Swift: Attaching instance variable to view controller

Question

if i have a ViewController, which has an instance ShowAlert. showAlert will show an alert controller, but is there any way the instance showAlert can know about who instantiated it? i.e. is there any way not to pass self to ShowAlert's instance variable viewController and instead infer it by parent or something similar? should i somehow be delegating this, instead?

class ViewController: UIViewController {
    var showAlert = ShowAlert()

    override viewDidLoad() {
        super.viewDidLoad()
        showAlert.viewController = self
        showAlert.now()
    }
}

class ShowAlert: NSObject {

    var viewController: UIViewController!

    func now() {
        let alert = UIAlertController(title: "Title", message: "Message", preferredStyle: .Alert)
        viewController.showViewController(alert, sender: self)
    }

}

thanks -

http://stackoverflow.com/questions/24594238/swift-how-to-pass-a-view-controllers-reference-to-a-sub-uiview-class — Shades, Mar 03 '16 at 01:24

score 1 · Accepted Answer · answered Mar 03 '16 at 01:23

sure instead of:

func now() {

do:

func now(parentVC : UIViewController ){
  let alert = UIAlertController(title: "Title", message: "Message", preferredStyle: .Alert)
    parentVC.showViewController(alert, sender: self)
}

and you can call it like:

showAlert.now(self)

Swift: Attaching instance variable to view controller

1 Answers1