public static function sprite_menu_icon_url($file, $fallback = true) {
$sprite_file = MPU::sprite_filename($file);
$sprite_url = self::menu_icon_url($sprite_file, false);
if ($sprite_url && $sprite_url != "") {
return $sprite_url;
}
if ($fallback) {
// if the sprite version doesn't exist, return the regular version
return self::menu_icon_url($file, $fallback);
}
}