- From: Phill Jenkins <pjenkins@us.ibm.com>
- Date: Thu, 26 Aug 2004 12:54:41 -0500
- To: w3c-wai-ig@w3.org, "Michael Cooper" <michaelc@watchfire.com>, Wendy Chisholm <wendy@w3.org>
- Message-ID: <OF03FEF97F.A84051C7-ON86256EFC.005C2FD8-86256EFC.00626459@us.ibm.com>
Dear Interest Group member, please send your comments directly to me or the list. Please do not include a discussion about whether to use CSS verses tables for layout. We already agree that CSS is the preferred solution. Whether we use CSS or tables for layout is not the disability issue, what really matters is that the reading order is logical when linearized. For example when CSS is off or not available, or when using a magnifier or screen reader software to navigate the content in a logical order. Proposal: For devices and user agents that do not support CSS layout and for older pages still using tables for layout, the proposal is to recommend a best practice for distinguishing between data tables and layout tables by including the summary attribute, but leaving the contents empty (null). Simple Example: <table title="layout table for navigation" summary=""> <tr><td>Home</td></tr> <tr><td>more content</td></tr> </table Layout tables are those tables in HTML that do NOT have row and/or column headings (TH's), do NOT have Captions, and do NOT have other mark-up associated with tabular data for which the table markup was originally specified. Data tables are those tables in HTML that do or should have row and/or column headings (TH's), do or should have captions, and do or should have other markup, such as summary, scope, and other attributes and elements associated with tabular data. Other proposals included using the title attribute to include the keyword "layout". The disadvantages to this proposal include having the tool tip show up on each and every layout table in graphical browsers, the title being spoken, depending on settings, when using screen reading software, and if we proposed using the null title="", then we wouldn't be able to provide additional contextual information for which the title attribute is specified. The proposal to use the null summary="" attribute has the following benefits: 1. The null summary="" attribute will not be spoken by screen reading software. 2. The summary attribute can be checked for null by authoring tools as a convention to indicate the table is for layout. If we eliminated the summary attribute completely from the markup, then there is less of a guarantee that the author made a conscience decision to identify the articular table as a layout table. 3. If the keyword "layout" were included in the summary attribute, screen reading software would currently speak the term "layout", the contents of the attribute, each time the user navigated to a layout table, which on many complex designed pages, would be annoying and too verbose for the user. It would approach the undesirable experience of reading the source HTML code. 4. The user agent could be configured to skip or ignore layout tables identified with the null summary="" attribute when navigating. 5. Authoring tools could be more intelligently configured to test for reading order in layout tables and correct tabular data markup in data tables. Acceptance of this proposal would require coordination between WCAG 2.0, UAAG, ATAG, and assistive technology vendors. Authors could immediately implement this best practice without negative side effects. Please feel free to forward this proposal to others. If forwarding to a list serv, please copy me. I will collect all the comments by the end of August and reply with an updated proposal to the WAI coordination group. Thank you, Phill Jenkins IBM Research - Accessibility Center http://www.ibm.com/able
Received on Thursday, 26 August 2004 17:57:23 UTC