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RE: [media] adding autoplay requirements to requirements doc

From: Sean Hayes <Sean.Hayes@microsoft.com>
Date: Thu, 21 Apr 2011 08:20:49 +0000
To: Ian Hickson <ian@hixie.ch>
CC: Eric Carlson <eric.carlson@apple.com>, Philip Jägenstedt <philipj@opera.com>, "public-html-a11y@w3.org" <public-html-a11y@w3.org>
Message-ID: <8DEFC0D8B72E054E97DC307774FE4B91442D134E@DB3EX14MBXC313.europe.corp.microsoft.com>
Ok. Its optional; I get that. The point was to include some words that require an opt in setting so that authors can use it without needing to worry about the WCAG 3 second rule.

-----Original Message-----
From: Ian Hickson [mailto:ian@hixie.ch] 
Sent: 21 April 2011 05:34
To: Sean Hayes
Cc: Eric Carlson; Philip Jägenstedt; public-html-a11y@w3.org
Subject: RE: [media] adding autoplay requirements to requirements doc

On Wed, 20 Apr 2011, Sean Hayes wrote:
> That all makes a certain amount of sense; it would carry a little more 
> weight if there were some language in the spec to the effect that 
> autoplay is a request that the user agent can deny. For example,
> Rather than defining autoplay as:
> " When present, the user agent (as described in the algorithm described 
> herein) will automatically begin playback of the media resource as soon 
> as it can do so without stopping "

That's not the definition, it's just a non-normative description. (You can 
tell it's non-normative because there's no normative requirement -- none 
of the works in that sentence are "must", "should", or "may".)

The actual requirement is in this section:


...where it says:

   If the autoplaying flag is true, and the paused attribute is true, and 
   the media element has an autoplay attribute specified, and the media 
   element's Document's browsing context did not have the sandboxed 
   automatic  features browsing context flag set when the Document was 
   created, then the user agent may also set the paused attribute to 
   false, queue a task to fire a simple event named play, and queue a task 
   to fire a simple event named playing.

Specifically, note that it says "may", not "must". That's what makes it 
optional for user agents.

Ian Hickson               U+1047E                )\._.,--....,'``.    fL
http://ln.hixie.ch/       U+263A                /,   _.. \   _\  ;`._ ,.
Things that are impossible just take longer.   `._.-(,_..'--(,_..'`-.;.'
Received on Thursday, 21 April 2011 08:21:19 UTC

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