Does first object in sequence diagram have to have activation rectangle or is it ok to not have it in the first object? I'm asking because in VS 2010 they do not bother with this in case of first object in sequence diagram.
Another question from this same ball park does name of the objects have to be underlined? In my university they teach us that they have to be but in VS 2010 they are not.
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37answers:
3
A:
I've never read anywhere that it's mandatory to have an activation rectangle on the first object. Checkout this website, there are some drawings that doesn't use it, and it seems fine: http://www.agilemodeling.com/artifacts/sequenceDiagram.htm
Gmoliv
2010-10-13 21:23:48
A:
The "activation rectangles" you mention are useful to show the lifespan of an object. Many times for the first object this is from the beginning to the end of the diagram since that object is the one initiating the interaction. I´d say when this is the case, it´s not strictly necessary. In all other cases, I think it is important to show it.
Jordi Cabot
2010-10-14 16:52:16
A:
Activation bar is important but this is now just a graphical information in UML2 which doesn't have any value in UML2. I mean that the activation bar has no model because this element doesn't exist anymore in the UML2 metamodel.
This is too bad because the activation bar is really an important value to understand better the sequence diagram.