I am designing a game using Artemis, although this is more of philosophical question about component-based design in general. Let's say I have non-primitive data which applies to a given component (a Component "animal" may have qualities such as "teeth" or "diet"). There are three ways to approach this in data-driven design, as I see it:
1) Generate classes for these qualities using "traditional" OOP. I imagine this has negative implications for performance, as systems then must be made aware of these qualities in order to process them. It also seems counter to the overall philosophy of data-driven design.
2) Include these qualities as sub-components. This seems off, in that we are now confusing the role of components with that of entities. Moreover out of the box Artemis isn't capable of mapping these subcomponents onto their parent components.
3) Add "teeth", "diet", etc. as components to the overall entity alongside "animal". While this feels odd hierarchically, it may simply be a peculiarity of component-based systems.
I suspect 3 is the correct way to think about things, but I was curious about other ideas.