Where should actor messages be declared?

Question

I'm developing an application using Akka, and a thing that kind of bugs me the whole time regards message declaration with the Actor's. Where should I declare the messages? In the receivers companion object or the senders companion object or on some third place?

Answer 1

The Akka team recommends Message should be defined in the same place the props method should be: in the Receiver's Companion object because the Receiver implements the receive partial function and needs to know about all the messages it supports. Also, multiple senders can send a set of messages (implemented by the Receiver), so you cannot put it in one single sender.