Good example of Domain Services

Here is a good example that Chris Richardson posted in response to one of my questions of the DDD Yahoo! Group. If you haven’t done so already you should take a look at his presentation at SpringOne in June. It goes over all the major DDD topics and gives a really good description of DDD in general.

This is the same manner that I try to use Domain/Application Services although I have found that it’s easy to go overboard with a Service layer and IMO should only be implemented when necessary. There is really no reason to have a Service class that just wraps a Repository. It’s just extra code that needs to be maintained. In Chris’s exmaple though, he illustrates how a Service would retrieve data from one or more Repositories, performs some small amount of work and thats it.

I will be posting more on this later. Just wanted to share the example that I saw. Cheers!


DDD Yahoo Group

If you haven’t seen it already, everyone interested in Domain Driven Design should check out the Yahoo Discussion group found at are many good discussions going on here. As well as alot of people that are actively involved in the DDD community. One of the most beneficial discussions I have seen in the last week is a large thread on aggregates. I learned a great deal about things I was overlooking when it came to aggregates in a domain model.Check it out!