Subclassing UIAlertView

Question

Am attempting to subclass UIAlertView to better handle error states in my app. The trouble am having is with the otherButtonTitles nil terminated parameter, when I

Answer 1

Instead of subclassing UIAlertView, I prefer to create simple classes that typically just have a show method that takes a delegate parameter. The delegate protocol then has expressive methods that correspond to the available options.

While this approach results in more delegate functions than the typical alert view delegate approach, I think it makes the code a lot more readable.

The code typically looks like this (Swift):

@objc protocol DeleteUniverseAlertViewDelegate {
    func deleteUniverseAlertViewDidConfirmDelete(view: DeleteUniverseAlertView)
}


class DeleteUniverseAlertView : NSObject, UIAlertViewDelegate {

    private weak var delegate: DeleteUniverseAlertViewDelegate? = nil

    class func showWithDelegate(delegate: DeleteUniverseAlertViewDelegate) -> DeleteUniverseAlertView {
        let view = DeleteUniverseAlertView()
        view.delegate = delegate
        UIAlertView(title: "Delete universe?", message: "Are you really, really sure about this?", delegate: view, cancelButtonTitle: "Cancel", otherButtonTitles: "Yes, delete!").show()
        return view
    }

    func alertView(alertView: UIAlertView, clickedButtonAtIndex buttonIndex: Int) {
        if (buttonIndex > 0) {
            delegate?.deleteUniverseAlertViewDidConfirmDelete(self)
        }
    }
}

When you then need to show this alert, just implement the protocol and show the custom alert like this (remember to keep a strong reference to the alert view):

deleteAlert = DeletePlaceAlertView.showWithDelegate(self)