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Re: SAWSDL Last Call

From: Jacek Kopecky <jacek.kopecky@deri.org>
Date: Sun, 25 Mar 2007 13:35:40 +0200
To: Ramkumar Menon <ramkumar.menon@gmail.com>
Cc: www-ws-desc@w3.org
Message-Id: <1174822540.27696.47.camel@localhost>

Dear Ram, 
the issue below is a WSDL issue, about creating a model for MEPs in the
WSDL RDF mapping. 

I personally have no experience in such modeling, and I'm not aware of
any standard RDFS or similar model for processes or something similar,
which could help us model the MEPs in terms of temporal sequencing and
optionality, both of which would be necessary to describe the current
MEPs. Further, modeling primitives sufficient to capture the current 8
MEPs may not be sufficient to capture other new MEPs as they (may) come,
because the WSDL spec does not really constrain the possible
relationships and interdependencies among messages in MEPs.

Therefore I don't plan to create a more extensive model of MEPs above
what the WSDL RDF mapping currently contains - the class
MessageExchangePattern, the property "defines" from an MEP to a
MessageLabel, and the three faulting-rules subclasses of MEP.

The beauty of RDF is that this limited model can be amended easily by
another specification, standard or not, even in a single application.
And if necessary, such a spec can be standardized as an extension of the
WSDL spec later.

Hope this is acceptable,
Jacek

On Mon, 2007-03-12 at 15:23 -0700, Ramkumar Menon wrote:
> Jacek/All,
>  
> Although late in the game, I realize that the following issue had no
> closure till date. 
> Just ensuring that its tracked.
> 
>  
> >> ---- Your response to my email on 23rd October, 06. -----
> >> 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.
>  
> rgds,
> Ram
>  
> On 10/23/06, Jacek Kopecky <jacek.kopecky@deri.org> wrote: 
>         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
>         
> 
> 
> 
> -- 
> Shift to the left, shift to the right!
> Pop up, push down, byte, byte, byte!
> 
> -Ramkumar Menon
> A typical Macroprocessor 
Received on Sunday, 25 March 2007 11:35:56 GMT

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