How to Split ConfigureServices method (of Startup) into multiple files

Question

Separation of concerns (SoC)

Dependency injunction registrtered in ConfigureServices (method of startup class) consist of different DI's like Repository, Fluent Validations etc.

How would I go about separating DI registration into separate files (as shown below)

Contingent

Separate file same project or in different projects?You can create an extension method – Moppet

@Moppet Its in same project. Surely i can use extensions, but is there a alternative way like reference delegations.. – Contingent

extension methods are the most common approach to reducing noise in the Startup class. – Moppet

You should use the extract method refactoring. – Keyte

Answer 1

Create an extension method to hold any additional configuration you want

public static class MyExtensions {
    public static IServiceCollection AddFluentValidation(this IServiceCollection services) {

        //...add services

        return services;
    }
}

And then called in the ConfigureServices in Startup

public void ConfigureServices(IServiceCollection services) {

    //...

    services.AddFluentValidation();
    services.AddRepository();

    //...

}

The use of extension methods for populating the services collection is commonly used by the framework and 3rd party extensions.

Moppet

Answer 2

startup.cs

public class Startup
{
        public void ConfigureServices(IServiceCollection services)
        {
            services.AddMyScoped();
            services.AddMyTransient();
        }
}

AddScopedExtension.cs

public static class AddScopedExtension
{
    public static IServiceCollection AddMyScoped(this IServiceCollection serviceCollection)
    {
        // TODO : Add your Scoped Objects here
        return serviceCollection;
    }
}

AddTransientExtension.cs

public static class AddTransientExtension
{
    public static IServiceCollection AddMyTransient(this IServiceCollection serviceCollection)
    {
        // TODO : Add your Scoped Objects here
        return serviceCollection;
    }
}

Religieuse

Answer 3

Hello you can try this way

Add Extension Method

 public static class SlightDIModuleConfigExtension
{
     public static IWebHostBuilder UseSlightDIModuleconfig(this IWebHostBuilder webHostBuilder)
    {

        return webHostBuilder.ConfigureServices(services =>
        {
            foreach (Type type in Assembly.GetEntryAssembly()
             .GetTypes()
             .Where(myType => myType.IsSubclassOf(typeof(SlightModuleConfigure))))
            {
                var instance = Activator.CreateInstance(type);
                MethodInfo mi = type.GetMethods(BindingFlags.NonPublic | BindingFlags.Instance).FirstOrDefault();
                mi.Invoke(instance, new object[] { services });
            }
        });
    }
}

Add abstract class

public abstract class SlightModuleConfigure
{
    protected virtual void Load(IServiceCollection services) { }
}

How to Use

in Program.cs add UseSlightDIModuleconfig()

 public static IWebHostBuilder CreateWebHostBuilder(string[] args) =>
        WebHost.CreateDefaultBuilder(args)
           .UseStartup<Startup>()
          .UseSlightDIModuleconfig(); //add this .

Add class inherit SlightModuleConfigure like this

public class PayModuleConfig : SlightModuleConfigure
{
    protected override void Load(IServiceCollection services)
    {
          services.AddTransient<Ipay, PayImp>();
    }
}

you can refer to SlightDIConfigure

Cordwood

Answer 4

Partial class - Just another way!

// Startup.cs
public partial class Startup {
    public void ConfigureServices(IServiceCollection services) {
        ConfigureScopedServices(services);
        ConfigureTransientServices(services);
    }
}

// ScopedServices.cs
public partial class Startup {
    private static void ConfigureScopedServices(IServiceCollection services) {
        Console.WriteLine("Scoped");
    }
}

// TransientServices.cs
public partial class Startup {
    private static void ConfigureTransientServices(IServiceCollection services) {
        Console.WriteLine("Transient");
    }
}

Susurrate

Never really considered using partials. – Religieuse

Do you mean it's a bad practice? Glad to know to know more if that's the case. – Susurrate

Not sure if its bad practice or just a personal preference. I generally do not use partials because it can make code harder to maintain. – Religieuse