Swift and CoreData, problems with relationship (NSSet) - [NSSet intersectsSet:]: set argument is not an NSSet

Question

I\'ve been trying to get my head around adding objects in relationships using CoreData and Swift. I am at a loss, I do not understand why my code does not work. I am trying to a

Answer 1

Yesss!! I found the answer!

I had created a new function in the class Events.swift (the other side of the relationship).

I had written the following code:

import Foundation
import CoreData

class Event: NSManagedObject {

    @NSManaged var timeStamp: NSDate
    @NSManaged var teams: NSSet

}

extension Event {

    func addTeamToEvent(team:Teams) {
        var teamz = self.mutableSetValueForKey("teams")
        teamz.addObject(team)
    }

    func getNumberOfTeams() -> Int {
        return self.teams.count;
    }

    func getTeams() -> [Teams] {
        var tmpsak: [Teams]
        tmpsak = self.teams.allObjects as [Teams]
        tmpsak = self.teams.allObjects as [Teams]

        return tmpsak
    }

}

which I thought was unrelated. However, renaming getTeams to getTeamsAsArray removed the problem. I am guessing that CoreData, when filling in the other end of the relationship, uses a built-in function called getTeams() (since the other class was called Teams). I accidentally overrode(?) it, causing it to fail.

Thank you for your suggestions, and I hope this can be helpful to someone else!

On a somewhat related note, a bug with similar symptoms was identified a few years ago (and appears to still be present), that shows itself in auto-generated code when using ordered many-to-many relationships.