- From: Charles McCathieNevile <charles@w3.org>
- Date: Tue, 19 Sep 2000 04:07:50 -0400 (EDT)
- To: "Leonard R. Kasday" <kasday@acm.org>
- cc: WAI AU Guidelines <w3c-wai-au@w3.org>, WAI ER group <w3c-wai-er-ig@w3.org>
There is a canonical XML spec that could be used. And IDs are better than
checksums, since you can find them faster - comparing checksums element by
element isn't as good, just possible and saves human time. But of course the
ids can also be changed (fragment identifiers aren't part of the URI in the
http transaction at the moment...)
Charles
On Mon, 18 Sep 2000, Leonard R. Kasday wrote:
And if someone simply re-arranged the elements you could still find the
originals... and without using id's, since you've got a hash of the checksums.
Yes. Neat.
Only suggestion is would be to cannonicalize whitespace before doing
checksums. E.g. replace all white space with exactly one space and omit
whitespace between > and < .
Len
Yes, I realised that. The value of doing it over elements specified by
xpointers is that you can also have a checksum for the particular elements,
so you can figure out which of those are different, break the document down
and up again keeping as much as is still fine.
Cheers
Charles
On Mon, 18 Sep 2000, Leonard R. Kasday wrote:
Good approach... at least for fixed web pages, or for reporting on the
status of a page at a particular time
Problem comes in if page has changed. You do spot that via the hash (or do
you mean checksum?).
But if a page does change, it would be useful to retain as much information
as possible, not just say that the RDF no longer applies. One way to do
this is to make sure all elements have unique id's that do not get
changed. Or, if a checkpoint refers to a regions of a page, with many
elements, that section should be wrapped in a <span> with a unique id.
Still have a problem if regions overlap instead of being nested.... hmmm...
can xpointer specify regions between two elements?
Len
At 11:19 AM 9/18/00 -0400, Charles McCathieNevile wrote:
>I wrote some very rough notes on how one could work.
>
>I am sending this mostly at this stage so the page doesn't get lost <grin/>
>
>http://www.w3.org/2000/09/conf-tool
>
>charles
>
>--
>Charles McCathieNevile mailto:charles@w3.org phone: +61 (0) 409
134 136
>W3C Web Accessibility Initiative http://www.w3.org/WAI
>Location: I-cubed, 110 Victoria Street, Carlton VIC 3053, Australia
>September - November 2000:
>W3C INRIA, 2004 Route des Lucioles, BP 93, 06902 Sophia Antipolis Cedex,
>France
--
Leonard R. Kasday, Ph.D.
Institute on Disabilities/UAP and Dept. of Electrical Engineering at Temple
University
(215) 204-2247 (voice) (800) 750-7428 (TTY)
http://astro.temple.edu/~kasday mailto:kasday@acm.org
Chair, W3C Web Accessibility Initiative Evaluation and Repair Tools Group
http://www.w3.org/WAI/ER/IG/
The WAVE web page accessibility evaluation assistant:
http://www.temple.edu/inst_disabilities/piat/wave/
--
Charles McCathieNevile mailto:charles@w3.org phone: +61 (0) 409 134 136
W3C Web Accessibility Initiative http://www.w3.org/WAI
Location: I-cubed, 110 Victoria Street, Carlton VIC 3053, Australia
September - November 2000:
W3C INRIA, 2004 Route des Lucioles, BP 93, 06902 Sophia Antipolis Cedex, France
--
Leonard R. Kasday, Ph.D.
Institute on Disabilities/UAP and Dept. of Electrical Engineering at Temple
University
(215) 204-2247 (voice) (800) 750-7428 (TTY)
http://astro.temple.edu/~kasday mailto:kasday@acm.org
Chair, W3C Web Accessibility Initiative Evaluation and Repair Tools Group
http://www.w3.org/WAI/ER/IG/
The WAVE web page accessibility evaluation assistant:
http://www.temple.edu/inst_disabilities/piat/wave/
--
Charles McCathieNevile mailto:charles@w3.org phone: +61 (0) 409 134 136
W3C Web Accessibility Initiative http://www.w3.org/WAI
Location: I-cubed, 110 Victoria Street, Carlton VIC 3053, Australia
September - November 2000:
W3C INRIA, 2004 Route des Lucioles, BP 93, 06902 Sophia Antipolis Cedex, France
Received on Tuesday, 19 September 2000 04:07:51 UTC