uw-dependency-injection

Dependency Injection (Reflex)

DI-first architecture for complex Unity projects. Only applies when ProjectConfig.yaml -> architecture_pattern: di-first. For simpler projects, use uw-scriptable-object-arch (SO-first) instead.

Before You Start

1. Read docs/ProjectConfig.yaml for:
   • architecture_pattern — must be "di-first" for this skill to apply.
   • di_framework — should be "reflex" (the default and recommended framework).
   • mcp.unity_mcp — if true, call refresh_unity after creating files.
2. Read docs/CODING_STANDARDS.md for async patterns (Awaitable + CancellationToken), access modifiers (internal for cross-class helpers within an asmdef), and class structure.
3. Read docs/NAMING_CONVENTIONS.md for file/class naming.
4. Ensure each feature module has its own .asmdef — create with uw-unity-feature-scaffold. Installers, Controllers, Services all live inside feature asmdefs.

When to Use DI vs SO-First

SO-First (default)	DI-First
Small/medium scope	Large/complex scope
Solo or small team	Team with testing culture
Rapid prototyping	Production architecture
Simple event-driven communication	Cross-feature orchestration via Commands
ScriptableObject event channels	Interface-based injection + factories

Both can coexist: DI containers can bind ScriptableObject data assets as singletons.

Reflex Setup

Install (OpenUPM): openupm install com.gustavopsantos.reflex Or UPM Git URL: https://github.com/gustavopsantos/reflex.git?path=/Assets/Reflex/

Container Hierarchy

RootScope (app lifetime — singletons, core services)
  +-- SceneScope (scene lifetime — per-scene services, controllers)
        +-- Manual child scopes (gameplay round, level, etc.)

Installer Pattern

Each feature module has one Installer that registers its bindings. The Installer lives inside the feature's .asmdef.

using Reflex.Core;
using UnityEngine;

namespace {RootNamespace}.Core
{
    public class CoreInstaller : MonoBehaviour, IInstaller
    {
        [SerializeField] private AudioSettingsData _audioSettings;

        public void InstallBindings(ContainerBuilder builder)
        {
            // Services (singleton, app lifetime)
            builder.AddSingleton(typeof(IAudioService), typeof(AudioService));
            builder.AddSingleton(typeof(IStateMachineService), typeof(StateMachineService));

            // SO data (inject existing asset as value)
            builder.AddInstance(_audioSettings);
        }
    }
}