Injection Extensions for View Coding

UIKit+Injection.swift

extension UIViewController {
    @objc func injected() {
        for subview in self.view.subviews {
            subview.removeFromSuperview()
        }
        loadView()
        viewDidLoad()
    }
}

extension UIView {

    func findAndInject() {
        for window in UIApplication.shared.windows {
            if let rootViewController = window.rootViewController {
                for viewController in topViewController(from: rootViewController) {
                    print("View Controller: \(viewController)")
                    if contains(viewController.view, contains: self) {
                        print("View Controller: \(viewController) with view")
                        viewController.injected()
                    }
                }
            }
        }
    }


    @objc func injected() {
        findAndInject()
    }
}

func contains(_ view: UIView, contains target: UIView) -> Bool {
    if view == target {
        return true
    } else {
        for subview in view.subviews {
            if contains(subview, contains: target) {
                return true
            }
        }
    }

    return false
}

func topViewController(from rootViewController: UIViewController?, controllers: [UIViewController] = []) -> [UIViewController] {

    guard let rootViewController = rootViewController else { return controllers }

    var newControllers: [UIViewController] = []

    newControllers += [rootViewController]
    if let presented = rootViewController.presentedViewController {
        newControllers += [presented] + topViewController(from: presented)
    }

    if let nav = rootViewController as? UINavigationController {
        let viewControllers = nav.viewControllers.flatMap { topViewController(from: $0) }
        newControllers += viewControllers
    }

    let set: Set<UIViewController> = Set(controllers + newControllers)
    return Array(set)
}