[whatwg] List Headers

[Lachlan Hunt]

Christian Svindseth wrote:
> On Feb 4, 2009, at 11:13 AM, Robert O'Rourke wrote:
>> Are there any plans to bring list headers from HTML3 into HTML5? 
>> They'd make a lot of markup patterns simpler and be very very useful 
>> when it comes to styling.
>>
>> http://www.w3.org/MarkUp/html3/listheader.html
> 
> Unless I'm misreading the spec completely, HTML5 supports h1-h6, and 
> even header elements inside list items.

While you can include headings within li elements, that's different from 
what the lh element in HTML3, or even the label element in XHTML2, were 
designed for.

I believe the use case is providing a title indicating the content of 
the list, but where the title itself shouldn't contribute to the 
document's outline.  In HTML5, the only way to do this is to precede a 
list with an heading (h1-h6) element.

As an example of this, consider the element summaries in the HTML 5 
Reference, the attribute list has the heading Attributes, but that 
heading is not meant to affect the document's outline and doesn't appear 
in the TOC.  I had to use class="no-num no-toc", which is recognised by 
anolis (the spec's pre-processor tool), to avoid it being included in 
the TOC.

http://dev.w3.org/html5/html-author/#the-elements

But note that the issue itself doesn't affect just lists.  The same 
issue occurs for the DOM Interfaces sections, but that content isn't 
marked up as a list, and I'm also considering changing the attributes to 
use a table instead of a list, providing the attributes and associated 
descriptions.

So I do not believe introducing the LH element from HTML3 would 
adequately address the use case.  It's possible that what could be 
needed is an element that can contain the heading and its associated 
content, and behaves as a sectioning root:

   "Certain elements are said to be sectioning roots, including
    blockquote and td elements. These elements can have their own
    outlines, but the sections and headers inside these elements do not
    contribute to the outlines of their ancestors."

http://www.whatwg.org/specs/web-apps/current-work/#sectioning-root

It's possible that the figure element could be used for this purpose, as 
it is already a sectioning root, in which case we wouldn't need to add 
anything new to address this use case.  Though it's not entirely clear 
to me whether the figure element's meaning allows for this case.

-- 
Lachlan Hunt - Opera Software
http://lachy.id.au/
http://www.opera.com/