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Re: [XHTML2] Specifying alternative resources/content

From: Al Gilman <Alfred.S.Gilman@IEEE.org>
Date: Mon, 18 Oct 2004 16:39:02 -0400
Message-Id: <p06110405bd99d7e9b2ec@[10.0.1.2]>
To: Risto Kankkunen <risto.kankkunen@iki.fi>, Edward Lass <elass@goer.state.ny.us>
Cc: www-html@w3.org

To me the issue is "can one for practical purposes fold the 
intrinsically tuple-space problem
into a choice tree?"

The constructive affirmative is explored by the DI Selection draft:

http://www.w3.org/TR/cselection/

Reasons for skepticism may also be found at:

Find "decisioning" in:
http://www.w3.org/2004/06/DI-MCA-WS/submissions/position-ag.html

In the end we need use cases such as Risto has provided and responses 
from the format
proponents as to how one would use the constructs they have provided 
to accomplish
the end desired.

This is a good thread, it bears careful development.

Al


At 8:32 PM +0300 10/18/04, Risto Kankkunen wrote:
>Thanks for your comments, Edward. Here's a quick reply to one of 
>your comments:
>
>>One of your examples is this:
>>
>>    <alt>
>>        <!-- Try to show a video clip -->
>>        <object
>>            src="holiday.mpeg"
>>            type="video/mpeg"
>>        </
>>
>>        <!-- Or show a still image and audio -->
>>        <div>
>>            <object src="holiday.jpeg" type="image/jpeg" />
>>            <object src="holiday-narration.mp3" type="audio/mp3" />
>>        </div>
>>
>>        <!-- Or show an image and some text -->
>>        <div>
>>            <object src="holiday.jpeg" type="image/jpeg" />
>>            <p>Our holiday started on Sunday, the 1st of August. ...</p>
>>        </div>
>>
>>        <!-- Or show just a place holder -->
>>        <p>(holiday picture here)</p>
>>    </alt>
>>
>>Now this is how one could do it under the current WD:
>>
>><!-- Try to show a video clip -->
>><object src="holiday.mpeg" type="video/mpeg">
>>
>>	<!-- Else, show a still image and audio -->
>>
>>	<object src="holiday.jpeg" type="image/jpeg">
>>
>>  	       <!-- If the image doesn't work, show just a place holder -->
>>	       <p>(holiday picture here)</p>
>>
>>	</object>
>>
>>	<object src="holiday-narration.mp3" type="audio/mp3">
>>
>>		<!-- If the audio doesn't work, show text -->
>>		<p>Our holiday started on Sunday, the 1st of August. ...</p>
>>
>>	</object>
>></object>
>
>That's different! Using my "<alt>" notation that would be:
>
>   <alt>
>       <!-- Try to show a video clip -->
>       <object src="holiday.mpeg" type="video/mpeg" />
>
>       <!-- Else, show a still image and audio -->
>
>       <alt>
>  	  <object src="holiday.jpeg" type="image/jpeg" />
>           <!-- If the image doesn't work, show just a place holder  -->
>  	  <p>(holiday picture here)</p>
>       </alt>
>
>       <alt>
>           <object src="holiday-narration.mp3" type="audio/mp3" />
>
>           <!-- If the audio doesn't work, show text -->
>           <p>Our holiday started on Sunday, the 1st of August. ...</p>
>       </alt>
>   </alt>
>
>>In the proposal above, the user agent has to look inside the <div/>
>  > element, and if it reports that it can accept JPEG but not MP3, it
>>  has to reject that block altogether and go to the next one?
>
>Right.
>
>The whole point of the example was that with "<alt>" you COULD 
>combine related resources so that they all have to be available for 
>a meaningful presentation or another alternative should be tried. 
>But you don't of course have to do that, if you don't want.
>
>The mechanism of the draft doesn't have this opportunity at all.
>
>(My example should have been better, e.g. with unique images so that 
>you cannot optimize the common part out of the equation...)
>
>
>Regards,
>Risto Kankkunen
Received on Monday, 18 October 2004 20:43:50 GMT

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