Create generic function to get indexpath from table and collection view - iOS - Swift

Question

I have a tableView and collectionView and to get indexPath i'm using below methods on tableViewCell and collectionViewCell (i dont want to use indexPathForSelectedRow/Item methods). Is there a way that I can make this generic?

Ideas please

// For Tableview 
    func getIndexPath() -> IndexPath? {
        guard let superView = self.superview as? UITableView else {
            return nil
        }
        let indexPath = superView.indexPath(for: self)
        return indexPath
    }

// For CollectionView
     func getIndexPath() -> IndexPath? {
        guard let superView = self.superview as? UICollectionView else {
            return nil
        }
        let indexPath = superView.indexPath(for: self)
        return indexPath
    }

I assume these methods are in `UITableViewCell` and `UICollectionViewCell` extensions? — Sweeper, Sep 20 '20 at 07:49
IMO if a cell needs to know its index path you are doing something wrong. — Paulw11, Sep 20 '20 at 09:11
@Paulw11 Now that I think about it, this is indeed weird. I was just treating this as another "removing duplicate code" exercise, and didn't think too deeply about it. — Sweeper, Sep 20 '20 at 10:14
I have collectionView within tableCell and there are few buttons in each collection cell..i need to know indexPath of button tapped (from collectionCell) to my viewController...since i have multiple buttons i needed to find indexPath — Ashh, Sep 21 '20 at 17:07

Sweeper · Accepted Answer · 2020-09-20T10:13:07.437

You could do this with two protocols, one that both UITableView and UICollectionView conforms to, and the other that both UITableViewCell and UICollectionViewCell conforms to.

protocol IndexPathQueryable: UIView {
    associatedtype CellType
    func indexPath(for cell: CellType) -> IndexPath?
}

protocol IndexPathGettable: UIView {
    associatedtype ParentViewType: IndexPathQueryable
}

extension UITableView : IndexPathQueryable { }
extension UICollectionView : IndexPathQueryable { }

extension UICollectionViewCell : IndexPathGettable {
    typealias ParentViewType = UICollectionView
}
extension UITableViewCell : IndexPathGettable {
    typealias ParentViewType = UITableView
}

extension IndexPathGettable where ParentViewType.CellType == Self {
    func getIndexPath() -> IndexPath? {
        guard let superView = self.superview as? ParentViewType else {
            return nil
        }
        let indexPath = superView.indexPath(for: self)
        return indexPath
    }
}

Really though, you shouldn't need a getIndexPath method on a table view cell. Cells should not know their index paths. I suggest you reconsider your design.

Thanks..I have collectionView within tableCell and there are few buttons in each collection cell..i need to know indexPath of button tapped (from collectionCell) to my viewController...since i have multiple buttons i needed to find indexPath — Ashh, Sep 21 '20 at 17:08

Create generic function to get indexpath from table and collection view - iOS - Swift

1 Answers1