Following on from my earlier article about referencing a Blueprint from another Blueprint, Unreal Engine has another interesting way for inter-object communication. Sometimes we need to reference more than one object, say when press a button and want several objects to react, all in their own different way. Imagine pressing a button and a light goes off, a particle effect gets triggered and several enemies get spawned. Event Dispatchers can do that, and here’s how we can use them.
In this example I’ll have a Switch object, and a Lamp object. When we press the switch, it’ll send out a message to which the Lamp (and other objects) can react. Each object can implement the function and execute different code. I’ll only show the abstracted Lamp code here for brevity, from which I’m sure you’ll understand the gist.
Sadly the terminology “dispatcher” is a little confusing. At least to me, it suggests that an event is dispatched (i.e. sent), whereas in reality the dispatcher is actually the listener rather than the sender. Hence the dispatcher needs to be setup on the event that needs to react. A real-world dispatch worker doesn’t work that way (thanks code people for confusing us non-coders).
