My UITabBarController has a method to switch to a tab of a certain View Controller type. The method takes a parameter for this VC type called newVC. Its type is UIViewController.Type. The method finds a tab with that type, and switches to it.
The method works fine when the newVC type is hard-coded inside the method. But when I put it as a variable, XCode complains that the newVC param isn't available inside the method.
For the love of god, why?
func animateToVC(_ newVC: UIViewController.Type){
guard let VCs = viewControllers else { return }
for (listIndex, vc) in VCs.enumerated(){
guard let navController = vc as? CustomNavBarController,
navController.rootViewController is newVC else { continue } --> "Cannot find type 'newVC' in scope"
animateToView(atTabIndex: listIndex)
selectedIndex = listIndex
}
}
CodePudding user response:
You cannot use a variable with the is
keyword in Swift for type checking. However, you can make the method generic and use the generic type parameter instead.
func animateToVC<ViewControllerType: UIViewController>(_ newVC: ViewControllerType.Type) {
guard let VCs = viewControllers else { return }
for (listIndex, vc) in VCs.enumerated(){
guard let navController = vc as? CustomNavBarController,
navController.rootViewController is ViewControllerType else { continue }
animateToView(atTabIndex: listIndex)
selectedIndex = listIndex
}
}