Question

我有这个实体：

<?php

namespace Comakai\MyBundle\Entity;

use Doctrine\ORM\Mapping as ORM,
    Symfony\Component\Validator\Constraints as Assert;

/**
 * @ORM\Entity
 */
class Stuff {

    /**
     * @ORM\Id
     * @ORM\Column(type="integer")
     * @ORM\GeneratedValue(strategy="IDENTITY")
     */
    private $id;

    /**
     * @ORM\Column(type="text")
     * @Assert\NotBlank()
     */
    private $content;

    /**
     * @ORM\ManyToMany(targetEntity="Apple", cascade={"persist"})
     */
    private $apples;

    /**
     * @ORM\ManyToMany(targetEntity="Pig")
     */
    private $pigs;

    public function __construct() {
        $this->apples = new \Doctrine\Common\Collections\ArrayCollection();
        $this->pigs = new \Doctrine\Common\Collections\ArrayCollection();
    }

    public function setApples($apples) {

        $this->getApples()->clear();

        foreach ($apples as $apple) {

            $this->addApple($apple);
        }
    }

    public function setPigs($pigs) {

        $this->getPigs()->clear();

        foreach ($pigs as $pig) {

            $this->addPig($pig);
        }
    }

    /**
     * Get id
     *
     * @return integer 
     */
    public function getId() {
        return $this->id;
    }

    /**
     * Set content
     *
     * @param text $content
     */
    public function setContent($content) {
        $this->content = $content;
    }

    /**
     * Get content
     *
     * @return text 
     */
    public function getContent() {
        return $this->content;
    }

    /**
     * Add apples
     *
     * @param Comakai\MyBundle\Entity\Apple $apples
     */
    public function addApple(\Comakai\MyBundle\Entity\Apple $apples) {
        $this->apples[] = $apples;
    }

    /**
     * Get apples
     *
     * @return Doctrine\Common\Collections\Collection 
     */
    public function getApples() {
        return $this->apples;
    }


    /**
    * Add pigs
    *
    * @param Comakai\MyBundle\Entity\Pig $pigs
    */
    public function addPig(\Comakai\MyBundle\Entity\Pig $pigs) {
        $this->pigs[] = $pigs;
    }

    /**
    * Get pigs
    *
    * @return Doctrine\Common\Collections\Collection 
    */
    public function getPigs() {
        return $this->pigs;
    }
}

和这个听众：

<?php

namespace Comakai\MyBundle\Listener;

use Comakai\MyBundle\Util\SluggerParser
    Doctrine\ORM\Event\OnFlushEventArgs,
    Comakai\MyBundle\Entity\Stuff,
    Comakai\MyBundle\Entity\Apple,
    Comakai\MyBundle\Entity\Pig;

class Listener {

    /**
     * @param \Doctrine\ORM\Event\OnFlushEventArgs $ea
     */
    public function onFlush(OnFlushEventArgs $ea) {

        $em = $ea->getEntityManager();
        $uow = $em->getUnitOfWork();

        foreach ($uow->getScheduledEntityInsertions() AS $entity) {

            $this->save($entity, $em, $uow);

        }

        foreach ($uow->getScheduledEntityUpdates() AS $entity) {

            $this->save($entity, $em, $uow);

        }
    }

    public function save($entity, $em, $uow) {

        if ($entity instanceof Stuff) {

            $pigRepository = $em->getRepository('Comakai\MyBundle\Entity\Pig');
            $content = $entity->getContent();

            preg_match_all('/@@ pig:(\d+) @@/i', $content, $matches);
            $entity->getPigs()->clear();

            foreach($matches[1] as $pigID) {

                $pig = $pigRepository->find($pigID);

                if(!empty($pig)) {

                    $entity->addPig($pig);

                }

            }

            $entity->setContent($content);

            $meta = $em->getClassMetadata(get_class($entity));
            $uow->recomputeSingleEntityChangeSet($meta, $entity);
            $uow->computeChangeSet($meta, $entity);

        }
    }

}

如果apple的集合是空的，它可以正常工作，但如果它有一些项目，我会收到重复错误。

我如何告诉UnitOfWork我只想重新计算猪的收藏品？

更新

有一个新的preFlush事件（https://github.com/doctrine/doctrine2/pull/169），我认为这种事情可以在那里完成。 PR不在我正在使用的分支中，但让我们试试吧！

Answer 1

在监听器的 onFlush 事件期间更新实体时，您需要调用的只是computeChangeSet()：

// make changes to entity
$entity->field = 'value';

// or assign an existing entity to an assocation
$entity->user = $myExistingUserEntity;
$entity->tags->add($myExistingTagEntity);

$meta = $em->getClassMetadata(get_class($entity));
$uow->computeChangeSet($meta, $entity);

如果您也在创建其他实体，则需要先保留它们并首先计算其更改！

$myNewUserEntity = new Entity\User;
$myNewTagEntity = new Entity\Tag;

$entity->user = $myNewUserEntity;
// make sure you call add() on the owning side for *ToMany associations
$entity->tags->add($myNewTagEntity);

$em->persist($myNewUserEntity);
$em->persist($myNewTagEntity);

$metaUser = $em->getClassMetadata(get_class($myNewUserEntity));
$uow->computeChangeSet($metaUser, $myNewUserEntity);

$metaTag = $em->getClassMetadata(get_class($myNewTagEntity));
$uow->computeChangeSet($metaTag, $myNewTagEntity);

$meta = $em->getClassMetadata(get_class($entity));
$uow->computeChangeSet($meta, $entity);

Answer 2

这可以通过新的preFlush事件（Symfony 2.1）完成。

为事件添加一个监听器（注入整个服务容器是一种不好的做法，但是sometimes is the way to go）：

services:
    mybundle.updater.listener:
        class: Foo\MyBundle\Listener\UpdaterListener
        arguments: ["@service_container"]
        tags:
            - { name: doctrine.event_listener, event: preFlush }

听众应该是这样的：

<?php

namespace Foo\MyBundle\Listener;

use Doctrine\ORM\Event\PreFlushEventArgs;
use Foo\MyBundle\SomeInterface;

class UpdaterListener
{
    /**
     * @param \Doctrine\ORM\Event\PreFlushEventArgs $ea
     */
    public function preFlush(PreFlushEventArgs $ea)
    {
        /* @var $em \Doctrine\ORM\EntityManager */
        $em = $ea->getEntityManager();
        /* @var $uow \Doctrine\ORM\UnitOfWork */
        $uow = $em->getUnitOfWork();

        foreach ($uow->getScheduledEntityInsertions() as $entity) {

            if($entity instanceof SomeInterface) {

               /*
                * do your stuff here and don't worry because
                * it'll execute before the flush
                */

            }

        }

    }

}

Answer 3

当想要更新当前发送给onFlush的实体并创建与该实体的关联时

（对于此示例，我将使用Parent对象和child对象）

让我们说当我将父对象属性'stress'更改为1时，我还想将一个全新的child对象与我的onflush方法中的父对象相关联，它将会看起来像这样：

public function onFlush(onFlushEventArgs $args)
{
    ....

    $child = $this->createChild($em, $entity); // return the new object. just the object.
    $uow->persist($child);
    $childMeta = $em->getMetadataFactory()->getMetadataFor('AcmeFamilyTreeBundle:Child');
    $uow->computeChangeSet($childMeta, $child)

    $parent->setStressed(1);
    $parentMeta = $em->getMetadataFactory()->getMetadataFor('AcmeFamilyTreeBundle:Parent');
    $uow->recomputeSingleEntityChangeSet($parentMeta, $parent)
}

所以你看到了：

您需要使用$uow->persist() $em->persist()
computeChangeSet关于子对象。
recomputeSingleEntityChangeSet

有关创建onFlush方法的帮助，请参阅the documentation

如何在onFlush事件监听器中更新实体的manyToMany集合？

3 个答案: