UIBarbuttonitem selector never gets triggered (Swift 3) - ios

Question

Sometimes the simplest things prove the hardest to work out! The picker is displayed when users select the user location text field but the selectors are not working. Gone through SO and Apple docs but can't work out why this is.
let locationPicker = UIPickerView()
var locationData = [String]()
override func viewDidLoad() {
super.viewDidLoad()
// Set textfield delegate
userID.delegate = self
userLocation.delegate = self
// Set up picker view for location selection
locationPicker.frame = CGRect(x:0, y: self.view.bounds.height, width: self.view.bounds.width, height: 140)
locationPicker.showsSelectionIndicator = true
let doneButton = UIBarButtonItem(title: "done", style: .plain, target: self, action: #selector(self.closePicker(sender:)))
let spaceButton = UIBarButtonItem(barButtonSystemItem: UIBarButtonSystemItem.flexibleSpace, target: nil, action: nil)
let cancelButton = UIBarButtonItem(title: "cancel", style: .plain, target: self, action: #selector(self.closePicker(sender:)))
let toolBar = UIToolbar()
toolBar.barStyle = UIBarStyle.blackOpaque
toolBar.isTranslucent = true
toolBar.setItems([cancelButton, spaceButton, doneButton], animated: false)
toolBar.isUserInteractionEnabled = true
userLocation.inputView = locationPicker
userLocation.inputAccessoryView = toolBar
// Load locations into array
let ref: FIRDatabaseReference = FIRDatabase.database().reference().child("venues")
ref.observe(.value, with: { snapshot in
// Pull out the keys to represent locations
if let snapshots = snapshot.children.allObjects as? [FIRDataSnapshot] {
for snap in snapshots {
print("snap key, \(snap.key) and snap value \(snap.value)")
let loc : String = snap.key
self.locationData.append(loc)
}
}
// Now stick the array of locations into the picker view
self.locationPicker.dataSource = self
self.locationPicker.delegate = self
self.locationPicker.reloadAllComponents()
})
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func textFieldShouldReturn(_ textField: UITextField) -> Bool {
textField.endEditing(true)
return false
}
func closePicker(sender: AnyObject) {
print("Close picker")
self.locationPicker.isHidden = true
}
func textFieldDidBeginEditing(_ textField: UITextField) {
if let iText = userID.text, let lText = userLocation.text, !iText.isEmpty, !lText.isEmpty
{
print("We have data")
// loginButton.isUserInteractionEnabled = true
// loginButton.alpha = 1.0
}
}
func numberOfComponents(in pickerView: UIPickerView) -> Int {
return 1
}
func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
return locationData.count
}
func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
return locationData[row]
}
func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
userLocation.text = locationData[row]
}