Swift - Present UIAlertController in extension function - swift

Question

I've wrote a label extension which detect links in the label.
It's attributed text with NSLinkAttributeName for links and I'm using
func handleTapOnLabel(_ tapGesture:UITapGestureRecognizer){} to detect where is the tap and which link to choose to open. The problem is that I use the function in extension for UILabel and I want to present an UIAlertController to ask the person - "You are about to open this link in Safari. Would you like to proceed?"... So I can't access viewcontroller to use the function present(UIAlertController... to display the alert. Any suggestions how this can be happened in extension? How to access label's viewcontroller directly from extension ?

Answer 1

Method 1) Present UIAlertController on top most ViewController in ViewController's hierarchy
extension UILabel { //your extension
func openLinkAction() { //your extension custom method
//code
if var topController = UIApplication.sharedApplication().keyWindow?.rootViewController {
while let presentedViewController = topController.presentedViewController {
topController = presentedViewController
}
}
// topController should now be your topmost view controller
// present alert on this controller
}
//and present here with vcInstance
}
}
Method 2) Pass ViewController's object as parameter
extension UILabel { //your extension
func openLink(vc: UIViewController) { //your extension custom method function
// code
// present alert on this vc
}
}
// For getting top most controller you ca use..
extension UIApplication {
class func topViewController(controller: UIViewController? = UIApplication.shared.keyWindow?.rootViewController) -> UIViewController? {
if let navigationController = controller as? UINavigationController {
return topViewController(controller: navigationController.visibleViewController)
}
if let tabController = controller as? UITabBarController {
if let selected = tabController.selectedViewController {
return topViewController(controller: selected)
}
}
if let presented = controller?.presentedViewController {
return topViewController(controller: presented)
}
return controller
}
}
// topController
if let topController = UIApplication.topViewController() {
}