Unable to load class warning? - ios

Question

I am making a sprite kit game and need to save three integers: currentLevel, maxLevelReached and highScore. I would also like to implement those to iCloud, but thats another step for me, first I want to figure out the problems I have right now. Basically, I am trying to use core data to store those. In my app delegate I added the following (basically I created new project and copied core data code)
// MARK: - Core Data stack
lazy var applicationDocumentsDirectory: NSURL = {
let urls = NSFileManager.defaultManager().URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask)
return urls[urls.count-1] as! NSURL
}()
lazy var managedObjectModel: NSManagedObjectModel = {
let modelURL = NSBundle.mainBundle().URLForResource("GameState", withExtension: "momd")!
return NSManagedObjectModel(contentsOfURL: modelURL)!
}()
lazy var persistentStoreCoordinator: NSPersistentStoreCoordinator? = {
var coordinator: NSPersistentStoreCoordinator? = NSPersistentStoreCoordinator(managedObjectModel: self.managedObjectModel)
let url = self.applicationDocumentsDirectory.URLByAppendingPathComponent("APPNAME.sqlite")
var error: NSError? = nil
var failureReason = "There was an error creating or loading the application's saved data."
if coordinator!.addPersistentStoreWithType(NSSQLiteStoreType, configuration: nil, URL: url, options: nil, error: &error) == nil {
coordinator = nil
// Report any error we got.
var dict = [String: AnyObject]()
dict[NSLocalizedDescriptionKey] = "Failed to initialize the application's saved data"
dict[NSLocalizedFailureReasonErrorKey] = failureReason
dict[NSUnderlyingErrorKey] = error
error = NSError(domain: "YOUR_ERROR_DOMAIN", code: 9999, userInfo: dict)
NSLog("Unresolved error \(error), \(error!.userInfo)")
abort()
}
return coordinator
}()
lazy var managedObjectContext: NSManagedObjectContext? = {
let coordinator = self.persistentStoreCoordinator
if coordinator == nil {
return nil
}
var managedObjectContext = NSManagedObjectContext()
managedObjectContext.persistentStoreCoordinator = coordinator
return managedObjectContext
}()
// MARK: - Core Data Saving support
func saveContext () {
if let moc = self.managedObjectContext {
var error: NSError? = nil
if moc.hasChanges && !moc.save(&error) {
// Replace this implementation with code to handle the error appropriately.
// abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
NSLog("Unresolved error \(error), \(error!.userInfo)")
abort()
}
}
}
when I did that, I created my data model (File->new->CoreData->Data model) and named it GameState. I then created the entity called CurrentLevel and added attribute of type Int16 and name currentLevel. I made the entity of class Appname.CurrentLevel. Then, in my game scene I added the following properties:
var currentLevel = [NSManagedObject]()
var levelToShow: Int16!
And created these two functions to handle core data stuff.
//Handling the fetching from the CoreData
func fetchTheStuff() {
//1
let appDelegate =
UIApplication.sharedApplication().delegate as! AppDelegate
let managedContext = appDelegate.managedObjectContext!
//2
let fetchRequest = NSFetchRequest(entityName:"CurrentLevel")
//3
var error: NSError?
let fetchedResults =
managedContext.executeFetchRequest(fetchRequest,
error: &error) as? [NSManagedObject]
if let results = fetchedResults {
currentLevel = results
println(currentLevel)
} else {
println("Could not fetch \(error), \(error!.userInfo)")
}
}
//Handling the saving
func saveCurrentLevel(cLevel: Int16){
let appDelegate =
UIApplication.sharedApplication().delegate as! AppDelegate
let managedContext = appDelegate.managedObjectContext!
let entity = NSEntityDescription.entityForName("CurrentLevel",
inManagedObjectContext:
managedContext)
let curLevel = NSManagedObject(entity: entity!,
insertIntoManagedObjectContext:managedContext)
curLevel.setValue(name, forKey: "currentLevel")
var error: NSError?
if !managedContext.save(&error) {
println("Could not save \(error), \(error?.userInfo)")
}
}
As you can see the fetch function is still in testing stage (I am simply printing the results). If I fetch it the first time I use the app, it gives me an empty string, as it should be. However, If I try to save a number using save function and then fetch the stuff, the log screen gives me the following warning:
CoreData: warning: Unable to load class named 'appname.CurrentLevel' for entity 'CurrentLevel'. Class not found, using default NSManagedObject instead.
Knowing the function I want to achieve, seeing the method I (try) to use, does anyone know how to solve my problem?
P.S. Also, it seems that this whole core data stuff is quite complicated, I have a hard time grasping how exactly it works even though I read a quite a lot about it. So if anyone has a suggestion on decreasing the complexity to achieve the same result (hence, not using any of the functionality) , tips are more than welcome.

Answer 1

Answer to the initial question
Please make sure, to generate the correct classes for your Coredata Model, highlighting your entities and then chosing Editor -> Create NSObject subclass