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Table Headers HTMLWG/PFWG Joint Discussion

The Table Headers Issue was a Face-2-Face Meeting Topic on October 23, 2008 in Mandelieu, France.

The minutes from this session are somewhat difficult to read. It seems like two meetings (HTMLMediaElement and @headers) may have taken place on IRC simultaneously. Below is an attempt to pullout the @headers dialogue from the dual stream in IRC.

Topic: table headers

16:16 <Lachy> Topic: table headers

16:16 <Lachy> Joshue: The issue is how to mark up complex data tables, header associations

16:17 <Joshue> this is scary url

16:17 <pimpbot> Title: HTML/IssueTableHeaders - ESW Wiki (at

16:18 * Hixie notes that he has 86 more e-mails of feedback on the issue of tables markup that he hasn't yet processed

16:19 * CWilso read faster, Hixie! :)

16:19 <Joshue> These are also relevent

16:19 <pimpbot> 5822:, P2, NEW, The headers attribute should be able to reference a td

16:19 <Lachy> Al Gilman: The operational requirement from the consumer is associating an arbitrary cell with any other cell that provide context for interpreting the data

16:19 * gsnedders thinks CWilso should do so himself :)

16:19 <Lachy> ... Chained headers

16:19 <Lachy> ... Multiple tiers of context information within tables

16:20 <Joshue> Gez's complex table example

16:20 <pimpbot> Title: Child investment portfolios (at

16:20 <Lachy> ... It doesn't work in HTML4 because you can't have a TH that is a header for a TH

16:21 <Lachy> AlGilman: There has been dispute on the mailing list, people using many different terms.

16:21 <Lachy> AlGilman: There are 2 ways to do it: 1. Have a TD cell be a target of a headers attribute.

16:21 <Lachy> ... 2. Allow TH to reference another TH with a headers attribute

16:22 <Joshue> some more background on a proposed solution using existing header/id combinations which is well supported in current AT

16:22 <pimpbot> Title: HTML/Action72Headers - ESW Wiki (at

16:22 <Lachy> ... We would certainly like to make scope more effective

16:22 <Joshue> Smart span algorithm

16:22 <pimpbot> Title: Smart span algorithm for table cells from James Graham on 2008-03-10 ( from March 2008) (at

16:22 <Lachy> ... But we need to come together on a proposal for what all of the markup features are, including the headers attribute, algorithm, etc.

16:23 <Lachy> ... We still have to work out detalis

16:24 <Joshue> +q

16:24 * Zakim sees Joshue on the speaker queue

16:25 <MikeSmith> ack Joshue

16:25 * Zakim sees no one on the speaker queue

16:25 <Lachy> Joshue: There are a couple of solutions

16:25 <Lachy> ... about half way down the wiki page

16:26 <Lachy> ... Smart headers algorithm, TH referencing TH, etc.

16:26 <Lachy> ... Smart Headers is a good algorithm

16:26 <Lachy> ... Allowing headers="" to reference a TD element

16:26 <Lachy> ... is also an elegant solution

16:26 <Lachy> ... headers="" is widely supported by screen readers

16:27 <Lachy> ... lets see if we can come to some kind of concensus

16:27 <Joshue>

16:27 <pimpbot> Title: HTML/IssueTableHeaders - ESW Wiki (at

16:27 <Lachy> BenMillard: At the moment, Firefox doesn't do anything with scope

16:27 <Lachy> AlGilman: But it's all in the DOM, even though it doesn't do anything special with them

16:28 <Lachy> Michael Cooper: A lot of accessibility is done through the acessibility API and would require the UA to do a mapping from the HTML DOM to that API

16:28 <Lachy> ... But it's also done through the DOM for web content

16:29 <Lachy> Joshue; it's important to bear in mind the limited support for scope="" in current UA and AT

16:30 <MikeSmith> q? [16:30] * Zakim sees no one on the speaker queue

16:30 <Lachy> MikeSmith: Is there a time line for when you'll get to the remaining table headers feedback?

16:31 <Lachy> Hixie: I'll get to it when I get to it, but I can prioritise it if there are vendors that need me to

16:31 <Lachy> AlGilman: This is not an urgent matter, because in the short term people can still use headers="" in HTML4

16:32 <hsivonen> q+

16:32 * Zakim sees hsivonen on the speaker queue

16:32 <MikeSmith> q+ Ben

16:32 * Zakim sees hsivonen, Ben on the speaker queue

16:32 <Lachy> ... I'd like us to work with Ben to tune the algorithm, and getting that into HTML5 and implemented in browsers

16:32 * karl wonders who support Ben to do this work (financially)

16:32 <Lachy> Hixie: It sounds like sooner rather than later would help, so I can help with that in the next few months

16:32 <Joshue> +q

  • Zakim sees hsivonen, Ben, Joshue on the speaker queue

16:33 <smedero> karl: ben doesn't have a laptop so I'll jump in: mozilla

16:33 <Lachy> AlGilman: If you only have headers="", then it's grotty for authors. But we should move forward with change to improve that

16:33 <Lachy> MikeSmith: Does that timeline work for you guys?

16:33 <Lachy> Joshue: I can't speak for any vendors, but it would be nice

16:34 <karl> smedero, I hope it is enough for him to be doing that correctly without making his "life at risk".

16:34 <Lachy> Hixie: The remaining ~2000 currently in the queue should be dealt with within a year or so

16:34 <MikeSmith> q?

16:34 * Zakim sees hsivonen, Ben, Joshue on the speaker queue

16:34 <MikeSmith> ack hsivonen

16:34 * Zakim sees Ben, Joshue on the speaker queue

16:34 <Lachy> hsivonen: There's an open moz bug about exposing table relationships to accessibility APIs

16:35 <Lachy> ... I encourage you to keep an eye on the mozilla bug, especially if the Smart Headers algorithm will be going in the spec

16:35 <Lachy> ... It would be a shame to have them implement what's in the current spec, and then have it updated in the spec later

16:35 <MikeSmith> ack Ben

16:35 * Zakim sees Joshue on the speaker queue

16:36 <Lachy> BenMillard: Al mentioned tuning the proposal. I wouldn't want to kind of shortcut the proposal

16:36 <anne> "hixified"

16:36 <Lachy> ... I think that the algorithm in Jame's inspector should be "Hixified" into the spec

16:36 <Lachy> ... I think an Action item would be to document the diff between the spec and Smart Headers algorithm

16:37 <MikeSmith> ack Joshue

16:37 * Zakim sees no one on the speaker queue

16:37 <MichaelC> q+ to ask if it's not more efficient to get a round of feedback from implementers before putting a proposal in the spec

16:37 * Zakim sees MichaelC on the speaker queue

16:37 <Lachy> Joshue: One of the things that came out in the PF meeting was that we were all talking about the same thing, using different names

16:37 <Lachy> ... We should know what we're talking about

16:37 <Lachy> ... get on the same page

16:38 * Philip wonders if "Hixification" is the process whereby you rewrite an algorithm as a very verbose linear sequence of prose with lots of gotos so that nobody can understand what it's doing any more :-p

16:38 <Lachy> q?

16:38 * Zakim sees MichaelC on the speaker queue

16:38 <MikeSmith> q?

16:38 * Zakim sees MichaelC on the speaker queue

16:38 <MikeSmith> ack MikeSmith

16:38 * Zakim sees MichaelC on the speaker queue

16:38 <MikeSmith> ack MichaelC

16:38 <Zakim> MichaelC, you wanted to ask if it's not more efficient to get a round of feedback from implementers before putting a proposal in the spec

16:38 * Zakim sees no one on the speaker queue

16:38 <Lachy> MichaelC: It might be more efficient if there is a round oof feedback from implementers before it's in the psec

16:39 <anne> q+

16:39 * Zakim sees anne on the speaker queue

16:39 <hsivonen> Hixie,

16:39 <pimpbot> Bug 441445: was not found.

16:39 <anne> q-

16:39 * Zakim sees no one on the speaker queue

16:40 <Joshue> From the PF meeting we found an issue around the use of terminology in this issue. Conceptual headers, chained headers, nested headers etc are all essentially the same. I would like to see the terminology tied up so we are all on the same page. This could help the process all round.

16:41 <Lachy> AlGilman: What we want to do in face time, we've done

16:42 <hsivonen> q+

16:42 * Zakim sees hsivonen on the speaker queue

16:42 <MikeSmith> ack hsivonen

16:42 * Zakim sees no one on the speaker queue

16:43 <Lachy> hsivonen: I heard that there was direction of concensus on the validation side that headers would point to th, be valid and point to td might not be valid

16:43 <MichaelC> Just to clarify, since it needed verbal clarification, I do not advocate implementation of proposals, but was suggesting implementers might have worthwhile insights on a proposal (but should not implement it until it matures)

16:43 <Lachy> AlGilman: The current practice doesn't use HTML5 validation yet, we don't need to trouble you now

[16:47] * Quits: Al (alfredsgil@ (Quit: Leaving)

[16:48] * Quits: Joshue (Joshue@ (Quit: Computer goes to sleep!)