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DI Integration

Aspid.MVVM supports Zenject and VContainer for resolving ViewModels through Dependency Injection.

Contents​

Overview​

DI integration lets you:

  • Resolve ViewModels from a DI container
  • Inject dependencies into ViewModels
  • Use ViewInitializer with InitializeStage.DiConstructor

Two DI frameworks are supported:

  • Zenject (Extenject)
  • VContainer

Zenject​

Step 1: Define the compilation symbol​

In Project Settings → Player → Scripting Define Symbols add:

ASPID_MVVM_ZENJECT_INTEGRATION

Step 2: Register the ViewModel in the container​

using Zenject;

public class GameInstaller : MonoInstaller
{
    public override void InstallBindings()
    {
        Container.Bind<PlayerViewModel>().AsSingle();
        Container.Bind<InventoryViewModel>().AsSingle();
    }
}

Step 3: Configure ViewInitializer​

  1. Add ViewInitializer to a GameObject
  2. Set InitializeStage → DiConstructor
  3. In the ViewModel section set ResolveType → Di
  4. In TypeSelector pick the ViewModel type (for example PlayerViewModel)

Zenject injects the container into ViewInitializerBase through [Inject].

A ViewModel with Zenject​

[ViewModel]
public partial class PlayerViewModel
{
    [OneWayBind] private string _name;
    [OneWayBind] private int _health;

    private readonly IPlayerService _playerService;

    // Zenject injects IPlayerService
    public PlayerViewModel(IPlayerService playerService)
    {
        _playerService = playerService;
        _name = playerService.Name;
        _health = playerService.Health;
    }
}

VContainer​

Step 1: Define the compilation symbol​

ASPID_MVVM_VCONTAINER_INTEGRATION

Step 2: Register the ViewModel​

using VContainer;
using VContainer.Unity;

public class GameLifetimeScope : LifetimeScope
{
    protected override void Configure(IContainerBuilder builder)
    {
        builder.Register<PlayerViewModel>(Lifetime.Scoped);
        builder.Register<InventoryViewModel>(Lifetime.Scoped);
    }
}

Step 3: Configure ViewInitializer​

Same as Zenject: in the Inspector with InitializeStage.DiConstructor.

DiConstructor​

InitializeStage.DiConstructor is a special stage where:

  1. The DI container injects itself into ViewInitializerBase
  2. On initialization a ViewModelInitializeComponent with ResolveType.Di asks the container
  3. The container creates the ViewModel with all dependencies resolved
  4. The View is initialized with that ViewModel

ViewModelInitializeComponent with Di​

In the Inspector:

  • ResolveType → Di
  • TypeSelector → pick the concrete ViewModel type

TypeSelector shows the type name (a string) by which the container finds the registration.

Without DI: manual initialization​

If you do not use DI:

  • The Bootstrap pattern with view.Initialize(viewModel), see Getting Started
  • ViewInitializer with ResolveType.Component or ResolveType.ScriptableObject
  • ViewInitializerManual with the ViewModel passed from code

See also​