Crash on Delete

[grifas]

In my project, I'm getting a crash when I try to delete an item. So I tried with your example with my configuration which is having number of section equals to emails.count and just one row in each section corresponding to the item. Of course I changed indexPath.row by indexPath.section in the right place.

It is possible to delete a row in a section and if it's the last row, delete in the same time the section ?

[Mijail]

It crashes because the action fulfill calls self.delegate?.swipeController(self, didDeleteSwipeableAt: indexPath)
and that delegate does this:
tableView?.deleteRows(at: [indexPath], with: .none)
And it doesn't delete the section if it is the last row of it, so yes there should be a check if the element is the last one of the section.

[kurabi]

@Mijail Please submit a PR.

[Mijail]

I can't do it right now, but I think this issue should be open. I will work on it when I can.

[kurabi]

I don’t see this crash occurring in the example mail app. So I am not clear on what the issue is.

[Mijail]

If I recall the example only has 1 section, the way to test it is having more than one. (numberOfSections(in tableView: UITableView) )

[kurabi]

@Mijail I tried that. Didn't work either.

[weakfl]

I've got the same issue:

• collectionview with 2 sections
• deleting last item in section 0 -> crashes in SwipeCollectionViewCell.swift, line 238:

    func swipeController(_ controller: SwipeController, didDeleteSwipeableAt indexPath: IndexPath) {
        collectionView?.deleteItems(at: [indexPath])
    }

*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** -[__NSDictionaryM setObject:forKey:]: key cannot be nil'

[kurabi]

@weakfl Thats not your issue.

[weakfl]

@kurabi Does it matter?

FWIW, it's an iOS bug anyway. I was able to work around the issue by using fulfill(with: .reset) and using collectionView.reloadData() instead of collectionView.performBatchUpdates if I'm dealing with the last item in the section...

[weakfl]

I didn't really like the collectionView.reloadData() solution because of the missing animation, so I've debugged this a little further.

It turns out the crash is triggered by returning CGSize.zero for a supplementary view during deletion. Returning CGSize(width: collectionView.bounds.size.width, height: CGFloat.leastNonzeroMagnitude) is a better workaround for the issue, as it will allow to run performBatchUpdates without problems.

@kurabi So it's definetely not an issue of SwipeCellKit (which is is a wonderful library btw).

[APvanGrootel]

Hi. I think the crash happens when didDeleteSwipeableAt is calling deleteRows when there is only one row inside a section. When this is the case, it should call deleteSections

[dbogatz]

@weakfl thanks for support. But where should I add CGSize(width: collectionView.bounds.size.width, height: CGFloat.leastNonzeroMagnitude)?
Wouldn't it better if the library adds a check for last row?

[weakfl]

@dbogatz

But where should I add CGSize(width: collectionView.bounds.size.width, height: CGFloat.leastNonzeroMagnitude)?

Depends on your layout. If you're using UICollectionViewFlowLayout for example, you'll have to return this as referenceSizeForHeaderInSection.

Wouldn't it better if the library adds a check for last row?

That's debatable ;) See @APvanGrootel's comment.