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Re: TTML XSD vallidation and extension problem (ISSUE-150)

From: Philippe Le Hegaret <plh@w3.org>
Date: Thu, 09 Feb 2012 16:37:44 -0500
To: Michael A Dolan <mdolan@newtbt.com>
Cc: public-tt@w3.org
Message-ID: <1328823464.2434.152.camel@chacal>
Hi Michael,

following this morning decision to relax the XML schema for TTML 1.0, I
updated the errata page for TTML 1.0:
 http://www.w3.org/2010/11/ttml-issues.html

I also added links on the errata page for new zip archives of the relax
NG and XML schema files.

In addition, the editor's copy of TTML 1.0 is up-to-date and include all
errata:
http://dev.w3.org/cvsweb/~checkout~/2008/tt/spec/ttaf1-dfxp.html?content-type=text/html;charset=utf-8

Regards,

Philippe

On Fri, 2012-01-27 at 08:10 -0800, Michael A Dolan wrote:
> Hello again-
> 
>  
> 
> Since there seems to be some receptiveness to addressing schema
> issues, here is another one…
> 
>  
> 
> TTML allows any foreign namespace attribute on the elements. For
> example, note the green-highlighted text below:
> 
>  
> 
> <tt
> 
>   tts:extent = string
> 
>   xml:id = ID
> 
>   xml:lang = string
> 
>   xml:space = (default|preserve) : default
> 
>   {any attribute in TT Parameter namespace}
> 
>   {any attribute not in default or any TT namespace}>
> 
>   Content: head?, body?
> 
> </tt>
> 
>  
> 
> However, the schema is constructed to reject all such attributes.
> 
>  
> 
> For example, the following XML would be rejected, even though it is
> clearly permitted by the Recommendation:
> 
>  
> 
>                 <p cff:forcedDisplayMode=”true”>translated from
> Klingon</p>
> 
>  
> 
> As a result, those working on derived schemas from TTML that add
> attributes to the existing elements are forced to do unusual things in
> their schemas to work around this and/or create schemas from scratch.
> And such instance documents cannot be validated against TTML since
> they are (wrongly) rejected.
> 
>  
> 
> Therefore, for the deployments I am aware of, the TTML schema is not
> useful as is except to the schema developer to borrow pieces of it
> perhaps.
> 
>  
> 
> The obvious way to correct this would be to add anyAttribute=”##other”
> to the element definitions, however, this would then enable false
> validations of non-default TT namespace elements (e.g. ttm: ), which
> is undesirable. So this issue is a  bit trickier to address than my
> last one about tts:extent.
> 
>  
> 
> I believe it would be beneficial to the industry for W3C to correct
> this in some manner to provide a schema that can be used by those
> developing derived (but TTML conformant) designs.
> 
>  
> 
> Regards,
> 
>  
> 
>                 Mike
> 
>  
> 
> 
> Michael A DOLAN
> 
> Television Broadcast Technology, Inc
> 
> PO Box 190, Del Mar, CA 92014 USA
> 
> +1-858-882-7497 (m)
> 
>  
> 
> 
Received on Thursday, 9 February 2012 21:37:51 GMT

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