Re: THEAD, TFOOT, TBODY

eva (eva@algonet.se)
Wed, 10 Sep 1997 08:29:31 +0200


Message-Id: <199709100630.CAA09639@www10.w3.org>
From: "eva" <eva@algonet.se>
To: "Arnaud Le Hors" <lehors@w3.org>
Cc: "W3org-html" <www-html@w3.org>
Date: Wed, 10 Sep 1997 08:29:31 +0200
Subject: Re: THEAD, TFOOT, TBODY

Arnaud Le Hors wrote:

>>eva wrote:
>> <!ELEMENT THEAD - O (TR+)>
>> <!ELEMENT TFOOT - O (TR+)>
>> <!ELEMENT TBODY O O (TR+)>
>>
>> The above is not quite true as the minimization depends on occurrences of
>> those elements and should rather say.
>>
>> <!ELEMENT THEAD - O (TR+)             -- when a TFOOT or TBODY start tag
>> follows -->
>> <!ELEMENT TFOOT - O (TR+)>           -- when a THEAD or TBODY start tag
>> follows -->
>> <!ELEMENT TBODY O O (TR+)          -- when only one TBODY occurs and
THEAD
>> and TBODY are absent-->

>Optional row group tags
>      When a table contains only one body and no head or foot sections,
>the TBODY start and end tags may be omitted.
>      When a table block contains a head, the start tag of the THEAD
>element is required. The end tag may be omitted
>      when a TFOOT or TBODY start tag follows.
>      When a table block contains a foot, the start tag of the TFOOT
>element is required. The end tag may be omitted
>      when a THEAD or TBODY start tag follows.


I guess I didn't make myself clear enough. All the "whens" that you just
listed are commented in the proposed DTD fragment above.  My point is this:
If optional tags are "when..."-dependent then the
statements
<!ELEMENT THEAD - O (TR+)>
<!ELEMENT THEAD - O (TR+)>
<!ELEMENT TBODY O O (TR+)>
are simply not true or one could perhaps say that they are only true under
certain circumstances. There is no mention of these circumstances in the DTD
making it specification dependent -- a specification is required to make any
sense out of DTD. Therefore I'd like to suggest that some kind of
clarification be included in the DTD

Furthermore according to the DTD a "when"  " when a THEAD or TBODY start tag
follows", meaning follows the TFOOT, is wrong as a THEAD cannot follow
TFOOT.

/e