UICollectionView w/ NSFetchedResultsController & NSBlockOperation. Idea originated from Blake Watters (https://github.com/AshFurrow/UICollectionView-NSFetchedResultsController/issues/13) Swift Version

gistfile1.swift

func controllerWillChangeContent(controller: NSFetchedResultsController) {
    self.shouldReloadCollectionView = false
    self.blockOperation = NSBlockOperation()
  }
  
  func controller(controller: NSFetchedResultsController, didChangeSection sectionInfo: NSFetchedResultsSectionInfo, atIndex sectionIndex: Int, forChangeType type: NSFetchedResultsChangeType) {
    let collectionView = self.collectionView
    switch type {
    case NSFetchedResultsChangeType.Insert:
      self.blockOperation.addExecutionBlock({
        collectionView.insertSections( NSIndexSet(index: sectionIndex) )
      })
    case NSFetchedResultsChangeType.Delete:
      self.blockOperation.addExecutionBlock({
        collectionView.deleteSections( NSIndexSet(index: sectionIndex) )
      })
    case NSFetchedResultsChangeType.Update:
      self.blockOperation.addExecutionBlock({
        collectionView.reloadSections( NSIndexSet(index: sectionIndex ) )
      })
    default:()
    }
  }
  
  func controller(controller: NSFetchedResultsController, didChangeObject anObject: AnyObject, atIndexPath indexPath: NSIndexPath?, forChangeType type: NSFetchedResultsChangeType, newIndexPath: NSIndexPath?) {
    let collectionView = self.collectionView
    switch type {
    case NSFetchedResultsChangeType.Insert:
      if collectionView.numberOfSections() > 0 {
        
        if collectionView.numberOfItemsInSection( newIndexPath!.section ) == 0 {
          self.shouldReloadCollectionView = true
        } else {
          self.blockOperation.addExecutionBlock({
            collectionView.insertItemsAtIndexPaths( [newIndexPath!] )
          })
        }

      } else {
        self.shouldReloadCollectionView = true
      }
      
    case NSFetchedResultsChangeType.Delete:
      if collectionView.numberOfItemsInSection( indexPath!.section ) == 1 {
        self.shouldReloadCollectionView = true
      } else {
        self.blockOperation.addExecutionBlock({
          collectionView.deleteItemsAtIndexPaths( [indexPath!] )
        })
      }
      
    case NSFetchedResultsChangeType.Update:
      self.blockOperation.addExecutionBlock({
        collectionView.reloadItemsAtIndexPaths( [indexPath!] )
      })
      
    case NSFetchedResultsChangeType.Move:
      self.blockOperation.addExecutionBlock({
        collectionView.moveItemAtIndexPath( indexPath!, toIndexPath: newIndexPath! )
      })
    default:()
    }
  }
  
  func controllerDidChangeContent(controller: NSFetchedResultsController) {
    // Checks if we should reload the collection view to fix a bug @ http://openradar.appspot.com/12954582
    if self.shouldReloadCollectionView {
      self.collectionView.reloadData()
    } else {
      self.collectionView.performBatchUpdates({
        self.blockOperation.start()
        }, completion: nil )
    }
  }

This is awesome.

I had to subclass NSBlockOperation to keep crashes out, though. Also seem to still be working out a few random issues.