Sure you can.
Layout response object has method 'setLayoutVariable'. One of accepted variables is 'submenu'. If you supply an array of Ip\Menu\Item objects, a submenu will be generated. Here is an example. Put it in Plugin\Application\Event.php file:
<?php
namespace Plugin\Application;
class Event
{
public static function ipBeforeController()
{
if (true) { //find out some kind of a condition when you want a submenu. (eg. ipRequest()->getControllerClass() == 'Plugin\XXX\AdminController')
$submenu = array();
$submenuItem = new \Ip\Menu\Item();
$submenuItem->setTitle('Test');
$submenuItem->setUrl('http://www.example.com');
$submenu[] = $submenuItem;
if (is_object(ipResponse()) && method_exists(ipResponse(), 'setLayoutVariable')) {
ipResponse()->setLayoutVariable('submenu', $submenu);
}
}
}
}
You can filter main menu too using filter. Add following code to Plugin\Application\Filter.php file:
<?php
namespace Plugin\Application;
class Filter {
/**
* @param \Ip\Menu\Item[] $menu
* @param $info
*/
public static function ipAdminMenu ($menu, $info)
{
//modify $menu
return $menu;
}
}