com.elestrago.unity.reflex


---

---

👀 Overview

- Fast: ~3x faster than VContainer, ~7x faster than Zenject.
- GC Friendly: ~2x less allocations than VContainer, ~9x less allocations than Zenject.
- AOT Support: Basically there's no runtime Emit, so it works fine on IL2CPP
builds. [^[*]](#-scripting-restrictions)
- Contract Table: Allows usages of APIs like container.All
- Immutable Container: Performant thread safety free of lock plus predictable behavior.

Compatible with the following platforms:

- iOS
- Android
- Windows/Mac/Linux
- PS4/PS5
- Xbox One/S/X and Xbox Series X/S
- WebGL

---

💾 Installation

Using the native Unity Package Manager introduced in 2017.2, you can add this library as a package by modifying your
manifest.json file found at /ProjectName/Packages/manifest.json to include it as a dependency. See the example below
on how to reference it.

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The package is available on the npmjs
registry.

#### Add registry scope

``
{
"dependencies": {
...
"com.elestrago.unity.reflex": "x.x.x",
...
},
"scopedRegistries": [
{
"name": "eLeSTRaGo",
"url": "https://registry.npmjs.org",
"scopes": [
"com.elestrago.unity"
]
}
]
}
`

#### Add package in PackageManager

Open Window -> Package Manager choose Packages: My Regestries and install package

---

🚀 Getting Started

1. Install Reflex
2. Create ProjectInstaller.cs with

`csharp
using Reflex.Core;
using UnityEngine;

public class ProjectInstaller : MonoBehaviour, IInstaller
{
public void InstallBindings(ContainerBuilder builder)
{
builder.AddSingleton("Hello");
}
}
`

3. In unity project window
5. Create directory Assets/Resources
6. Select just created Resources dir
7. Right click, Create → Reflex → ProjectScope
8. With just created ProjectScope selected
9. Add ProjectInstaller.cs created at step 2 as a component
10. Create new scene Greet
11. Add Greet to Build Settings → Scenes In Build
12. Create Greeter.cs with

`csharp
using UnityEngine;
using System.Collections.Generic;
using Reflex.Attributes;

public class Greeter : MonoBehaviour
{
[Inject] private readonly string[] _strings;

private void Start()
{
Debug.Log(string.Join(" ", _strings));
}
}
`

12. Add Greeter.cs to any gameobject in Greet scene
13. Inside Greet scene, create a new empty gameobject named SceneScope and attach SceneScope component
14. Create GreetInstaller.cs with

`csharp
using Reflex.Core;
using UnityEngine;

public class GreetInstaller : MonoBehaviour, IInstaller
{
public void InstallBindings(ContainerBuilder builder)
{
builder.AddSingleton("World");
}
}
`

15. Add GreetInstaller.cs to Greet.unity SceneScope
16. Create new scene Boot
17. Add Boot to Build Settings → Scenes In Build
18. Create Loader.cs with

`csharp
using Reflex.Core;
using UnityEngine;
using UnityEngine.SceneManagement;

public class Loader : MonoBehaviour
{
private void Start()
{
// If you are loading scenes without addressables
var scene = SceneManager.LoadScene("Greet", new LoadSceneParameters(LoadSceneMode.Single));
ReflexSceneManager.PreInstallScene(scene, builder => builder.AddSingleton("Beautiful"));

// If you are loading scenes with addressables
Addressables.LoadSceneAsync("Greet", activateOnLoad: false).Completed += handle =>
{
ReflexSceneManager.PreInstallScene(handle.Result.Scene, builder => builder.AddSingleton("Beautiful"));
handle.Result.ActivateAsync();
};
}
}
`

19. Assign it to any gameobject at Boot scene
20. Thats it, hit play while on Boot scene
21. When Greet scene is loaded, there should be 3 instances implementing string contract
22. So when Greeter::Start is called, you should see the following log in the unity console: Hello Beautiful world

---

🎬 Execution Order

---

🎯 Injection Strategy

Beginning from version 8.0.0, Reflex stops injecting all scenes automatically on Start, to start injecting only scenes
with a SceneScope on Awake.
This allows users to consume injected dependencies on callbacks such as Awake and OnEnable while giving more granular
control on which scenes must be injected or not.

---

🌱 Container Hierarchy

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Reflex's default strategy for creating containers involves initially generating a root project container. For each newly
loaded scene, an additional container is created, which always inherits from the root project container. This container
hierarchy mirrors the flat hierarchy of Unity scenes. You can see how the structure looks like below:

`mermaid
graph
ProjectContainer --> BootScene
ProjectContainer --> LobbyScene
ProjectContainer --> GameModeOneScene
ProjectContainer --> GameModeTwoScene
`

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If you want a scene to inherit services from another scene, you can use the
ReflexSceneManager::OverrideSceneParentContainer method. This feature provides developers with more granular control
over which parent container is used for each newly loaded scene.

`csharp
// Scene Manager Sample
var bootScene = SceneManager.GetSceneByName("Boot");
var sessionScene = SceneManager.LoadScene("Session", new LoadSceneParameters(LoadSceneMode.Additive));
ReflexSceneManager.OverrideSceneParentContainer(scene: sessionScene, parent: bootScene.GetSceneContainer());

// Addessable Sample
var handle = Addressables.LoadSceneAsync("Session", LoadSceneMode.Additive, activateOnLoad: false);
await handle.Task;
var bootScene = SceneManager.GetSceneByName("Boot");
ReflexSceneManager.OverrideSceneParentContainer(scene: handle.Result.Scene, parent: bootScene.GetSceneContainer());
handle.Result.ActivateAsync();
`

By utilizing this API, you can create hierarchical structures such as the one shown below:

`mermaid
graph
ProjectContainer-->BootScene
BootScene-->LobbyScene
LobbyScene-->GameModeOneScene
LobbyScene-->GameModeTwoScene
`

> 1. Please note that it is not possible to override the parent container for the initial scene loaded by Unity.
>2. Exercise caution when managing the scene lifecycle with this type of hierarchy. For example, unloading a parent
scene before its child scenes can lead to unexpected behavior, as the parent container will be disposed while the
child scenes are still active. As a general rule, always unload the scene hierarchy from the bottom up, starting
with the child scenes and progressing to the parent scenes.

---

📦 Scopes

Container scoping refers to the ability of being able to create a container inheriting the registrations of its parent
container while also being able to extend it.

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It is root scope.
It is created just before first scene opens by relying on
[RuntimeInitializeOnLoadMethod(RuntimeInitializeLoadType.BeforeSceneLoad)]
To register bindings to it, create a prefab, name it how you wish, the name is not used as a identifier, put it inside
any Resources folder, and attach a "ProjectScope" component to it.
Then, create your installer as MonoBehaviour and implement IInstaller interface.
Remember to attach your installer to the ProjectScope prefab, as ProjectScope searches for every child implementing
IInstaller when it's time to create the ProjectScope container.
There's a menu item to ease the process: Assets > Create > Reflex > ProjectScope
You can create multiple ProjectScope in many different Resources folders across the project, and when its time to create
the project container, all active ProjectScope prefabs will be merged, this allow a better separation of concerns if
required.
Note that ProjectScope prefab is not required, in case Reflex does not find any ProjectScope, an empty root will be
created.
ProjectScope instance will be disposed once app closes/app quits.
> Note that unity does not call OnDestroy deterministically, so rule of thumb is do not rely on injected dependencies on
> OnDestroy event functions.

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It is scoped from ProjectScope, inheriting all bindings from ProjectScope.
It is created and injected before Awake.
To register bindings to it, create a gameobject on desired scene, name it "SceneScope", put it as root game object, and
attach a "SceneScope" component to it.
Then, create your installer as MonoBehaviour and implement IInstaller interface.
Remember to attach your installer to your SceneScope gameobject, as SceneScope searches for every child implementing
IInstaller when it's time to create the SceneScope container.
There's a menu item to ease the process: GameObject > Reflex > Scene Context
Remember to have a single SceneScope to avoid undesired behaviour.
Note that SceneScope gameobject is required only if you want its scene to be injected, in case Reflex do not find
SceneScope, the scene injection will be skipped for that specific scene missing SceneScope.
SceneScope instance will be disposed once scene is unloaded.
> Note that unity does not call OnDestroy deterministically, so rule of thumb is do not rely on injected dependencies on
> OnDestroy event functions.

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`csharp
using var scopedContainer = parentContainer.Scope(builder =>
{
// Extend your scoped container by adding extra registrations here
});
`

🔩 Bindings

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`csharp
ContainerBuilder::AddSingleton(Type concrete, params Type[] contracts)
`

Adds a deferred object creation based on the type to be constructed and its contracts.
The object will be constructed lazily, once first request to resolve any of its contracts is called.
Then same object will always be returned.
If object implements IDisposable it will be disposed when its parent Container are disposed.
There's no need to pass IDisposable as contract to have your object disposed, however, if you want to retrieve all
IDisposable by any API Single, Resolve or All then yes, you have to specify it.

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`csharp
ContainerBuilder::AddSingleton(object instance, params Type[] contracts)
`

Adds an object already constructed by the user to the container as a singleton, everytime the contracts given is asked
to be resolved, the same object will be returned.
If object implements IDisposable it will be disposed when its parent Container are disposed.
There's no need to pass IDisposable as contract to have your object disposed, however, if you want to retrieve all
IDisposable by any API Single, Resolve or All then yes, you have to specify it.

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`csharp
ContainerBuilder::AddSingleton(Func factory, params Type[] contracts)
`

Adds a deferred object creation based on the given factory and its contracts.
The object will be constructed lazily, once first request to resolve any of its contracts is called.
The factory will be ran once, and then the same object will always be returned.
If object implements IDisposable it will be disposed when its parent Container are disposed.
There's no need to pass IDisposable as contract to have your object disposed, however, if you want to retrieve all
IDisposable by any API Single, Resolve or All then yes, you have to specify it.

$3

`csharp
ContainerBuilder::AddTransient(Type concrete, params Type[] contracts)
`

Adds a deferred object creation based on the type to be constructed and its contracts.
The object will be constructed lazily, once first request to resolve any of its contracts is called.
Then for any request of any contract, a new object will be created, use this carefully.
If object implements IDisposable it will be disposed when the container who constructed the instance are disposed, and
eventually collected when GC kicks in.
There's no need to pass IDisposable as contract to have your object disposed, however, if you want to retrieve all
IDisposable by any API Single, Resolve or All then yes, you have to specify it.

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`csharp
ContainerBuilder::AddTransient(Func factory, params Type[] contracts)
`

Adds a deferred object creation based on the given factory and its contracts.
The object will be constructed lazily, once first request to resolve any of its contracts is called.
Then for any request of any contract, a new object will be created, use this carefully.
If object implements IDisposable it will be disposed when the container who constructed the instance are disposed, and
eventually collected when GC kicks in.
There's no need to pass IDisposable as contract to have your object disposed, however, if you want to retrieve all
IDisposable by any API Single, Resolve or All then yes, you have to specify it.

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`csharp
ContainerBuilder::AddScoped(Type concrete, params Type[] contracts)
`

Very similar to AddSingleton API, however, instead of having a single global instance, AddScoped creates one object
instance per container.
If object implements IDisposable it will be disposed when the container who constructed the instance are disposed, and
eventually collected when GC kicks in.
There's no need to pass IDisposable as contract to have your object disposed, however, if you want to retrieve all
IDisposable by any API Single, Resolve or All then yes, you have to specify it.

$3

`csharp
ContainerBuilder::AddScoped(Func factory, params Type[] contracts)
`

Very similar to AddSingleton API, however, instead of having a single global instance, AddScoped creates one object
instance per container.
If object implements IDisposable it will be disposed when the container who constructed the instance are disposed, and
eventually collected when GC kicks in.
There's no need to pass IDisposable as contract to have your object disposed, however, if you want to retrieve all
IDisposable by any API Single, Resolve or All then yes, you have to specify it.

🔍 Resolving

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If your type is non-mono, and it's going to be created by the container, then the most recommended way to inject
dependencies into it its by constructor injection.
It's simply as just requesting the contracts you need as following example:

`csharp
private class Foo
{
...

public NumberManager(IInputManager inputManager, IManager[] managers)
{
...
}
}
`

> Note that constructor injection relies on Resolve API, so in case there's two objects with
IInputManager contract, the last one will be injected.

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Attribute injection is the way to go for MonoBehaviours.
You can use it to inject fields, writeable properties and methods like following:

`csharp
class Foo : MonoBehaviour
{
[Inject] private readonly IInputManager _inputManager;
[Inject] public IManager[] Managers { get; private set; }

[Inject]
private void Inject(int[] numbers) // Method name here does not matter
{
...
}
}
`

> Note that attribute injection also works on non-mono classes.

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Container::Single actually validates that there's a single binding implementing given contract, and returns
it.
If there's more than one the following exception will be thrown.

`
InvalidOperationException: Sequence contains more than one element
`

It's recommended for every binding that you know that there should be a single binding implementing the contract.

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Container::Single runs no validations, and return the last valid object implementing given contract.

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Container::All returns all objects implementing given contract.
Example:

`csharp
private void Documentation_Bindings()
{
var container = new ContainerBuilder()
.AddSingleton(1)
.AddSingleton(2)
.AddSingleton(3)
.Build();

Debug.Log(string.Join(", ", container.All())); // Prints: 1, 2, 3
}
`

---

🪝 Callbacks

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OnContainerBuilt is a instance callback of ContainerBuilder, it is called once the container is fully built and
initialized properly.

---

🔖 Attributes

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Should be used to inject fields, writeable properties and methods like following:

`csharp
class Foo : MonoBehaviour
{
[Inject] private readonly IInputManager _inputManager;
[Inject] public IManager[] Managers { get; private set; }

[Inject]
private void Inject(int[] numbers) // Method name here does not matter
{
...
}
}
`

> Note that InjectAttribute also works on non-mono classes.

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Can be placed on constructors, telling reflex which constructor to use when instantiating an object.
By default its not required, as usually injected classes have a single constructor, so by default reflex tries to find
the constructor with most arguments.
But sometimes this can be required if you need more granular control on which construtor reflex should use.

---

💉 Manual Injection

If objects (plain old c# objects or unity objects) are created during runtime, theres no way reflex can detect this
creation to auto inject the object, this needs to be done manually using one of the following methods:

`csharp
AttributeInjector::void Inject(object obj, Container container)
// Injects given object fields, properties and methods that was annotated with Inject attribute
`

`csharp
ConstructorInjector::object Construct(Type concrete, Container container)
// construct object of given type, using the constructor with most parameters, using given container to pull the constructor arguments
`

`csharp
GameObjectInjector::void InjectSingle(GameObject gameObject, Container container)
// Optimized code meant to find injectables (MonoBehaviours) from a given GameObject, to then, inject using AttributeInjector
// This option injects only the first MonoBehaviour found on the given GameObject
`

`csharp
GameObjectInjector::void InjectObject(GameObject gameObject, Container container)
// Optimized code meant to find injectables (MonoBehaviours) from a given GameObject, to then, inject using AttributeInjector
// This option injects all MonoBehaviours found on the given GameObject (not recursively, so it does not account for children)
`

`csharp
GameObjectInjector::void InjectRecursive(GameObject gameObject, Container container)
// Optimized code meant to find injectables (MonoBehaviours) from a given GameObject, to then, inject using AttributeInjector
// This option injects all MonoBehaviours found on the given GameObject and its childrens recursively
`

`csharp
GameObjectInjector::void InjectRecursiveMany(List gameObject, Container container)
// Optimized code meant to find injectables (MonoBehaviours) from a given GameObject, to then, inject using AttributeInjector
// This option injects all MonoBehaviours found on the given list of GameObject and its childrens recursively
`

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An alternative approach is to utilize the GameObjectSelfInjector, which can be attached to a prefab to resolve its
dependencies at runtime. Through the inspector, you can select the injection strategy: Single, Object, or
Recursive. Each strategy invokes the corresponding method in the GameObjectInjector class.

---

🧩 Extensions

`csharp
// Allows you to get a scene container, allowing you to resolve/inject dependencies in a different way during runtime
SceneExtensions::GetSceneContainer(this Scene scene)
{
return UnityInjector.ContainersPerScene[scene];
}

// Usage example:
var foo = gameObject.scene.GetSceneContainer().Resolve();
`

---

🐛 Debugger

It can be accessed from menu item Window → Analysis → Reflex Debugger, or from shortcut CTRL + E.
To enable reflex debug mode you must go to Edit → Project Settings → Player, then in the Other Settings panel, scroll
down to Script Compilation → Scripting Define Symbols and add REFLEX_DEBUG. This can be easily achieved by clicking on
the bug button at bottom right corner inside Reflex Debugger Window.
> Note that debug mode reduces performance and increases memory pressure, so use it wisely.

!Preview

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| Icon | Name | Description |
|--------------------------------------------------------------------------------------------------------|:------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|:-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| | Name taken from Name property of a Container instance. Scene containers uses scene.name + scene.GetHashCode(), so you can differentiate between two instances of the same opened scene. | Represents a container, containers has a collection of bindings |
| | Name created from the array of contracts you described your binding. | Represents a binding, bindings has a collection of instances, singleton will have only one instance, transients can have many instances and factories depends on your implementation |
| | Name taken from Name property of the Type of the concrete object. | Represents a instance, it's the concrete object that were created by the parent binding and it's being injected to consumers |

Debugger window allows you to inspect the following:

- Hierarchy of Containers, Bindings and Instances
- Binding Contracts, Kind and Lifetime
- Binding Resolution Count
- Container construction call stack (who created the container)
- Binding construction call stack (who created the binding)
- Instance construction call stack (who resolved the binding making selected instance to be instantiated)

---

🪛 Settings

It's a ReflexSettings scriptable object instance, named ReflexSettings that should live inside a Resources
folder.
It can be created by asset menu item Assets → Create → Reflex → Settings.

Currently, logging verbosity is configured in this file, and default value is set to Info`

> Non-obligatory to have but projects without it will fallback using default settings

---

📊 Performance

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

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| | GC | Time | GC Ratio | Time Ratio |
|------------|--------:|-------:|---------:|-----------:|
| Reflex | 54.7KB | 9.3ms | 1x | 1x |
| Zenject | 512KB | 63.2ms | 9.36x | 6.79x |
| VContainer | 128.9KB | 29.8ms | 2.35x | 3.20x |

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| | GC | Time | GC Ratio | Time Ratio |
|------------|--------:|-------:|---------:|-----------:|
| Reflex | 140.6KB | 7.4ms | 1x | 1x |
| Zenject | 1024KB | 23.6ms | 7.28x | 3.18x |
| VContainer | 257.8KB | 9.2ms | 1.83x | 1.24x |

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| | GC | Time | GC Ratio | Time Ratio |
|------------|--------:|------:|---------:|-----------:|
| Reflex | 109.4KB | 1.2ms | 1x | 1x |
| Zenject | 1024KB | 9.2ms | 9.36x | 7.66x |
| VContainer | 257.8KB | 3.3ms | 2.35x | 2.75x |

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| | GC | Time | GC Ratio | Time Ratio |
|------------|--------:|------:|---------:|-----------:|
| Reflex | 140.6KB | 2.9ms | 1x | 1x |
| Zenject | 1024KB | 9.3ms | 7.28x | 3.20x |
| VContainer | 257.8KB | 5.1ms | 1.83x | 1.75x |

🤝 Support

Ask your questions and participate in discussions regarding Reflex related and dependency injection topics at the Reflex
Discord server.

---

📜 License

Reflex is distributed under the terms of the MIT License.
A complete version of the license is available in the LICENSE file in
this repository. Any contribution made to this project will be licensed under
the MIT License.