Entity-Control-Boundary Pattern

Question

I am studying about Entity-Control-Boundary Pattern and trying to make class diagram for Online learning platform site. Answers from This question helped me a lot. While designing Boundary classes I'm facing a design issue. I've not found any example of Boundary or Control classes where inheritance has been used. But In my design I'm trying to bring inheritance.

I've converted this to the following:

So, the partial design looks like this:

My questions:

1. Is it mandatory or convention to write <<Boundary>> in the interface to show that it is a interface of Boundary class ? I've just written <<interface>> .
2. Should I use parameters in a Boundary class ? I know that the main logical work is done by the Control class. But user interacts with the Boundary class directly and then Boundary class passes information to Control class.
3. If I chose selectTutorial operation of TutorialListUI user's Boundary class will be changed to IndividualTutorialUI . Should I just draw a line between these two Boundary classes to show the transition ?
4. Apart from these, please mention any improvements that can be made.

Answer 1

1. Writing just <<interface>> is correct.
2. The boundary class usually just holds attributes which usually correspond to screen fields and operations corresponding buttons.
3. No. This is behavior and does not fit in a (static) class diagram.

4. see below

   • Your boundaries rather look like being controllers.
   • You write "But In my design I'm trying to bring inheritance." but you rather (correctly) use a realization in your diagram
   • There should be tons of examples out there. Also look for MVC which is almost the same with other words (I said almost!).