellID", for: indexPath) as! TableCell
return cell
}
}
func tableView(_ tableView: UITableView, willDisplay cell: UITableViewCell, forRowAt indexPath: IndexPath) {
if indexPath.row == 0 {
if let cell = cell as? CollectionTableViewCell {
cell.collectionView.delegate = self
cell.collectionView.dataSource = self
cell.collectionView.contentInset = UIEdgeInsets(top: 0, left: 8, bottom: 0, right: 8)
}
}
}
TableView Cell
class CollectionTableViewCell: UITableViewCell {
#IBOutlet weak var collectionView: UICollectionView!
}
CollectionView extension
extension MyController: UICollectionViewDelegate, UICollectionViewDataSource, UICollectionViewDelegateFlowLayout {
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
return cell
}
Data call in TableViewController
public func getData() {
ref.observe(.childAdded, with: { (snapshot) in
self.data.append(snapshot)
}
DispatchQueue.main.async {
//MARK: - collectionView.reloadData() <- not available
}
}
})
}

Answer 1

Call the table view's cellForRow(at:) to get a reference to the cell at section 0 row 0, cast that reference to a CollectionTableViewCell, and refer to its collectionView.

Answer 2

I had a tough time to configure the same issue (https://stackoverflow.com/a/45618501/3400991) . Here is few points regarding this :
Your Controller should conforms UICollectionViewDataSource, UICollectionViewDelegate, UICollectionViewDelegateFlowLayout
Create CollectionView cell and set its custom class into CollectionView cell .
Tableview dont have any idea about how much height its cell needed to render complete collectionview data inside tableview cell so you have to use this :
yourTableView.rowHeight = UITableViewAutomaticDimension
yourTableView.estimatedRowHeight = 90
Set Height of Tableview accordingly :
// since Collectionview explicitly telling its Parent to provide height
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
//Checking MIME Type
if condition for collectionview cell {
// set here
}
//Normal autolayout cell
else {
return UITableViewAutomaticDimension
}
}
Make Collectionview reference in Tableview Custom Cell class :
class customTableViewCell: UITableViewCell
{
#IBOutlet weak var collectionview: UICollectionView
}
Inside Tableview willDisplayCell :
func tableView(_ tableView: UITableView, willDisplay cell: UITableViewCell, forRowAt indexPath: IndexPath) {
cell.collectionview.delegate = self
cell.collectionview.datasource = self
//Reload it also
cell.collectionview.reloadData()
}

Answer 3

So what I ended up doing was creating a Header View for the table and adding a collectionView to it.
func configureHeaderView() {
let layout = UICollectionViewFlowLayout()
layout.scrollDirection = .horizontal
layout.sectionInset = UIEdgeInsets(top: 0, left: 8, bottom: 0, right: 8)
collectionView = UICollectionView(frame: CGRect(x: 0, y: 0, width: view.frame.width, height: 105), collectionViewLayout: layout)
collectionView.backgroundColor = UIColor(red: 248/255, green: 248/255, blue: 248/255, alpha: 1)
collectionView.isPagingEnabled = false
collectionView.isUserInteractionEnabled = true
collectionView.dataSource = self
collectionView.delegate = self
collectionView.register(UINib(nibName: "cell", bundle: nil), forCellWithReuseIdentifier: "cell")
collectionView.showsHorizontalScrollIndicator = false
tableView.tableHeaderView = collectionView
}
Then from anywhere I can now access:
DispatchQueue.main.async {
self?.collectionView.reloadData()
}