Recursion without calling previous functions - ios

Question

How one can create a recursion function that once called will only execute the current called function that has the next index?
The collection view to be auto scrolled is nested inside the first table view cell.
I've been trying to create a recursion function that would work as a regular loop. The loops can not be used because it runs on a background thread.
This is my code:
var indexItem = 1
func autoScroll(time: Int) {
DispatchQueue.main.async {
self.run(after: time) {
cell._collectionView.scrollToItem(
at: IndexPath(row: indexItem, section: 0),
at: .centeredHorizontally, animated: true
)
indexItem += 1
autoScroll(time: 3)
return
}
}
}
autoScroll(time: 3)
The problem is that it always calls the function with the previous index first, then it executes the function with the actual index.

Answer 1

I believe what you're trying to do is this:
func autoScroll(time: DispatchTimeInterval, indexItem: Int = 1) {
DispatchQueue.main.asyncAfter(deadline: .now() + time) {
cell._collectionView.scrollToItem(at: IndexPath(row: indexItem, section: 0), at: .centeredHorizontally, animated: true)
autoScroll(time: time, indexItem: indexItem + 1)
}
}
autoScroll(time: .seconds(3))
Just pass the value to the function.
You really need some flag that will stop this, though. As written, this is ensuring that cell can never be released. And if multiple cells run this, then it's definitely going to cause a problem a they fight. I would expect this to run directly on the collection view rather than on the cell.