RE: Higher-level support for SOAP extensions/modules

I agree that we need this requirement. In fact, WSDL 1.1 let's you put
extensibility elements into the binding, and explicitly states that you
do not need to describe each header specifically.

-----Original Message-----
From: Glen Daniels [mailto:gdaniels@macromedia.com] 
Sent: Thursday, March 28, 2002 3:57 AM
To: 'www-ws-desc@w3.org'
Subject: REQ: Higher-level support for SOAP extensions/modules


Hi all!

Got up early this morning, and had a little time to read over the
current requirements doc.  I was a bit dismayed not to find one of my
pet issues there, namely the mechanism by which WSDL supports SOAP
extensions... so, no time like the present to make a suggestion. :)

At present, it is possible with WSDL 1.1 to specify particular headers
which should be included with particular messages.  This was, I believe,
a reasonable first stab at integrating headers with a description
language, but it falls far short of being able to support the kind of
rich semantic additions that are going to be coming down the line as
SOAP extensions over the next few months/years.

Without going into too much detail, I'd like to see us require the
ability to specify that a particular SOAP "module" is offered by, or
required by, particular services or operations.  SOAP 1.2 (part 1, sec
3) discusses the concept of SOAP "features", which are semantic
extensions named with a URI and implemented by either SOAP extensions
(headers) or bindings.  Bindings already have a requirement for URI
naming, and I'm attempting to push for extensions to do the same.  Once
we have URIs for such things, it becomes possible to say something like
"this operation supports the
'http://www.w3.org/2002/06/reliable-message' extension", which would
imply some set of headers/exchanges mandated by that specification.
It's unclear to me as to whether we would require a schema description
of every possible header which such an extension might produce, but
that's another facet of this which we should discuss.

This is also a potentially complex issue in that it gets into situations
where messages that are not actually specified directly in the WSDL may
become part of the exchange due to the extension specs, but I think we
need to figure this stuff out if we hope to live in a world with true
"orthogonal extensibility" and some hope of negotiation/interop.

Thanks,
--Glen

Received on Thursday, 28 March 2002 22:46:35 UTC