Re: Element Whitelisting (was: SVG Feedback on HTML5 SVG Proposal)

On Tue, 10 Mar 2009, Doug Schepers wrote:
> >
> > It seems dangerous to split the definition of how to parse text/html 
> > into multiple specifications. However, updating the list should be 
> > easy and quick, and in practice shouldn't affect implementations (who 
> > would just update their lists regardless of what the specs say). What 
> > is the concern?
> 
> It seems riskier to bottleneck element parsing to one time-frozen 
> specification.  I agree that implementations will update their internal 
> list of supported non-HTML elements and attributes regardless of what 
> HTML5 says, so it doesn't seem practical to include any such list in the 
> HTML5 spec.
> 
> Let's say that 2 months after HTML5 becomes a Rec, SVG comes out with the
> <pony> element, which has a the @hands attribute.

I assume you mean more something like fePony with a jazzHands attribute, 
since all-lowercase names would work fine.


> Obviously, all browser vendors would implement this element and its 
> attribute, post-haste.  Now, either HTML5 is out of date, or it needs to 
> have an errata issued and ultimately a second edition.

By the time HTML5 becomes a REC, it will have been out of date for a long 
time. I would fully expect work on HTML6 to be in full swing by then, and 
HTML6 would be able to track the new features easily.

Adding a new attribute or element name requires a careful study of 
existing content, which is far more work than any sort of editing of a 
spec. I think worrying about which spec the list is in is optimising the 
easy part while ignoring the real bottlenecks.

Note that nothing stops a future version of SVG adding names and 
attributes to the list anyway, acting as a kind of errata to HTML itself, 
should it be found that the HTML working group at the time is no longer 
responsive to feedback of this nature.


> In the worst-case scenario, some implementers (or authors) might feel 
> gated by the whitelist of elements in HTML5, and might not implement (or 
> use) <pony hands="13.7"/>.  That would be a real shame.

The odds of an implementor feeling like they shouldn't do something 
because the spec doesn't justify it are spectacularily remote.

-- 
Ian Hickson               U+1047E                )\._.,--....,'``.    fL
http://ln.hixie.ch/       U+263A                /,   _.. \   _\  ;`._ ,.
Things that are impossible just take longer.   `._.-(,_..'--(,_..'`-.;.'

Received on Wednesday, 11 March 2009 01:17:15 UTC