Question

I am using AutoMapper.org to map my DTO objects to Model objects in MVC4. DTO objects are retrieved from SOAP web services. The operations on the services are mostly CRUD.

This works nicely.

I have 2 questions. Firstly, is it bad practise to map both ways (2 way mapping). So when I update on screen map the Model to a DTO, as well as the orginal mapping of DTO to Model?

Second question, is it possible for AutoMapper to map enums?

Answer 1

I map both ways without issue – I map from the DTOs to the business objects to get the data, and map back the other way to save the data. This is so that the DTOs that are used in my WCF service are reusable (I’m using CSLA framework and the data portal model in CSLA doesn’t really let 3rd parties consume the service without having access to my bizobj library).

It does mean that some of the business logic is repeated in the web layer, but since the rules are sparse this isn’t a big issue

In my case I don’t think it’s a bad thing. I have a very simple data model which is mostly reads, there is only the occasional time when data goes back across to be modified.

As far as I know it maps enums natively (assuming it’s a direct enum to enum – since enum is just a primitive underneath), but you can always provide your own custom type converters to resolve any enum issues or if you need to do string parsing for enums.