Call api at specific scrollpoint while scrolling table view

Question

I have one tableview and displaying products within custom cell.

There are so many records so i am using pagination right now but i want to call api for pagination when scroll point match with tableview cell scroll point before last 3 rows remains to scroll.

In short, I want to call api before last 3 rows is remains to scroll in table.

If there is other way to do like this then it will be appreciate.

Thank you in advance.

Answer 1

You can use the UITableView delegate method willDisplayCell:ForRowIndexPath:

func tableView(tableView: UITableView, willDisplayCell cell: UITableViewCell, forRowAtIndexPath indexPath: NSIndexPath) {

    let needToFetchNewData = indexPath.row + 3 == datasource.count

    if needToFetchNewData {
        fetchData()
    }
}

I'd like to consider also a variable isAlreadyDownloading since the user can still scroll while you're fetching new data and it'll generate more than once the same request