- From: Laura Carlson <laura.lee.carlson@gmail.com>
- Date: Sun, 24 Aug 2008 15:47:46 -0500
- To: "HTML WG" <public-html@w3.org>
- Cc: "Gez Lemon" <gez.lemon@gmail.com>, "James Graham" <jg307@cam.ac.uk>, "Ian Hickson" <ian@hixie.ch>, "W3C WAI-XTECH" <wai-xtech@w3.org>, "Joshue O Connor" <joshue.oconnor@cfit.ie>
For your information from Jim Thatcher June 4, 2007: > "It may be true that it is possible to > restructure many complex data tables by adding rowgroup or colgroup > elements to the table and by altering the spans of cells in such a > way that the scope attribute can specify the header cells for all > data cells. I am not convinced but it is true for some of the > "classic" examples. That process is complicated and cumbersome. It > basically requires rewriting the table. Compare that with the > headers/id approach. ANY Table with ANY relationship between heading > cells and data cells can be defined directly by adding id attributes > and headers attributes to the cells - not touching the structure of > the table. ANY table ANY relationship. That is part of the reason why > you see many examples of simple tables marked up with headers/id when > they are not necessary and simple scope would work. The simple and > algorithmic aspects of headers/id is why the screen reader vendors > all now support it and none support rowgroup and colgroup. The > algorithm the AT vendors would have to implement for the scope/group > approach is much more complex to the point that I think it unlikely > they would ever support it AND it would not catch everything." User Agent Working Group comments: > "The 'headers' attribute is > supported by the major screen readers used in the world (JAWS, > WindowEyes, ??HAL/SuperNova-still waiting for a reply). WindowEyes > uses the headers and id attribute combination. WindowEyes does *not* > use the scope attribute. JAWS has support for headers/id, row and > column span, and the 'axis' attribute. Assistive technologies, > browser extensions, and tools that use DOM access also support the > headers attribute and expose that information through their > accessibility APIs and to their end users with disabilities and to > developers. Examples of this include Firefox extensions like FireVox > and the University of Illinois Firefox accessibility extension, and > developer tools like Parasoft's WebKing and IBM's RAVEN tool. In > addition, platform accessibility APIs such as IAccessible2 on > Windows, ATK/AT-SPI on Linux, and the Java accessibility API all have > functions for getting the row and column headers. The headers > attribute, scope attrte, and TH all provided explicit, engineered > ways for browsers to get row and column headers and expose that > information to assistive technologies through the accessibility APIs. > Without these, the browsers and assistive technologies are forced to > resort to heuristics such as font styling and location (topmost and > leftmost cells), which is insufficient for complex tables with > spanned and multiple row/column headers." - Jim Allan. http://esw.w3.org/topic/HTML/IssueTableHeaders#head-33a3d0ffbf5c6936b165f1ef92a80d98015073fb Best Regards, Laura
Received on Sunday, 24 August 2008 20:48:29 UTC