How ABP generate IRepository<TEntity> for Entity

Question

I am trying to understand how ABP does the above.

The normal workflow in ABP is:

1. Add the entity class inheriting from Entity based class to the Core project
2. Add the DbSet to the context in EFCore project
3. Add a new IEntityAppService interface and implementation to Application project
4. In the IEntityAppService implementation inject the IRepository to the constructor
5. Enjoy!!

What I have done to try to understand:

1. I have looked at the Abp source code and got the impression that this is being done by Open Generics between IRepository<T> and EfCoreRepositoryBase<T> with Factory magic. However, I tried to do this in AspNetCore DI with:

   public void ConfigureServices(IServiceCollection services)
   {
       // Add framework services.
       // adding DbContext
       // adding Mvc etc....
   
       // RepositoryBase => like EfCoreRepositoryBase in ABP
       // Error on this line, DI can not instantiate RepositoryBase as it is abstract
       services.AddTransient<IRepository<>, RepositoryBase<>);
   }
   

Please can someone explain the mechanism to me?

Answer 1

The magic is in EfGenericRepositoryRegistrar.cs where:

foreach (var entityTypeInfo in _dbContextEntityFinder.GetEntityTypeInfos(dbContextType))
{
    // ...

    iocManager.IocContainer.Register(
        Component
            .For(genericRepositoryType)
            .ImplementedBy(implType)
            .Named(Guid.NewGuid().ToString("N"))
            .LifestyleTransient()
}

Note that EfCoreRepositoryBaseOfTEntityAndTPrimaryKey.cs is not abstract.