Re: basic q about sequence diagrams

From: Gawnsoft (xlucid_at_users.sourceforge.remove.this.antispam.net)
Date: 03/16/04 

Date: Tue, 16 Mar 2004 10:36:12 +0000

On Tue, 16 Mar 2004 02:43:52 GMT, "Karl Hungus"
<nnnnndddddd@hotmail.com> wrote (more or less):

>If two objects are represented in a sequence diagram with one message
>joining them, and the message is a method call, which object is supposed to
>have the method as one of its members?
>
>example if I have a car object and I want to call a method
>car.getPassengers() to return a collection of passengers
>
>do I model it this way:
>
>[car] ------getPassengers----->[passengers]
>or
>[system] ------getPassengers----->[car]
>
>..brackets are boxes there...forgive the simplification

The question's really about what process you are then going to draw in
the diagram.

In this example there is a Car object, associated with a number of
Passenger objects, yes?

A Car object keeps track of how many Passenger objects it is
associated with.

A user wants to know how many, so enquires from the system, by sending
a 'how many passengers do you have?' message to the car.

so the answer is:
[system] ------getPassengers----->[car]

HTH

Cheers,
   Euan
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