Re: Media typs and XPointer, XLink, XPath, and XSLT

[I've cross-posted this to www-xml-linking-comments@w3.org.  It seems like
it might be a good idea for the XPointer folk to be aware of the MIME type
discussions going on in ietf-xml-mime, and that text/xml and
application/xml may not always remain the only MIME types for XML documents.]

The latest (9 July 1999) XPointer draft states that:
>XPointer defines the meaning of the "selector" or "fragment identifier"
>portion of URIs that locate resources of MIME media types "text/xml" and 
>"application/xml".

At 09:12 AM 7/13/99 -0400, John Cowan wrote (on ietf-xml-mime@imc.org):

> The real issue is whether XPointers can point into
>things like SMIL documents, which "just happen" to be encoded
>in XML.

This doesn't make sense to me.

First, I can see where 'smarter' SMIL documents might make use of
XLink/XPointer in more sophisticated ways than is presently possible with
their simple href linking.  SMIL 2.0, for instance, might take fuller
advantage of its XML heritage than SMIL 1.0 did.  (If, of course, there
ever is a SMIL 2.0.)

Second, it seems extremely reasonable that other XML documents might well
point into SMIL documents and take advantage of the information stored
there.  While embedding fragments of multimedia presentations may raise
some complex questions, doing something like embedding the closed-caption
information (text) from a SMIL presentation inside another document seems
perfectly reasonable.

In other words, why is this even an issue for the XPointer spec to worry
about?  It might be something that potentially gives application designers
a headache, _if_ they want to present SMIL fragments as multimedia
presentations, but that doesn't seem like something the XPointer standard
itself should care about.

XPointer can work with any kind of XML document.  If the application can't
deal with how that document is supposed to be displayed, it had better have
some alternatives ready.  Not displaying it is one option, displaying it as
text is another, applying a stylesheet is yet another, etc....

Simon St.Laurent
XML: A Primer / Building XML Applications
Inside XML DTDs: Scientific and Technical
Sharing Bandwidth / Cookies
http://www.simonstl.com

Received on Tuesday, 13 July 1999 09:55:16 UTC