ArrayControllerBugFixed.swift

import Cocoa

class ArrayControllerBugFixed: NSArrayController {
    override func awakeFromNib() {
        super.awakeFromNib()
        
        NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("coreDataEntityDidChange:"), name: NSManagedObjectContextObjectsDidChangeNotification, object: self.managedObjectContext)
    }
    
    func coreDataEntityDidChange(notification: NSNotification) {
        if self.sortDescriptors?.count > 0 {
            if let userInfo = notification.userInfo {
                let insertedEntityNames = userInfo[NSInsertedObjectsKey]?.valueForKeyPath("entity.name") as? NSSet ?? NSSet()
                let updatedEntityNames = userInfo[NSUpdatedObjectsKey]?.valueForKeyPath("entity.name") as? NSSet ?? NSSet()
                let deletedEntityNames = userInfo[NSDeletedObjectsKey]?.valueForKeyPath("entity.name") as? NSSet ?? NSSet()

                if let entityName = self.entityName {
                    if insertedEntityNames.containsObject(entityName) || updatedEntityNames.containsObject(entityName) || deletedEntityNames.containsObject(entityName) {
                        self.rearrangeObjects()
                    }
                }
            }
        }
    }
}