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RE: Web Service Definition [Was "Some Thoughts ..."]

From: Krishna Sankar <ksankar@cisco.com>
Date: Sat, 2 Mar 2002 22:59:15 -0800
To: "Champion, Mike" <Mike.Champion@SoftwareAG-USA.com>, <www-ws-arch@w3.org>

	Good points. Quick question:

	1.	Are we restricting web services to XML on the wire or just
Internet-protocols and marshalling ?
	2.	If Yes (i.e. only XML) what about XHTML ?
	3.	If yes, what about a browser which translates XML to HTML and after
getting the input from a human sends back an XML ?
		Basically, my point is, we do not care if there is human interaction or
not. Just that it is XML in, XML out.

	4.	I agree with your definition, clearly defined vocabulary, schema,
documented payload (with XML Schema or we are Ok with binary payload ?),
defined and described using WSDL (includes interfaces and binding at the
min), ... are all (mandatory) attributes of a web service. These all could
be implied in standard definition and description/interact using

		Our definition *should* include what we all think would be in a web
service. IMHO, we should strive for as specific as possible.

 | -----Original Message-----
 | From: www-ws-arch-request@w3.org [mailto:www-ws-arch-request@w3.org]On
 | Behalf Of Champion, Mike
 | Sent: Saturday, March 02, 2002 10:13 PM
 | To: www-ws-arch@w3.org
 | Subject: RE: Web Service Definition [Was "Some Thoughts ..."]
 | > -----Original Message-----
 | > From: Gaertner, Dietmar [mailto:Dietmar.Gaertner@softwareag.com]
 | > Sent: Saturday, March 02, 2002 4:23 PM
 | > To: 'jasnell@us.ibm.com'
 | > Cc: 'www-ws-arch@w3.org'
 | > Subject: RE: Web Service Definition [Was "Some Thoughts ..."]
 | >
 | >
 | > Take for example the stockquote "service", which we all know and love
 | > returning, a plain HTML page. It can be implemented as an
 | application or
 | > component, identified by an URI
 | > (e.g. http://www.stockquote.org/quotes?symbol=xzy), can be
 | > described (the URI is enough
 | > of a description, if you wish), can be accessed by software via
 | > internet-based protocols, and the interaction does not
 | necessarily require
 | human
 | > interaction (the client could scrape the HTML).
 | Hi Dietmar,
 | I think this is exactly the kind of question that will clarify
 | what we want
 | to do, and *perhaps* allow a crisper definition of "web service"
 | somewhere
 | down the road.
 | I personally think this is sortof a web service, but I wouldn't
 | dispute that
 | it is not what we want to focus on.  Let's talk about what would
 | make it a
 | web service:
 | a) If the result were HTML with well-documented div/span tags
 | and class/id
 |    attributes to identify the   specific information being
 | returned (to make
 |    "scraping" easier)?
 | b) If the result was XML with the vocabulary clearly documented?
 | c) If the result was XML that matched a specific schema?
 | d) If the result was SOAP with the payload documented in human-readable
 | form?
 | e) If the result was SOAP and the payload documented with WSDL?
 | f) If URI encoded a SOAP invocation message and the result was
 | SOAP with the
 |    payload documented with WSDL.
 | OK, NOBODY would dispute that f) is a "web service", right?
 | Likewise, e) is
 | pretty clearly a "web service" under our charter; to insist that the
 | invocation is a SOAP message rather than a "human readable" URI would be
 | unacceptable to a signficant number of people in the W3C,
 | probably including
 | the Director (as I read his various musings on the Web Architecture,
 | anyway).
 | d) is also a "web service" in what I take to be the consensus of
 | the WG as
 | expressed on teleconferences and the mailing list.  I doubt if very many
 | people here would vote against c) either.
 | b) is getting fuzzy for most of us, I'll bet ... and a) is
 | really fuzzy.  I
 | personally would say that both are within our scope so long as the
 | documentation of the result is unambiguous enough to be used by ordinary
 | programmers to write the code to "scrape" the result into the calling
 | application's data structures.  To insist that the documentation
 | has to be a
 | schema or WSDL, I believe, leads to the "it's turtles all the way down"
 | problem, i.e., sooner or later, the documentation, code or schema or
 | whatever has to be sensible to a human being.  See Clay Shirky's
 | article at
 | http://www.xml.com/pub/a/2001/10/03/webservices.html ... and the
 | "turtles"
 | reference is explained at http://www.the-funneled-web.com/Hawking.htm
 | Nevertheless, I wouldn't insist on a) or b) being "web services"
 | if that's
 | what it takes to move forward.
Received on Sunday, 3 March 2002 01:59:52 GMT

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