How to show an alert from another class in Swift?

Question

I have a main class, AddFriendsController, that runs the following line of code:

ErrorReporting.showMessage(\"Error\", msg: \"Could not add student          


        

Answer 1

Swift 3 version of Maksym Musiienko's answer would be the following:

extension UIApplication {

    static func topViewController(base: UIViewController? = UIApplication.shared.delegate?.window??.rootViewController) -> UIViewController? {

        if let nav = base as? UINavigationController {
            return topViewController(base: nav.visibleViewController)
        }

        if let tab = base as? UITabBarController, let selected = tab.selectedViewController {
            return topViewController(base: selected)
        }

        if let presented = base?.presentedViewController {
            return topViewController(base: presented)
        }

        return base
    }
}