NavBar Button doesn't work when being clicked - swift

Question

I'm trying to implement a button to my navbar which should call the function addTap.
Unfortunately though, when I click the add button in the simulator, nothing happens. I put a print statement in the addTap function but I doesn't get called, meaning the function never gets called.
Have any ideas?
class ViewController: UIViewController {
var names : [String] = []
let TableView = UITableView() // view
var addButton: UIBarButtonItem = UIBarButtonItem(title: "Add", style: .done, target: self, action: #selector(addTap))
override func loadView() {
super.loadView()
setupComponents()
setupTableView()
}
func setupComponents() {
self.title = "Core Data"
self.navigationItem.rightBarButtonItem = self.addButton
}
func setupTableView() {
view.addSubview(TableView)
TableView.translatesAutoresizingMaskIntoConstraints = false
TableView.topAnchor.constraint(equalTo: view.topAnchor).isActive = true
TableView.leftAnchor.constraint(equalTo: view.leftAnchor).isActive = true
TableView.bottomAnchor.constraint(equalTo: view.bottomAnchor).isActive = true
TableView.rightAnchor.constraint(equalTo: view.rightAnchor).isActive = true
}
#objc func addTap() {
print("reached")
let alert = UIAlertController(title: "New Friend", message: "Add the name of your friend", preferredStyle: .alert)
let saveAction = UIAlertAction(title: "Add Now", style: .default) { [unowned self] action in
guard let textField = alert.textFields?.first, let nameToSave = textField.text else { return }
self.names.append(nameToSave)
self.TableView.reloadData()
}
let cancelAction = UIAlertAction(title: "Cancel", style: .cancel)
alert.addTextField()
alert.addAction(saveAction)
alert.addAction(cancelAction)
present(alert, animated: true)
}
}

Answer 1

Your issue is with the construction of your UIBarButtonItem. You are trying to access self before self exists.
If you construct it like this you will find that it works.
func setupComponents() {
self.title = "Core Data"
let addButton: UIBarButtonItem = UIBarButtonItem(title: "Add", style: .done, target: self, action: #selector(addTap))
self.navigationItem.rightBarButtonItem = addButton
}
Or if you need access to the button instance you can create the UIBarButtonItem lazily and replace the declaration in your class with the following:
lazy var addButton: UIBarButtonItem = {
UIBarButtonItem(title: "Add", style: .done, target: self, action: #selector(addTap))
}()