Publish-subscribe channel messages are passed by reference?

[maxvor]

Hi Integrators,

I have a question about a publish-subscribe channel. It seems to me, that the very idea of this channel is to send a separate message to subscribed listeners, but what I see in my test project is that if one of the listeners attempts to change the incoming message, this change is propagated to all other listeners, so the message is passed by reference, not a separate copy created for every listener. Is it by design? Or am I missing something?

Thanks in advance for your response!

[Gary Russell]

No; while the message itself is immutable, but the payload can be changed by other subscribers unless it, too, is immutable.

The message simply holds a reference to the payload.

If you want to leave the original payload unchanged, you need to clone it, perhaps in a transformer.

Hope that helps.