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RE: Draft agenda: 24 June TAG teleconference (Arch document, WSA update)

From: David Orchard <dorchard@bea.com>
Date: Mon, 24 Jun 2002 11:55:57 -0700
To: <www-tag@w3.org>
Message-ID: <052501c21bb0$c7b2e7e0$6d0ba8c0@beasys.com>



>
> David Orchard wrote:
>
> > It is clear the description of GET binding that uses
> parameters in WSDL does
> > not have the same level of information that the POST Binding does.
> > Specifically, the GET binding uses the form "urlencoded",
> and none of the
> > parameters can be described - beit names, types, order.
> The WSDL GET
> > binding does support types and parts for non-parameters.  So
> > http://example.org/foo/foo2/foo3 can have types associated
> with foo, foo2,
> > foo3.  This also conveiently deals with ordering of
> parameters and names.
> >
> > The problem comes about when parameters are used.  WSDL
> does not define any
> > mechanism for typing the query parameter, ie
> > http://example.org/foo?symbol=BEAS.
>
> I hope that the rest of the TAG is better-educated on this
> stuff than I
> am, because I just read these two paras and don't understand
> them in the
> slightest.  I think I basically don't understand the usage of
> the word
> "type" that's being used here... what do you mean by "typing
> the query
> parameter"?

Or I'm just a lousy educator...

WSDL SOAP (POST) Binding allows service provider to define types (using xml
schema), messages that contain types, and ports that pass those messages
around.

WSDL HTTP GET binding allows types for only for URLs without the query
string.

Example #1: port1: GET, URL="http://example.com/o1/A1B2/3" the 1, 2, and 3
can have types (string, int, string in the wsdl examples).

Example #2: port2: GET, URL="http://example.com/o1?p1=1&p2=2&p3=3".  Types
are NOT available for p1, p2 or p3.  So the contents of the query string
(after the ?) can't be defined in any way by WSDL.  It can't say the names
(p1, p2, p3), the types (string, int, string) or even the content model (p1
AND p2 AND p3)

>
> > The WSDL 1.1 GET binding with query parameters - the type
> suggested by the
> > SOAP 1.2 specification for GET - does not provide any mechanism for
> > expressing the syntactice schema of the types expressed in
> the GET query.
> > This poses a significant problem for interoperability for
> SOAP with GET
> > implementations, compared to the HTTP POST binding for SOAP.
>
> An example would really help here.... in many services I'm
> aware of, the
> receiver & sender of a message both know what the datatypes of the
> message components are supposed to be, so this info isn't included at
> runtime; consider a Google "advanced search" URI
>
> http://www.google.ca/search?as_q=dave+orchard&num=10&hl=en&ie=
ISO-8859-1&btnG=Google+Search&as_epq=&as_oq=&as_eq=&lr=&as_ft=i&as_filetype=
pdf&as_qdr=all&as_occt=any&as_dt=i&as_sitesearch=&safe=images

>I see no type information.... what am I missing?

There's no type available at EITHER run-time or WSDL-time.  Which is the
point of this whole discussoin.

> > I think I've provided sufficient background material, possible
solutions,
> > and potential action items for a fruitful discussion today.

> Pardon me being dense. -Tim

I've certainly provided enough info for us to start discussions like this,
which was what I was trying to get at.  In the same way we had to have a
discussion about rpc versus document, encoded versus literal wrt soap, we
need to have a WSDL discussion as well.

One of the interesting places this might lead us, is that if we think that
there should be typing available for the GET query string, I'm not sure that
it's a WSD problem.  Seems like mapping Schema to url-encoded nvp is more
general than wsd.

Cheers,
Dave
Received on Monday, 24 June 2002 14:56:05 GMT

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