two arrays from NSFetchedResultsController swift

Question

I have a table that is populated using data from CoreData and NSFetchedResultsController. It populates two sections using one attribute having a boolean value. But I want to have the data in each section into two arrays for further processing.

Is there a way to save the data in the two sections generated by the Fetched Results Controller into separate arrays.

i tried to create two predicates using the attribute value used to create the sections using the code:

var context = (UIApplication.sharedApplication().delegate as! AppDelegate).managedObjectContext!
var frc: NSFetchedResultsController = NSFetchedResultsController()
    func getFetchedResultsController() -> NSFetchedResultsController {
    frc = NSFetchedResultsController(
        fetchRequest: fetchRequest(),
        managedObjectContext: context,
        sectionNameKeyPath: "frequent",
        cacheName: nil)
    return frc
}
//Fetch request of done Items to populate the two sections (Frequent and nonFrequent)
func fetchRequest() -> NSFetchRequest {
    let fetchRequest = NSFetchRequest(entityName: "Item")
    let frequentSortDescriptor = NSSortDescriptor(key: "frequent", ascending: false)
    let nameSortDescriptor = NSSortDescriptor(key: "name", ascending: true)
    let predicate = NSPredicate(format: "done == %@", true)
    fetchRequest.predicate = predicate
    fetchRequest.sortDescriptors = [frequentSortDescriptor, nameSortDescriptor]
    return fetchRequest
}

override func viewDidLoad() {
    super.viewDidLoad()

    frc = getFetchedResultsController()
    frc.delegate = self
    frc.performFetch(nil)

    frc.fetchRequest.predicate = NSPredicate(format: "frequent == %@", true)
    if let freqResults = frc.fetchedObjects as? [Item] {
        freq = freqResults
    }

    frc.fetchRequest.predicate = NSPredicate(format: "frequent == %@", false)
    if let nonFreqResults = frc.fetchedObjects as? [Item] {
        nonFreq = nonFreqResults
    }
    println("\(freq.count) Fav and \(nonFreq.count) Non Fav")
}

But the 'println()' at the end prints the two arrays as having 10 counts each. But in reality, 'freq.count' should have 7 and 'nonFreq.count' should have 3 items in them, for the total of 10 items in the two sections combined.

The sections display the correct items. I just can not save those items into arrays.

Is it possible that since the first 'fetchRequst()' has a predicate applied to it already and I'm trying to apply a second predicate on it or what? If that's the case, how can I resolve it?

Answer 1

You have to call performFetch() before the fetched results controllers's fetchedObjects will change.

Instead, you might just use a filter.

let frequent =   fetchedObjects.filter() {   $0.frequent }
let infrequent = fetchedObjects.filter() {  !$0.frequent }