symfony - Doctrine 2 : disable lazy loading/proxy generation.

Question

使用 Doctrine 2，是否有可能:

从生成的代理类中排除属性？

完全禁用延迟加载/代理生成？

我在序列化我的实体时遇到问题(使用 Symfony 和 JMS Serializer)。我只想序列化我在查询中明确获取的关联实体。

f.e. 中描述的解决方案Disable Doctrine 2 lazy loading when using JMS Serializer?只是部分工作。当您拥有虚拟属性(property)时:

use Doctrine\ORM\Mapping as ORM;
use JMS\Serializer\Annotation as Serializer;

/**
 * Profile
 *
 * @ORM\Table(name="profile")
 * @ORM\Entity
 */
class Profile
{
    // ...

    /**
     * @return string
     *
     * @Serializer\VirtualProperty()
     */
    public function getLabel()
    {
        return implode(' ', [$this->firstname, $this->lastname]) . " ({$this->email})";
    }
}

关联的类在序列化过程中仍然通过代理加载。

Answer 1

这是迄今为止我想出的最好的解决方案来解决上述问题。它不涉及更改 JMSSerializer 代码。完整代码在此 Gist 中:
https://gist.github.com/Jaap-van-Hengstum/0d400ea4f986d8f8a044

诀窍是创建一个空的“假”类:

namespace MyApp\ApiBundle\Serializer;

class SerializerProxyType
{
  // this class is supposed to be empty
}

并在自定义 DoctrineProxySubscriber ，将事件类型设置为该类。这样 JMSSerializer 将使用该类型进行注释处理，因此在遇到类似 @VirtualProperty 的注释时不会触发 Doctrine 代理。 .

class DoctrineProxySubscriber implements EventSubscriberInterface
{
    public function onPreSerialize(PreSerializeEvent $event)
    {
        $object = $event->getObject();
        $type = $event->getType();

        ...
        // This line is commented, so proxy loading on serializing is disabled
        // $object->__load();

        if ( ! $virtualType) {
            // This line is commented because a different type is used
            // $event->setType(get_parent_class($object));

            // This assumes that every Doctrine entity has a single 'Id' primary
            // key field.
            $event->setType('MyApp\ApiBundle\Serializer\SerializerProxyType',
                ["id" => $object->getId()]);
        }
    }

    public static function getSubscribedEvents()
    {
        return array(
            array('event' => 'serializer.pre_serialize', 'method' => 'onPreSerialize'),
        );
    }
}

然后您可以使用 JMSSerializer 处理程序为空类添加自定义处理程序。这个处理程序只会在序列化的 json/xml 中包含实体的 ID:

class DoctrineProxyHandler implements SubscribingHandlerInterface
{
    /**
     * {@inheritdoc}
     */
    public static function getSubscribingMethods()
    {
        $methods = [];

        foreach (array('json', 'xml') as $format)
        {
            $methods[] = [
                'direction' => GraphNavigator::DIRECTION_SERIALIZATION,
                'format' => $format,
                'type' => 'MyApp\\ApiBundle\\Serializer\\SerializerProxyType',
                'method' => 'serializeTo' . ucfirst($format),
            ];
        }

        return $methods;
    }

    public function serializeToJson(VisitorInterface $visitor, $entity, array $type, Context $context)
    {
        $object = new \stdClass();
        $object->id = $type['params']['id'];

        return $object;
    }

    public function serializeToXml(XmlSerializationVisitor $visitor, $entity, array $type, Context $context)
    {
        $visitor->getCurrentNode()->appendChild(
            $node = $visitor->getDocument()->createElement('id', $type['params']['id'])
        );

        return $node;
    }
}

要配置 Symfony 以使用这些类:

parameters:
    jms_serializer.doctrine_proxy_subscriber.class: MyApp\ApiBundle\Serializer\DoctrineProxySubscriber

services:
  doctrineproxy_handler:
    class: MyApp\ApiBundle\Serializer\DoctrineProxyHandler
    tags:
        - { name: jms_serializer.subscribing_handler }