NSFetchedResultsController Usage Pattern

NSFetchedResultsController_Example.swift

class GoalsViewController: UITableViewController, NSFetchedResultsControllerDelegate {
...
    let managedContext = (UIApplication.sharedApplication().delegate as AppDelegate).managedObjectContext
    var fetchedResultsController: NSFetchedResultsController = NSFetchedResultsController()
...
    func getFetchedResultsController() -> NSFetchedResultsController {
        fetchedResultsController = NSFetchedResultsController(fetchRequest: goalFetchRequest(), managedObjectContext: managedContext!, sectionNameKeyPath: nil, cacheName: nil)
        return fetchedResultsController
    }
    
    override func viewDidLoad() {
        super.viewDidLoad()

        fetchedResultsController = getFetchedResultsController()
        fetchedResultsController.delegate = self
        fetchedResultsController.performFetch(nil)
    }
    
    override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
        // Return the number of sections.
        return fetchedResultsController.sections!.count
    }

    override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        // #warning Incomplete method implementation.
        // Return the number of rows in the section.
        return fetchedResultsController.sections![section].numberOfObjects
    }

    override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
        let goal = fetchedResultsController.objectAtIndexPath(indexPath) as Goal
        ...
    }
    
    // Override to support editing the table view.
    override func tableView(tableView: UITableView, commitEditingStyle editingStyle: UITableViewCellEditingStyle, forRowAtIndexPath indexPath: NSIndexPath) {
        if editingStyle == .Delete {
            let managedObject:NSManagedObject = fetchedResultsController.objectAtIndexPath(indexPath) as NSManagedObject
            managedContext?.deleteObject(managedObject)
            managedContext?.save(nil)
        } else if editingStyle == .Insert {
            // Create a new instance of the appropriate class, insert it into the array, and add a new row to the table view
        }    
    }
...
}