在doctrine2中使用事务性方法进行显式事务处理

我尝试使用EntityManager::transactional(function($em) {});方法实现简单的表单处理。看起来很简单，但问题是:我如何将附加值传递给这样的实现?确切地说，我想做以下操作

$em  = $this->getServiceLocator()->get('Doctrine'ORM'EntityManager');
$request = $this->getRequest();
$form = new BugForm();
$form->get('reporter')->setValueOptions(
    $em->getRepository('Application'Entity'Person')->getPersonListArray()
);
$form->get('engineer')->setValueOptions(
    $em->getRepository('Application'Entity'Person')->getPersonListArray()
);
$form->get('products')->setValueOptions(
    $em->getRepository('Application'Entity'Product')->getProductListArray()
);
$confirmation = "";
if($request->isPost()) {
    $em->transactional(function($em) {
        $form = new BugForm();
        $request = $this->getRequest();
        $form->setData($request->getPost());
        if($form->isValid()) {
            $form = new BugForm();
            $hydrator = new DoctrineHydrator($em);
            $data = $form->getData();
            $data['created'] = time();
            $data['status'] = 'OPEN';
            $bug = $hydrator->hydrate($data, new Bug());
            $em->persist($bug);
            $em->flush();
            $confirmation = "Created bug with ID ".$bug->getId()."<br/>";
        }
    });
}
return array(
    'form'         => $form,
    'confirmation' => $confirmation
);

问题是匿名函数中的this->getRequest()调用不创建数据，因此我无法填充BugForm对象。当然，我可以在这里使用超全局_POST数组但它似乎不对。