Unity GameObject Aspect

Aspect-oriented programming for Unity GameObjects

Changelog

⚠️ Development is paused ⚠️
No new features will be added or bugs fixed unless requested through an issue.
If you wish to fork this repository and continue the work, you are very welcome to do so.

---

This package allows the user to define types or classes of GameObjects. For example you can say that all GameObjects witch contains a RigidBody and a Collider are PhysicsObjects. Such a type of GameObject is called an aspect.

You can then test if GameObjects have a defined aspect in order to guarantee that it has required components.

// Aspects are interfaces
// They must implement IGameObjectAspect
public interface IPhysicsObject : IGameObjectAspect {

    // Add component requirements using read-only properties
    
    public RigidBody RigidBody { get; }
    
    public Collider Collider { get; }

    // Any other types of members, such as methods, are not allowed
}

// Attempt to get the aspect from some GameObject
var physicsObject = someGameObject.TryAspect<IPhysicsObject>();

// Will be null if game-object does not have the required components
if(phyicsObject != null) {

    // Do something with the components 
    physicsObject.RigidBody ...
    phsysicsObject.Collider ...
}

Features

Currently properties of the following types are supported in aspects

• GameObject - Will always point to the host game-object
• Single Components - Searches for the component on the host game-object
  • This also works with interfaces such as searching for IXRInteractable

Attempt to get an aspect from a GameObject using the TryAspectextension method.

gameObject.TryAspect<IMyAspect>();

// You can also use TryAspect on components and other aspects

transform.TryAspect<IMyAspect>();
someAspect.TryAspect<IMyAspect>();

You can compare aspects using Equals which will be true if the stem from the same game-object.

Installation

Install via OpenUpm using openupm add dev.comradevanti.gameobject-aspect

Compatibility

Designed with/for Unity 2021.3 and up. Should work on all build targets.

How it works

We use System.Emit to generate an implementation class for your aspect-interfaces at runtime. This has a slight performance penalty and so the generated types are cached.

The TryAspect methods then attempt to populate all properties defined in the aspect-interface by resolving the requested components on the given host game-object.

Roadmap

• Find game-objects
• Find other aspects
• Support searching on parents
• Support searching in children
• Support searching in custom locations
• Array support
• Nullable support
• Live values
• Setter support
• Useful error messages
• Allow to check if game-object has components without needing access to them ( tag-components)