Doctrine ORM-事件订阅服务器，它计算“子实体”的值并将其保留在另一个实体上

Question

我对在哪里实现事件订阅服务器感到困惑（实际上，我什至不确定是否应该使用实体监听器）。

因此，我有一个称为ServiceDoctrineEntity的实体，并且该实体有很多存储设备：

class ServiceDoctrineEntity {

    /**
     * One Service has many storage devices.
     *
     * @OneToMany(targetEntity="ServiceStorageDevicesDoctrineEntity", mappedBy="service", cascade={"all"})
     * @OrderBy({"order" = "ASC"})
     * @var ServiceStorageDevicesDoctrineEntity $storage_devices Description.
     */
    private $storage_devices;
}

并且每个存储设备都有其自己的“存储空间/值”

class ServiceStorageDevicesDoctrineEntity {
    /**
     * @Column(type="bigint", nullable=true, options={"comment":"The normalised value, calculated from $amount * $unit."})
     * @var int $value The normalised value, calculated from $amount * $unit.
     */
    private $value;
}

我的问题是，我应该运行一个计算逻辑，该逻辑将在每次存储设备发生更改时触发（添加/删除新的存储设备或更改存储空间等）。

1. 我需要计算此服务具有的“存储设备”总数。
2. 汇总或汇总每个存储设备的总“值”

这些“摘要”将保存在名为：ServiceStorageSummaryDoctrineEntity]的实体上

class ServiceStorageSummaryDoctrineEntity {

    /**
     * One Service Support type has One Service.
     *
     * @OneToOne(targetEntity="ServiceDoctrineEntity", inversedBy="storage_summary")
     * @JoinColumn(name="service_id", referencedColumnName="id")
     */
    private $service;

    /**
     * @Column(type="bigint", nullable=true, options={"default":0, "comment":"The total value (normalised) of storage space."})
     * @var integer $total_value The total value (normalised) of storage space.
     */
    private $total_value;

    /**
     * @Column(type="integer", nullable=true, options={"default":0, "comment":"The total amount of storage devices."})
     * @var integer $device_count The total amount of storage devices.
     */
    private $device_count;

}
我试图为此编写一个EventSubscriber类，以监听EventSubscriber事件：

onFlush
但是我不确定如何进行此操作：

1. 我可以使用事件订阅服务器吗？
2. 我是否有权听

   class ServiceStorageDevicesEventListener implements EventSubscriber {
   
       /**
        * Returns an array of events this subscriber wants to listen to.
        *
        * @return string[]
        */
       public function getSubscribedEvents() {
           return array(
               Events::onFlush,
           );
       }
   
       public function onFlush( OnFlushEventArgs $eventArgs ) {
           $em  = $eventArgs->getEntityManager();
           $uow = $em->getUnitOfWork();
   
           foreach ( $uow->getScheduledEntityInsertions() as $entity ) {
               // Should I run the computation here?
               // Which entity should I be listening to? `ServiceDoctrineEntity` or `ServiceStorageSummaryDoctrineEntity`?
           }
   
           foreach ( $uow->getScheduledEntityUpdates() as $entity ) {
               // Should I run the computation here?
               // Which entity should I be listening to? `ServiceDoctrineEntity` or `ServiceStorageSummaryDoctrineEntity`?
           }
   
           foreach ( $uow->getScheduledEntityDeletions() as $entity ) {
               // Should I run the computation here?
               // Which entity should I be listening to? `ServiceDoctrineEntity` or `ServiceStorageSummaryDoctrineEntity`?
           }
       }
   }

   事件

3. 我应该列出哪个实体：

（（a）onFlush实体并遍历每个存储设备？

（（b）或ServiceDoctrine，但这是否意味着计算逻辑将针对每个存储设备更改而运行？

我对应该在哪里实现事件订阅器感到困惑（实际上，我什至不确定我是否应该使用实体监听器）。因此，我有一个名为ServiceDoctrineEntity的实体，并且...

Answer 1

我可以使用事件订阅服务器吗？