Class in closure delegate pattern for UIAlertView

gistfile1.txt

/*
Idea for this comes from https://gist.github.com/austinzheng/8fda3f61e1fd06383928#file-main-swift-L19

In an iOS 7.x supporting app which can't use UIAlertController, rather than fork execution paths based on iOS version, we could wire up an old fashioned UIAlertView this way. Still feels more 'block' based and clean to handle, since all the UIAlertViewDelegate stuff is contained within the 'nested-class-in-closure'.
*/

class SampleViewController: UIViewController {
    var askTheUserSomethingAlert: UIAlertView
    var strongAlertDelegate: UIAlertViewDelegate?
    
    required init(coder aDecoder: NSCoder) {
        askTheUserSomethingAlert = UIAlertView()
        super.init()
        setup()
    }
    
    func setup() {
        strongAlertDelegate = {
            [weak self] in
            class AnonymousAlertDelegate: NSObject, UIAlertViewDelegate {
                var parent: SampleViewController?
                
                private func alertView(alertView: UIAlertView, clickedButtonAtIndex buttonIndex: Int) {
                    parent?.handleAlertViewButtonTap(forIndex: buttonIndex)
                }
            }
            let anonymousDelegate = AnonymousAlertDelegate()
            anonymousDelegate.parent = self
            return anonymousDelegate
        }()
        askTheUserSomethingAlert.delegate = strongAlertDelegate
    }
    
    func handleAlertViewButtonTap(forIndex index: Int) {
        //do things here
    }
}