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[whatwg] [HTML5] Named start values for lists?

From: James Graham <jg307@cam.ac.uk>
Date: Wed, 28 Jun 2006 13:20:53 +0100
Message-ID: <44A27425.4080707@cam.ac.uk>
Henri Sivonen wrote:
> Hopefully, the issue list adequately demonstrates that the continue 
> attribute is way too complicated considering that the old start 
> attribute solves the numbering problem in a very pragmatic way.

I'm not sure it does...

 > * 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?

IDREF. The other possibility is a nightmare.

 > * 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"/>

The obvious choice is to use source order i.e. the ID must be defined before the 
continuation in the source, otherwise the attribute is ignored. I don't know how 
hard this would be to implement though.

 > * 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)

Pragmatically, there is little need for this to work at-all with <ul>.

 > * What does it mean if it references any other element that isn't a <ul>
 > or <ol>?

The continue attribute should be ignored.

 > * What should happen if it references a non-existent element?

The continue attribute should be ignored.

 > * 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"/>

That's fine. They both continue from the last value of the list they reference. 
(I can imagine cases where this would be right e.g. a list of instructions for a 
recipe with two variations at the end).

 > * 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">?

continue should take priority over start.

 > * Backwards compatibility is also an issue, though it could possibly be
 > handled with some JavaScript that dynamically calculates and sets the
 > start attribute.

There's not really a backwards compatibility problem here -anybody who cares can 
easily implement this in js.

 > * Would implementations have difficulty with re-numbering list items in
 > linked lists, when a new <li> is dynamically inserted into a previous list?

I would hope not since that's one of the big attractions of this model.

 > * How does it interact with CSS counters.

Good question; don't know. CSS counters seem to have the undesirable property of 
taking content and putting it in the presentation layer.

-- 
"You see stars that clear have been dead for years
But the idea just lives on..." -- Bright Eyes
Received on Wednesday, 28 June 2006 05:20:53 UTC

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