[whatwg] Fallback behavior

Martin Atkins mart at degeneration.co.uk
Tue Mar 13 00:59:40 PDT 2007

Maciej Stachowiak wrote:
> As far as I can tell, the current spec does not adequately define how 
> fallback behavior works. Specifically, what should be done with fallback 
> content when not falling back?
> Presumably it should be parsed into the DOM, but should not render - 
> that's the de facto behavior.


<object id="movie" data="movie.ogg">
    <object id="movie" data="movie.mov">
       <object id="movie" data="movie.asf">
          <p>Blah blah movie alternative text...</p>

If these things remain in the DOM, authors will presumably need to give 
them all distinct "id" values.

Now if I want to access these things from script, such as to provide an 
alternative player UI, I need to somehow determine which one is actually 
being used in order to target it. If they're all in the DOM, I can't 
just rely on getElementById returning null for the unused cases.

What's the solution in this case?

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