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Re: SAWSDL Last Call

From: Jacek Kopecky <jacek.kopecky@deri.org>
Date: Mon, 23 Oct 2006 16:57:37 +0200
To: Ramkumar Menon <ramkumar.menon@gmail.com>
Cc: public-ws-semann@w3.org, www-ws-desc@w3.org
Message-Id: <1161615457.4158.80.camel@localhost>

Hi Ramkumar,

regarding the capturing of user-defined MEP semantics using SAWSDL, 
I'd say that it would be more in the spirit of the SemWeb to describe
the semantics somewhere at the MEP IRI, not in SAWSDL. In other words,
the IRI should point to something that will (re)direct the requestor (in
some fashion) to a description of the MEP. SAWSDL is about annotating
WSDL instances, not about describing WSDL or its extensions (like the
user-defined MEPs or e.g. new bindings).

The WSDL WG might be interested in creating an ontology for modeling
MEPs and putting MEP descriptions at the MEP IRIs (plus some
WebArch-friendly magic). The WSDL RDF mapping ontology actually does
contain a primitive model of MEPs: it only says that an MEP follows
specific faulting rules, and what message labels it defines. There's no
ordering among message labels in the model, but it can be added.
Actually, that would be trivial, if we restrict ourselves to something
like "labelA precedes labelB". Then there's the optionality of messages,
also fairly trivial. I can take a stab at this, maybe.

I'll talk to some colleagues about whether this could be useful for
semantic web services tooling.

I think we don't quite need to state that the MEP IRI may dereference to
a description of the MEP, but such a note wouldn't do any harm, either.

What do you think?

Jacek

On Tue, 2006-10-17 at 19:32 -0700, Ramkumar Menon wrote:
> Hi All,
>  
> I happened to go through the SAWSDL spec and had a few thoughts to
> share.
>  
> a) Is it worth capturing semantics of user-defined [and possibly
> predefined] Message Exchange patterns defined by WSDL2.0 within
> SAWSDL? - esp. the former variant. Since MEPs can be "re-used" across
> operations within/across services, wd it be better to capture the
> semantics of these separate from the annotations for each operation
> that uses them ?
>  
> On a parallel thought, how plausible wd it be to state in the WSDL
> spec that the IRI for an MEP MAY [yes, its a MAY :-) ] be derefencible
> to a machine/human understandable document that describes the
> semantics of the MEP ? [similar to the "targetNamespace" attribute for
> the description]
>  
>  
>  
> On 10/16/06, Jonathan Marsh <jonathan@wso2.com> wrote: 
>         
>         I have an action item to review SAWSDL, hereby discharged.  In
>         section 2.1,
>         SAWSDL says:
>         
>         "In terms of the WSDL 2.0 component model, a model reference
>         is a new
>         property. In particular, when used on an element that
>         represents a WSDL 2.0
>         Component (e.g. wsdl:interface, wsdl:operation, top-level
>         xsd:element,
>         etc.), the modelReference extension attribute introduces an
>         OPTIONAL 
>         property {model reference} whose value is a set of URIs taken
>         from the value
>         of the attribute. The absence of the {model reference}
>         property is equal to
>         its presence with an empty value."
>         
>         1) Editorially, it would be nice to refer to WSDL 2.0
>         Components by name
>         instead of by their corresponding element.  Esp. in the case
>         of xsd:*, there
>         is both a WSDL component and a Schema component, so by naming
>         an xsd element
>         it's not clear which component one might be referring to (the
>         context makes 
>         it clear in this case, but still, we invented names for
>         components, you
>         might as well use them!)  The same style can also apply to the
>         last
>         paragraph of section 2.2.
>         
>         2) Secondly, there are two ways to interpret the last
>         sentence.  Presumably, 
>         an empty attribute would result in the presence of an empty
>         {model
>         reference} property, which would be _semantically_ equivalent
>         to no {model
>         reference} property.   However, it might also be interpreted
>         that in this 
>         situation the property could simply be omitted from the
>         component model.  We
>         had some similar text in places in WSDL that gave us a bit of
>         a headache in
>         the interchange format, which requires a canonical component
>         model. 
>         Basically, two processors that are both SAWSDL aware might
>         have different
>         component models - one might omit {model reference} and one
>         might include it
>         with an empty value.  This could be dealt with in the
>         comparison algorithm 
>         between two component models, but we've found it easier to
>         just define a
>         single clear mapping from XML to the component model.  In this
>         case, for
>         instance, you could state "when non-empty and used on an
>         element..." and 
>         simply omit the last sentence, or you could state "The absence
>         of the {model
>         reference} property is semantically equivalent to its presence
>         with an empty
>         value."  The former seems cleaner to me as it doesn't augment
>         the component 
>         model with meaningless information.
>         
>         3) Along the lines of (1), it would be nice to be explicit
>         about the
>         components being annotated with properties in section 2.1.x.
>         
>         
>         I'm afraid most of the Usage Guide is over my head, but in
>         section 2.1, I
>         notice an extra # on the schema namespace.  Perhaps they
>         should be validated
>         more carefully - namely by submitting them to the WSDL test
>         suite ;-).
>         
>         
>         
>         Jonathan Marsh - http://www.wso2.com -
>         http://auburnmarshes.spaces.live.com
>         
>         
>         > -----Original Message-----
>         > From: www-ws-desc-request@w3.org
>         [mailto:www-ws-desc-request@w3.org] On
>         > Behalf Of Jacek Kopecky
>         > Sent: Thursday, October 12, 2006 11:30 AM
>         > To: WS-Description WG; public-sws-ig@w3.org;
>         semantic-web@w3.org
>         > Subject: SAWSDL Last Call
>         >
>         >
>         > Dear all,
>         >
>         > the Semantic Annotations for WSDL Working Group is happy to 
>         > announce that our specification has progressed to Last Call.
>         The
>         > specification, Semantic Annotations for WSDL, is available
>         at
>         > http://www.w3.org/TR/2006/WD-sawsdl-20060928/
>         >
>         > The document is accompanied by a usage guide (intended
>         > eventually to be published as a WG Note), available at
>         > http://www.w3.org/TR/2006/WD-sawsdl-guide-20060928/
>         >
>         > We will welcome any comments on our spec, especially with
>         respect to how
>         > it may interact with your work, and whether you find it
>         useful, at
>         > public-ws-semann-comments@w3.org, a mailing list with a
>         public archive
>         > at
>         http://lists.w3.org/Archives/Public/public-ws-semann-comments/ .
>         >
>         > Best regards,
>         >
>         > Jacek Kopecký
>         > chair of the SAWSDL WG
>         >
>         > --
>         > Researcher
>         > DERI - Digital Enterprise Research Institute
>         > University of Innsbruck, Austria 
>         > Phone: +43 512 5076481
>         > Org:   http://www.deri.org/
>         > Blog:  http://jacek.cz/blog/
>         >
>         
>         
>         
> 
> 
> 
> -- 
> Shift to the left, shift to the right!
> Pop up, push down, byte, byte, byte!
> 
> -Ramkumar Menon
> A typical Macroprocessor 
Received on Monday, 23 October 2006 14:57:50 GMT

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