Re: Comment on Fragment Identifiers

A comment or two.

On Fri, 22 Dec 2006 08:01:38 -0800
"Jonathan Marsh" <jonathan@wso2.com> wrote:
>> From: David Orchard [mailto:dorchard@bea.com]
>> Sent: Thursday, December 21, 2006 5:27 PM
>> Ah, very very interesting.  I for one had forgotten that the meps had
>> in|out as component names rather than the syntax local names of input
>> and output.

Err, I don't believe so.  Checking ... nope, there's no component called "in" or "out" either.  Or "input" or "output".  The component is named "interface message reference".  Its XML representation is <input> or <output>.  It has a property called "direction" with the values "in" or "out".

None of this is used in the fragment identifier syntax.  Zero, zip, zilch, nada.

Fragment identifiers use the "message label" property of the interface message reference component, which is reflected in the XML as the "messageLabel" attribute.  For all MEPs defined in the Adjuncts specification, the only labels used are in the set "In" and "Out".

>> Now just to confirm my understanding.  If the wsdl meps are used,
>> they have no multiple messages in a single direction so component
>> names are sufficient and they are used as the message labels.  

No.

>> If
>> different meps are used, particularly a mep that has multiple
>> messages in a single direction, then each message will have a unique
>> message label and that will be used.

Each message *always* has a unique message label, and consequently the message labels are *always* used in the syntax of fragment identifiers.

>Essentially.  More precisely:

Jonathan, with respect, I think that your answer is misleading, which is why I provide the above response.  David's premise, that "component" names are being used, is not in fact correct.  I think we are far better situated if we make it clear that the "message label" property is REQUIRED on the "interface message reference" component, and is REQUIRED to be unique, so is ideally suited for use within a fragment identifier.  There is no complexity.  The message label is *always* used, regardless of how many messages a MEP has in however many directions.

>  If the wsdl meps are used, they have no multiple placeholder
> messages in a
>single direction so the unique-per-direction message labels can be
>used.  If different meps are used, with no multiple placeholder
>messages in a single direction, the unique-per-direction message
>labels can be used.  If a different mep is used which has multiple
>messages in a single direction, then one is required to disambiguate
>the message references with the messageLabel attribute on each <input>
>or <output> corresponding with that placeholder message in the MEP.

I can't tell if this is actually accurate or not; I think it is too complex.  It tries to consider information that isn't relevant, such as the number of messages in a given direction, when, regardless of that, the message label property is always unique.

"It's the message label!"  The end.

Amy!
-- 
Amelia A. Lewis
Senior Architect
TIBCO/Extensibility, Inc.
alewis@tibco.com

Received on Wednesday, 3 January 2007 20:50:33 UTC