Jan 17 2009
DDD and generic repositories
Reuse is good. That’s what we learn, so we all strive to reuse code, but sadly sometimes we over generalize and try to be too clever. I have had the suspicion that creating generic repositories that takes criteria/queries as input parameters is one such over generalization. Some things, in fact a lot of things, are worth making explicit.
As Greg Young points out in this excellent article, this over generalization can even hurt you when it comes to tackling performance at a later stage. It’s well worth the read. 
3 responses so far
blog: DDD and generic repositories http://tinyurl.com/74oz2h
All things being equal, I would prefer specific repositories like this. However, this seems to explode the amount of configuration that I need to wire up stuff. There are ways around this again, but the once I’ve tried had the same problems with hiding intent as universal repositories have. Maybe I just need to use more autowiring…
I’m not sure auto wiring is the correct way. I see your argument about more configuration, but still think the explicitness trumps this.
I suspect your main concern here is how to handle these things the best way when you are writing tests. In the case of testing; as with so much else, the clue is to reuse and centralize set up code like this in a way that avoids it being all over the place.