用EntityManager扩展EntityManagerDecorator在UnitOfWork中留下错误的引用

Question

我正在尝试使用EntityManagerDecorator扩展EntityManagerDecorator中的UnitOfWork，但是遇到了一个问题，即引用UnitOfWork中的基本EntityManager通过$eventArgs传递给prePersist事件。

看起来，在创建EntityManager时，EntityManager::__construct中的UnitOfWork被传递给了UnitOfWork。

我认为解决方案可能是我可以在MyEntityManagerDecorator::getUnitOfWork()中覆盖默认的MyEntityManagerDecorator::getUnitOfWork()，如下所示：

public function getUnitOfWork()
{
    if ($this->unitOfWork === null) {
        $this->unitOfWork = new UnitOfWork($this);
    }

    return $this->unitOfWork;
}

但是，我注意到UnitOfWork::__construct()需要一个EntityManager而不是EntityManagerInterface，所以这是行不通的。

我正在寻找如何从MyEntityManagerDecorator $eventArgs->getEntityManager()而不是基本EntityManager中获取EntityManager。我想在不直接继承 EntityManager的情况下执行这个EntityManager。文档还说：“永远不要尝试从EntityManager继承:继承不是EntityManager的有效扩展点。”

我不知道你需要什么代码样本，如果有的话，请告诉我，如果你需要更多的信息。我可以像预期的那样访问项目中其他地方的MyEntityManagerDecorator (到目前为止我已经尝试过了)。我在yml中设置了装饰器，如下所示：

my_multi_tenant_entity_manager:
    public: false
    class: My\MultiTenantBundle\ORM\MyEntityManagerDecorator
    decorates: doctrine.orm.default_entity_manager
    arguments: [ "@my_multi_tenant_entity_manager.inner" ]

下面是我从composer中使用的软件包和版本号列表：

installed:
doctrine/annotations                 v1.2.3             Docblock Annotations Parser
doctrine/cache                       v1.4.0             Caching library offering...
doctrine/collections                 v1.2               Collections Abstraction ...
doctrine/common                      v2.4.2             Common Library for Doctr...
doctrine/dbal                        v2.5.1             Database Abstraction Layer
doctrine/doctrine-bundle             v1.3.0             Symfony DoctrineBundle
doctrine/doctrine-cache-bundle       v1.0.1             Symfony2 Bundle for Doct...
doctrine/doctrine-migrations-bundle  dev-master 6a1bd73 Symfony DoctrineMigratio...
doctrine/inflector                   v1.0.1             Common String Manipulati...
doctrine/instantiator                1.0.4              A small, lightweight uti...
doctrine/lexer                       v1.0.1             Base library for a lexer...
doctrine/migrations                  dev-master 058a463 Database Schema migratio...
doctrine/orm                         v2.4.7             Object-Relational-Mapper...
incenteev/composer-parameter-handler v2.1.0             Composer script handling...
jdorn/sql-formatter                  v1.2.17            a PHP SQL highlighting l...
kriswallsmith/assetic                v1.2.1             Asset Management for PHP
monolog/monolog                      1.12.0             Sends your logs to files...
phpdocumentor/reflection-docblock    2.0.4              
phpspec/prophecy                     v1.3.1             Highly opinionated mocki...
phpunit/php-code-coverage            2.0.15             Library that provides co...
phpunit/php-file-iterator            1.3.4              FilterIterator implement...
phpunit/php-text-template            1.2.0              Simple template engine.
phpunit/php-timer                    1.0.5              Utility class for timing
phpunit/php-token-stream             1.4.0              Wrapper around PHP's tok...
phpunit/phpunit                      4.5.0              The PHP Unit Testing fra...
phpunit/phpunit-mock-objects         2.3.0              Mock Object library for ...
psr/log                              1.0.0              Common interface for log...
raven/raven                          dev-master 407d770 A PHP client for Sentry ...
sebastian/comparator                 1.1.1              Provides the functionali...
sebastian/diff                       1.2.0              Diff implementation
sebastian/environment                1.2.1              Provides functionality t...
sebastian/exporter                   1.2.0              Provides the functionali...
sebastian/global-state               1.0.0              Snapshotting of global s...
sebastian/recursion-context          1.0.0              Provides functionality t...
sebastian/version                    1.0.4              Library that helps with ...
sensio/distribution-bundle           v3.0.16            Base bundle for Symfony ...
sensio/framework-extra-bundle        v3.0.4             This bundle provides a w...
sensio/generator-bundle              v2.5.2             This bundle generates co...
sensiolabs/security-checker          v2.0.1             A security checker for y...
swiftmailer/swiftmailer              v5.3.1             Swiftmailer, free featur...
symfony/assetic-bundle               v2.6.1             Integrates Assetic into ...
symfony/monolog-bundle               v2.7.1             Symfony MonologBundle
symfony/swiftmailer-bundle           v2.3.8             Symfony SwiftmailerBundle
symfony/symfony                      v2.6.4             The Symfony PHP framework
twig/extensions                      v1.2.0             Common additional featur...
twig/twig                            v1.18.0            Twig, the flexible, fast...

Answer 1

我建议装饰(而不是直接扩展) EntityManager，因为它放松了实现与继承组件之间的耦合。

为了能够区分那些确实与租户有关系的实体，实现/扩展这些类与interface或mapped superclass之间的关系。

securityContext (用于演示目的)是为了获得对租户的引用。

/**
 * `EntityManagerDecorator` exists since v2.4
 */
class MultiTenantEntityManager extends EntityManagerDecorator {

    private $securityContext;

    public function __construct(EntityManagerInterface $entityManager, $securityContext) {
        parent::__construct($entityManager);
        $this->securityContext = $securityContext;
    }

    public function persist($entity) {
        // set the tenant before persisting an entity
        if ($entity instanceof MultiTenantEntity) {
            $userId = $this->securityContext->getUserId();
            $tenant = $this->wrapped->find($userId,...);
            $entity->setTenant($tenant);
        }
        return $this->wrapped->persist($entity);
    }
}