UIAlerView with Swift closures

AlertView.swift

//
//  AlertView.swift
//

import UIKit


// holding array so the AlertView objects don't go out of scope
internal var alerts = [AlertView]()


// simple structure to hold button name and its closure
struct AlertViewButton {
    var title : String
    var action: () -> Void
}


// the alert view class

class AlertView: NSObject, UIAlertViewDelegate {
    
    var title : String!
    var message: String!
    var cancelButton : AlertViewButton!
    var otherButtons = [AlertViewButton]()

    
    init(title: String, message: String, cancelButtonTitle: String, cancelButtonAction: () -> Void) {
        super.init()
        self.title = title
        self.message = message
        self.cancelButton = AlertViewButton(title: cancelButtonTitle, action: cancelButtonAction)
    }
    
    func addButtonWithTitle(title: String, action: () -> Void) -> Void {
        let button = AlertViewButton(title: title, action: action)
        otherButtons.append(button)
    }
    
    
    func show() {
        let alertView = UIAlertView(title: self.title, message: self.message, delegate: self, cancelButtonTitle: self.cancelButton.title)
        for button in otherButtons {
            alertView.addButtonWithTitle(button.title)
        }
        // add to holding array; otherwise the object is released & delegate method never gets called
        alerts.append(self)
        alertView.show()
    }
    
    
    // UIAlertViewDelegate
    
    func alertView(alertView: UIAlertView, clickedButtonAtIndex buttonIndex: Int) {
        if buttonIndex == 0 {
            cancelButton.action()
            return
        }
        if otherButtons.count <= buttonIndex {
            let button = otherButtons[buttonIndex - 1]
            button.action()
        }
        
        // remove from holding array
        if let index = alerts.indexOf(self) {
            alerts.removeAtIndex(index)
        }
    }
    
}