One-to-Many Relationship in Swift Core Data - swift

Question

I'm building a journal app where you create a FocusArea object, which then contains 30 journal Entry objects.
So I created a one-to-many relationship in my data model.
Then I implemented two NSManagedObject Classes:
#objc(FocusArea)
class FocusArea: NSManagedObject {
#NSManaged var focusName: String
#NSManaged var focusStart: NSDate
#NSManaged var focusEnd: NSDate
#NSManaged var completeFlag: Bool
//#NSManaged var entries: NSSet
var entries: NSMutableOrderedSet {
return self.mutableOrderedSetValueForKey("entries")
}
}
#objc(Entry)
class Entry: NSManagedObject {
#NSManaged var entryJournal: String
#NSManaged var entryDate: NSDate
#NSManaged var completeFlag: Bool
#NSManaged var entryStatus: Bool
#NSManaged var focus: FocusArea
}
I'm able to add a FocusArea with no problems, but when I try to create 30 Entry objects and store in FocusArea.entries, everything keeps crashing.
What's the correct way to add multiple Entry objects to the FocusArea object?
Am I way off here?
#IBAction func saveFocusArea(sender: AnyObject) {
if txtFocusName.text != nil {
let appDel: AppDelegate = UIApplication.sharedApplication().delegate as! AppDelegate
let context: NSManagedObjectContext = appDel.managedObjectContext!
//create new focus area
let entFocus = NSEntityDescription.entityForName("FocusArea", inManagedObjectContext: context)
let newFocus = FocusArea(entity:entFocus!, insertIntoManagedObjectContext: context)
newFocus.focusName = txtFocusName.text!
newFocus.focusStart = NSDate()
newFocus.focusEnd = NSDate().dateByAddingTimeInterval(60*60*24*30)
newFocus.completeFlag = false
//initialize 30 new entries into core data
let entEntry = NSEntityDescription.entityForName("Entry", inManagedObjectContext: context)
for var i = 0; i < 30; i++ {
let newEntry = Entry(entity:entEntry!, insertIntoManagedObjectContext: context)
let c = Double(i)
newEntry.entryDate = NSDate().dateByAddingTimeInterval(60*60*24*c)
newEntry.entryJournal = ""
newEntry.entryStatus = false
newEntry.completeFlag = false
//THIS IS THE PROBLEM AREA
newFocus.entries.append(newEntry)
}
do {
try context.save()
} catch {
print("There's a problem!")
}
}
}

Answer 1

I figured it out. All I had to do was:
newEntry.focus = newFocus.
So instead of setting the relationship between the parent to the child, set it from the child to the parent.