ItemPropertyChangeListener and nested entities not working

Support
#1

Hi all,

I have created a screen fragment that has an InstanceDataContainer, which in turn includes another instance container. Here’s an example:

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<fragment xmlns="http://schemas.haulmont.com/cuba/screen/fragment.xsd">
	<data>
		<instance id="entityDc"
		          class="com.company.Entity"
		          view="Entity-view">
			<instance id="relatedEntityDc" property="relatedEntity" />
		</instance>

	</data>
	<layout>
		<form id="form" dataContainer="entityDc">
			<textField id="field1" property="field1" dataContainer="entityDc" />
			<textField id="field2" property="field2" dataContainer="entityDc" />
			<textField id="field3" property="field3" dataContainer="relatedEntityDc" />
		</form>
	</layout>
</fragment>

In the controller, I have something like this:

@Inject
private InstanceContainer<Entity> entityDc;

@Inject
private InstancePropertyContainer<RelatedEntity> relatedEntityDc;

@Subscribe
public void onInit(InitEvent event) {
	// Capture the changes of the Entity 
	entityDc.addItemPropertyChangeListener(propertyChangeEvent -> {
		entityDc.setItem(propertyChangeEvent.getItem());
	});

	// Capture the changes of the inner entity RelatedEntity
	relatedEntityDc.addItemPropertyChangeListener(propertyChangeEvent -> {
		relatedEntityDc.setItem(propertyChangeEvent.getItem());
	});
}

When I edit field1 or field2, the Table UI showing the list of entities (of type Entity) is automatically updated. However when I edit the field3, which belongs to the nested entity RelatedEntity, the Table UI doesn’t get updated. I checked with printing out messages, the event is generated on changes of field3 but the line relatedEntityDc.setItem(propertyChangeEvent.getItem()) seem not to have an effect. It seems that the “setItem” method doesn’t have an impact if nested entities get changed.

Any idea how can I get this working.

Thanks,
Samy

Persistence tools do not detect dirty entity in property listener - bug?
#3

Hi Samy,

In fact, since CUBA v.7 you don’t need to create nested container to edit properties of nested entities. The following should work:

<textField id="field3" property="relatedEntity.field3" dataContainer="entityDc" />

If it doesn’t, please create a small test project demonstrating the problem (use gradlew zipProject to make an archive).

#4

Hi Konstantin,

Here’s a sample project. If you try to modify the field1 or field2, the table data is updated. However updating field1 or field2 of the related entity doesn’t refresh the table.

entity-related.zip (81.5 KB)

Thanks for your help.

Best,
Samy

#6

I have implemented a workaround that seems to work, but it is really ugly.

private Entity currentEntity;

@Subscribe(target = Target.DATA_CONTEXT)
public void onChange(DataContext.ChangeEvent event) {
           if(event.getEntity() instanceof RelatedEntity) {
                 dataContext.merge(event.getEntity())
                 if(currentEntity != null) {
                       String oldValue = currentEntity.getField1();
                       currentEntity.setField1("dummyData")
                       entityDc.setItem(entity)
                       currentEntity.setField1(oldValue)
                       entityDc.setItem(entity)
                 }
           }
    }

I think the issue in Cuba code is that changes of sub-entities are not firing the event due to reference equality for change check instead of object equality. As you can see, the workaround is not nice.

#7

Hi Samy,

The project you have attached doesn’t work correctly because the related entity instance just doesn’t exist. You need to create it somehow, for example when you create the master entity:

public class MainEntityBrowse extends MasterDetailScreen<MainEntity> {

    @Inject
    private DataContext dataContext;

    @Subscribe
    public void onInitEntity(InitEntityEvent<MainEntity> event) {
        RelatedEntity relatedEntity = dataContext.create(RelatedEntity.class);
        event.getEntity().setField3(relatedEntity);
    }
}

Notice that the RelatedEntity instance is created using DataContext, which ensures the new instance will be saved when the screen commits.