Core Data Cheat Sheet for Swift iOS Developers

coreDataCheatSheet.swift

// Fetch entities

let fetchRequest = NSFetchRequest(entityName: "Note")
        
var sortDescriptor = NSSortDescriptor(key: "text", ascending: false)
fetchRequest.sortDescriptors = [sortDescriptor]

let predicate = NSPredicate(format: "MyEntityAttribute == %@", "Matching Value")
fetchRequest.predicate = predicate

fetchRequest.fetchLimit = 10

let fetchedResults = context.executeFetchRequest(fetchRequest, error: nil) as? [Note]
        
if let results = fetchedResults{
   println(results.description)
}




//NSFetchedResultsController 

lazy var fetchedResultsController : NSFetchedResultsController = {
    let context = CoreDataController.sharedCoreDataController.managedObjectContext!
    
    let fetchRequest = NSFetchRequest(entityName: "TimeTable")
    var sortDescriptor = NSSortDescriptor(key: "dateTime.timeStamp", ascending: true)
    fetchRequest.sortDescriptors = [sortDescriptor]
    
    NSFetchedResultsController.deleteCacheWithName("TimeTable")
    let frc = NSFetchedResultsController(fetchRequest: fetchRequest, managedObjectContext: context, sectionNameKeyPath: nil, cacheName: "TimeTable")
    frc.delegate = self
    
    return frc
}()

override func viewDidLoad() {
        super.viewDidLoad()
        
        fetchedResultController.performFetch(nil) //Executes the receiver’s fetch request.
}

fetchedResultController.objectAtIndexPath(indexPath) as? Note

let firstSection = fetchedResultsController.sections?.first as? NSFetchedResultsSectionInfo
irstSection.numberOfObjects



//Insert a new entity

var newNote = NSEntityDescription.insertNewObjectForEntityForName("Note", inManagedObjectContext: context) as! Note
//----
let dateTime = NSEntityDescription.insertNewObjectForEntityForName("DateTime", inManagedObjectContext: context) as! DateTime
dateTime.dateTime = 534634
let image = NSEntityDescription.insertNewObjectForEntityForName("Photos", inManagedObjectContext: context) as! Photos
image.photoFile = UIImageJPEGRepresentation(UIImage(named: "testImage")!, 1)
image.photoName = "testImage"
let coordinate = NSEntityDescription.insertNewObjectForEntityForName("Coordinate", inManagedObjectContext: context) as! Coordinate
coordinate.lat = 42.324535
coordinate.lng = 30.342532
coordinate.address = "test address"
//----
newNote.text = "test)"
newNote.dateTime = dateTime
newNote.photos = NSSet(object: image)
newNote.coordinate = coordinate
newNote.sent = false

context.save(nil)
context.reset()