Load More data on Scroll Demand on CollectionView

Question

I am implementing a feature on the collectionView where user scrolls the collectionView at the bottom (20 items) and it requests another set of data (20 more items) from the

Answer 1

Swift 4.2

When you call reloadData() inside CollectionView delegate method you will see blank cells. You need call it like this.

func collectionView(_ collectionView: UICollectionView, willDisplay cell: UICollectionViewCell, forItemAt indexPath: IndexPath) {
    if indexPath.row == collectionView.numberOfItems(inSection: indexPath.section) - 1 {
        updateNextSet()
    }
}

func updateNextSet(){
    print("On Completetion")
    //requests another set of data (20 more items) from the server.
    DispatchQueue.main.async(execute: collectionView.reloadData)
}