register_hook('TOOLBAR_DEFINE', 'AFTER', $this, 'handle_toolbar', array ()); } function handle_toolbar(&$event, $param) { $event->data[] = array ( 'type' => 'format', 'title' => 'Chem plugin', 'icon' => '../../plugins/chem/img/pl_chem.png', 'open' => '', 'close' => '', ); } }