RE: Question re: XML embedding in XML-dist protocols

In ICE 1.1 such a mechanism exists.  Formal extensions to the protocol can
be described and even negotiated between sydicator and subscriber at the
outset of the exchange formalization.

-----Original Message-----
From: Dave Reynolds [mailto:der@hplb.hpl.hp.com]
Sent: Monday, May 08, 2000 9:01 AM
To: xml-dist-app@w3.org
Subject: Question re: XML embedding in XML-dist protocols


One of the attractions to me in using an XML-based protocol is that it
should be easy to exchange information already encoded in XML. For
example, as part of a command I might like to be able to pass a block of
metadata encoded in RDF, or a signed assertion encoded using
XMLSignature, or an embedded web document fragment in raw XML. To be
clear, I'm not talking about just sending such an XML packet over HTTP
(an easy job) I'd like the packet to be one of a number of parameters to
a service and to use some RPC mechanism to encode the other parameters.

The protocols I've looked at so far (XML-RPC, SOAP 1.0 and 1.1) provide
serialization algorithms for conveying standard datatypes over XML. They
don't seem to include any hooks for including a datatype to represent an
embedded XML node tree which I could include within the payload. Soap
1.1 would *allow* me to define such a thing by using the encodingStyle
attribute but doesn't seem to have such a thing out of the box. I guess
I'm looking for an <embedded-xml> element which would prevent the
deserialization algorithm descending further and would expose the XML
sub-tree to the client/server as a DOM (or DOM2, or jdom or whatever)
node for further parsing.

So:
1. Is this a reasonable sort of requirement? Am I just unusual in even
trying to do this!
2. Is there some capability along these lines already available or
planned?

Dave Reynolds
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