[Help] NSInternalInconsistencyException on Embedded/Nested Section

[bernaferrari]

Hi! This is probably not related to IGListKit in the way "there is something wrong with the library", but in "I can't figure out this, and it is related to it, please help".

I thought it was a great idea to have a nested/embedded section controller, but I want to do operations inside them and between them. For example, in an attendance app example, I would like to tap the user in the top section (if you download the app and run, you will understand) and it goes to the second section; or if the user is in the second section, when tapping it goes to the first. Deleting or renaming is also allowed.

The problem is.. I have no idea how to do this with the current structure I have. EVERYTHING I try I get a "NSInternalInconsistencyException.. expected 3, but found 2" kind of thing. My structure is currently an array of ListDiffable's inside a ListDiffable. I'm not even doing a "move", only trying to remove before add anything and it is not working.

I tried a collectionContext?.performBatch inside the SectionController, tried to remove items from an array, like self.presence?.items.removeAll(), tried to make a forEach() on data[Any], get the value I want, then perform the operation.. But I'm missing something (and probably not hard, but I don't know what). The self.adapter.performUpdates(..) is always there, so I'm not sure what it is..

BTW, if it is Ryan reading this, check my viewDidLayoutSubviews+viewWillTransition inside CollectionParent; it was the best solution for IGListKit rotation I've found to date. Might help your other apps.

NSInternalInconsistencyException.zip

[weyert]

Yes, if you are not using IGListCollectionLayout you could use something like below to invalidate the layout. I have had some issues myself with invalidating the layout after rotation only until now I have been unable to set breakpoints in IGListKit from inside my problematic app for some reason.

        let layout = collectionView.collectionViewLayout
        layout.invalidateLayout()
        coordinator.animate(alongsideTransition: { _ in
            self.adapter.performUpdates(animated: true, completion: nil)
            layout.invalidateLayout(with: layout.invalidationContext(forBoundsChange: CGRect(x: 0, y: 0, width: size.width, height: size.height)))
        })

I am curious the code of #976 might help with your query somehow?

[bernaferrari]

I thought it was implemented yet, I'm going to use different sections for everything for now.. Thanks!
In 3.2.0, if I have any issue with it, I warn you. Thanks!