C# and Ninject question, Inheriting a class runs a method, but how does this happen behind the scene?

Question

I can't seem to find the right answers in several related questions here.

I'm learning Ninject from an article (created a console app in C#), I created a class I named DILoader and inherited NinjectModule:

public class DILoader : NinjectModule
    {
        public override void Load()
        {
            Bind<ICustomer>().To<RetailCustomer>();
            Bind<ICustomer>().To<WholesaleCustomer>();
        }
    }

So in the start up:

 static void Main(string[] args)
        {
            var kernel = new StandardKernel();
            kernel.Load(Assembly.GetExecutingAssembly()); }

My question is, the Load() method above is triggered. How does this happen behind the scene when NinjectModule has an abstract Load() method? Where is this triggered?

Thanks

Answer 1

Here: https://github.com/ninject/Ninject/blob/master/src/Ninject/Modules/NinjectModule.cs

Inside the NinjectModule,

/// <summary>
/// Called when the module is loaded into a kernel.
/// </summary>
/// <param name="kernelConfiguration">The kernel configuration that is loading the module.</param>
/// <param name="settings">The ninject settings.</param>
/// <exception cref="ArgumentNullException"><paramref name="kernelConfiguration"/> is <see langword="null"/>.</exception>
/// <exception cref="ArgumentNullException"><paramref name="settings"/> is <see langword="null"/>.</exception>
public void OnLoad(IKernelConfiguration kernelConfiguration, INinjectSettings settings)
{
    Ensure.ArgumentNotNull(kernelConfiguration, nameof(kernelConfiguration));
    Ensure.ArgumentNotNull(settings, nameof(settings));

    this.KernelConfiguration = kernelConfiguration;
    this.Components = this.KernelConfiguration.Components;
    this.Settings = settings;

    this.Load();
}

And then in the KernelConfiguration implementation you can see it calling module.OnLoad(...) here,

    /// <summary>
    /// Loads the module(s) into the kernel.
    /// </summary>
    /// <param name="modules">The modules to load.</param>
    /// <exception cref="ArgumentNullException"><paramref name="modules"/> is <see langword="null"/>.</exception>
    public void Load(IEnumerable<INinjectModule> modules)
    {
        Ensure.ArgumentNotNull(modules, nameof(modules));

        modules = modules.ToList();
        foreach (INinjectModule module in modules)
        {
            if (string.IsNullOrEmpty(module.Name))
            {
                throw new NotSupportedException(ExceptionFormatter.ModulesWithNullOrEmptyNamesAreNotSupported());
            }

            if (this.modules.TryGetValue(module.Name, out INinjectModule existingModule))
            {
                throw new NotSupportedException(ExceptionFormatter.ModuleWithSameNameIsAlreadyLoaded(module, existingModule));
            }

            module.OnLoad(this, this.Settings);

            this.modules.Add(module.Name, module);
        }

        foreach (INinjectModule module in modules)
        {
            module.OnVerifyRequiredModules();
        }
    }

Have a look at the source and you can trace it around a bit more thoroughly.