Custom image for MKAnnotationView in RubyMotion

beer_map_controller.rb

  ViewIdentifier = 'ViewIdentifier'
  def mapView(mapView, viewForAnnotation:beer)
    if view = mapView.dequeueReusableAnnotationViewWithIdentifier(ViewIdentifier)
      view.annotation = beer
    else
      view = MKAnnotationView.alloc.initWithAnnotation(beer, reuseIdentifier:ViewIdentifier)
      view.image = UIImage.imageNamed('signpost.png')
      view.canShowCallout = true
#      view.animatesDrop = true
      button = UIButton.buttonWithType(UIButtonTypeDetailDisclosure)
      button.addTarget(self, action: :'showDetails:', forControlEvents:UIControlEventTouchUpInside)
      view.rightCalloutAccessoryView = button
    end
    view
  end