Changing data of UIPickerView Swift - swift

Question

I was searching very much, but i did not find an answer for my question.
My app should change the data of one picker after the other picker was changed.
As you can see, in the titleForRow method, I want to set the data and I also know that this method is just called once, but I just do not know where and also how I should do it then.
I think, on the didSelectRow method I could set the data, too, but there I do not have a gleam how I should do it.
Here is my code, I hope this is helpful.
class ViewController: UIViewController, UIPickerViewDelegate, UIPickerViewDataSource {
var x = 0
#IBOutlet weak var leaguePicker: UIPickerView!
#IBOutlet weak var clubPicker: UIPickerView!
let league = ["Bundesliga", "Premier League"]
let club = [["ManCity", "Arsenal"],["Bayern", "Dortmund"]]
override func viewDidLoad() {
super.viewDidLoad()
leaguePicker.delegate = self
leaguePicker.dataSource = self
clubPicker.delegate = self
clubPicker.dataSource = self
}
func numberOfComponents(in picker: UIPickerView) -> Int {
return 1
}
func pickerView(_ picker: UIPickerView, numberOfRowsInComponent component: Int) -> Int
{
switch (picker){
case leaguePicker:
return league.count
case clubPicker:
return club.count
default:
return 1
}
}
func pickerView(_ picker: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
switch (picker){
case leaguePicker:
return league[row]
case clubPicker:
if (x==0){
print("titleForRow call.. x=0")
return club[0][row]
// this is just happening at the beginning
} else {
print("titleForRow call.. x=1")
return club[1][row]
// this does not happen
}
default: return "an error occurred"
}
}
func pickerView(_ picker: UIPickerView, didSelectRow row: Int, inComponent component: Int)
{
if (picker == leaguePicker) {
if (row==0){
//clubPicker.selectRow(0, inComponent: 0, animated: true)
x=0
} else {
x=1 // this call is working
//clubPicker.selectRow(0, inComponent: 1, animated: true)
}
}
picker.reloadAllComponents()
//this does not lead to call titleForRow
}
}

Answer 1

You need to reload the 2nd picker when the value in the 1st picker changes.
func pickerView(_ picker: UIPickerView, didSelectRow row: Int, inComponent component: Int)
{
if (picker == leaguePicker) {
x = row
clubPicker.reloadAllComponents()
}
}
You also need to fix the numberOfRowsInComponent:
func pickerView(_ picker: UIPickerView, numberOfRowsInComponent component: Int) -> Int
{
switch (picker){
case leaguePicker:
return league.count
case clubPicker:
return club[x].count
default:
return 1
}
}
And your titleForRow can be simplified:
func pickerView(_ picker: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
switch (picker){
case leaguePicker:
return league[row]
case clubPicker:
return club[x][row]
default: return "an error occurred"
}
}
I also suggest you renamed your x variable to something more useful such as selectedLeague.