Re: proper count of <td> tags, colspan attribute, rowspan attribute

On Tue, 11 Nov 2003 FJ_Thuringia@web.de wrote:

> in the real world of creating HTMLs I often have errors, that result
> from missing <td> tags, surplus <td> tags, incorrect colspan attributes
> and incorrect rowspan attributes. Am I right, that W3Cs HTML validator
> can't detect such errors?

A validator is supposed to report only those errors that are reportable
markup errors. Whether a missing or surplus <td> tag is such an error
depends on the context (and the DTD, of course). For example,
in HTML, a tr element shall contain one or more th or td elements
and nothing else, see the DTD fragment at
http://www.w3.org/TR/html4/struct/tables.html#edef-TR
so any violation of this would be reported. But there is no requirement
that all tr elements in a table element contain the same number of cells
(th and td) elements, so this is of no concern to a validator; in fact, it
would be impossible to express such a requirement in SGML.

In HTML the colspan and rowspan attributes are declared as being of type
NUMBER, which means that the value shall be an unsigned integer
(i.e., a sequence of digits). That's all that a validator checks.

-- 
Jukka "Yucca" Korpela, http://www.cs.tut.fi/~jkorpela/