UITableViewDiffableDataSource is not calling tableView(_:commit:forRowAt:)

Question

There is a UITableView that uses UITableViewDiffableDataSource. I subclassed UITableViewDiffableDataSource to add canEditRowAt. This correctly shows the swipeable delete action when gesturing the row. However, clicking the delete option does not call tableView(_:commit:forRowAt:). I have read that you have to use tableView(_:trailingSwipeActionsConfigurationForRowAt:indexPath:) because the other function is not supported. I wanted to confirm that was true. If we subclass tableView(_:commit:forRowAt:) as well, we need a clean way to call a function on the original View Controller.

// MyViewController
override func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCell.EditingStyle, forRowAt indexPath: IndexPath) {
    if editingStyle == .delete {
      // Delete cell
    }
}
// Subclass DiffableDataSource used in MyViewController
final class CustomDiffableDatasource: UITableViewDiffableDataSource<MyViewController.Section, MyViewController.Item> {
    override func tableView(_ tableView: UITableView, canEditRowAt indexPath: IndexPath) -> Bool {
        guard let item = itemIdentifier(for: indexPath) else {
            return false
        }
        return item.isEditable
    }
}

Answer 1

Here is the custom trailingSwipeActionsConfigurationForRowAtfunc looks like for adding a delete swipe. I saw this in another StackOverflow question that referenced a blog post.

    override func tableView(_ tableView: UITableView, trailingSwipeActionsConfigurationForRowAt indexPath: IndexPath) -> UISwipeActionsConfiguration? {
        guard self.dataSource?.tableView(tableView, canEditRowAt: indexPath) == true else {
            return nil
        }
        
        let delete = UIContextualAction(style: .destructive, title: "Delete") { [weak self] action, view, success in
            self?.remove(at: indexPath)
            success(true)
        }
        
        let swipeActionConfig = UISwipeActionsConfiguration(actions: [delete])
        swipeActionConfig.performsFirstActionWithFullSwipe = false
        
        return swipeActionConfig
    }