public function handleGetChildren($parent)
{
$this->setDataSource(call_user_func($this->tree_view_children_callback, $parent));
if ($this->getPresenter()->isAjax()) {
$this->getPresenter()->payload->_datagrid_url = $this->refresh_url;
$this->getPresenter()->payload->_datagrid_tree = $parent;
$this->redrawControl('items');
$this->onRedraw();
} else {
$this->getPresenter()->redirect('this');
}
}