Installation: "io.finalclick.services": "https://github.com/FinalClick/io.finalclick.services.git?path=/Assets/Package",

FinalClick – Services

Unity Package: io.finalclick.services

A simple lightweight service locator and dependency injection system for Unity.
Use it to replace hard-referenced singletons with decoupled, testable services.

Example

Instead of this:

GameManager gameManager = GameManager.Instance;

Write this:

GameManager gameManager = ApplicationServices.Get<GameManager>();

or this:

GameManager gameManager = gameObject.GetService<GameManager>();

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Overview

FinalClick.Services allows you to register and resolve services both at the Project/Application level or at an Individual Scene level. Services can be pure C# classes or MonoBehaviours if you require references to assets or scene objects.

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Features

• 🔍 Automatic Service Discovery via RegisterServices and RegisterAsService attributes.
• 🧩 *Automatic Dependency Injection via the InjectService property attribute.
• 💡 Project Level Services via ApplicationServices.
• 🎬 Scene-scoped Services via SceneServices.
• ⚙️ Lifecycle Hooks via the IService interface. (OnServiceStart, OnServiceUpdate, OnServiceStop)
• 🚀 Disable Domain Reload Support: automatic start and stops services during scene load and unload, and when entering or exiting Play Mode.

*Automatic Dependency Injection can only be used within service

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🔍 Getting Services

Inside a Service

[InjectService] 
            │
            └─ SceneServices.Get<T>(scene)
                │
                └─ ApplicationServices.Get<T>()

Within a Service you can use the [InjectService] attribute on a property

[RegisterAsService]
public class ExampleComponent : MonoBehavour
{
    [InjectService] 
    private IMyService MyService { get; } = null;
    
    // ...
}

The service will be injected into the backing field of the property.

Note, the InjectService attribute can only be used if the MonoBehaviour or csharp class is a registered service.

Outside a Service

Note, there are corresponding TryGet functions for the following Get functions

There are 3 ways to get services if the requester is not a service.

GameObject.GetService<T>()
                │
                └─ SceneServices.Get<T>(scene)
                    │
                    └─ ApplicationServices.Get<T>()

GameObject Level

ITimeService timeService = gameObject.GetService<ITimeService>;

This method requires access to a GameObject. It will first check if the scene the GameObject is in has the service it needs. If not found, it will then see if the Application has the service. This means you can have different service instances for each scene.

Scene Level

ITimeService timeService = SceneServices.Get<ITimeService>(scene);

This will require a reference to a scene, usually via gameObject.scene. It will first check if the scene has the service it needs. If not, it will check the ApplicationServices

Application/Project Level

ITimeService timeService = ApplicationServices.Get<ITimeService>(scene);

This can be called anywhere and requires no references to any Unity Object

⚙️ Application Service Registration

Registering Pure C# Services

To register services at the project/application level create a static method marked with the [RegisterServices] attribute.

Example:

[RegisterServices]
public static void RegisterMyServices(ServiceCollectionBuilder builder)
{
    builder.Register<IMyService, MyService>();
}

• The method must be static.
• It must accept exactly one parameter: ServiceCollectionBuilder.
• These methods are automatically called before the first scene is loaded.

Registering Unity MonoBehaviour Services

Using MonoBehaviours allows you to reference Assets/Unity Objects easily via the inspector.

Create a Prefab with your services. The services should be on the root GameObject of the prefab.

[RegisterAsService]
public class MyService : MonoBehavour
{
    ///
}

or

public class ServiceRegister : MonoBehavour
{
    [RegisterServices]
    private void MyRegisterFunction(ServiceCollectionBuilder builder)
    {
        builder.Register<OtherService>(OtherService);
    }
}

Assign the prefab in the Project Settings under FinalClick > Services

• Any [RegisterServices] methods on components on the prefab will be called with the application service collection builder.
• Any [RegisterServiceAs(Type[])] components on the prefab will be automatically registered.

This prefab will be automatically instantiated into the first scene that's loaded.

Note, at build time this prefab is instantiated into the first scene. This causes it to be unpacked and baked at build time so there is no instantiation costs in builds.

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⚙️ Scene Service Registration

Scene services can be registered via MonoBehaviours. However, the MonoBehaviour services must be on a root GameObject in the scene.

1. Any [RegisterServices] methods on a root GameObjects MonoBehaviour will be called on scene load.
2. Any [RegisterAsService] MonoBehaviours, which are also on roo GameObjects, will be registered on scene load

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Service Lifecycle (IService)

For services that need structured startup, update, and shutdown behavior, implement the IService interface:

namespace FinalClick.Services
{
    public interface IService
    {
        void OnServiceStart();
        void OnServiceUpdate();
        void OnServiceStop();
    }
}

Method	Application Service Called When	Scene Service Called When
OnServiceStart()	On Application startup	On Scene Loaded
OnServiceUpdate()	Once per frame	Once per frame
OnServiceStop()	On Application shutdown	On Scene Unloaded

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Lifecycle Overview

Event	Action
Entering Play Mode	Application services are registered and started.
Loading a Scene	Scene services are registered and started.
Unloading a Scene	Scene services are stopped.
Exiting Play Mode / Application Quit	Application and scene services are stopped.

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