Re: Proposed Text for Unresolved Resources

Cameron McCormack:
>> Presumably this paragraph shouldn’t apply to things like:
>>
>>   <image xlink:href='good' width='100' height='100' filter='url(#bad)'/>
>>
>> which I’d say is “an element in the rendering tree [that] contains an
>> invalid reference”?

Doug Schepers:
> Good catch, correct.  Instead of "contains a invalid reference", I've  
> updated the spec to say, "has an unresolved reference for the  
> 'xlink:href' attribute".  Maybe I should say instead that it has to do  
> with "replaced content" elements (which are listed in Rendering Model  
> [1] but not defined... should there be a definition for that?)?

So it’d apply to replaced content, <audio> and <use>.  If you want to
use that term, sure, add a definition for it.

>> What about for <use>,
>> where no size (only position) can be supplied, or <audio> which doesn’t
>> have any location?
>
> Maybe something that doesn't have a bounding box shouldn't have  
> title/desc fallback content rendered either?

Maybe.  Would this then fail to meet Jonathan’s use case?

>> I think the definition for rendering tree should be updated to state
>> that graphical content children of one of these referencing elements
>> whose reference is OK are not in the rendering tree.  The text you have
>> in linking.html#unresolved-resources seems to assume that these fallback
>> children are already in the rendering tree, and then says that these
>> must then be rendered.
>
> Yes, you're right.  Looking at the definition for rendering tree [2], I  
> don't see any mention of this circumstance at all.  Obviously, a  
> <circle> child of a <rect> element shouldn't render, but I'm having  
> trouble finding that explicitly in the spec.  If anyone can point me to  
> it, please do... otherwise I will update the spec to state the details.

As it’s currently worded, it’s sort of implicit, because it says the
“rendering tree is the set of elements being rendered”, and unsupported
elements (like a <circle> child of a <rect>) aren’t rendered.

I think it would be good to have a more rigorous definition of the
rendering tree.

-- 
Cameron McCormack ≝ http://mcc.id.au/

Received on Sunday, 27 July 2008 22:58:19 UTC