Enterprise Architect Communication Diagrams question

Question

I want to achieve something like this in Enterprise Architect's Communication Diagrams:

   start()    ----------------    1. create()   ------------
------------> | RGController | ---------------> | U : User |
              ----------------                  ------------

But I am facing 2 problems:

1. It seems I have to always make a connection between 2 objects (I can't have the start() message just come out of nowhere, like I'd want).
2. I can't control the numbering as I'd want. Is there any way I could just set the numbering by myself? If I define that an actor is calling start() on RGController, it will call it message 1 when I'd want message 1 to be User.create().

Answer 1

A) Which Object is sending the start() message to RGController? Add it to the diagram and create the connection between these two objects.

Alternatively you could send the initial message from an Inital element (in the Activity toolbox).

You could also hack an invisible start element by creating an empty shape rendering script.

Just create a new Stereotype in Settings->UML...->Stereotypes, set the name to hidden, applied to , and set the shape script as:

shape main {
}

Then apply this stereotype to your initial element. It should be rendered as invisible.

B) I'm not sure how to manually set the message labeling. Are you aware of the message numbering settings?

• right clicking one of the message labels an selecting "Sequence Communication Messages".

• checking "start new group" in the Message Properties->Sequnce Expressions section.

Answer 2

Are you trying to draw an architecture which uses a Front-controller or Facade for handling incoming request? If so in that case the client will call the start(). E.g. In case of an ASP.net application, it will be the UI code or presentation logic.

Client/User/Customer ---start()---> RGBController--- create() ---> u: User