- From: Robin Berjon <robin@berjon.com>
- Date: Wed, 18 Mar 2009 13:14:12 +0100
- To: Andrew Welch <andrew.j.welch@gmail.com>
- Cc: public-webapps WG <public-webapps@w3.org>
On Mar 18, 2009, at 11:33 , Andrew Welch wrote:
> - when multiple versions of the xml exist, you need some way to
> differentiate them other than checking for the existence of certain
> elements/attribute
You state that as a requirement but don't explain what the use case
for it is. Personally, I don't see any while I see several pointing in
the other direction.
> That's how XSLT 2.0 does it, and I think XHTML 2.0, but I notice XSD
> 1.1 is going down a different route...
XSLT 2.0 is a programming language (as opposed to a configuration file
for instance), and if you're using 2.0 features you want it to break
early (IIRC they also changed the semantics of some bits). Me, given
the changes, I would've gone with a new namespace but that's water
under the bridge.
XHTML 2.0 is not trying to be backwards compatible, that's HTML5's
job. It initially had a different namespace, and its recent attempt to
reverting to using the XHTML 1.x namespace is IMHO a poor decision
that I am rather confident will be overturned (if it hasn't already).
The reason there isn't One True Way of doing XML versioning is because
the use cases vary across languages. If you add a <pony> element to
SVG it's probably fine if it's not displayed as you can fallback, but
if you add a <transfer-me-money/> element to a SOAP message you
probably don't want people to ignore it.
Our usage scenarios for improved configurations don't involve the sort
of stringent versioning that would require variants on @version or
@mustUnderstand. Furthermore, the complexity of using a version
attribute has to take into account the fact that the widget stack is
modularised: what happens when a separate specification (signatures,
window modes, etc.) adds an element to the configuration file (as they
well can)? Do you increment the version? Add other version attributes?
Add some tokens as in version="1.0 +dsig +wm"?
I understand the draw to flagging versions, it somehow "feels neater",
and that's why people tend to want to throw them in (I just made the
very same comments to Bondi). But for our usage scenarios, it neither
helps nor scales.
--
Robin Berjon - http://berjon.com/
Feel like hiring me? Go to http://robineko.com/
Received on Wednesday, 18 March 2009 12:14:49 UTC