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;
}
}
而这个侦听器：
<?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);
}
}
}
如果苹果的集合是空的，它工作正常，但如果它有一些项目，我会收到重复错误。
我怎样才能告诉单位我只想重新计算猪的收藏？
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。该 PR 不在我正在使用的分支中，但让我们尝试一下！
在侦听器的 onFlush 事件期间更新实体时，只需调用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);
如果还要创建其他实体，则需要先保留它们并计算它们的更改！
$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);
这可以通过新的preFlush事件（Symfony 2.1）来完成。
向事件添加侦听器（注入整个服务容器是一种不好的做法，但有时是要走的路）：
services:
mybundle.updater.listener:
class: Foo'MyBundle'Listener'UpdaterListener
arguments: ["@service_container"]
tags:
- { name: doctrine.event_listener, event: preFlush }
侦听器应该是这样的：
<?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
*/
}
}
}
}
当想要更新要发送到onFlush的当前实体并创建与该实体的关联时
（在本例中，我将使用Parent对象和child对象）
假设当我将父对象属性"stressed"更改为1时，我还想在我的onflush方法中将一个全新的child对象与父对象相关联，它将如下所示：
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：
- 您需要使用
$uow->persist()而不是$em->persist()来持久化子对象 -
computeChangeSet子对象上。 - 父对象
recomputeSingleEntityChangeSet
有关创建 onFlush 方法的帮助，请参阅文档