Automatic Dependency Injection

Art Admin uses the [Service] attribute and assembly scanning to automatically register services into the DI container. No manual registration in Program.cs is needed.

Usage

[Service(ServiceLifetime.Scoped)]
public class UserService
{
    private readonly ArtDbContext _db;
    private readonly RequestContext _user;

    public UserService(ArtDbContext db, RequestContext user)
    {
        _db = db;
        _user = user;
    }
}

Simply add the [Service] attribute — the framework scans all assemblies at startup and auto-registers.

Lifecycle Options

Lifecycle	Usage
Scoped	One instance per request; default for most services
Singleton	Global singleton, for stateless utilities
Transient	New instance every injection; Worker tasks use this

How It Works

At startup, ServiceCollectionExtensions scans all classes with [Service]:

// Framework auto-scans — services don't need manual registration
var types = assemblies
    .SelectMany(a => a.GetTypes())
    .Where(t => t.GetCustomAttribute<ServiceAttribute>() != null);

foreach (var type in types)
{
    var attr = type.GetCustomAttribute<ServiceAttribute>()!;
    services.Add(new ServiceDescriptor(type, type, attr.Lifetime));
}

Important Rules

WARNING

1. Do NOT register in Program.cs — adding [Service] is sufficient; manual registration causes duplicates
2. Workers must use Transient — Workers run outside HTTP scope, Scoped lifetime will throw
3. Workers must NOT inject RequestContext — no user context in background tasks

RequestContext

RequestContext provides the current user's identity info (extracted from Token by middleware):

public class RequestContext
{
    public long Id { get; set; }           // User ID
    public string? TenantId { get; set; }  // Tenant ID
    // ...
}

Available in Admin/ and App/ services only. Workers/ and Shared/ must not inject it.