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Observer Design Pattern

Observer is a very important design pattern which is being used in almost every single self-respecting codebase as a way to efficienty communicate between objects in an event-based function. It wouldn't be an understatement to say it is the foundation of event based programming.

Underlying the popular, ever-present in networking, “Model View Controller” (MVC) design pattern, is the observer pattern.

Observers are used in every single game engine - they're known there mostly as “Event dispatchers”. This includes Unreal Engine.

The pattern promotes loose coupling since the Subjects don't need to know anything about the observers.

Alternative terminology for this pattern includes the following: - Subscribe-Publish - Listener-Publisher - Delegate-Model - Sink-Source, where the Subject is the source of events and the Observers are sinks of events


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