Scriptable-Events

Quickly setup static events with scriptable objects using the observer pattern. Custom events can also be created.

How to install

This package can be installed through the Unity Package Manager with Unity version 2019.3 or greater.

Open up the package manager Window/Package Manager and click on Add package from git URL....

Paste in this repository's url.

https://github.com/Jason-Skillman/Scriptable-Events.git

Click Add and the package will be installed in your project.

---

NOTE: For Unity version 2019.2 or lower

If you are using Unity 2019.2 or lower than you will not be able to install the package with the above method. Here are a few other ways to install the package.

1. You can clone this git repository into your project's Packages folder.
2. Another alternative would be to download this package from GitHub as a zip file. Unzip and in the Package Manager click on Add package from disk... and select the package's root folder.

---

Git submodule

Alternatively you can also install this package as a git submodule.

$ git submodule add https://github.com/Jason-Skillman/Scriptable-Events.git Packages/Scriptable-Events

How to setup

You can create an event by going to Create/Scriptable Events/<Event Type> in the Project window. Each event is a scriptable prefab. Multible events can be created for your project and different event types exist. Some of the primitive event types include void, int, float, string and bool.

Subscribing to an event

To subscribe to an event you can attach a method to the OnInvoked event in the scriptable object.

This is an example of a monobehavior script subscriping to EventVoid. Note: Dont forget to unsubscribe from the event when you no longer need to.

[SerializeField]
private Event myEvent;

private void OnEnable() {
	myEvent.OnInvoked += SpawnBall;
}

private void OnDisable() {
	myEvent.OnInvoked -= SpawnBall;
}

private void SpawnBall() {
	//Instantiate ball here...
}

Drag the scriptable object event into the EventVoid variable in the inspector and the game object will subscribe to the event when enabled/start.

[SerializeField]
private Event myEvent;

Invoking an event

To trigger an existing event call the Invoke() method from the scriptable object. Every subscribed listener will get the fired event.

This is an example of a monobehavior who will trigger the Event by calling Invoke() when the player enters it's trigger box.

[SerializeField]
private Event myEvent;

private void OnTriggerEnter(Collider other) {
    if(!other.CompareTag("Player")) return;

    myEvent.Invoke();
}

Event diagram

Creating custom events

If the existing primitive event types are not enough, custom event types can be written. Using the UnityAction<> delegate you specify different arguments and data.

Ex. Dictionary event with int as the key and string as the value UnityAction<int, string>.

Create a new script which extends ScriptableObject and follow a near similar format to the primitive types. Source code examples can be found in ScriptableEvents/Runtime/Scripts/Events/PrimitiveTypes.

EventInt class example

Property/Method	Description
UnityAction<int> OnInvoked	Event called when the scriptable event is invoked.
Invoke()	Invokes the event.

Supported event types

Primitive events

• void
• int
• float
• double
• long
• bool
• string

Primitive array events

• int
• float
• double
• long
• bool
• string

Unity events

• GameObject
• Scene

Origin

Original idea was inspired by Unity's open-project-1 scriptable event system.

Check out the full project here.

https://github.com/UnityTechnologies/open-project-1