Populating dropdowns/selection lists

Question

Hello!

I'm still in the process of learning DDD. I'm writing an ASP.NET MVC Application and I have several drop downs that I need to populate from the database. I've created mapped entities for every type (status, result, etc.)

What I can't figure out is from where I should be getting the data. Creating a separate repository for each type of selection list feels like a pain when you have to inject plenty of repositories into the MVC controllers. Also, all these selection lists are read-only so a repository per selection list seems overkill. Creating a single super repository for all selection list types doesn't seem right either, since a repository should be like a collection of one entity type.

I've been reading a little about CQS and having a reporting layer, but I don't know how that would be implemented correctly.

Answer 1

First of all - do not even look at CQRS if You don't feel comfortable with DDD. I mean - do look, but don't try to implement real project with it. Yet.

When we aren't separating read from write sides of our application, repository gets messed up a little bit cause of mixed responsibilities.

From one point of view - it is responsible for persisting aggregate root, from other - it's responsible for reporting too.

That means - there is nothing wrong (at least in my mind), if repository contains functionality to retrieve data for presentation purposes only.

In Your case - i would just build dropdowns using data from according repositories. So - Product dropdown list would take data from ProductRepository.Find(bySomething) (or Repository<Product>(bySomething) in case I decide to use generic repository).

P.s. Be warned that DDD isn't that much about patterns. It's more about ubiquitous language and making Your domain model explicit.