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Ordering in Sequence Diagram [message #477470] Tue, 03 June 2008 10:10 Go to next message
Timothy Marc is currently offline Timothy MarcFriend
Messages: 547
Registered: July 2009
Senior Member
Hi all,

i have specified a Sequence Diagram with some Messages and Execution
Specifications, etc., manually with the UML tree editor. My problem is:
Where is the sequence of the messages, which are being send, specified?
Currently it is so, that I have defined two messages a and b, were a occurs
before b. Now i've inserted a third message c, which should be placed before
the occurence of a. But that message c is physically represented in the XMI
after b. So, how does the "diagram" knows that c should be occure before a,
even if it was later added?

In the UML Superstructure there is a General Ordering, but i think, this is
not the correct element to define the implicit sequence of messages?

Any help will be appreciated.

Thx
Timothy
Re: Ordering in Sequence Diagram [message #477474 is a reply to message #477470] Tue, 03 June 2008 10:55 Go to previous messageGo to next message
Timothy Marc is currently offline Timothy MarcFriend
Messages: 547
Registered: July 2009
Senior Member
Okay,

the questions was answered. I'm wondering, that there is no semantical
ordering of messages, but a physical one. The actual ordering of messages
are derived from the physical representation of their corresponfig
OccurenceSpecifications in the XMI. I can't image, that this is the best
solution?
Are there other opinios outthere?

Timothy
"Timothy Marc" <timothymarc@freenet.de> schrieb im Newsbeitrag
news:g2359p$o7e$1@build.eclipse.org...
> Hi all,
>
> i have specified a Sequence Diagram with some Messages and Execution
> Specifications, etc., manually with the UML tree editor. My problem is:
> Where is the sequence of the messages, which are being send, specified?
> Currently it is so, that I have defined two messages a and b, were a
> occurs before b. Now i've inserted a third message c, which should be
> placed before the occurence of a. But that message c is physically
> represented in the XMI after b. So, how does the "diagram" knows that c
> should be occure before a, even if it was later added?
>
> In the UML Superstructure there is a General Ordering, but i think, this
> is not the correct element to define the implicit sequence of messages?
>
> Any help will be appreciated.
>
> Thx
> Timothy
>
Re: Ordering in Sequence Diagram [message #477483 is a reply to message #477474] Wed, 04 June 2008 04:05 Go to previous messageGo to next message
Rafael Chaves is currently offline Rafael ChavesFriend
Messages: 362
Registered: July 2009
Senior Member
Timothy, this is my understanding:

1 - a message has a send and receive events, which are MessageEnds.

2 - MessageEnd is abstract. One of the concrete subclasses (the one that
seems to be interesting in the context of sequence diagrams) is
MessageOccurrenceSpecification.

3 - a MessageOccurrenceSpecification is a subclass of
OccurenceSpecification, which can participate in a GeneralOrdering. From:

http://download.eclipse.org/modeling/mdt/uml2/javadoc/2.2.0/ org/eclipse/uml2/uml/GeneralOrdering.html

"A general ordering represents a binary relation between two occurrence
specifications, to describe that one occurrence specification must occur
before the other in a valid trace. This mechanism provides the ability
to define partial orders of occurrence cpecifications that may otherwise
not have a specified order."

Hope this helps. Never done anything in that area, so I might be
completely off here.

Cheers,

Rafael
http://abstratt.com/textuml/

Timothy Marc wrote:
> Okay,
>
> the questions was answered. I'm wondering, that there is no semantical
> ordering of messages, but a physical one. The actual ordering of messages
> are derived from the physical representation of their corresponfig
> OccurenceSpecifications in the XMI. I can't image, that this is the best
> solution?
> Are there other opinios outthere?
>
> Timothy
> "Timothy Marc" <timothymarc@freenet.de> schrieb im Newsbeitrag
> news:g2359p$o7e$1@build.eclipse.org...
>> Hi all,
>>
>> i have specified a Sequence Diagram with some Messages and Execution
>> Specifications, etc., manually with the UML tree editor. My problem is:
>> Where is the sequence of the messages, which are being send, specified?
>> Currently it is so, that I have defined two messages a and b, were a
>> occurs before b. Now i've inserted a third message c, which should be
>> placed before the occurence of a. But that message c is physically
>> represented in the XMI after b. So, how does the "diagram" knows that c
>> should be occure before a, even if it was later added?
>>
>> In the UML Superstructure there is a General Ordering, but i think, this
>> is not the correct element to define the implicit sequence of messages?
>>
>> Any help will be appreciated.
>>
>> Thx
>> Timothy
>>
>
>
Re: Ordering in Sequence Diagram [message #477486 is a reply to message #477483] Wed, 04 June 2008 12:34 Go to previous message
Timothy Marc is currently offline Timothy MarcFriend
Messages: 547
Registered: July 2009
Senior Member
Dear Rafael,

of course, i've read the spec before. The main purpose of GeneralOrdering is
for partial ordering of Events, which are commonly not ordered (e.g. for
asynchronous messaging). The GeneralOrdering object is not to be intendend
to order the message occurences.
It is so that the physically appearance of the occurences (physically means,
the order of appearance in the XMI) defines the ordering of message and
execution occurences.
I was wondering conerning that mechanism, even if it is very simple to
understand. But this way implies a semantical dependency between the storage
and the interpretation of a sequence diagram.

Timothy
"Rafael Chaves" <rafael@abstratt.com> schrieb im Newsbeitrag
news:g254aa$p6h$1@build.eclipse.org...
> Timothy, this is my understanding:
>
> 1 - a message has a send and receive events, which are MessageEnds.
>
> 2 - MessageEnd is abstract. One of the concrete subclasses (the one that
> seems to be interesting in the context of sequence diagrams) is
> MessageOccurrenceSpecification.
>
> 3 - a MessageOccurrenceSpecification is a subclass of
> OccurenceSpecification, which can participate in a GeneralOrdering. From:
>
> http://download.eclipse.org/modeling/mdt/uml2/javadoc/2.2.0/ org/eclipse/uml2/uml/GeneralOrdering.html
>
> "A general ordering represents a binary relation between two occurrence
> specifications, to describe that one occurrence specification must occur
> before the other in a valid trace. This mechanism provides the ability to
> define partial orders of occurrence cpecifications that may otherwise not
> have a specified order."
>
> Hope this helps. Never done anything in that area, so I might be
> completely off here.
>
> Cheers,
>
> Rafael
> http://abstratt.com/textuml/
>
> Timothy Marc wrote:
>> Okay,
>>
>> the questions was answered. I'm wondering, that there is no semantical
>> ordering of messages, but a physical one. The actual ordering of messages
>> are derived from the physical representation of their corresponfig
>> OccurenceSpecifications in the XMI. I can't image, that this is the best
>> solution?
>> Are there other opinios outthere?
>>
>> Timothy
>> "Timothy Marc" <timothymarc@freenet.de> schrieb im Newsbeitrag
>> news:g2359p$o7e$1@build.eclipse.org...
>>> Hi all,
>>>
>>> i have specified a Sequence Diagram with some Messages and Execution
>>> Specifications, etc., manually with the UML tree editor. My problem is:
>>> Where is the sequence of the messages, which are being send, specified?
>>> Currently it is so, that I have defined two messages a and b, were a
>>> occurs before b. Now i've inserted a third message c, which should be
>>> placed before the occurence of a. But that message c is physically
>>> represented in the XMI after b. So, how does the "diagram" knows that c
>>> should be occure before a, even if it was later added?
>>>
>>> In the UML Superstructure there is a General Ordering, but i think, this
>>> is not the correct element to define the implicit sequence of messages?
>>>
>>> Any help will be appreciated.
>>>
>>> Thx
>>> Timothy
>>>
>>
Re: Ordering in Sequence Diagram [message #626656 is a reply to message #477470] Tue, 03 June 2008 10:55 Go to previous message
Timothy Marc is currently offline Timothy MarcFriend
Messages: 547
Registered: July 2009
Senior Member
Okay,

the questions was answered. I'm wondering, that there is no semantical
ordering of messages, but a physical one. The actual ordering of messages
are derived from the physical representation of their corresponfig
OccurenceSpecifications in the XMI. I can't image, that this is the best
solution?
Are there other opinios outthere?

Timothy
"Timothy Marc" <timothymarc@freenet.de> schrieb im Newsbeitrag
news:g2359p$o7e$1@build.eclipse.org...
> Hi all,
>
> i have specified a Sequence Diagram with some Messages and Execution
> Specifications, etc., manually with the UML tree editor. My problem is:
> Where is the sequence of the messages, which are being send, specified?
> Currently it is so, that I have defined two messages a and b, were a
> occurs before b. Now i've inserted a third message c, which should be
> placed before the occurence of a. But that message c is physically
> represented in the XMI after b. So, how does the "diagram" knows that c
> should be occure before a, even if it was later added?
>
> In the UML Superstructure there is a General Ordering, but i think, this
> is not the correct element to define the implicit sequence of messages?
>
> Any help will be appreciated.
>
> Thx
> Timothy
>
Re: Ordering in Sequence Diagram [message #626665 is a reply to message #477474] Wed, 04 June 2008 04:05 Go to previous message
Rafael Chaves is currently offline Rafael ChavesFriend
Messages: 362
Registered: July 2009
Senior Member
Timothy, this is my understanding:

1 - a message has a send and receive events, which are MessageEnds.

2 - MessageEnd is abstract. One of the concrete subclasses (the one that
seems to be interesting in the context of sequence diagrams) is
MessageOccurrenceSpecification.

3 - a MessageOccurrenceSpecification is a subclass of
OccurenceSpecification, which can participate in a GeneralOrdering. From:

http://download.eclipse.org/modeling/mdt/uml2/javadoc/2.2.0/ org/eclipse/uml2/uml/GeneralOrdering.html

"A general ordering represents a binary relation between two occurrence
specifications, to describe that one occurrence specification must occur
before the other in a valid trace. This mechanism provides the ability
to define partial orders of occurrence cpecifications that may otherwise
not have a specified order."

Hope this helps. Never done anything in that area, so I might be
completely off here.

Cheers,

Rafael
http://abstratt.com/textuml/

Timothy Marc wrote:
> Okay,
>
> the questions was answered. I'm wondering, that there is no semantical
> ordering of messages, but a physical one. The actual ordering of messages
> are derived from the physical representation of their corresponfig
> OccurenceSpecifications in the XMI. I can't image, that this is the best
> solution?
> Are there other opinios outthere?
>
> Timothy
> "Timothy Marc" <timothymarc@freenet.de> schrieb im Newsbeitrag
> news:g2359p$o7e$1@build.eclipse.org...
>> Hi all,
>>
>> i have specified a Sequence Diagram with some Messages and Execution
>> Specifications, etc., manually with the UML tree editor. My problem is:
>> Where is the sequence of the messages, which are being send, specified?
>> Currently it is so, that I have defined two messages a and b, were a
>> occurs before b. Now i've inserted a third message c, which should be
>> placed before the occurence of a. But that message c is physically
>> represented in the XMI after b. So, how does the "diagram" knows that c
>> should be occure before a, even if it was later added?
>>
>> In the UML Superstructure there is a General Ordering, but i think, this
>> is not the correct element to define the implicit sequence of messages?
>>
>> Any help will be appreciated.
>>
>> Thx
>> Timothy
>>
>
>
Re: Ordering in Sequence Diagram [message #626668 is a reply to message #477483] Wed, 04 June 2008 12:34 Go to previous message
Timothy Marc is currently offline Timothy MarcFriend
Messages: 547
Registered: July 2009
Senior Member
Dear Rafael,

of course, i've read the spec before. The main purpose of GeneralOrdering is
for partial ordering of Events, which are commonly not ordered (e.g. for
asynchronous messaging). The GeneralOrdering object is not to be intendend
to order the message occurences.
It is so that the physically appearance of the occurences (physically means,
the order of appearance in the XMI) defines the ordering of message and
execution occurences.
I was wondering conerning that mechanism, even if it is very simple to
understand. But this way implies a semantical dependency between the storage
and the interpretation of a sequence diagram.

Timothy
"Rafael Chaves" <rafael@abstratt.com> schrieb im Newsbeitrag
news:g254aa$p6h$1@build.eclipse.org...
> Timothy, this is my understanding:
>
> 1 - a message has a send and receive events, which are MessageEnds.
>
> 2 - MessageEnd is abstract. One of the concrete subclasses (the one that
> seems to be interesting in the context of sequence diagrams) is
> MessageOccurrenceSpecification.
>
> 3 - a MessageOccurrenceSpecification is a subclass of
> OccurenceSpecification, which can participate in a GeneralOrdering. From:
>
> http://download.eclipse.org/modeling/mdt/uml2/javadoc/2.2.0/ org/eclipse/uml2/uml/GeneralOrdering.html
>
> "A general ordering represents a binary relation between two occurrence
> specifications, to describe that one occurrence specification must occur
> before the other in a valid trace. This mechanism provides the ability to
> define partial orders of occurrence cpecifications that may otherwise not
> have a specified order."
>
> Hope this helps. Never done anything in that area, so I might be
> completely off here.
>
> Cheers,
>
> Rafael
> http://abstratt.com/textuml/
>
> Timothy Marc wrote:
>> Okay,
>>
>> the questions was answered. I'm wondering, that there is no semantical
>> ordering of messages, but a physical one. The actual ordering of messages
>> are derived from the physical representation of their corresponfig
>> OccurenceSpecifications in the XMI. I can't image, that this is the best
>> solution?
>> Are there other opinios outthere?
>>
>> Timothy
>> "Timothy Marc" <timothymarc@freenet.de> schrieb im Newsbeitrag
>> news:g2359p$o7e$1@build.eclipse.org...
>>> Hi all,
>>>
>>> i have specified a Sequence Diagram with some Messages and Execution
>>> Specifications, etc., manually with the UML tree editor. My problem is:
>>> Where is the sequence of the messages, which are being send, specified?
>>> Currently it is so, that I have defined two messages a and b, were a
>>> occurs before b. Now i've inserted a third message c, which should be
>>> placed before the occurence of a. But that message c is physically
>>> represented in the XMI after b. So, how does the "diagram" knows that c
>>> should be occure before a, even if it was later added?
>>>
>>> In the UML Superstructure there is a General Ordering, but i think, this
>>> is not the correct element to define the implicit sequence of messages?
>>>
>>> Any help will be appreciated.
>>>
>>> Thx
>>> Timothy
>>>
>>
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