How to publish an event to another context

dbeaudry · February 21, 2022, 7:19pm

Hello AxonIQers,

I try to publish an event to a different context than the application’s context.
I tried to create a TargetContextResolver, but it does not get called when I issue a eventGateway.publish(event)

 @Bean
    public TargetContextResolver<Message<?>> targetContextResolver(ContextNameResolver contextNameResolver) { ...}

lfgcampos · February 21, 2022, 7:45pm

Hi @dbeaudry,

Indeed, a TargetContextResolver should do the trick as shown here:

github.com

AxonIQ/hotel-demo/blob/master/booking/src/main/java/io/axoniq/demo/hotel/booking/command/config/BookingCommandCloudConfiguration.java#L41-L50

      
        
            @Bean
            public TargetContextResolver<org.axonframework.messaging.Message<?>> targetContextResolver() {
                return message -> {
                    if (message.getPayloadType().getPackage().getName().contains(".inventory.")) {
                        return INVENTORY;
                    } else {
                        return BOOKING;
                    }
                };
            }

You also have to make sure that the application has the correct rights to publish events to that context!

KR,

Yvonne_Ceelie · February 21, 2022, 7:51pm

Bonjour Daniel,

Ça va?

The TargetContextResolver Bean is only invoked when using a command or query and is not when publishing an event. As @lfgcampos mentioned you need to assign the correct access rights.

Best regards,

Yvonne

Yvonne_Ceelie · February 21, 2022, 8:09pm

Hi Daniel,

Lucas and I had a little discussion about this what could be the use case for handling a command in a certain context and applying the event in another instead of sending a command to the other context. Can you elaborate a little bit more on it?

Kind Regards

Yvonne

dbeaudry · February 21, 2022, 9:17pm

In fact, the TargetContextResolver works realy well for commands and queries, but does not seems to be invoked when semding an event.

We want to achieve some sort of error collecting by sending an event to a “failuremgmt” context from within many of our applications. We do not want to polute those applications context with such messages. Therefore, we want to collect them separately.