[whatwg] <object>, type, and fallback

[Simon Pieters]

On Mon, 05 Dec 2011 22:19:33 +0100, Brady Eidson <beidson at apple.com> wrote:

> I can't find a definitive answer for the following scenario:
>
> 1 - A page has a plug-in with fallback specified as follows:
>
> <object type="application/x-shockwave-flash">
> <param name="movie" value="Example.swf"/>
>     <img src="Fallback.png">
> </object>
>
> 2 - The page is loaded, the browser instantiates the plug-in, and the  
> plug-in content is shown.
>
> 3 - A script later comes along and dynamically changes the <object>'s  
> type attribute to "application/some-unsupported-type"
>
> Should the browser dynamically and immediately switch from the plug-in  
> to the fallback image?
> If not, what should it do?
> And is this specified anywhere?
>
> Thanks,
> ~Brady


"... when neither its classid attribute nor its data attribute are  
present, whenever its type attribute is set, changed, or removed: the user  
agent must queue a task to run the following steps to (re)determine what  
the object element represents. The task source for this task is the DOM  
manipulation task source."

http://www.whatwg.org/specs/web-apps/current-work/multipage/the-iframe-element.html#the-object-element

The algorithm then determines in step 5 that there's no suitable plugin,  
and falls back.

-- 
Simon Pieters
Opera Software