CollectionView2.swift

/*code snippet shows how we can delete items from collection view without reloading it
the below function is attcahed as selector to a button embedded in collection view cell*/
func removeItem(sender : UIButton){
        if let collectionViewCell = sender.superview?.superview as? UICollectionViewCell{
            if let indexPath = self.docsCollectionView.indexPathForCell(collectionViewCell){
                self.items.removeAtIndex(indexPath.row)
                self.collectionView.deleteItemsAtIndexPaths([indexPath])
            }
        }
    }