RE: Possible requirement to update SOAP 1.2 for XML 1.0 5th Edition

Noah,

Thanks for cc-ing the XML Core WG on this message.

Just to confirm for the sake of the process, this is 
a comment to the XMLP WG, and not a comment on the 
XML 1.0 5th Edition PER, correct?

paul

> -----Original Message-----
> From: public-xml-core-wg-request@w3.org 
> [mailto:public-xml-core-wg-request@w3.org] On Behalf Of 
> noah_mendelsohn@us.ibm.com
> Sent: Tuesday, 2008 February 12 13:17
> To: xmlp-comments@w3.org
> Cc: chrisfer@us.ibm.com; public-xml-core-wg@w3.org
> Subject: Possible requirement to update SOAP 1.2 for XML 1.0 
> 5th Edition
> 
> 
> The XML Core working group has published a Proposed Edited 
> Recommendation 
> (PER) Extensible Markup Language (XML) 1.0 (Fifth Edition).  
> The major 
> change in that edition is the proposal to expand the set of legal XML 
> element and attribute names.  Without commenting either for 
> myself or for 
> IBM on the merits of this proposal, I note that there appears 
> to be an 
> interdependency with the SOAP 1.2 Recommendation.  
> Specifically, the way 
> that SOAP 1.2 guarantees that all nodes agree on what's legal 
> and what's 
> not in a SOAP envlope is by reference to XML 1.0 
> serialization rules. From 
> SOAP 1.2 Part 1 Chapter 5 "Message Construct" [2]:
> 
> "A SOAP message is specified as an XML infoset whose comment, 
> element, 
> attribute, namespace and character information items are able to be 
> serialized as XML 1.0. Note, requiring that the specified information 
> items in SOAP message infosets be serializable as XML 1.0 
> does NOT require 
> that they be serialized using XML 1.0.  [...] The Infoset 
> Recommendation 
> [XML InfoSet] allows for content not directly serializable 
> using XML; for 
> example, the character #x0 is not prohibited in the Infoset, but is 
> disallowed in XML. The XML Infoset of a SOAP Message MUST 
> correspond to an 
> XML 1.0 serialization [XML 1.0]."
> 
> In other words, all SOAP nodes must follow the same rules for 
> what's a 
> legal envelope, and those rules depend heavily on the well-formedness 
> rules for XML 1.0.  Hop by hop, some bindings will actually use the 
> obvious XML 1.0 serialization while others may use 
> compressed, encrypted, 
> etc. alternatives, but either way there must be nothing in 
> the envelope 
> infoset that could not be sent using XML 1.0.  But which 
> edition of XML 
> 1.0? The last reference in that paragraph is a hyperlink to the 
> bibliography.  I think most readers would taking that as 
> applying to the 
> first sentence, but it's a bit unclear.  Anyway, it gets a 
> bit worse. When 
> you follow the hyperlink to the bibliography you get [3]:
> 
> "[XML 1.0]
>  
> Extensible Markup Language (XML) 1.0 (Fourth Edition), Jean 
> Paoli, Eve 
> Maler, Tim Bray, et. al., Editors. World Wide Web Consortium, 
> 16 August 
> 2006. This version is http://www.w3.org/TR/2006/REC-xml-20060816. The 
> latest version is available at http://www.w3.org/TR/REC-xml."
> 
> So, SOAP 1.2 explicitly references XML 1.0 4th edition, but 
> then it also 
> tells you to go looking for a new one too!  If you believe it's 4th 
> edition only, then the new XML 1.0 PER has no impact, except 
> insofar as 
> you might sometime decide to update the Recommendation to 
> explicitly point 
> to 5th, should that be your wish (that will, of course, raise some 
> interoperability concerns, since for the first time SOAP 
> nodes won't all 
> agree on what's legal.)  Conversely, if one believes the bit 
> about the 
> "latest version", then one can read the SOAP Recommenation as 
> requiring 
> support for the new characters as soon as 
> http://www.w3.org/TR/REC-xml is 
> updated to point to 5th edition.
> 
> For those reasons, I request that the XML Protocols WG:
> 
> 1) Figure out what SOAP behavior is desired should it come to 
> pass that 
> XML 1.0 5th edition comes out as planned.  In particular, is 
> it the case 
> that conforming nodes MAY, MUST, SHOULD, SHOULD NOT, or MUST 
> NOT accept 
> the new characters in tag names in SOAP envelopes.  I believe 
> it's clear 
> that as long as 4th edition is current, the answer is MUST 
> NOT.  Does that 
> change if XML 1.0 5th edition reaches Recommendation?
> 
> 2) Coordinate with the Core WG to ensure that publications 
> are properly 
> synchronized (or instead, if appropriate, provide feedback 
> that XML 1.0 
> 5th edition is a problem for SOAP and should not be 
> published, if that is 
> what you believe.)
> 
> 3) Consider a bit the impact bindings,  faults and errors, should you 
> decide to allow for the new content.  Presumably, some nodes will be 
> trying to send new content, perhaps to old nodes that aren't 
> expecting it. 
>  Maybe or maybe not the outbound end of the binding implementation 
> notices.  Is that a binding-level error or something else?  
> Is there a 
> standard SOAP fault to be defined to indicate that the wrong 
> edition of 
> XML has been used.  Maybe the outbound binding implementation 
> is happy 
> with the new chars, but the receiving node is old.  If an XML 1.0 
> serialization is being used, then by far the most likely 
> failure mode is 
> just that the receiving binding (if it's checking well 
> formedness and not 
> trusting the sender), will reject the message as not well 
> formed.  I'm not 
> sure if there are more subtle issues with bindings that use 
> non-XML 1.0 
> forms on the wire.
> 
> 4) In any case, I suggest you clarify the ambiguity as to 
> whether the text 
> at [2] and [3] is to be read as referring to the latest 
> Recommendation-level edition of XML 1.0, or else as being to 
> specifically 
> 4th edition.
> 
> Thank you.
> 
> Noah
> 
> P.S. In case some of those on the cc: list are not aware, I 
> have not been 
> a member of the Protocols WG for some time.  I am just 
> commenting as an 
> interested member of the W3C community.
> 
> [1] http://www.w3.org/TR/2008/PER-xml-20080205/
> [2] http://www.w3.org/TR/soap12-part1/#soapenv
> [3] http://www.w3.org/TR/soap12-part1/#XML
> 
> --------------------------------------
> Noah Mendelsohn 
> IBM Corporation
> One Rogers Street
> Cambridge, MA 02142
> 1-617-693-4036
> --------------------------------------
> 
> 
> 
> 
> 
>

Received on Tuesday, 12 February 2008 19:29:31 UTC