Load more activity cell CollectionViewCell - ios

Question

I'm trying to create a activityCell, so when the user reach the button it will show an cell with an activity indicator. This seem to work fine however if moreDataAvailable is false it should remove this cell. However i keep getting following error?
'NSInternalInconsistencyException', reason: 'attempt to delete item 0 from section 1 which only contains 0 items before the update'
numberOfItemsInSection
override func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int
{
if section == 0 {
return organizationArray.count
} else {
if self.moreDataAvailable == true {
return 1
} else {
return 0
}
}
}
Hide Collection Cell
func hideCollectionViewFooter() {
self.collectionView!.deleteItemsAtIndexPaths([NSIndexPath(forRow: 0, inSection: 1)])
}
numberOfSectionsInCollectionView
override func numberOfSectionsInCollectionView(collectionView: UICollectionView) -> Int {
return 2
}
cellForItemAtIndexPath
override func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
if indexPath.section == 0 {
let cell = collectionView.dequeueReusableCellWithReuseIdentifier("OrganizationCell", forIndexPath: indexPath) as! OrganizationCollectionViewCell
cell.customerLabel?.text = organizationArray[indexPath.item].name.uppercaseString
cache.fetch(key: organizationArray[indexPath.item].coverPhoto).onSuccess { data in
cell.customerImageView?.image = UIImage(data: data)
}
return cell
} else {
let cell = collectionView.dequeueReusableCellWithReuseIdentifier("ActivityCell", forIndexPath: indexPath) as UICollectionViewCell
return cell
}
}
Load More when reach bottom
override func collectionView(collectionView: UICollectionView, willDisplayCell cell: UICollectionViewCell, forItemAtIndexPath indexPath: NSIndexPath) {
if !loadingData && indexPath.item == organizationArray.count - 1 && self.moreDataAvailable {
self.loadingData = true
proposeAccess(false, success: {
self.loadingData = false
})
}
}
Update Organization and check if more data is available
func updateOrganizations(refresh: Bool) {
let realm = try! Realm()
GetOrganization.request(String(self.lastLoadedPage), limit: String(limit), location: self.lastLocation!, radius: String(100), refresh: refresh,
success: { numberOfResults in
//Sort by distance
self.organizationArray = GetOrganization.sortOrganizationsByDistanceFromLocation(realm.objects(Organization), location: self.lastLocation!)
self.lastLoadedPage = self.lastLoadedPage + 1
if numberOfResults < self.limit {
//Hide FooterView
self.moreDataAvailable = false
self.hideCollectionViewFooter()
}
}, error: {
self.organizationArray = GetOrganization.sortOrganizationsByDistanceFromLocation(realm.objects(Organization), location: self.lastLocation!)
print("error")
})
}

Answer 1

This error means that you're trying to delete cell that not existed in current table view state. Probably moreDataAvailable already was false before request in updateOrganizations was finished.
I would recommend you using table footer view for displaying activity indicator. Also, after data is loaded you can display a number of loaded items.