原则ORM-事件订阅服务器，用于计算“子实体”的值并将其保留在另一个实体上

2024-09-08 • 问答

我对应该在哪里实现事件订阅器感到困惑（实际上，我什至不确定是否应该改为使用实体监听器）。

因此，我有一个名为ServiceDoctrineEntity的实体，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;
}

每个存储设备都有自己的“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（添加/删除新的存储设备或更改存储空间等）时触发。

我需要计算该服务具有的“存储设备”总数。
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",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","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类来监听onFlush事件：

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`?
        }
    }
}

但是我不确定如何进行此操作

我可以使用事件订阅服务器吗？
我有权听onFlush事件
我应该列出哪个实体：

（a）ServiceDoctrine实体并遍历每个存储设备？

（b）还是ServiceStorageDevicesDoctrineEntity，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？

class ServiceStorageDevicesEventListener implements EventSubscriber { public function getSubscribedEvents() { return array( Events::prePersist,Events::preUpdate,Events::preRemove,); } public function prePersist(LifecycleEventArgs $args) { $entity = $args->getObject(); // don't perform operations for other entities if (!$entity instanceof ServiceStorageDevicesDoctrineEntity) { return; } // update your related entity here,ex: $entity->getServiceStorageDevices()->getServiceStorageSummary()->setTotalValue(10); } public function preUpdate(PreUpdateEventArgs $args) { // ... } public function preRemove(LifecycleEventArgs $args) { // ... } }

原则ORM-事件订阅服务器，用于计算“子实体”的值并将其保留在另一个实体上

linyilun 回答：原则ORM-事件订阅服务器，用于计算“子实体”的值并将其保留在另一个实体上

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