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Re: targetResource wording

From: Sanjiva Weerawarana <sanjiva@watson.ibm.com>
Date: Fri, 20 Jun 2003 17:33:47 +0600
Message-ID: <14a401c3371f$d28fd020$72545ecb@lankabook2>
To: "VAMBENEPE,WILLIAM \(HP-Cupertino,ex1\)" <vbp@hp.com>, "'David Booth'" <dbooth@w3.org>, <www-ws-desc@w3.org>
Cc: "Mark Baker" <distobj@acm.org>, "Champion, Mike" <Mike.Champion@SoftwareAG-USA.com>

+1 .. very nicely written.

Sanjiva.

----- Original Message -----
From: "VAMBENEPE,WILLIAM (HP-Cupertino,ex1)" <vbp@hp.com>
To: "'David Booth'" <dbooth@w3.org>; <www-ws-desc@w3.org>
Cc: "Mark Baker" <distobj@acm.org>; "Sanjiva Weerawarana"
<sanjiva@watson.ibm.com>; "Champion, Mike"
<Mike.Champion@SoftwareAG-USA.com>
Sent: Friday, June 20, 2003 3:17 AM
Subject: RE: targetResource wording


>
> +1. Excellent summary David.
>
> William
>
> > -----Original Message-----
> > From: David Booth [mailto:dbooth@w3.org]
> > Sent: Thursday, June 19, 2003 12:14 PM
> > To: www-ws-desc@w3.org
> > Cc: Mark Baker; Sanjiva Weerawarana; Champion, Mike
> > Subject: Re: targetResource wording
> >
> >
> >
> > It looks to me like there is some misconception of what the
> > targetResource
> > means, partly (I think) because some of the statements in
> > this discussion
> > have been a little imprecise.
> >
> > The targetResource attribute has nothing to do with describing a
> > service.  It is used to indicate a relationship *between*
> > services.  Its
> > purpose is to allow two WSDL <service> descriptions, d1 and
> > d2, to assert
> > that (behind the scenes) the services s1 and s2 that they
> > describe are
> > actually "manipulating" the same resource.  In other words,
> > if d1 and d2
> > both state "targetResource='u'", where u is some URI, then they have
> > asserted that s1 and s2 "manipulate" the resource r that is
> > identified by
> > URI u.
> >
> > As we know from RFC2396[1], a resource can be anything -- a physical
> > object, an abstract concept -- anything.  So what does it
> > mean to say that
> > s1 and s2 "manipulate" the same resource r?  Without knowing
> > the semantics
> > of d1 and d2 you don't know.  That is not defined by the WSDL 1.2
> > specification.  (Nor should it be, IMO.)  Until you know the
> > semantics of
> > d1 and d2, the only concrete thing you can conclude is that
> > s1 and s2 are
> > somehow related to each other through r.
> >
> > (Just in case there is confusion about this, the "targetResource='u'"
> > attribute is NOT asserting that s1 and s2 are the same
> > resource as each
> > other, nor is it asserting that s1 and s2 are the same resource as r.)
> >
> > Does this vagueness present a problem?  No.  Different
> > applications will
> > know what they wish to do with this.  (The canonical example is a
> > printDocument service s1 and a managePrinter service s2, both
> > manipulating
> > the same physical printer r.)  The reason the WG described the
> > targetResource as "manipulating" the same resource was to give users
> > guidance about its intended use, even though the precise
> > meaning of the
> > word "manipulate" is impossible to nail down in this context.
> >
> > Regarding the name "targetResource", u does identify a
> > resource, so the
> > "Resource" part of the name definitely is appropriate.  Furthermore,
> > proponents of the targetResource attribute like to think of r
> > as being the
> > ultimate "target" of interactions with s1 or s2; hence the name
> > "targetResource".
> >
> > I hope this helps to clarify the situation.
> >
> >
> > 1. RFC2396: http://www.ietf.org/rfc/rfc2396.txt
> >
> >
> > --
> > David Booth
> > W3C Fellow / Hewlett-Packard
> > Telephone: +1.617.253.1273
> >
Received on Friday, 20 June 2003 07:33:42 GMT

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