Entity Event Listener on Composition relationships

Support
#1

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Suppose i have an Order and OrderLine entities, with a composition relationship.

I’ve coded the following entity listener:

@EventListener
public void onPosOrderChangedBeforeCommit(final EntityChangedEvent<PosOrder> event) {
    if (event.getType() == EntityChangedEvent.Type.CREATED) {
        Id<PosOrder> posOrderId = event.getEntityId();
        PosOrder posOrder = dataManager.load(posOrderId).one();
        List<OrderLine> orderLineList = posOrder.getOrderLines();
        for (OrderLine orderLine : orderLineList) {
            log.info(orderLine.getQuantity().toPlainString());
            subtractProductStock(orderLine.getProduct().getId(), orderLine.getQuantity());
        }
    }

    if (event.getType() == EntityChangedEvent.Type.DELETED) {
        Id<PosOrder> oldOrderId = event.getEntityId();
        log.info("Old Order Id: {}",event.getEntityId());
        UUID oldOrderUUID = (UUID) oldOrderId.getValue();
        List<OrderLine> orderLineList = dataManager.load(OrderLine.class)
                .query("select e from OrderLine e where e.posOrder.id = :posOrderId")
                .parameter("posOrderId", oldOrderUUID)
                .list();

        for (OrderLine orderLine : orderLineList) {
            log.info(orderLine.getQuantity().toPlainString());
            addProductStock(orderLine.getProduct().getId(), orderLine.getQuantity());
        }
    }
}

In this case, when a PosOrder is deleted entirely from the PosOrder list view, the line:

    List<OrderLine> orderLineList = dataManager.load(OrderLine.class)

is returning an empty list, even though there actually are entites related.

Why is that? How can i achieve my purpose?

#2

Hi

do you have any cascading options in your entities? have you considered to do changes in buisness code instead of using listeners?

#3

Hi Aleksey

Yes, I do have cascading as it is set by default by jmix studio when creating attributes with composition, in this case, in the OrderLine class that is related to PosOrder.

@OnDeleteInverse(DeletePolicy.CASCADE)
@JoinColumn(name = "POS_ORDER_ID", nullable = false)
@ManyToOne(fetch = FetchType.LAZY, optional = false)
private PosOrder posOrder;

About your question, yes, I have considered using other way around, but was given it a try since I thought it would be more straightforward using the entity listeners.

Is this then the expected behavior for entity listeners?

#4

have your tried to remove cacading?

#5

Your OrderLines are deleted together with Order because of DeletePolicy.CASCADE on the relationship. Perhaps you need to invoke your business methods in a OrderLine entity listener.