On 11/07/2012 05:52 PM, Ojan Vafai wrote:
On Wed, Nov 7, 2012 at 6:23 AM, Simon Pieters <sim...@opera.com> wrote:
My impression from TPAC is that implementors are on board with the idea of
adding <main> to HTML, and we're left with Hixie objecting to it.
For those of use who couldn't make it, which browser vendors voiced
support? I assume Opera since you're writing this thread.
To be clear, "Opera" didn't voice support for anything. Some people from
Opera suggested that it seemed like a reasonable idea (I think it seems
like a reasonable idea).
Hixie's argument is, I think, that the use case that <main> is intended to
address is already possible by applying the Scooby-Doo algorithm, as James
put it -- remove all elements that are not main content, <header>, <aside>,
etc., and you're left with the main content.
I think the Scooby-Doo algorithm is a heuristic that is not reliable
enough in practice, since authors are likely to put stuff outside the main
content that do not get filtered out by the algorithm, and vice versa.
Implementations that want to support a "go to main content" or "highlight
the main content", like Safari's Reader Mode, or whatever it's called, need
to have various heuristics for detecting the main content, and is expected
to work even for pages that don't use any of the new elements. However, I
think using <main> as a way to opt out of the heuristic works better than
using <aside> to opt out of the heuristic. For instance, it seems
reasonable to use <aside> for a pull-quote as part of the main content, and
you don't want that to be excluded, but the Scooby-Doo algorithm does that.
If there is anyone besides from Hixie who objects to adding <main>, it
would be useful to hear it.
This idea doesn't seem to address any pressing use-cases.
I think that finding the main content of a page has clear use cases. We
can see examples of authors working around the lack of this feature in
the platform every time they use a "skip to main" link, or (less
commonly) aria role=main. I believe we also see browsers supporting
role=main in their AT mapping, which suggests implementer interest in
this approach since the solutions are functionally isomorphic (but with
very different marketing and usability stories).
I think the argument that the Scooby Doo algorithm is deficient because
it requires many elements of a page to be correctly marked up, compared
to <main> which requires only a single element to get the same
functional effect, has merit. The observation that having one element on
a page marked — via class or id — "main" is already a clear cowpath
enhances the credibility of the suggested solution. On the other hand, I
agree that now everyone heading down the cowpath was aiming for the same
place; a <div class=main> wrapping the whole page, headers, footers, and
all is clearly not the same as one that identifies the extent of the
primary content. I don't know how these different uses stack up
(apologies if it is in some research that I overlooked).
I don't expect
authors to use it as intended consistently enough for it to be useful in
practice for things like Safari's Reader mode. You're stuck needing to use
something like the Scooby-Doo algorithm most of the time anyways.
I think Maciej commented on this. IIRC, he said that it wouldn't be good
enough for reader mode alone, but might usefully provide an extra piece
of data for the heuristics.
I don't
outright object, but I think our time would be better spent on addressing
more pressing problems with the web platform.
I think that's a very weak argument. In fact, given the current
landscape I would expect this to swallow more of the web standards
communities' time if it is not adopted than if it is. But I don't think
that's a strong argument in favour of adopting it either.
