It's simple, there is no need here for reverse engineering (constructing the model from code).
Main
has three associations: one with Model
, one with View
and one with Controller
, while Controller
has two associations: one with Model
and one with View
.
Notice that there is no need for the associations Main-Model
and Main-View
because they can be derived via main.controller.model
and main.controller.view
.
The association Main-Controller
(as well as Main-Model
and Main-View
) can be viewed/modeled as a composition, since a main program instance (a process) is composed of a controller instance, which is bundled with a model and a view instance. All three compositions come with a lifecylce dependency: any model, view and controller instance existentially depends on its main aggregate instance.