Domain Layer Associations in 4 Layer Architecture

Question

I saw a 4 layer architecture example(first picture) in a web site. According to that, domain layer classes have association with only controller. But in my design(second picture) I need them to have association with each other. Is it legal for controller pattern or 4 layer architecture.

Answer 1

Yes, it is absolutely legal. The only limitation is that there should be less connections between components of neighbouring levels and no connections between non-neighbouring levels. Components of the same levels are free to be connected at maximum.