Notifying entities when entity state changes in Lagom - persistence

Question

Assuming a Record entity, CreateRecord command and a RecordCreated event. I want to invoke some command on one or more other entities (in different modules). What would be the suggested approach to achieve this?
I was thinking about sending a message from the ReadSide handler of the Record entity, which could be received by corresponding service(s), which would convert it to a command and invoke on an entity.
EDIT, thanks #ignasi35: According to Message Broker API publishing of the messages could be possible with this code.
AggregateEventTag<RecordEvent> RECORD_EVENT_TAG = AggregateEventTag.of(RecordEvent.class);
public Topic<RecordMessage> recordsTopic() {
return TopicProducer.singleStreamWithOffset(offset -> {
return persistentEntityRegistry
.eventStream(RECORD_EVENT_TAG, offset)
.map(this::convertEventToRecordMessage);
});
}
Records are created, and corresponding events are persisted, but no messages are received by the following consumer:
#Singleton
public class RecordsConsumer {
#Inject
public RecordsConsumer(RecordService recordService){
recordService.recordsTopic().subscribe()
.atLeastOnce(Flow.fromFunction(this::displayMessage));
}
}
What am I doing wrong?

Answer 1

Finally solved it.
I ended up with a singleton service listening to RecordCreated events from PersistentEntityRegistry.eventStream. The service converts them to RecordMessage and exposes as a Topic (see my question above).
The issue with not receiving any enents from the exposed Topic was missing dependency to kafka-broker (strange that there was no warning about this, and the topic was just not exposed), in my case this was:
<dependency>
<groupId>com.lightbend.lagom</groupId>
<artifactId>lagom-javadsl-kafka-broker_2.12</artifactId>
</dependency>