RE: XSL Discussion

["James K. Tauber" <jtauber@xxxxxxxxxxx>]

On Monday, 23 February 1998 16:00, Jeremie Miller [SMTP:jeremie@xxxxxxxxxx] 
wrote:
> First off, I've mentioned in the past that I think a simple separation of
> the patterns and actions should happen.

Yes. It certainly makes things easier.

> Lets talk about the patterns for a bit.  Maybe it's just a matter of syntax,
> but I would feel more comfortable writing something like:
>   <chapter>
>     <p type="introduction" xml:style="target"/>
>   </chapter>
> instead of
>   <element type="chapter">
>     <target-element type="p">
>       <attribute name="type" value="chapter"/>
>     </target-element>
>   </element>
> There might be some good reasons why the first simpler and more
> understandable(IMHO) pattern just won't work, but I haven't found any
> killers yet.

With the latter, only predefined element types ("element", "target-element", 
"attribute") are used. With the former, the XSL stylesheet is using element 
types specific to the element types of your document. With <p type="introduc  
tion" xml:style="target"/> you are getting around this using attributes (a la 
HyTime). You'd probably want to do likewise with the chapter element as well 
and have <chapter xml:style="element">. But this is starting to look not much 
better than the original.

> Based on the options above, why not allow attributes on the <pattern/>,
> <action/>, and <style/> sections to determine the type of content?  Like:
>   <style format="xml"></style>
> and
>   <style format="css1"></style>
> But this raises LOTS of issues(and great ideas :).  Firstly, for an XSL
> Stylesheet to be valid XML, the DTD would have to set the content types of
> the <pattern/>, <action/>, and <style/> , to CDATA(for reasons I'll point
> out below).  This can cause headaches when you want to be well-formed or
> exist w/o a DTD.

As you no doubt realise, this issue goes well beyond XSL and is relevant to any 
application of XML. In short, you are asking for content models triggered off 
attribute values. This isn't going to happen with XML 1.0 unless you have a 
namespace mechanism that uses attributes to determine which <style> you mean.

Thanks for raising these issues. I'm looking forward to discussions on this 
list.

James
--
James K. Tauber / jtauber@xxxxxxxxxxx
James Tauber & Associates
Perth, Western Australia
XML Pages: http://www.jtauber.com/xml/
XML Tutorial: http://www7.conf.au/tutorialsday.html


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