Is Eventbus a Mediator or Observer Pattern?

Question

Is Eventbus more a Mediator or an Observer? According to Google, \"eventbus mediator\" gets 2.430 hits and \"eventbus observer\" gets 3.850 hits.

From the descriptio

Answer 1

I'd say that a typical event bus utilises both of these patterns:

• event bus essentially encapsulates how other objects communicate, so it is a mediator
• objects that register as event handlers/listeners are observers (and the subjects of their observations are event types and/or objects that produce these events, not the bus itself), so as wikipedia says observer pattern "is mainly used to implement distributed event handling systems" (emphasis mine), but an event bus is not an observer per se.