W3C home > Mailing lists > Public > www-ws-desc@w3.org > February 2005

Re: SOAP Header Blocks in WSDL (was RE: First Class Headers - Pr oposed Resolution for LC76d

From: Amelia A Lewis <alewis@tibco.com>
Date: Wed, 2 Feb 2005 15:45:09 -0500
To: Asir Vedamuthu <asirv@webmethods.com>
Cc: www-ws-desc@w3.org
Message-Id: <20050202154509.4a95a294.alewis@tibco.com>

Dear Asir,

On Wed, 2 Feb 2005 14:05:57 -0500 
Asir Vedamuthu <asirv@webmethods.com> wrote:
> > 1) it can't be validated
> 
> I didn't say that. It can be validated. But, the order is
> insignificant.

Nope.  I did.  It doesn't contain a splat to permit other headers, it
enforces order.

So I'll correct my statement: it can't be validated using existing XML
Schema tools; it's effectively a different schema language with a
passing resemblance to XML Schema.

> Similar (not the same) to http://www.w3.org/XML/Group/2000/11/lc200
> (member only).

Member-only note last modified in 2000?

> > 3) it's brittle
> > A deployed service cannot reasonably and easily extend the types
> > defined for headers in a way that describes new requirements,
> 
> I like to know how status quo supports this.

Ah?  Add additional features/properties that contain new requirements to
the binding.  Using WS-Policy, do this in an external document that
points into the WSDL.

> > 4) it's obscure
> > Information about binding requirements are buried in the type
> > system, requiring an author to find the required use (in the
> > example) of
> 
> I like to know how status quo supports this. BTW, in Part 2, section
> 3.1.4,
> http://www.w3.org/TR/2004/WD-wsdl20-extensions-20040803/#adf-dp-desc,
> required, optional, choice, maxOccurs, etc. are buried in the type
> system.

Hmmm.  And that feature is also guilty of failure to validate, for that
matter, creating the same sort of bogus complex type definition as this
proposal.  How annoying.  The AD feature does have the grace of putting
a generic marker into the binding and, for that matter, can be
serialized into HTTP headers as well as SOAP headers.

So ... hmm.  ADF also provides an HTTP serialization, and restricts the
content of headers intended for serialization in HTTP to string or
anyURI (but not QName, interesting).  SOAP header blocks is then a
SOAP-specific proposal?  If so, why prefer it over something that can
(and is shown to) be bound to other situations in which, as David
Orchard has noted, there is a division between "message headers"
(metadata) and "message body" (content)?

Amy!
-- 
Amelia A. Lewis
Senior Architect
TIBCO/Extensibility, Inc.
alewis@tibco.com
Received on Wednesday, 2 February 2005 20:45:34 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Monday, 7 December 2009 10:58:34 GMT