Tables: Loose and tight binding between rows and columns

Gavin Matthews (gavin@relay1.ug.eds.com)
Tue, 01 Aug 1995 13:27:01 +0100


Date: Tue, 01 Aug 1995 13:27:01 +0100
From: Gavin Matthews <gavin@relay1.ug.eds.com>
Subject: Tables: Loose and tight binding between rows and columns
To: www-html@www10.w3.org
Cc: gavin@sdlhpp11.w3.org
Message-Id: <9508011227.AA10308@sdlunix.ug.eds.com>

When writing or generating TABLEs in HTML, I often feel the need to 
indicate a tighter or looser semantic association between particular 
rows or columns.  

For example, a table with headings at the left and top should show that
such headings are set apart from the data, especially if there is more than
one row or column of headings.

On the other hand, if a table contains several pairs of columns which are
strongly associated, e.g. a table of temperature by month, each temperature
given in Celsius and Farenheit, they should be set together,

    +------++----------------------------+
    | Temp ||January|February|March|April|       Note single, double and
    +------++-------+--------+-----+-----+       absent borders.
    |Place || C   F | C    F | C F | C F |  
    +======++=======+========+=====+=====+       Temperature conversions are
    |London|| 1   2 | 3    4 | 5 6 | 7 8 |       not accurate. 
    +------++-------+--------+-----+-----+
    |Paris || 1   2 | 3    4 | 5 6 | 7 8 |
    +------++-------+--------+-----+-----+

In a typesetting language like LaTeX, I am accustomed to indicating these
strong and loose bindings by omitting and doubling the border respectively,
as indicated in the above ASCII picture.

In HTML, the loose binding between the rows containing headers and those
containing data can be inferred from the CLASS attribute of the TR element.  
No such inference is possible for columns, however, nor for strong bindings.

I have seen people attempt to indicate loose binding by leaving empty rows
or columns.  This is surely an abuse of structure-markup.  Indicating
tight binding by consolidation within one row or column (or span thereof)
is highly unsatisfactory.

I have two questions:
    ? Is there a need to be able to indicate stronger or weaker semantic
association between rows and columns in a table?
    ? What would the syntax for such stucture markup be?

Gavin