4

Based on this Question and its answer :

Object in Business layer same as DTO with logic?

I want to ask :

What if instead of DAL, I'm getting data from a remote service (API) through DTOs. My DTOs here represent prettymuch the business objects with all the relationships in between. Although there is BOs in the API that I'm calling I cannot put the behavior that I need there as it is specific for me. How can I deal with this ?

if no behavior on DTO so what ? This look crappy

(API) <--DTO--> (mappingService) <--Domain object--> (domainService) <--DTO--> (UI) ??

  • Are you using an anemic or rich domain? – candied_orange Jun 10 '17 at 1:21
  • If your system doesn't need rich domain data models, because it's a mere proxy between UI and 3rd party services. Why do you care about the business? The schema you have suggested makes sense. Your system acts like a integration facade. – Laiv Jun 10 '17 at 12:50
2

There are several architectural patterns for your choice:

  • The DTO is a distribution pattern and aims to transfer data between processes and remote services. The goal is to reduce the number of interprocess function/method calls that are inefficient when crossing the boundaries of a single process.
  • The domain model object leaves transfer and persistance to a data gateway or a mapper.
  • The active record is a mix between both. It aims at encapsulating data access together with domain logic.

Basically, combining your DTO with domain logic looks pretty much like an active record. It's a viable solution if your domain model is simple and if the domain object is very close to the DTO.

However, be aware of its major drawbacks :

  • you no longer benefit from the decoupling offered by the DTO. A DTO isolates your internal domain model, from the back-end implementation, and let each of it evolve at its own pace.
  • it's not really aligned with the clean design principle of single responsibility

And attention: use it only if the domain model is simple. It's not a good idea if one object is simple but the whole model would be rather complex, because active records raise a lot of issues if you'd need to combine it with unit of work, an identity map or other patterns of enterprise application architecture.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.