- From: Yvette P. Hoitink <y.p.hoitink@heritas.nl>
- Date: Tue, 10 Feb 2004 16:46:05 +0100
- To: "'Chris Ridpath'" <chris.ridpath@utoronto.ca>, "'WAI WCAG List'" <w3c-wai-gl@w3.org>
Chris: > > How to determine if a table is data or layout: > > Discussed at length on this mailing list[2][3][4] etc. > In summary - If cells can be moved without affecting their > intrinsic meaning then it's a layout table. Corollary - If > moving a cell affects its intrinsic meaning then it's a data table. > Sorry to open this cesspit again, but I really think tables used for LAYOUT are layout tables, even if moving a cell can affect its intrinsic meaning. There will always be grey areas: tables used for layout that might benefit from semantic markup. But does that make them data tables? Hypothetical example: If I have have a 2x2 (layout) table to divide my text in two rows with headers to the left in separate cells, exchanging those cells can affect their intrinsic meaning as well because those texts are now associated with different headings. Does that make it a data table? I don't think so. The table has no benefit here besides the visual aspect, the same effect could be achieved through CSS. I see no value in using the semantic markup for data tables here so to me this is definitely a layout table even if it fits your definition. A more interesting example is if you use a table to do the layout of a form (labels in column 1, inputs in column 2) Moving a cell changes its intrinsic meaning so it fits your definition of a data table, a viewpoint shared by Jim Thatcher [1]. I still think of this as a layout table though, but I can see the value in associating headers with the cells. From a practical point of view it may be very helpful to use the semantic markup for data tables in tables used to layout forms, but on a principal level I do not regard tables used for form layout as data tables. An example of a search form which would benefit from more semantic markup for the table can be found in a Dutch genealogical website: http://www.genlias.nl. I can't give you a direct link to the search page, so please select English (top right corner) -> Searching the Genlias database (text above the looking glass). This search form consists of three columns: column one has the labels, column two has the inputs for the first person you're looking for and column three has the inputs for the second person you're looking for. The meaning of an input is derived from two axis: the label and the person. Associating the labels correctly with their inputs in HTML is not possible in this case, since HTML only allows one input per label. The authors have used <th> to indicate the column headers, but no other semantic markup. Yvette Hoitink CEO Heritas, Enschede, The Netherlands E-mail: y.p.hoitink@heritas.nl [1] Jim Thatcher argues tables to layout forms are data tables: http://lists.w3.org/Archives/Public/w3c-wai-gl/2000JanMar/0406.html
Received on Tuesday, 10 February 2004 10:46:43 UTC