[whatwg] question on @width and @height attributes on <video>

Silvia Pfeiffer silviapfeiffer1 at gmail.com
Mon Nov 8 06:36:38 PST 2010

On Tue, Nov 9, 2010 at 12:16 AM, Simon Pieters <simonp at opera.com> wrote:
> On Mon, 08 Nov 2010 08:27:30 +0100, Silvia Pfeiffer
> <silviapfeiffer1 at gmail.com> wrote:
>> Hi all,
>> I am staring at the @width and @height attributes of the <video>
>> element, because I have just noticed that the implementation of IE9
>> doesn't respect percentage values in there. I remembered Hixie saying
>> that if you gave them a value that included "px", that's strictly
>> speaking not valid, since the value is a unsigned long but a browser
>> will just drop the "px" and interpret it correctly.
> That it's unsigned long is only relevant for getting and setting the .width
> and .height IDL attributes, it's not relevant for how the content
> attribute's value is interpreted.
>> I am now wondering if a percentage value is correct,
> Following the link for <video width> I come to
> http://www.whatwg.org/specs/web-apps/current-work/complete/the-map-element.html#attr-dim-width
> which says
> "Author requirements: The width and height attributes [...] if specified,
> must have values that are valid non-negative integers."
> and
> "A string is a valid non-negative integer if it consists of one or more
> characters in the range U+0030 DIGIT ZERO (0) to U+0039 DIGIT NINE (9)."
> So that makes it clear that percentage values are invalid as far as document
> conformance goes.
> But the UA requirements gives:
> http://www.whatwg.org/specs/web-apps/current-work/complete/rendering.html#dimRendering
> http://www.whatwg.org/specs/web-apps/current-work/complete/rendering.html#maps-to-the-dimension-property
> http://www.whatwg.org/specs/web-apps/current-work/complete/common-microsyntaxes.html#rules-for-parsing-dimension-values
> ...which supports percentage values.

So, now I am even more confused: are they invalid or supported? How do
you reconcile these two seemingly opposing positions?


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