how to call presentViewController from within a UICollectionViewCell

Question

calling this function from a UIViewController results in no problems, but calling it from a UICollectionViewCell raises a pre-compilation error

Answer 1

UITableViewCell should never handle any business logic. It should be implemented in a view controller. You should use a delegate:

UICollectionViewCell subclass:

protocol CustomCellDelegate: class {
    func sharePressed(cell: MyCell)
}

class CustomCell: UITableViewCell {
    var delegate: CustomCellDelegate?

    func didTapShare(sender: UIButton) {
        delegate?.sharePressed(cell: self)
    }
}

ViewController:

class TableViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {

    @IBOutlet weak var tableView: UITableView!

    //...

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: cellIdentifier, for: indexPath) as! CustomCell
        cell.delegate = self
        return cell
    }
}

extension TableViewController: CustomCellDelegate {
    func sharePressed(cell: CustomCell) {
        guard let index = tableView.indexPath(for: cell)?.row else { return }
        //fetch the dataSource object using index
    }
}