php - 使用 EventSubscriber 将函数的返回值作为属性传递给 json

Question

我使用 JMS 序列化包构建了一个 api。此外，我有一个实体 Ticket，它有一个名为 TicketRepository 的存储库。该存储库包含以下方法:

/**
 * @param Ticket $object
 *
 * @return string
 */
public function findByTicketDeadline($object)
{
  // some logic
}

我的目标:使用EventSubscriber将此函数的返回值传递给json。

这是我的类(class)TicketSerializationSubscriber

 class TicketSerializationSubscriber implements EventSubscriberInterface
{


    /**
     * @param ObjectEvent $event
     */
    public function onPostSerialize(ObjectEvent $event)
    {
        /** @var JsonSerializationVisitor $visitor */
        $visitor = $event->getVisitor();
        $visitor->setData('ticketDeadline', 'TEST TICKET'); // WORKS

        /** @var Ticket $ticket */
        $ticket = $event->getObject();
        /** @var TicketRepository $ticketRepo */
        $ticketRepo = $event->getObject();

        $visitor->setData('TESTING', $ticketRepo->findByTicketDeadline($ticket));

//        $visitor->setData('uri',
//                $this->router->generate('ticket_api_show', [
//                    'ticketDeadline' => $ticketRepo->findByTicketDeadline($ticket)
//                ])
//        );

    }

    public static function getSubscribedEvents()
    {
        return array(
            array(
                'event' => 'serializer.post_serialize',
                'method' => 'onPostSerialize',
                'class' => 'CMS3\CoreBundle\Entity\Ticket', // if no class, subscribe to every serialization
                //'class' => 'CMS3\CoreBundle\Repository\TicketRepository', // if no class, subscribe to every serialization
                'format' => 'json', // optional format
                //'priority' => 0, // optional priority
            ),
        );
    }

}

当我将存储库方法传递给 $visitor->setData() 函数时，出现以下错误:

Answer 1

您当前的代码失败，因为 $ticketRepo = $event->getObject(); 返回上面行中的 Ticket 对象，而不是预期的 TicketRepository。

您需要将 EntityManager 或 Repository(如果您有存储库作为服务)注入(inject) TicketSerializationSubscriber::__construct()检索 TicketRepository。

假设您有 autowire为包含 TicketSerializationSubscriber 的目录启用。

use Doctrine\ORM\EntityManagerInterface;

class TicketSerializationSubscriber implements EventSubscriberInterface
{
    /**
     * @var \Doctrine\ORM\EntityManager
     */
    private $em;

    public function __construct(EntityManagerInterface $em)
    {
         $this->em = $em;
    }

    public function onPostSerialize(ObjectEvent $event)
    {
        /** @var JsonSerializationVisitor $visitor */
        $visitor = $event->getVisitor();

        $ticket = $event->getObject();
        if (!$ticket instanceof Ticket) {
            //ensure object is of expected type
            return;
        }

        /** @var TicketRepository $ticketRepo */
        $ticketRepo = $this->em->getRepository(Ticket::class);

        $visitor->setData('TESTING', $ticketRepo->findByTicketDeadline($ticket));
        //...
    }

    //...

}

如果不使用 autowire，您需要手动将其添加到 TicketSerializationSubscriber 服务声明参数中。

#app/config/services.yml

services:
    #...

    TicketSerializationSubscriber:
        public: false
        arguments: ['@doctrine.orm.entity_manager']
        tags:
            - { name: kernel.event_subscriber }
            #...

进行更改后，请务必清除并预热 Symfony 缓存。