Refreshing UIPicker from user input - swift

Question

I am new to Xcode/Swift and working on an assignment for which I need some help. I have a simple program that displays a list of names when started. I want to take a new name, from the UITextField, and add it to the data for the picker after the item that is currently selected. The new added name should be shown in the picker as the selected item (so the previously selected item would be immediately above it on the picker’s display at that point). I have the program working thus far, however, my "picker.reloadAllComponents()" function seems to be breaking something. When I leave this in place, none of the data in the picker is being shown. When I remove it, I don't know if my insertButton action is working. Where can I refresh the picker data such that the picker data is being seen in my simulator? Thanks.
import UIKit
class ViewController: UIViewController,
UIPickerViewDelegate, UIPickerViewDataSource {
var characterNames = [
"Luke", "Leia", "Han", "Chewbacca", "Artoo",
"Threepio", "Lando"]
#IBOutlet weak var userInput: UITextField!
#IBOutlet weak var picker: UIPickerView!
#IBAction func selectButton(_ sender: UIButton) {
let row = picker.selectedRow(inComponent: 0)
let selected = characterNames[row]
let title = "You selected \(selected)!"
let alert = UIAlertController(
title: title,
message: "Thank you for choosing",
preferredStyle: .alert)
let action = UIAlertAction(
title: "You're welcome",
style: .default,
handler: nil)
alert.addAction(action)
present(alert, animated: true, completion: nil)
}
#IBAction func insertButton(_ sender: UIButton) {
characterNames.insert(userInput.text!, at: picker.selectedRow(inComponent: 0))
}
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
// MARK:-
// MARK: Picker Data Source Methods
func numberOfComponents(in pickerView: UIPickerView) -> Int {
return 1
}
func pickerView(_ pickerView: UIPickerView,
numberOfRowsInComponent component: Int) -> Int {
return characterNames.count
}
// MARK: Picker Delegate Methods
func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
picker.reloadAllComponents()
return characterNames[row]
}
}

Answer 1

Don't call picker.reloadAllComponents() from within the titleRorRow method as I think this may be invoking an infinite loop - this delegate method should return the title for that row only, as your second line is doing correctly. So remove it from there.
Instead, place it in your insertButton method after you have updated the source. This will cause the data to be reloaded, and the data source methods called again to repopulate the picker.
func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
return characterNames[row]
}
#IBAction func insertButton(_ sender: UIButton) {
characterNames.insert(userInput.text!, at: picker.selectedRow(inComponent: 0))
picker.reloadAllComponents()
}