alert_self.rb

class Alert
  def initialize(title, message, *buttons)
    #
    # Delegating to self.
    #
    @alert = UIAlertView.alloc.initWithTitle(title, message:message, delegate:self, cancelButtonTitle:"Cancel", otherButtonTitles:"OK", nil)
    @alert.show
    self
  end

  # Never gets called...
  def alertView(alertView, clickedButtonAtIndex:buttonIndex)
    NSLog "clickedButtonAtIndex(#{buttonIndex})"
  end
   
  # Never gets called...
  def alertView(alertView, didDismissWithButtonIndex:buttonIndex)
    NSLog "didDismissWithButtonIndex(#{buttonIndex})"
  end
end

alert_self_class.rb

class Alert
  def initialize(title, message, *buttons)
    #
    # Delegating to self.class.
    #
    @alert = UIAlertView.alloc.initWithTitle(title, message:message, delegate:self.class, cancelButtonTitle:"Cancel", otherButtonTitles:"OK", nil)
    @alert.show
    self
  end

  def self.alertView(alertView, clickedButtonAtIndex:buttonIndex)
    NSLog "clickedButtonAtIndex(#{buttonIndex})"
  end

  def self.alertView(alertView, didDismissWithButtonIndex:buttonIndex)
    NSLog "didDismissWithButtonIndex(#{buttonIndex})"
  end
end

app_delegate.rb

class AppDelegate
  def application(application, didFinishLaunchingWithOptions:launchOptions)
    alert = Alert.new("Title", "Message")
    NSLog "alert: #{alert.inspect}"
    true
  end
end