[news.eclipse.tools.uml2] Re: Message signature

["Eric Kop" <koperic@xxxxxxxxxxx>]

James,

Thank you. Good explanation.

Eric

"James Bruck" <jbruck@xxxxxxxxxx> wrote in message
news:ehilu1$hif$1@xxxxxxxxxxxxxxxxxxxx
> Hi Eric,
>
> It makes sense to me that the message signature is obtained from the
sending
> end in the case where a receiving event is present.
> Ultimately, it is the sending end that knows what is trying to call or
> invoke.   There are scenarios where what is received might get "mixed up"
in
> which case the receiving event and sending event might not match up.
> Also, when you say "the signature would be an operation of the
> receiveOperationEvent because it is a call to an operation on ClassB"...
> this might not be true.   An interface would define the contract between
> communicating parts (lifeline), however, a particular part (lifeline)
might
> not implement the contract in question in which case it would not know how
> to respond to the message.
> It is the sender that is aware of the contract and is trying to
communicate
> in terms of that contract.
>
> The spec is trying to cover all the bases when it says to use the sending
> end... although in your specific scenario, it might be ok to use the
> receiving end.
>
>  I would guess that the reason we even bother with receiving events for
> signature derivation is when gates are introduced.   In that case, the
> sending event might not be obtainable since it is outside the context of
the
> interaction being modeled.
>
> One might argue that the message itself should know about the signature of
> the operation, however, I believe that events were introduced as a way of
> decoupling the message from the event so that the same event might be used
> for other action modeling.  Events are a way of tieing together concepts
> spread across different diagrams.
>
>
>
> Cheers,
>
> - James.
>
>
>
> "Eric Kop" <koperic@xxxxxxxxxxx> wrote in message
> news:ehaeb8$ifi$1@xxxxxxxxxxxxxxxxxxxx
> > Hi,
> >
> > I have a question regarding the signature of a message. The UML2.1
> > specification says that "if both a sending and a receiving message event
> are
> > present, the signature is obtained from the sending event". This seems
odd
> > to me, I would expect it to be the receiving event?
> >
> > I created two lifelines with connectable elements of respectively Class
A
> > and Class B.
> > I created a synchCall message between the lifelines with a 'sending'
> > messageOccurrenceSpecification referring to a sendOperationEvent
referring
> > to an operation defined on Class A; and with a 'receiving'
> > messageOccurrenceSpecification referring to a receiveOperationEvent
> > referring to an operation defined on Class B. I would expect the
signature
> > of the message would be the operation of the receiveOperationEvent,
> because
> > it is a call to an operation on Class B.
> >
> > Is the specification wrong or is my interpretation/expectation wrong?
> >
> > Regards,
> > Eric Kop
> >
> >
>
>