16

我在我的 Zend 项目中使用 Doctrine 2 ORM，并且在几种情况下需要将我的实体序列化为 JSON。

ATM 我使用 Querybuilder 并加入我需要的所有表。但是我的序列化程序导致学说延迟加载每个关联的实体，这会导致大量数据并引发递归。

现在我正在寻找一种完全禁用 Doctrine 延迟加载行为的方法。

我选择数据的方法如下：

$qb= $this->_em->createQueryBuilder()
            ->from("\Project\Entity\Personappointment", 'pa')
            ->select('pa', 't', 'c', 'a', 'aps', 'apt', 'p')
            ->leftjoin('pa.table', 't')
            ->leftjoin('pa.company', 'c')
            ->leftjoin('pa.appointment', 'a')
            ->leftjoin('a.appointmentstatus', 'aps')
            ->leftjoin('a.appointmenttype', 'apt')
            ->leftjoin('a.person','p')

我希望我的结果集只包含选定的表和关联。

任何帮助将不胜感激。

4

5 回答 5

12

在最新版的JMSSerializer中，你该看的地方是

JMS\Serializer\EventDispatcher\Subscriber\DoctrineProxySubscriber

代替

Serializer\Handler\DoctrineProxyHandler

要覆盖默认的延迟加载行为，应该定义自己的事件订阅者。

在你app/config.yml添加这个：

parameters:
    ...
    jms_serializer.doctrine_proxy_subscriber.class: Your\Bundle\Event\DoctrineProxySubscriber

您可以将类从 JMS\Serializer\EventDispatcher\Subscriber\DoctrineProxySubscriber 复制到 Your\Bundle\Event\DoctrineProxySubscriber 并注释掉 $object->__load(); 线

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

    // If the set type name is not an actual class, but a faked type for which a custom handler exists, we do not
    // modify it with this subscriber. Also, we forgo autoloading here as an instance of this type is already created,
    // so it must be loaded if its a real class.
    $virtualType = ! class_exists($type['name'], false);

    if ($object instanceof PersistentCollection) {
        if ( ! $virtualType) {
            $event->setType('ArrayCollection');
        }

        return;
    }

    if ( ! $object instanceof Proxy && ! $object instanceof ORMProxy) {
        return;
    }

     //$object->__load(); Just comment this out

    if ( ! $virtualType) {
        $event->setType(get_parent_class($object));
    }
}
于 2013-05-29T01:19:51.527 回答
9

在 Doctrine 中寻找答案后，我的团队发现 JMS 序列化器是“问题”。它自动触发了 Doctrine Proxies 的使用。我们为 JMS Serializer 编写了一个补丁来避免延迟加载。

我们实现了自己的DoctrineProxyHandler，它不会触发 Doctrine 延迟加载机制，并将其注册到我们的 SerializationHandlers 数组中。

class DoctrineProxyHandler implements SerializationHandlerInterface {

public function serialize(VisitorInterface $visitor, $data, $type, &$handled)
{
    if (($data instanceof Proxy || $data instanceof ORMProxy) && (!$data->__isInitialized__ || get_class($data) === $type)) {
        $handled = true;

        if (!$data->__isInitialized__) {

            //don't trigger doctrine lazy loading
            //$data->__load();

            return null;
        }

        $navigator = $visitor->getNavigator();
        $navigator->detachObject($data);

        // pass the parent class not to load the metadata for the proxy class
        return $navigator->accept($data, get_parent_class($data), $visitor);
    }

    return null;
}

现在我可以简单地选择我的表，加入我需要的关联——我的 JSON 将只包含我选择的数据，而不是无限深度的关联和递归 :)

$qb= $this->_em->createQueryBuilder()
        ->from("\Project\Entity\Personappointment", 'pa')
        ->select('pa', 't', 'c', 'a')
        ->leftjoin('pa.table', 't')
        ->leftjoin('pa.company', 'c')
        ->leftjoin('pa.appointment', 'a')

JSON将只包含

{  
  Personappointment: { table {fields}, company {fields}, appointment {fields}}
  Personappointment: { table {fields}, company {fields}, appointment {fields}}
  Personappointment: { table {fields}, company {fields}, appointment {fields}}
  .
  .
}
于 2012-07-27T07:01:16.317 回答
4

这很可能被称为丑陋的拐杖，但您可以只选择（）您真正需要的数据，然后使用 Query 对象的 getArrayResult() 方法将结果水合到一个数组中......

于 2012-07-23T19:31:17.940 回答
3

使用 Doctrine 的查询构建器时，您不能禁用链接模型类的延迟加载。如果你想绕过这种行为，你最好用 Doctrine 的 DBAL 请求数据。

不要使用\Doctrine\ORM\QueryBuilder但是\Doctrine\DBAL\Query\QueryBuilder。

$qb = new QueryBuilder($this->_em->getConnection());
$expr = $qb->expr();

$qb->select('pa.*', 't.*', 'c.*', 'a.*', 'aps.*', 'apt.*', 'p.*')
   ->from('person_appointment', 'pa')
   ->leftJoin('pa', 'table', 't', $expr->eq('pa.table_id', 't.table_id'))
   // put other joints here
   // ...
   ->leftjoin('a', 'person', 'p', $expr->eq('a.person_id', 'p.person_id'));
于 2012-07-23T09:23:21.057 回答
1

如果您希望务实地使用您的或默认订阅者，

@DavidLin 回答：

您可以将类从 JMS\Serializer\EventDispatcher\Subscriber\DoctrineProxySubscriber 复制到 Your\Bundle\Event\DoctrineProxySubscriber 并注释掉 $object->__load(); 线

<?php

/*
 * Copyright 2013 Johannes M. Schmitt <schmittjoh@gmail.com>
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

namespace Your\Bundle\Event;

use Doctrine\ORM\PersistentCollection;
use Doctrine\ODM\MongoDB\PersistentCollection as MongoDBPersistentCollection;
use Doctrine\ODM\PHPCR\PersistentCollection as PHPCRPersistentCollection;
use Doctrine\Common\Persistence\Proxy;
use Doctrine\ORM\Proxy\Proxy as ORMProxy;
use JMS\Serializer\EventDispatcher\PreSerializeEvent;
use JMS\Serializer\EventDispatcher\EventSubscriberInterface;

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

        // If the set type name is not an actual class, but a faked type for which a custom handler exists, we do not
        // modify it with this subscriber. Also, we forgo autoloading here as an instance of this type is already created,
        // so it must be loaded if its a real class.
        $virtualType = ! class_exists($type['name'], false);

        if ($object instanceof PersistentCollection
            || $object instanceof MongoDBPersistentCollection
            || $object instanceof PHPCRPersistentCollection
        ) {
            if ( ! $virtualType) {
                $event->setType('ArrayCollection');
            }

            return;
        }

        if ( ! $object instanceof Proxy && ! $object instanceof ORMProxy) {
            return;
        }


        //Avoiding doctrine lazy load proxyes
        //$object->__load();

        if ( ! $virtualType) {
            $event->setType(get_parent_class($object));
        }
    }

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

并像这样初始化序列化：

$serializer = JMS\Serializer\SerializerBuilder::create()
    //remove this to use lazy loading 
    ->configureListeners(function(JMS\Serializer\EventDispatcher\EventDispatcher $dispatcher) {
        $dispatcher->addSubscriber(new Your\Bundle\Event\AvoidDoctrineProxySubscriber());
    })  
    // !remove this to use lazy loading 
    ->build();

//and serialize the data with/without Lazy

serializer->serialize($data, 'json');
于 2016-10-10T19:44:27.857 回答