RE: SYMM WG comments on XBase 2nd last call

> -----Original Message-----
> From: Lloyd Rutledge [mailto:Lloyd.Rutledge@cwi.nl]

> > Does the following syntax proposal illustrate your request?
> > 
> >   <a xml:base="http://www.media.com">
> >     <mediabase id="video" xml:base="/daily/video"/>
> >     <mediabase id="audio" xml:base="/daily/audio"/>
> >     <b xml:baseref="video">vid1</b>
> >     <c xml:baseref="audio">aud1</c>
> >   </a>
> > 
> > b = http://www.media.com/daily/video/vid1
> > c = http://www.media.com/daily/audio/aud1
> > (and "id" is of type ID).
> 
> I'd rework the syntax as:
> 
> <head>
>   <xml:base id="video" xml:base="/daily/video"/>
>   <xml:base id="audio" xml:base="/daily/audio"/>
> </head>
> <body>
>   <par>
>     <video xml:baseref="video" src="billwaves.mpg"/>
>     <audio xml:baseref="audio" src="billtalks.au"/>
>   </par>
> </body>
> 
> > Of course, there are circularity problems with this 
> particular approach...
> 
> ... can you elaborate?
> 

One of the first things I'd attempt with this would be to retrofit the HTML
BASE so I could write a single document that would have the same base under
text/xml and text/html:

  <html xml:baseref="htmlbase">
    <head>
      <base id="htmlbase" xml:base="..."/>
      ...

This example is circular if xml:base happens to contain a relative URI.  Can
we define references in such a way that works or must we just report an
error?

> We would not augment XML Base.  We would add SMIL-specific and
> SMIL-only constructs to SMIL's use of XML Base.  That is, we would use
> the XBase constructs of non-referential establishing of URI bases.
> And we would dot all the XML i's and cross all the XML t's in doing so
> (so we hope ;).  For referential URI bases, we would make SMIL
> constructs such as those used in the example syntax above.  This would
> existing in the SMIL namespace and would not be recognized as XBase.
> Their behavior would be stated in the SMIL specification.
> 
> This would mean that SMIL browsers would resolve different URI's than
> non-SMIL XBase-aware XML processors would.

Exactly my point.  I don't think this is desireable.

How badly does SMIL need this capability?  Are you already planning
something similar or are you thinking ahead to a future version?

- Jonathan Marsh

Received on Monday, 3 July 2000 11:18:49 UTC