NSManagedObject Error - ios

Question

I have started learning core data in iOS now. I am currently getting fatal error: unexpectedly found nil while unwrapping an Optional value on the line of code below. I have been following lectures on youtube and few other places and had a look at their code too but failed to know the reason behind this error. If someone could provide me with an overview of it will be really helpful. Currently in my code I am just assigning values from entity, no fetching.
App Delegate:
lazy var applicationDocumentsDirectory: NSURL = {
// The directory the application uses to store the Core Data store file. This code uses a directory named "com.alakh.singh.okejhbs" in the application's documents Application Support directory.
let urls = NSFileManager.defaultManager().URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask)
return urls[urls.count-1]
}()
lazy var managedObjectModel: NSManagedObjectModel = {
// The managed object model for the application. This property is not optional. It is a fatal error for the application not to be able to find and load its model.
let modelURL = NSBundle.mainBundle().URLForResource("ActivityMonitor", withExtension: "momd")!
return NSManagedObjectModel(contentsOfURL: modelURL)!
}()
lazy var persistentStoreCoordinator: NSPersistentStoreCoordinator = {
// The persistent store coordinator for the application. This implementation creates and returns a coordinator, having added the store for the application to it. This property is optional since there are legitimate error conditions that could cause the creation of the store to fail.
// Create the coordinator and store
let coordinator = NSPersistentStoreCoordinator(managedObjectModel: self.managedObjectModel)
let url = self.applicationDocumentsDirectory.URLByAppendingPathComponent("SingleViewCoreData.sqlite")
var failureReason = "There was an error creating or loading the application's saved data."
do {
try coordinator.addPersistentStoreWithType(NSSQLiteStoreType, configuration: nil, URL: url, options: nil)
} catch {
// 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 as NSError
let wrappedError = NSError(domain: "YOUR_ERROR_DOMAIN", code: 9999, userInfo: dict)
// Replace this 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 \(wrappedError), \(wrappedError.userInfo)")
abort()
}
return coordinator
}()
lazy var managedObjectContext: NSManagedObjectContext = {
// Returns the managed object context for the application (which is already bound to the persistent store coordinator for the application.) This property is optional since there are legitimate error conditions that could cause the creation of the context to fail.
let coordinator = self.persistentStoreCoordinator
var managedObjectContext = NSManagedObjectContext(concurrencyType: .MainQueueConcurrencyType)
managedObjectContext.persistentStoreCoordinator = coordinator
return managedObjectContext
}()
// MARK: - Core Data Saving support
func saveContext () {
if managedObjectContext.hasChanges {
do {
try managedObjectContext.save()
} catch {
// 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.
let nserror = error as NSError
NSLog("Unresolved error \(nserror), \(nserror.userInfo)")
abort()
}
}
}
}
ViewController:
#IBAction func cofirmLogin(sender: UIButton) {
let oct = ((UIApplication.sharedApplication().delegate as? AppDelegate)?.managedObjectContext)
var userNameValue = NSEntityDescription.insertNewObjectForEntityForName("LoginInformation", inManagedObjectContext: oct!) as! LoginInformation
userNameValue.loginUserName = loginUserName.text!
userNameValue.loginPin = Int(loginPin.text!)!
userNameValue = loginInfo
saveContext(oct!)
}
func saveContext (context : NSManagedObjectContext) {
if context.hasChanges {
do {
try context.save()
} catch {
let nserror = error as NSError
NSLog("Unresolved error \(nserror), \(nserror.userInfo)")
}
}
}
}

Answer 1

Maybe something is not working as expected with the lazy variable. You could refactor your managed object context like this.
var managedObjectContext: NSManagedObjectContext {
get {
if _managedObjectContext == nil {
let coordinator = self.persistentStoreCoordinator
let moc = NSManagedObjectContext(concurrencyType: .MainQueueConcurrencyType)
moc.persistentStoreCoordinator = coordinator
_managedObjectContext = moc
}
return _managedObjectContext!
}
}
var _rootContext: NSManagedObjectContext?
Also, make sure that the app delegate is returned as expected (perhaps break this up into several lines and check in the debugger).