Trouble calling NSFetchedResultsControllerDelegate methods - ios

Question

I've managed to create my UICollectionViewController with swift, and implement the NSFetchedResultsController and fetch stuff from my CoreData model. All good there... But...
I can't seem to call any of the NSFetchedResultsControllerDelegate methods from within my extension. Code is as follows:
extension MainsViewController: NSFetchedResultsControllerDelegate {
func fetchedResultsController() -> NSFetchedResultsController {
// if(fetchedResultsController != nil){
// return fetchedResultsController()
// }
var fetchRequest = NSFetchRequest()
var context: NSManagedObjectContext = RKObjectManager.sharedManager().managedObjectStore.mainQueueManagedObjectContext
var entity = NSEntityDescription.entityForName("Dessert", inManagedObjectContext: context)
fetchRequest.entity = entity
fetchRequest.fetchBatchSize = 20
var sortDescriptor = NSSortDescriptor(key: "createdAt", ascending: false)
let sortDescriptors = [sortDescriptor]
fetchRequest.sortDescriptors = sortDescriptors
fetchedResultsController().delegate = self
var aFetchedResultsController = NSFetchedResultsController(fetchRequest: fetchRequest, managedObjectContext: context, sectionNameKeyPath: nil, cacheName: "Master")
var error: NSError?
if !aFetchedResultsController.performFetch(&error){
println("An error:\(error) occured.")
}
return aFetchedResultsController
}
//Here is where i would call *#optional func controllerWillChangeContent(_ controller: NSFetchedResultsController!)* etc. etc.
}
But swift doesnt recognise theese methods. I can't figure out what it is I am missing.
Would be great if someone could help me out.
Thanks in advance
Chris

Answer 1

I think it should something like this:
var fetchedResultsController: NSFetchedResultsController {
get {
var fetchRequest = NSFetchRequest()
var context: NSManagedObjectContext = RKObjectManager.sharedManager().managedObjectStore.mainQueueManagedObjectContext
var entity = NSEntityDescription.entityForName("Dessert", inManagedObjectContext: context)
fetchRequest.entity = entity
fetchRequest.fetchBatchSize = 20
var sortDescriptor = NSSortDescriptor(key: "createdAt", ascending: false)
let sortDescriptors = [sortDescriptor]
fetchRequest.sortDescriptors = sortDescriptors
self.fetchedResultsController.delegate = self
var aFetchedResultsController = NSFetchedResultsController(fetchRequest: fetchRequest, managedObjectContext: context, sectionNameKeyPath: nil, cacheName: "Master")
var error: NSError?
if !aFetchedResultsController.performFetch(&error){
println("An error:\(error) occured.")
}
return aFetchedResultsController
}
}
So your MainsViewController is a class, as I said in the comment above, so the first line has to look like this:
class MainsViewController: UIViewController, NSFetchedResultsControllerDelegate {
Unfortunatly I cannot test the code, but this can be understood like this: You have a property called fetchedResultsController and this will execute, when the fetchedResultsController is getting. So in the getter like you would do it in objective-c with a lazy getting method.

Answer 2

I found out that it was simply the auto complete feature that wasn't suggesting the method to me. Typing it out manually 'fixed' the issue. Sorry for wasting everybody's time...
Chris