Warning: Attempt to present * on * whose view is not in the window hierarchy - swift

Question

I\'m trying to present a ViewController if there is any saved data in the data model. But I get the following error:

Warning: A

Answer 1

All implementation for topViewController here are not fully supporting cases when you have UINavigationController or UITabBarController, for those two you need a bit different handling:

For UITabBarController and UINavigationController you need a different implementation.

Here is code I'm using to get topMostViewController:

protocol TopUIViewController {
    func topUIViewController() -> UIViewController?
}

extension UIWindow : TopUIViewController {
    func topUIViewController() -> UIViewController? {
        if let rootViewController = self.rootViewController {
            return self.recursiveTopUIViewController(from: rootViewController)
        }

        return nil
    }

    private func recursiveTopUIViewController(from: UIViewController?) -> UIViewController? {
        if let topVC = from?.topUIViewController() { return recursiveTopUIViewController(from: topVC) ?? from }
        return from
    }
}

extension UIViewController : TopUIViewController {
    @objc open func topUIViewController() -> UIViewController? {
        return self.presentedViewController
    }
}

extension UINavigationController {
    override open func topUIViewController() -> UIViewController? {
        return self.visibleViewController
    }
}

extension UITabBarController {
    override open func topUIViewController() -> UIViewController? {
        return self.selectedViewController ?? presentedViewController
    }
}