Auto-Register 8.0.2

Auto-Register

Overview

The Auto-Register package simplifies service registration for ASP.NET Core applications by automatically discovering and registering services based on custom attributes. This package eliminates the need for manually adding services in Program.cs, supports multiple service lifetimes, and ensures no duplicate registrations occur.

With Auto-Register, services are identified using the RegisterAttribute and are automatically registered as self, interface, or base class implementations.

Installation

To install Auto-Register, add it to your project using the NuGet Package Manager or .NET CLI:

Using Package Manager:

Install-Package Auto-Register

Using .NET CLI:

dotnet add package Auto-Register

Usage

Once the Auto-Register package is installed, you can easily use it in your ASP.NET Core project to auto-register services.

Step 1: Mark Services with RegisterAttribute

Services that need to be registered must be decorated with the RegisterAttribute. This attribute takes the ServiceLifetime (Singleton, Scoped, or Transient) as a parameter.

Example:

using AutoRegister;

// Singleton service
[Register(ServiceLifetime.Singleton)]
public class MySingletonService : IMySingletonService
{
    // Implementation
}

// Scoped service
[Register(ServiceLifetime.Scoped)]
public class MyScopedService : IMyScopedService
{
    // Implementation
}

// Transient service
[Register(ServiceLifetime.Transient)]
public class MyTransientService : IMyTransientService
{
    // Implementation
}

Step 2: Register Services in Program.cs

In your ASP.NET Core application, use the AddAutoregister extension method to automatically register services from a given assembly.

If using ASP.NET Core 5.0+ with a minimal hosting model (Program.cs), add the auto-registration in the ConfigureServices section

using AutoRegister;
using System.Reflection;
using Microsoft.Extensions.DependencyInjection;

var builder = WebApplication.CreateBuilder(args);

// Automatically register services marked with the RegisterAttribute
builder.Services.AddAutoregister(Assembly.GetExecutingAssembly());

var app = builder.Build();
app.Run();

Example Scenario

Consider an ASP.NET Core application where you want to automatically register several services:

[Register(ServiceLifetime.Singleton)]
public class AuthService : IAuthService
{
    // Singleton service for authentication
}

[Register(ServiceLifetime.Scoped)]
public class ShoppingCartService : IShoppingCartService
{
    // Scoped service for managing shopping carts
}

[Register(ServiceLifetime.Transient)]
public class PaymentService : IPaymentService
{
    // Transient service for handling payments
}

// Program.cs (ASP.NET Core 5.0+)
var builder = WebApplication.CreateBuilder(args);

// Automatically register services
builder.Services.AddAutoregister(Assembly.GetExecutingAssembly());

var app = builder.Build();
app.Run();

In this example:

AuthService will be registered as a Singleton

ShoppingCartService will be registered as a Scoped

PaymentService will be registered as a Transient

The services will automatically be resolved and injected where required, without needing to manually specify them in Program.cs

Components

RegisterAttribute

This attribute is used to mark classes for automatic registration. It defines the lifetime of the service (Singleton, Scoped, or Transient) via the constructor.

Constructor:

public RegisterAttribute(ServiceLifetime lifetime)

Parameter:

ServiceLifetime lifetime: Specifies the lifetime of the service to be registered (Singleton, Scoped, or Transient)

Example:

[Register(ServiceLifetime.Singleton)]
public class MyService : IMyService
{
    // Implementation
}

Key Features

1. Automatic Service Discovery and Registration:

Services marked with the RegisterAttribute are automatically discovered and registered based on their lifetime (Singleton, Scoped, or Transient)

2. Interface and Base Class Registration:

Classes can be registered not only as themselves but also as their interfaces, abstract or any base classes.

3. Self-Registration:

Classes that do not implement interfaces or inherit from abstract base classes can still be self-registered in the service collection.

4. Duplicate Prevention:

Services are registered only once, preventing multiple registrations of the same type.

5. Lifetime Control:

Service lifetime is controlled via the RegisterAttribute, making it easy to specify whether a service should be Singleton, Scoped, or Transient

Advanced Usage

Registering External Assemblies

If you want to register services from multiple assemblies, you can pass those assemblies to the AddAutoregister method. For example:

using AutoRegister;
using System.Reflection;
using Microsoft.Extensions.DependencyInjection;

var builder = WebApplication.CreateBuilder(args);

// Register services from multiple assemblies
builder.Services.AddAutoregister(AppDomain.CurrentDomain.GetAssemblies());

var app = builder.Build();
app.Run();

Ignoring Specific Services

Currently, all services marked with the RegisterAttribute in the provided assemblies will be registered. If you want to exclude certain services, you would need to manually intervene before the registration process.

Supported Platforms

Auto-Register is designed for use any types of .NET applications that support Microsoft Dependency Injection, including:

• ASP.NET Core Applications
• Worker Services
• Blazor Applications
• WPF Applications
• Windows Forms Applications

I am showing some examples through a console application

Example 1: Simple Open Generic Interface and Class

using AutoRegister;
using Microsoft.Extensions.DependencyInjection;
using System.Reflection;

var services = new ServiceCollection();
services.AddAutoregister(Assembly.GetExecutingAssembly());
using var serviceProvider = services.BuildServiceProvider();

var myService = serviceProvider.GetRequiredService<IMyService<int>>();
myService.DoExecute();

public interface IMyService<T>
{
    void DoExecute();
}

[Register(ServiceLifetime.Scoped)]
public class MyService<T> : IMyService<T>
{
    public void DoExecute()
    {
        Console.WriteLine($"Executed Scoped Service with type {typeof(T)}");
    }
}

[Output] : Executed Scoped Service with type System.Int32

Example 2: Closed Generic Interface and Class

using AutoRegister;
using Microsoft.Extensions.DependencyInjection;
using System.Reflection;

var services = new ServiceCollection();
services.AddAutoregister(Assembly.GetExecutingAssembly());
using var serviceProvider = services.BuildServiceProvider();

var myService = serviceProvider.GetRequiredService<IClosedGenericService<int>>();
myService.Process(99);

public interface IClosedGenericService<T>
{
    void Process(T type);
}

[Register(ServiceLifetime.Scoped)]
public class ClosedGenericService : IClosedGenericService<int>
{
    public void Process(int type)
    {
        Console.WriteLine($"Processing Closed Generic Service with int {type}");
    }
}

[Output] : Processing Closed Generic Service with int 99

Example 3: Multiple Generic Types

using AutoRegister;
using Microsoft.Extensions.DependencyInjection;
using System.Reflection;

var services = new ServiceCollection();
services.AddAutoregister(Assembly.GetExecutingAssembly());
using var serviceProvider = services.BuildServiceProvider();

var myService = serviceProvider.GetRequiredService<IMyService<int, string>>();
myService.DoExecute(5, "Auto-Register");

public interface IMyService<T1, T2> 
{
    void DoExecute(T1 type1, T2 type2); 
}

[Register(ServiceLifetime.Transient)]
public class MyService : IMyService<int, string>
{
    public void DoExecute(int type1, string type2)
    {
        Console.WriteLine($"Executed Transient with {type1} and {type2}");
    }
}

[Output] : Executed Transient with 5 and Auto-Register

Example 4: Non-Generic Interface and Class

using AutoRegister;
using Microsoft.Extensions.DependencyInjection;
using System.Reflection;

var services = new ServiceCollection();
services.AddAutoregister(Assembly.GetExecutingAssembly());
using var serviceProvider = services.BuildServiceProvider();

var myService = serviceProvider.GetRequiredService<IMyService>();
myService.DoExecute();

public interface IMyService 
{
    void DoExecute(); 
}

[Register(ServiceLifetime.Singleton)]
public class MyService : IMyService
{
    public void DoExecute()
    {
        Console.WriteLine("Non-generic service executed (Singleton)");
    }
}

[Output] : Non-generic service executed (Singleton)

Example 5: Closed Generic Class with Concrete Types

using AutoRegister;
using Microsoft.Extensions.DependencyInjection;
using System.Reflection;

var services = new ServiceCollection();
services.AddAutoregister(Assembly.GetExecutingAssembly());
using var serviceProvider = services.BuildServiceProvider();

var myService = serviceProvider.GetRequiredService<IMyService>();
myService.DoExecute();

public interface IMyService 
{
    void DoExecute(); 
}

[Register(ServiceLifetime.Scoped)]
public class MyService : MyGenericService<int>, IMyService
{
}

[Register(ServiceLifetime.Scoped)]
public class MyGenericService<T>
{
    public void DoExecute()
    {
        Console.WriteLine($"Executed with closed generic type: {typeof(T)}");
    }
}

[Output] : Executed with closed generic type: System.Int32

Example 6: Complex Generic Class with Constraints

using AutoRegister;
using Microsoft.Extensions.DependencyInjection;
using System.Reflection;

var services = new ServiceCollection();
services.AddAutoregister(Assembly.GetExecutingAssembly());
using var serviceProvider = services.BuildServiceProvider();

var myService = serviceProvider.GetRequiredService<IMyService<int>>();
myService.DoExecute();

public interface IMyService<T> where T : struct 
{ 
    void DoExecute(); 
}

[Register(ServiceLifetime.Singleton)]
public class MyService<T> : IMyService<T> where T : struct
{
    public void DoExecute()
    {
        Console.WriteLine($"Executed Singleton with {typeof(T)}");
    }
}

[Output] : Executed Singleton with System.Int32

Example 7: Generic with Multiple Constraints

using AutoRegister;
using Microsoft.Extensions.DependencyInjection;
using System.Reflection;

var services = new ServiceCollection();
services.AddAutoregister(Assembly.GetExecutingAssembly());
using var serviceProvider = services.BuildServiceProvider();

var myService = serviceProvider.GetRequiredService<IMyService<int>>();
myService.DoExecute();

public interface IMyService<T> where T : struct, IComparable 
{ 
    void DoExecute(); 
}

[Register(ServiceLifetime.Scoped)]
public class MyService<T> : IMyService<T> where T : struct, IComparable
{
    public void DoExecute()
    {
        Console.WriteLine($"Executed Scoped with {typeof(T)} and constraint");
    }
}

[Output] : Executed Scoped with System.Int32 and constraint

Example 8: Nested Generics

using AutoRegister;
using Microsoft.Extensions.DependencyInjection;
using System.Reflection;

var services = new ServiceCollection();
services.AddAutoregister(Assembly.GetExecutingAssembly());
using var serviceProvider = services.BuildServiceProvider();

var myService = serviceProvider.GetRequiredService<IMyService<List<int>>>();
myService.DoExecute();

public interface IMyService<T> 
{ 
    void DoExecute(); 
}

[Register(ServiceLifetime.Transient)]
public class MyService<T> : IMyService<T>
{
    public void DoExecute()
    {
        Console.WriteLine($"Executed Transient with nested {typeof(T)}");
    }
}

[Output] : Executed Transient with nested System.Collections.Generic.List`1[System.Int32]

Example 9: Hybrid Non-Generic and Generic Services

using AutoRegister;
using Microsoft.Extensions.DependencyInjection;
using System.Reflection;

var services = new ServiceCollection();
services.AddAutoregister(Assembly.GetExecutingAssembly());
using var serviceProvider = services.BuildServiceProvider();

var myService = serviceProvider.GetRequiredService<HybridService>();
myService.DoExecute<int>();

[Register(ServiceLifetime.Scoped)]
public class HybridService
{
    private readonly OpenGenericService<int> _openGenericService;

    public HybridService(OpenGenericService<int> openGenericService)
    {
        _openGenericService = openGenericService;
    }

    public void DoExecute<T>()
    {
        Console.WriteLine("Executing Scoped HybridService.");
        _openGenericService.DoExecute();
    }
}

[Register(ServiceLifetime.Scoped)]
public class OpenGenericService<T>
{
    public void DoExecute()
    {
        Console.WriteLine($"Executing Scoped OpenGenericService with type: {typeof(T)}.");
    }
}

[Output] :

Executing Scoped HybridService.

Executing Scoped OpenGenericService with type: System.Int32.

Example 10: Multi-Layer Inheritance (Non-Generic and Generic)

using AutoRegister;
using Microsoft.Extensions.DependencyInjection;
using System.Reflection;

var services = new ServiceCollection();
services.AddAutoregister(Assembly.GetExecutingAssembly());
using var serviceProvider = services.BuildServiceProvider();

var myService = serviceProvider.GetRequiredService<LayeredService>();
myService.DoExecute<int>();

public abstract class BaseService
{
    public abstract void DoExecute<T>();
}

[Register(ServiceLifetime.Singleton)]
public class GenericBaseService<U> : BaseService
{
    public override void DoExecute<T>()
    {
        Console.WriteLine("Executing Singleton GenericBaseService with type: " + typeof(T));
    }
}

[Register(ServiceLifetime.Singleton)]
public class LayeredService : GenericBaseService<int>
{
    public override void DoExecute<T>()
    {
        Console.WriteLine("Executing Singleton LayeredService.");
        base.DoExecute<T>();
    }
}

[Output] :

Executing Singleton LayeredService.

Executing Singleton GenericBaseService with type: System.Int32

Example 11: Multiple Implementations of Interface Non-Generic and Generic Services

using AutoRegister;
using Microsoft.Extensions.DependencyInjection;
using System.Reflection;

var services = new ServiceCollection();
services.AddAutoregister(Assembly.GetExecutingAssembly());
using var serviceProvider = services.BuildServiceProvider();

var myService = serviceProvider.GetRequiredService<IServiceFactory>()
    .GetService("A");

myService.DoExecute<string>();

public interface IService
{
    void DoExecute<T>();
}

[Register(ServiceLifetime.Scoped)]
public class ServiceImplementationA : IService
{
    public void DoExecute<T>()
    {
        Console.WriteLine($"Executing Scoped ServiceImplementationA with type: {typeof(T)}.");
    }
}

[Register(ServiceLifetime.Scoped)]
public class ServiceImplementationB : IService
{
    public void DoExecute<T>()
    {
        Console.WriteLine($"Executing Scoped ServiceImplementationB with type: {typeof(T)}.");
    }
}

[Register(ServiceLifetime.Scoped)]
public class ServiceFactory : IServiceFactory
{
    private readonly IServiceProvider _serviceProvider;

    public ServiceFactory(IServiceProvider serviceProvider)
    {
        _serviceProvider = serviceProvider;
    }

    public IService GetService(string implementationType)
    {
        return implementationType switch
        {
            "A" => _serviceProvider.GetRequiredService<ServiceImplementationA>(),
            "B" => _serviceProvider.GetRequiredService<ServiceImplementationB>(),
            _ => throw new ArgumentException($"Service type {implementationType} is not supported.")
        };
    }
}

public interface IServiceFactory
{
    IService GetService(string implementationType);
}

[Output] : Executing Scoped ServiceImplementationA with type: System.String.

Example 12: Complex Generic Class with inheritance and interface implementation

using AutoRegister;
using Microsoft.Extensions.DependencyInjection;
using System.Reflection;

var services = new ServiceCollection();
services.AddAutoregister(Assembly.GetExecutingAssembly());
using var serviceProvider = services.BuildServiceProvider();

var myCar = serviceProvider.GetRequiredService<ElectricCar>();
myCar.Drive();

[Register(ServiceLifetime.Scoped)]
public class Vehicle
{
    public virtual void StartEngine()
    {
        Console.WriteLine("Engine started.");
    }
}

public abstract class LandVehicle : Vehicle
{
    public abstract void Drive();
}

public interface ITransport
{
    void GetTransportMode();
}

[Register(ServiceLifetime.Scoped)]
public class Car<T> : LandVehicle, ITransport where T : Vehicle, new()
{
    public override void Drive()
    {
        Console.WriteLine("Driving on the road.");
    }

    public void GetTransportMode()
    {
        Console.WriteLine("Land transport");
    }

    public override void StartEngine()
    {
        Console.WriteLine("Car engine started.");
    }
}

[Register(ServiceLifetime.Scoped)]
public class ElectricCar : Car<ElectricCar>
{
    public override void Drive()
    {
        Console.WriteLine("Driving silently on electric power.");
    }
}

[Output] : Driving silently on electric power.

Conclusion

The Auto-Register NuGet package provides a powerful and flexible way to manage service registration in ASP.NET Core. By automating service discovery and registration, it reduces boilerplate code and helps maintain clean and maintainable service registration logic, especially in large projects with many services.