How to do some stuff in viewDidAppear only once?

Question

I want to check the pasteboard and show an alert if it contains specific values when the view appears. I can place the code into viewDidLoad to ensure it\'s onl

Answer 1

By reading other comments (and based on @rmaddy 's answer), I know this is not what OP asked for, but for those who come here because of title of the question:

extension UIViewController {
    var isPresentingForFirstTime: Bool {
        return isBeingPresented() || isMovingToParentViewController()
    }
}

UPDATE

You should use this method in viewDidAppear and viewWillAppear. (thanks to @rmaddy)

UPDATE 2

This method only works with modally presented view controllers and pushed view controllers. it's not working with a childViewController. using didMoveToParentViewController would be better with childViewControllers.