Populating UIPickerview values from CoreData in Swift - swift

Question

I am trying to populate a UIPicker with data that is stored in coreData. they way i have gone about this is i have set up a global variable array and when the screen loads a fetch request is sent to core data which populates the global array. The UIPicker then reads this global array and populates itself with its array of strings.
the problem is that the UIPicker populates fine the first time i load it, but then the second time i get the original entries repeated, and the 3rd time and 4th etc...
global array:
var savedWorkoutNamesPulled = [String]()
UIPicker set up:
//needed picker function (number of columns in picker view)
func numberOfComponents(in pickerView: UIPickerView) -> Int {
return 1
}
//needed picker function (number of rows in pickr view)
func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
savedWorkoutNamesPulled.count
}
func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
//setting exercisesInSelectedWorkout(exercise names within workout) to the elements of the uipicker
let row = savedWorkoutNamesPulled[row]
return row
}
Calling coredata function:
override func viewDidAppear(_ animated: Bool) {
//calling function that deals show picker
showUiPicker()
//going into core data swift file and calling a function (this function sets global array to fill workout names into picker view)
print("your workouts are as follows")
CoreDataManager.sharedInstance.retrieveWorkoutDataFromCoreData()
}
The core data function that appends values to global array:
func retrieveWorkoutDataFromCoreData() -> [Contact]{
let fetchRequest = NSFetchRequest<NSFetchRequestResult>(entityName: "ContactsData")
let result = try? context.fetch(fetchRequest)
var contacts = [Contact]()
for data in result as! [NSManagedObject]{
guard let id = data.value(forKey: "id") as? String else {continue}
guard let fullName = data.value(forKey: "fullName") as? String else {continue}
guard let excercise = data.value(forKey: "excersizes") as? [Exercise] else {continue}
var contact = Contact(id: id, fullname: fullName, exercises: excercise)
contact.id = id
contacts.append(contact)
print(fullName)
print(id)
savedWorkoutNamesPulled.append(fullName)
}
return contacts
}

Answer 1

I was able to fix it by just by setting the array to nothing when the view was dismissed.
override func viewDidDisappear(_ animated: Bool) {
savedWorkoutNamesPulled = []
}