How to correctly set a value from another class?

Question

Swift

class ViewController: NSViewController {
  @IBOutlet weak var foldersLbl: NSTextField!

func setVal() {
foldersLbl.stringValue = "some"
}
}
//srcVC.swift:
class srcVC: NSImageView {
let vc = ViewController()
//vc.foldersLbl.stringValue = "some"<- crash
//vc.setVal() <- crash
}

Answer 1

Before the window is displayed, the fields of your `NSViewController` are disabled.
What to do -- make changes from some callback, for example `viewDidLoad`.