Re: [xsl] xml-stylesheet p.i. and other options

Subject: Re: [xsl] xml-stylesheet p.i. and other options
From: David Carlisle <davidc@xxxxxxxxx>
Date: Wed, 26 Jun 2002 11:40:58 +0100
> Those other options often do involve an HTML user-agent requesting XML,
> though, and getting back HTML. So while raw XML wasn't served, XML was
> requested, and a server-side application decided that the request should be
> interpreted as a request for the data within that XML, formatted in a manner
> more appropriate for that particular client. As I keep trying to say, this
> kind of decision and the determinations that go along with it (such as what
> the client's capabilities are and what an appropriate transformation would be,
> if any) is for the application to make. These needs are not very well-met by
> the PI approach at all.

I agree that's a common use and that the PI is not much help in that
scenario, but in that scenario the xml is just the back end data, it
could be a database or SGML or anything. XML was explictly developed
to allow another option: serving the "back end" data direct to the
client. That doesn't mean the older way is bad or not important
(no one wants to ship terrabytes of database so the client can generate
a five line welcome page). If you are serving XML over the web then
you need some way of associating some processing with what you are
serving. This is mainly only true for browsers rendering XML for human
consumption, in the case of mechanical uses of XML your processing
mechanisms mean that probably you know what type of XML you are getting
and know how to process it (and fail if it's not the right thing) but an
XML browser accepts arbitary XML but its default behaviour for general
XML is unlikely to be optimal for human reading. This is the primary use
case for the PI. I never said that the processing instruction was
always useful, I just assert that it is useful (with currently no
implemented alternative) for an important (and originally motivating)
use of XML. Which is why I disagreed with your original assesment
that 
   "<?xml-stylesheet?> tends to be one of the less sensible solutions."

David


_____________________________________________________________________
This message has been checked for all known viruses by Star Internet
delivered through the MessageLabs Virus Scanning Service. For further
information visit http://www.star.net.uk/stats.asp or alternatively call
Star Internet for details on the Virus Scanning Service.

 XSL-List info and archive:  http://www.mulberrytech.com/xsl/xsl-list


Current Thread