Recognizing a "forms over data" app vs, say, DDD app

Question

I often see statements like "App x doesn't have a complicated enough domain to justify the overhead of a multi-tiered architecture. It is better suited to a forms over data approach." I'm wondering what the characteristics are of a domain which would compel one to go with a particular approach. That is, how can you tell when to do something simple like forms over data or when should you build in multiple tiers, a domain, DTO's, etc.

Answer 1

Both options seem to describe the more heavyweight mouse-driven frameworks where software helps write the software. (These are the usual suspects - frameworks you pay for directly or indirectly.)

I think it's possible to have patterns and practices that lie somewhere in the middle; where you write the software but most cases fit something your already comfortable with. (I think the key word is a strongly bonded relationship with "Patterns".)

A good specific example is the newly popular MVC conceptual framework (and its kindred). These can be treated pretty generically; and you may or may not choose to pay for the tools based on your platform, context and/or personal preferences. But I think there aren't many situations where MVC etc. would be underwhelmed or overwhelmed (but one of the two options proffered in the question would be a decisively better fit.)

At least I'd try real hard to find a middle path, if for no other reason that not doing so tends to lead to short-lifecycle patterns and tools, and scalability issues (which the question refers to directly.)

Answer 2

This is by no means definitive, but I would say forms over data refers mostly to domains that are slim and light on business rules. That is, if you are just inputting data from a screen into a flat data structure that is more or less going straight to persistence, I would think a DDD architecture isn't quite as critical. But if your domain consists of multiple aggregates, and/or is very business rule heavy, then you should probably think about DDD.

Of course, as with all things in our world, there is a lot of grey area in the middle and your best judgment is all you have to make the decision.

You might try asking this question on the DDD message board