2.1.13 XML-Patch-Ops (xmlpatch)

NOTE: This charter is a snapshot of the 64th IETF Meeting in Vancouver, British Columbia Canada. It may now be out-of-date.

Last Modified: 2005-10-31


Lisa Dusseault <lisa@osafoundation.org>

Applications Area Director(s):

Ted Hardie <hardie@qualcomm.com>
Scott Hollenbeck <shollenbeck@verisign.com>

Applications Area Advisor:

Ted Hardie <hardie@qualcomm.com>

Mailing Lists:

General Discussion:
To Subscribe:

Description of Working Group:

This BoF will discuss the IETF taking on generic work in XML resource
manipulation. It is not the intent of this BoF to charter a working
group, but to review a proposal currently being put forward in SIMPLE
and to discuss whether work of this type is a reduplication of
existing work, a useful adjunct to existing work, or an appropriate
replacement for existing work.  The BoF will discuss: draft-urpalainen-
simple-xml-patch-ops, and attendees should review it carefully.

Goals and Milestones:

No Current Internet-Drafts

No Request For Comments

Current Meeting Report

The goal of this BOF was to confirm whether the work on XML diff algorithms 
taking place in the SIMPLE WG should continue in that working group, and 
whether it should be designed for general use and/or reviewed generally.

The SIMPLE WG has XCAP drafts that are relevant and require operations 
included in those provided by a generic XML patch algorithm.  Netconf and 
WIDEX were also mentioned as having related work and/or use cases as well but 
probably not precisely the same requirements.

Jari Urpalainen presented the architecture of a generic XML patch algorithm 
and demonstrated it working:
 - http://opensource.nokia.com/projects/xmlpatch/index.html
 - http://www.ietf.org/internet-drafts/
 - http://validate.openlaboratory.net/patch/

We discussed whether character data within XML elements needs to be patched as 
well. Note that currently Jari's solution does not allow that but only allows 
replacing the entire enclosing XML element, and it would not be trivial or 
simple to extend it to allowing character data patching.

Overall, we considered whether a fully general XML patch algorithm was needed, 
or whether individual use cases could be addressed separately, possibly with 
simpler approaches.  While there are general use cases (patching large XML 
format documents on HTTP/WebDAV servers, source control scenarios and possibly 
WIDEX), there was not a large call for a general solution for immediate use.  
Thus, this implies that there's not a need to extend Jari's mechanism 
immediately to support text patching or other functionality not already 
covered, nor is it necessary to pursue this work outside of SIMPLE.  It is 
possible that Jari's mechanism could be extended later although versions of 
content formats can be difficult to manage.

We discussed whether this work ought to go on in the W3C.  They've been pinged 
on this topic and suggested looking at XUpdate, but that work is dormant and 
didn't meet the requirements of at least the SIMPLE use case.

Since there wasn't sufficient interest in pursuing a general solution outside 
SIMPLE, we ended by discussing the process within SIMPLE.  A separate mailing 
list (to allow people to follow the XML patch work without having to filter 
out general SIMPLE work) was suggested and rejected by the SIMPLE chairs. Ted 
Hardie promised help from outside SIMPLE, and offers to relay relevant stuff 
to people who don't want to be on the SIMPLE list.


Jari Urpalainen's proposal for XML patch