How to upgrade from MessageBus
Event interfaces have been removed
A message (command, event, etc.) can be any object now, so just remove any type-hint or replace type-hints by more specific ones.
Message type-hint has been removed from the following methods:
MessageHandler interface has been removed
Message handlers can be any callable now, so just remove the
implements MessageHandler from your message handler
MessageSubscriber interface has been removed
Message subscribers can be any callable now, so just remove the
implements MessageSubscriber from your message
handler class definitions.
MessageSubscriberCollection have been removed
Instead, handlers and subscribers can now be any callable you like. Also, they are assumed to be always lazy-loading (because they should never all be instantiated at the same time). See the updated documentation for examples on how to configure these objects.