核心数据子类ManagedObject的多对多关系addObject无法正常工作

Question

I have two subclass of ManagedObject as below

which is one-to-many relationship between them.

In order to add definition to word, I implement the func below:

func addDefinition(definition: MODefinition) {

    self.mutableSetValueForKey("definitions").addObject(definition)

}

But when I run the function, it crashed and show message below:

'NSInvalidArgumentException', reason: '*** -[NSSet initWithArray:range:copyItems:]: array argument is not an NSArray'

I also try to assign word to definition like : definition.word = word

But it appear the same crash message.

However, I can assign NSSet to word.definitons like this:

let definitionSet = NSSet(array: definitions)
    word.definitions = definitionSet

But this method will not let me append object...

Also, my other managedObject can use this kind of function self.mutableSetValueForKey to addObject. So I don't know where did it go wrong.

EDIT:

I'm trying to removeObject :

func removeDefinition(definition: MODefinition) {

    let muSet = self.mutableSetValueForKey("definitions")
    muSet.removeObject(definition)

}

And It shows

Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSSingleObjectSetI objectAtIndex:]: unrecognized selector sent to instance

I'd trying to implement on other objects, but only this object can't work.

What should I check for this problem, I'm really stuck now.

EDIT2 :

I add the new relationship to test if the problem is due to the relationship.

So, I added the test relationship.

And.... It work...

Although, I still don't know the reason, I can run normally now.

Answer 1

i'm also new to ios.hope this will help you.

make NSManaged in Moword class. like:

@NSManaged var word: NSSet?

and then make NSMutableSet object

let wordMutableSet = NSMutableSet()

and every time create new object of MoDefination

let entity =  NSEntityDescription.entityForName("MoDeination", inManagedObjectContext: Utilities.getAppManagedContext())

let obj = MoDefination(entity: entity!, insertIntoManagedObjectContext: Utilities.getAppManagedContext())

wordMutableSet.addObject(obj)

and add it now in Moword object Moword entity1 = NSEntityDescription.entityForName("Moword", inManagedObjectContext: Utilities.getAppManagedContext())

let obj = Moword(entity: entity!, insertIntoManagedObjectContext: Utilities.getAppManagedContext())
obj?.scores = wordMutableSet