dolphinling wrote:
HTML5 brings back the |start| attribute on ordered lists. This allows a
list to semantically start with a number other than one. It seems like
the major use case for this is to split lists up, so that a single list
is marked by multiple <ol>s.
Other use cases include the ability to include an excerpt from another
list in a page while retaining the list item indexes, or breaking a long
list across several pages.
e.g. Search results with 10 results per page could be marked up as a
list: <ol start="1"> on the first page, <ol start="11"> on the second
page, etc.
Would it therefore make sense to allow named start values, so that the
author doesn't have to go through and re-number everything when a new
item is added at the top? And if so, should they be considered
semantically one list? And if so, would it make sense for it to also
apply to unordered lists, so that they can be split up, too?
I recall similar suggestions made on www-html in the past. Something
like this could be useful:
<ol id="part1">
<li>Item 1</li>
<li>Item 2</li>
<li>Item 3</li>
</ol>
<ol id="part2" continue="part1">
<li>Item 4</li>
<li>Item 5</li>
<li>Item 6</li>
</ol>
However, there are several issues that would need to be addressed:
* Should |continue| be an IDREF that can only continue a previous list
in the same page, or should it be a URI that can continue lists from
other pages?
* Can it be defined and implemented in a way that avoids circular
references. e.g.
<ol id="part1" continue="part2"/>
<ol id="part2" continue="part1"/>
* What does it mean if <ol contine="foo"> references a <ul id="foo">?
Should it only be able to link lists of the same type? (i.e. ol with
another ol and ul with another ul)
* What does it mean if it references any other element that isn't a <ul>
or <ol>?
* What should happen if it references a non-existent element?
* What does it mean if two lists continue from the same previous list? e.g.
<ol id="part1" continue="part2"/>
<ol id="part2" continue="part1"/>
<ol id="part3" continue="part1"/>
* How are references duplicate IDs handled in this situation? (That
could probably be the same way <label for=""> handles it)
* Which takes precedence out of <ol continue="part1" start="2"> and <li
value="3">?
* Backwards compatibility is also an issue, though it could possibly be
handled with some JavaScript that dynamically calculates and sets the
start attribute.
* Would implementations have difficulty with re-numbering list items in
linked lists, when a new <li> is dynamically inserted into a previous list?
--
Lachlan Hunt
http://lachy.id.au/
