Reflex: A C# repository from Ragueel

Reflex is an Dependency Injection framework for Unity. Making your classes independent of its dependencies, granting better separation of concerns. It achieves that by decoupling the usage of an object from its creation. This helps you to follow SOLID’s dependency inversion and single responsibility principles. Making your project more readable, testable and scalable.

Features

Blazing fast
IL2CPP Friendly
Minimal code base
Contructor injection
[Inject] Property, field and method injection attribute

Performance

Resolving ten thousand times a transient dependency with four levels of chained dependencies. See NestedBenchmarkReflex.cs.

Android

Mono

IL2CPP

	GC	Time
Reflex	54KB	10ms
Zenject	464KB	73ms
VContainer	128KB	51ms

	GC	Time
Reflex	70KB	15ms
Zenject	480KB	77ms
VContainer	128KB	18ms

Windows

Mono

IL2CPP

	GC	Time
Reflex	109KB	1ms
Zenject	900KB	7ms
VContainer	257KB	3ms

	GC	Time
Reflex	140KB	1ms
Zenject	900KB	7ms
VContainer	257KB	2ms

The performance on IL2CPP (AOT) backend is not so good because the expressions are actually interpreted, unlike Mono (JIT), where they are actually compiled.

I'm investigating whether dealing with IL Reweaving is worth the complexity it brings.

Installation

Requires Unity 2019+

Install via UPM (using Git URL)

"com.gustavopsantos.reflex": "https://github.com/gustavopsantos/reflex.git?path=/Assets/Reflex/#3.5.1"

Install manually (using .unitypackage)

Download the .unitypackage from releases page.
Import Reflex.X.X.X.unitypackage

Getting Started

Installing Bindings

Create a Installer to install your bindings in the project context, and remember to add this component in the ProjectContext prefab, and reference it in the Installers list of the ProjectContext. See ProjectContext.prefab.

public class ProjectInstaller : Installer
{
    public override void InstallBindings(Container container)
    {
        container.BindInstance<int>(42);
        container.BindTransient<IDependencyOne, DependencyOne>();
        container.BindSingleton<IDependencyTwo, DependencyTwo>();
    }
}

MonoBehaviour Injection

Be aware that fields and properties with [Inject] are injected only into pre-existing MonoBehaviours within the scene after the SceneManager.sceneLoaded event, which happens after Awake and before Start. See MonoInjector.cs.

If you want to instantiate a MonoBehaviour/Component at runtime and wants injection to happen, use the Instantiate method from Container.

public class MonoBehaviourInjection : MonoBehaviour
{
    [Inject] private readonly Container _container;
    [Inject] public IDependencyOne DependencyOne { get; private set; }

    [Inject]
    private void Inject(Container container, IDependencyOne dependencyOne)
    {
        var dependencyTwo = container
            .Resolve(typeof(IDependencyTwo));
    }

    private void Start()
    {
        var dependencyTwo = _container
            .Resolve(typeof(IDependencyTwo));

        var answerForLifeTheUniverseAndEverything = _container
            .Resolve<int>();
    }
}

Non MonoBehaviour Injection

public class NonMonoBehaviourInjection
{
    private readonly Container _container;
    private readonly IDependencyOne _dependencyOne;
    private readonly int _answerForLifeTheUniverseAndEverything;

    public NonMonoBehaviourInjection(Container container, IDependencyOne dependencyOne, int answerForLifeTheUniverseAndEverything)
    {
        _container = container;
        _dependencyOne = dependencyOne;
        _answerForLifeTheUniverseAndEverything = answerForLifeTheUniverseAndEverything;
    }
}

Order of Execution when a Scene is Loaded

Events
SceneContext.Awake(DefaultExecutionOrder(-10000))
↓
Reflex.Injectors.SceneInjector.Inject
↓
MonoBehaviour.Awake
↓
MonoBehaviour.Start

Reflex.Injectors.SceneInjector.Inject injects fields, properties and methods decorated with [Inject] attribute.

Contexts

Project Context

A single prefab named ProjectContext that should live inside a Resources folder and should contain a ProjectContext component attached

Non-Obligatory to have

Scene Context

A single root gameobject per scene that should contain a SceneContext component attached

Non-Obligatory to have, but scenes without it wont be injected

Bindings

Bind Function

Binds a function to a type. Every time resolve is called to this binding, the function binded will be invoked.

Bind Instance

Binds a object instance to a type. Every time resolve is called, this instance will be returned.

Instances provided by the user, since not created by Reflex, will not be disposed automatically, we strongly recomend using BindSingleton.

Bind Transient

Binds a factory. Every time the resolve is called, a new instance will be provided.

Instances will be disposed once the container that provided the instances are disposed.

Bind Singleton

Binds a factory. Every time the resolve is called, the same instance will be provided.

The instance will be disposed once the container that provided the instance are disposed.

Author

License

Reflex is licensed under the MIT license, so you can comfortably use it in commercial applications (We still love contributions though).

Ragueel/Reflex