Nat1Wizard Event System

Unity Package for a Scriptable Object Based Event System.

Description

This repository contains a Unity package for a simple scriptable object based event system designed to facilitate script communication across scenes without spaghetti references or anti-patterns (like singletons).

The system works by creating Game Events, which are scriptable objects that can be invoked to pass data. When invoking the created game event, you pass a (possibly null) instance of the Game Event Context class, which can hold any object as data. To listen for game event invokation, add the Game Event Listener monobehavior to a game objects, and set the callback method which recieves the Game Event Context.

Getting Started

Installation

The event system can be installed through the Unity Package Manager using this repository's git URL:

https://github.com/kbvatral/SO-Event-System

Basic Usage

• Create a Game Event scriptable object for your event
• Pass a reference of this scriptable object to the invoking class
• Add the Game Event Listener monobehavior to the receiving game object
  • Set the Game Event parameter of this monobehavior to the desired game event scriptable object
  • Set the Callback Unity event to invoke the desired behaviors when the game event is invoked. These callback methods can optionally take a GameEventContext parameter.
• In the invoking class, invoke the game event scriptable object, which optional context parameters
  • gameEvent.Invoke() will invoke the event with a null context. Use this appoach to pass a message without any data.
  • gameEvent.Invoke(GameEventContext ctx) will invoke the event with the specified context object
  • gameEvent.Invoke(Object data) will create a new GameEventContext with its data set to the specified object and then invoke the event with this created context
• In the recieving class, create a callback method to handle the game event invokation and read any relevant data
  • gameEventContext.GetData<T> will return the data associated with the GameEventContext cast to type T. Use this to retrieve the passed data from the invoking class.
  • Note: The GetData<T> will attempt to cast the passed data to the specified type regardless of what was passed. If the cast is unsuccessful, it will return default(T).
  • Note: The GameEventContext will not handle objects which no longer exist (e.g., garbage collected or destroyed by Unity), so take extra care to check the resulting data if using in a case where this may happen.

Version History

• 1.0.0
  • Initial Public Release

License

This project is licensed under the GPL 3.0 License - see the LICENSE file for details

Acknowledgments

Portions of this codebase were adapted and expanded from the Game Events Unity Tutorial by Jason Weimann.