hsivonen at iki.fi
Wed Nov 8 15:01:07 PST 2006
On Nov 6, 2006, at 09:36, Matthew Paul Thomas wrote:
> On Nov 4, 2006, at 1:53 AM, Henri Sivonen wrote:
>> None of Opera 9.02, Firefox 2.0, IE7 and Safari 2.0.4 implement
>> colspan="0" as specified in HTML 4.01. Trident, Presto and WebKit
>> at least agree on what to do with it: they treat it like colspan="1".
>> I suggest that only positive integers be conforming and that non-
>> conforming values be treated as 1.
> I know browser vendors have had a long time to implement this, but
> still, I think giving up on it would be a shame. The number of rows
> or columns in a table is often rather expensive to calculate ahead
> of time. As long as this has to be done to calculate the rowspan=
> or colspan= of header cells, this can substantially increase the
> time an application takes to generate a table. For the browser to
> interpret colspan="0" or rowspan="0" instead would both make life
> easier for application authors, and make such pages faster overall.
That won't work for colspan='0' and explicit column groups, because
you'd still have to calculate the column groups and output them
before you output any rows.
What Gecko does with the last cell on a row having colspan="0"
rowspan="1" might be marginally useful for your use case, but I don't
think this particular case is worth breaking the interop that now
exist between Trident, Presto and WebKit.
If the colspan="0" cell is not the last on a row in Gecko, the
results are weird.
With colspan="0" and rowspan greater than 1, the rules for finding
free slots for later cells fall apart. How would you spec the
handling of the following table?
<tr><td colspan="0" rowspan='2'>1</td></tr>
The Gecko treatment is just weird.
So I stand by my suggestion that colspan="0" be non-conforming and be
treated as colspan="1" by UAs.
rowspan='0' is interoperable as defined in HTML 4.01, so no reason to
change that one. It doesn't cause weirdness, because the search for
available cell slots works horizontally and rowspan='0' extends cells
hsivonen at iki.fi
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