Domain-Driven-Design question
- by Michael
Hello everyone,
I have a question about DDD. I'm building a application to learn DDD and I have a question about layering. I have an application that works like this:
UI layer calls =
Application Layer -
Domain Layer -
Database
Here is a small example of how the code looks:
//****************UI LAYER************************
//Uses Ioc to get the service from the factory.
//This factory would be in the MyApp.Infrastructure.dll
IImplementationFactory factory = new ImplementationFactory();
//Interface and implementation for Shopping Cart service would be in MyApp.ApplicationLayer.dll
IShoppingCartService service = factory.GetImplementationFactory<IShoppingCartService>();
//This is the UI layer,
//Calling into Application Layer
//to get the shopping cart for a user.
//Interface for IShoppingCart would be in MyApp.ApplicationLayer.dll
//and implementation for IShoppingCart would be in MyApp.Model.
IShoppingCart shoppingCart = service.GetShoppingCartByUserName(userName);
//Show shopping cart information.
//For example, items bought, price, taxes..etc
...
//Pressed Purchase button, so even for when
//button is pressed.
//Uses Ioc to get the service from the factory again.
IImplementationFactory factory = new ImplementationFactory();
IShoppingCartService service = factory.GetImplementationFactory<IShoppingCartService>();
service.Purchase(shoppingCart);
//**********************Application Layer**********************
public class ShoppingCartService : IShoppingCartService
{
public IShoppingCart GetShoppingCartByUserName(string userName)
{
//Uses Ioc to get the service from the factory.
//This factory would be in the MyApp.Infrastructure.dll
IImplementationFactory factory = new ImplementationFactory();
//Interface for repository would be in MyApp.Infrastructure.dll
//but implementation would by in MyApp.Model.dll
IShoppingCartRepository repository = factory.GetImplementationFactory<IShoppingCartRepository>();
IShoppingCart shoppingCart = repository.GetShoppingCartByUserName(username);
//Do shopping cart logic like calculating taxes and stuff
//I would put these in services but not sure?
...
return shoppingCart;
}
public void Purchase(IShoppingCart shoppingCart)
{
//Do Purchase logic and calling out to repository
...
}
}
I've seem to put most of my business rules in services rather than the models and I'm not sure if this is correct?
Also, i'm not completely sure if I have the laying correct? Do I have the right pieces in the correct place? Also should my models leave my domain model? In general I'm I doing this correct according DDD?
Thanks!
