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

Christopher B Ferris <[email protected]> Tue, 12 Feb 2008 14:35:04 -0500
Newsgroups gmane.text.xml.distributed
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Thanks, Noah.

I'll add the issue to the XMLP WG's agenda and we'll get back to you once 
we have taken up the issue.

Cheers,

Christopher Ferris
STSM, Software Group Standards Strategy
email: [email protected]
blog: http://www.ibm.com/developerworks/blogs/page/chrisferris
phone: +1 508 234 2986

Noah Mendelsohn/Cambridge/IBM wrote on 02/12/2008 02:16:39 PM:

> 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
> --------------------------------------
> 
> 
> 

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<br><font size=2 face="sans-serif">Thanks, Noah.</font>
<br>
<br><font size=2 face="sans-serif">I'll add the issue to the XMLP WG's
agenda and we'll get back to you once we have taken up the issue.</font>
<br>
<br><font size=2 face="sans-serif">Cheers,</font>
<br>
<br><font size=2 face="sans-serif">Christopher Ferris<br>
STSM, Software Group Standards Strategy<br>
email: [email protected]<br>
blog: </font><a href=http://www.ibm.com/developerworks/blogs/page/chrisferris><font size=2 face="sans-serif">http://www.ibm.com/developerworks/blogs/page/chrisferris</font></a><font size=2 face="sans-serif"><br>
phone: +1 508 234 2986</font>
<br>
<br><tt><font size=2>Noah Mendelsohn/Cambridge/IBM wrote on 02/12/2008
02:16:39 PM:<br>
<br>
&gt; The XML Core working group has published a Proposed Edited <br>
&gt; Recommendation (PER) Extensible Markup Language (XML) 1.0 (Fifth <br>
&gt; Edition). &nbsp;The major change in that edition is the proposal to
<br>
&gt; expand the set of legal XML element and attribute names. &nbsp;Without
<br>
&gt; commenting either for myself or for IBM on the merits of this <br>
&gt; proposal, I note that there appears to be an interdependency with
<br>
&gt; the SOAP 1.2 Recommendation. &nbsp;Specifically, the way that SOAP
1.2 <br>
&gt; guarantees that all nodes agree on what's legal and what's not in
a <br>
&gt; SOAP envlope is by reference to XML 1.0 serialization rules. &nbsp;From
<br>
&gt; SOAP 1.2 Part 1 Chapter 5 &quot;Message Construct&quot; [2]:</font></tt>
<br><tt><font size=2>&gt; <br>
&gt; &quot;A SOAP message is specified as an XML infoset whose comment,
<br>
&gt; element, attribute, namespace and character information items are
<br>
&gt; able to be serialized as XML 1.0. Note, requiring that the specified<br>
&gt; information items in SOAP message infosets be serializable as XML
1.<br>
&gt; 0 does NOT require that they be serialized using XML 1.0. &nbsp;[...]
The<br>
&gt; Infoset Recommendation [XML InfoSet] allows for content not directly<br>
&gt; serializable using XML; for example, the character #x0 is not <br>
&gt; prohibited in the Infoset, but is disallowed in XML. The XML Infoset<br>
&gt; of a SOAP Message MUST correspond to an XML 1.0 serialization [XML
1.0].&quot;</font></tt>
<br><tt><font size=2>&gt; <br>
&gt; In other words, all SOAP nodes must follow the same rules for what's<br>
&gt; a legal envelope, and those rules depend heavily on the well-<br>
&gt; formedness rules for XML 1.0. &nbsp;Hop by hop, some bindings will
<br>
&gt; actually use the obvious XML 1.0 serialization while others may use
<br>
&gt; compressed, encrypted, etc. alternatives, but either way there must
<br>
&gt; be nothing in the envelope infoset that could not be sent using XML
<br>
&gt; 1.0. &nbsp;But which edition of XML 1.0? The last reference in that
<br>
&gt; paragraph is a hyperlink to the bibliography. &nbsp;I think most readers
<br>
&gt; would taking that as applying to the first sentence, but it's a bit
<br>
&gt; unclear. &nbsp;Anyway, it gets a bit worse. &nbsp;When you follow
the <br>
&gt; hyperlink to the bibliography you get [3]:</font></tt>
<br><tt><font size=2>&gt; <br>
&gt; &quot;[XML 1.0]</font></tt>
<br><tt><font size=2>&gt; &nbsp;</font></tt>
<br><tt><font size=2>&gt; Extensible Markup Language (XML) 1.0 (Fourth
Edition), Jean Paoli, <br>
&gt; Eve Maler, Tim Bray, et. al., Editors. World Wide Web Consortium,
16<br>
&gt; August 2006. This version is </font></tt><a href="http://www.w3.org/TR/2006/REC-xml-20060816"><tt><font size=2>http://www.w3.org/TR/2006/REC-xml-20060816</font></tt></a><tt><font size=2>.
<br>
&gt; The latest version is available at </font></tt><a href="http://www.w3.org/TR/REC-xml"><tt><font size=2>http://www.w3.org/TR/REC-xml</font></tt></a><tt><font size=2>.&quot;</font></tt>
<br><tt><font size=2>&gt; <br>
&gt; So, SOAP 1.2 explicitly references XML 1.0 4th edition, but then it
<br>
&gt; also tells you to go looking for a new one too! &nbsp;If you believe
it's<br>
&gt; 4th edition only, then the new XML 1.0 PER has no impact, except <br>
&gt; insofar as you might sometime decide to update the Recommendation
to<br>
&gt; explicitly point to 5th, should that be your wish (that will, of <br>
&gt; course, raise some interoperability concerns, since for the first
<br>
&gt; time SOAP nodes won't all agree on what's legal.) &nbsp;Conversely,
if <br>
&gt; one believes the bit about the &quot;latest version&quot;, then one
can read <br>
&gt; the SOAP Recommenation as requiring support for the new characters
as soon as <br>
&gt; </font></tt><a href="http://www.w3.org/TR/REC-xml"><tt><font size=2>http://www.w3.org/TR/REC-xml</font></tt></a><tt><font size=2>
is updated to point to 5th edition.</font></tt>
<br><tt><font size=2>&gt; <br>
&gt; For those reasons, I request that the XML Protocols WG:</font></tt>
<br><tt><font size=2>&gt; <br>
&gt; 1) Figure out what SOAP behavior is desired should it come to pass
<br>
&gt; that XML 1.0 5th edition comes out as planned. &nbsp;In particular,
is it<br>
&gt; the case that conforming nodes MAY, MUST, SHOULD, SHOULD NOT, or <br>
&gt; MUST NOT accept the new characters in tag names in SOAP envelopes.
&nbsp;<br>
&gt; I believe it's clear that as long as 4th edition is current, the <br>
&gt; answer is MUST NOT. &nbsp;Does that change if XML 1.0 5th edition
reaches<br>
&gt; Recommendation?</font></tt>
<br><tt><font size=2>&gt; <br>
&gt; 2) Coordinate with the Core WG to ensure that publications are <br>
&gt; properly synchronized (or instead, if appropriate, provide feedback
<br>
&gt; that XML 1.0 5th edition is a problem for SOAP and should not be <br>
&gt; published, if that is what you believe.)</font></tt>
<br><tt><font size=2>&gt; <br>
&gt; 3) Consider a bit the impact bindings, &nbsp;faults and errors, should
<br>
&gt; you decide to allow for the new content. &nbsp;Presumably, some nodes
<br>
&gt; will be trying to send new content, perhaps to old nodes that aren't<br>
&gt; expecting it. &nbsp;Maybe or maybe not the outbound end of the binding
<br>
&gt; implementation notices. &nbsp;Is that a binding-level error or something
<br>
&gt; else? &nbsp;Is there a standard SOAP fault to be defined to indicate
that<br>
&gt; the wrong edition of XML has been used. &nbsp;Maybe the outbound binding
<br>
&gt; implementation is happy with the new chars, but the receiving node
<br>
&gt; is old. &nbsp;If an XML 1.0 serialization is being used, then by far
the <br>
&gt; most likely failure mode is just that the receiving binding (if it's<br>
&gt; checking well formedness and not trusting the sender), will reject
<br>
&gt; the message as not well formed. &nbsp;I'm not sure if there are more
<br>
&gt; subtle issues with bindings that use non-XML 1.0 forms on the wire.</font></tt>
<br><tt><font size=2>&gt; <br>
&gt; 4) In any case, I suggest you clarify the ambiguity as to whether
<br>
&gt; the text at [2] and [3] is to be read as referring to the latest <br>
&gt; Recommendation-level edition of XML 1.0, or else as being to <br>
&gt; specifically 4th edition.</font></tt>
<br><tt><font size=2>&gt; <br>
&gt; Thank you.</font></tt>
<br><tt><font size=2>&gt; <br>
&gt; Noah</font></tt>
<br><tt><font size=2>&gt; <br>
&gt; P.S. In case some of those on the cc: list are not aware, I have not<br>
&gt; been a member of the Protocols WG for some time. &nbsp;I am just <br>
&gt; commenting as an interested member of the W3C community.</font></tt>
<br><tt><font size=2>&gt; <br>
&gt; [1] </font></tt><a href="http://www.w3.org/TR/2008/PER-xml-20080205/"><tt><font size=2>http://www.w3.org/TR/2008/PER-xml-20080205/</font></tt></a>
<br><tt><font size=2>&gt; [2] </font></tt><a href="http://www.w3.org/TR/soap12-part1/#soapenv"><tt><font size=2>http://www.w3.org/TR/soap12-part1/#soapenv</font></tt></a>
<br><tt><font size=2>&gt; [3] </font></tt><a href="http://www.w3.org/TR/soap12-part1/#XML"><tt><font size=2>http://www.w3.org/TR/soap12-part1/#XML</font></tt></a>
<br><tt><font size=2>&gt; <br>
&gt; --------------------------------------<br>
&gt; Noah Mendelsohn <br>
&gt; IBM Corporation<br>
&gt; One Rogers Street<br>
&gt; Cambridge, MA 02142<br>
&gt; 1-617-693-4036<br>
&gt; --------------------------------------<br>
&gt; <br>
&gt; <br>
&gt; <br>
</font></tt>
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