NSSet and Core Data - swift

Question

I am trying to save two lists of objects in core data. I have a protocol method which adds my tags as (Tag) and puts them into an array of tags. I am not able to save these objects as I am using an NSSet and the extension (for swift) as:
extension CurrentTransaction {
func addTagObject(value:Tag) {
var items = self.mutableSetValueForKey("tagMembers");
items.addObject(value)
}
func removeTagObject(value:Tag) {
var items = self.mutableSetValueForKey("tagMembers");
items.removeObject(value)
}
}
The two objects from core data I am trying to save are:
class Pic: NSManagedObject {
#NSManaged var picName: String!
#NSManaged var picNumber: String!
#NSManaged var currentTransaction: CurrentTransaction
class func createInManagedObjectContext(moc: NSManagedObjectContext, name: String, number: String) -> Pic {
let newPic = NSEntityDescription.insertNewObjectForEntityForName("Pic", inManagedObjectContext: moc) as! Pic
newPic.picName = name
newPic.picNumber = number
return newPic
}
}
class Tag:
class Tag: NSManagedObject {
#NSManaged var tagName: String!
#NSManaged var tagNumber: String!
#NSManaged var currentTransaction: CurrentTransaction
class func createInManagedObjectContext(moc: NSManagedObjectContext, name: String, number: String) -> Tag {
let newTag = NSEntityDescription.insertNewObjectForEntityForName("Tag", inManagedObjectContext: moc) as! Tag
newTag.tagName = name
newTag.tagNumber = number
return newTag
}
}
class currentTransaction:
class CurrentTransaction: NSManagedObject {
#NSManaged var destinationPIC: String
#NSManaged var sourcePIC: String
#NSManaged var nvdNumber: String
#NSManaged var numberOfAnimals: NSNumber
#NSManaged var requestType: String
#NSManaged var date: NSDate
#NSManaged var tagMembers: NSSet
#NSManaged var picMembers: NSSet?
class func createInManagedObjectContext(moc: NSManagedObjectContext, toPic: String, fromPic: String, nvd: String, numAnimals: NSNumber, request: String, date: NSDate, tags: NSSet, pics: NSSet) -> CurrentTransaction {
let newTransaction = NSEntityDescription.insertNewObjectForEntityForName("CurrentTransaction", inManagedObjectContext: moc) as! CurrentTransaction
newTransaction.destinationPIC = toPic
newTransaction.sourcePIC = fromPic
newTransaction.nvdNumber = nvd
newTransaction.numberOfAnimals = numAnimals
newTransaction.requestType = request
newTransaction.tagMembers = tags
newTransaction.picMembers = pics
newTransaction.date = date
return newTransaction
}
}
When I call the CurrentTransaction.addTagObject(tag:Tag) I get "Cannot invoke 'addTagObject' with an argument list of type '(Tag)'
Here is my addTags protocol method:
func addTags(tag: Tag) {
//println("IN ADD TAGS")
//println(tag.tagNumber)
self.tagList.append(tag)
CurrentTransaction.addTagObject(tag) //Error on this line
}

Answer 1

Reason: addTagObject() is not defined as class function and cannot be invoked on class CurrentTransaction. If you intended to use it as class fucntion, change it to:
class func addTagObject(value:Tag) {
var items = self.mutableSetValueForKey("tagMembers");
items.addObject(value)
}