iOS Collection View shifts up when data reloads - ios

Question

I have a TableView that manages two rows of data. Each row is managed by a CollectionView which allows the user to scroll horizontally and filter the data. The filters are part of the table view and above the CollectionView.
Here's a visual:
When I click the filters along row one (off screen in the image above) the ui smoothly updates the data. However when I click the filters along row two the collection view shifts up briefly before back down to the proper position.
I'm fairly confident that the issue has to do with my interface builder configuration but for the record, this is the code that reloads the collection views.
func onFetchCompleted() {
if shouldRefreshRow() {
//tableView.reloadData() // reload all rows
tableView.reloadRows(at: [IndexPath(row: viewModel!.rowToFetch!, section: 0)], with: .none)
}
}
func shouldRefreshRow() -> Bool {
return self.viewModel?.businessesStore[viewModel!.rowToFetch!].previousPage == 1
}
And here's the TableView config:
func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 2
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
if let cell = tableView.dequeueReusableCell(withIdentifier: "TableViewCell", for: indexPath) as? BusinessesTableViewCell {
cell.configureCell(dataSourceDelegate: self, filterDelegate: self, forPath: indexPath, indexPathsToReload:
return cell
}
return UITableViewCell()
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
if(viewModel?.businessesStore[collectionView.tag].businesses.count ?? 0 > 0) {
return (viewModel?.businessesStore[collectionView.tag].total)!
}
return 0
}
In interface builder I have my table view leading, trailing and bottom constraints set to 0 with respect to the superview and top to 0 with respect to the view above the table view (the solid black one in the image above).
I'm fairly certain this is an interface builder issue because If I remove my bottom constraint and set my TableView height to something like 400, the view behaves properly when a filter is clicked. The catch is that the user has to be scrolled down to the bottom of the screen otherwise it behaves in the janky manner explained above.
Here's the layout:
Any ideas?

Answer 1

I was able to find a solution to this issue after quite a bit of persistence. I had two things wrong in my configuration.
1: When I was reloading data with this line of code tableView.reloadRows(at: [IndexPath(row: viewModel!.rowToFetch!, section: 0)], with: .none) it seems to be including some sort of bounce animation on the collection view. I replaced that with tableView.reloadData() which fixed most of the bounce that was occurring.
2: I increased the size of my table view rows which removed the rest of the bounce.