W3C home > Mailing lists > Public > public-rdf-in-xhtml-tf@w3.org > July 2005

Re: strengthening support for non-XSLT languages

From: Dan Brickley <danbri@w3.org>
Date: Wed, 06 Jul 2005 15:33:14 +0100
Message-ID: <42CBEBAA.9070600@w3.org>
To: Dominique HazaŽl-Massieux <dom@w3.org>
Cc: Robin Berjon <robin.berjon@expway.fr>, public-rdf-in-xhtml-tf@w3.org

Dominique HazaŽl-Massieux wrote:

>Hi Robin,
>
>Le mercredi 29 juin 2005 ŗ 13:34 +0200, Robin Berjon a ťcrit :
>  
>
>>there is one part of the current GRDDL editor's draft that I believe is 
>>problematic:
>>
>>"""
>>While javascript, C, or any other programming language technically 
>>expresses the relevant information, XSLT is specifically designed to 
>>express XML to XML transformations and has some good safety characteristics.
>>"""
>>--http://www.w3.org/2004/01/rdxh/spec#txforms
>>
>>I understand the wish to use XSLT most of the time, and were I to deploy 
>>GRDDL XSLT would likely be my choice.
>>
>>However at WWW2005 I had an interesting conversation with the 
>>microformats people, and how their efforts could be made to also fit 
>>into the SemWeb if they used GRDDL. I started explaining how it worked 
>>and the second I said "XSLT" someone shouted "Stop! You've already lost 
>>most of the people you're trying to cater to." And the fact of the 
>>matter is it's true.
>>    
>>
I sympathise. RDF's supposed to be hard, but XSLT...
just makes me feel stupid. I prefer to code in Ruby or similar.
XSLT has the advantage of clearer sandboxing at least? But
then such issues have also been worked through in the Java
and Javascript worlds at least as thoroughly.

I guess XQuery deserves a mention here, too. I can't use that
either, but I'd be interested to see a side-by-side comparison
of an XSLT and an XQuery GRDDL for some useful task.

>I wish I could respond in longer terms to your very interesting message,
>but I'd rather respond briefly now rather than leaving your message
>sitting in my needsAReply box too long :)
>
>So, my opinion on this is:
>* the more languages that are required in GRDDL, the harder it becomes
>to write GRDDL processor; in particular, as far as I know, XSLT
>libraries that conform to the spec are much easier to find than
>Javascript libraries - (which is also probably bound to the fact that
>Javascript is not so well-defined as a technology)
>  
>
Yup. Even the split between XSLT 1 and 2 is costly...

>* for the microformats developers, there is no need that every single
>page author writes its own XSLT, a single person can do it for the whole
>community; 
>
s/community/planet/

If we have to buy a beer or lunch for each major piece of
GRDDL'ing, its still pretty cheap.

Getting agreement on what the 'correct' RDF view of some
piece of microformattery is... now that's not so easy.

>	I believe there are enough people knowing how to use XSLT
>that this should not be a problem, at least for microformats that are
>popular enough
>  
>
I agree

>* however, given how GRDDL works, if someone is willing to implement a
>processor using Javascript, it's perfectly possible to serve both an
>XSLT and a javascript version of the transformation algorithm using
>content negotiation (using the brand new MIME-type for javascript :)
>  
>
I'm not sure conneg is enough, for the XSLT case (which after
all is at heart of GRDDL)...

http://www.w3.org/TR/xslt
The MIME media types |text/xml| and |application/xml| [RFC2376]
<http://www.w3.org/TR/xslt#RFC2376> should be used for XSLT stylesheets.
It is possible that a media type will be registered specifically for
XSLT stylesheets; if and when it is, that media type may also be used.

http://www.ietf.org/rfc/rfc3023.txt

 8.17 Application/xslt+xml . . . . . . . . . . . . . . . . . . . .  24
[[
8.17 Application/xslt+xml

   Content-type: application/xslt+xml

   <?xml version="1.0" ?>

   Extensible Stylesheet Language (XSLT) documents are XML documents
   whose content describes stylesheets for other XML documents, as
   defined by [XSLT].  As a format based on XML, XSLT documents SHOULD
   use the '+xml' suffix convention in their MIME content-type
   identifier.  However, no content type has yet been registered for
   XSLT and so this media type should not be used until such
   registration has been completed.
]]



http://www.w3.org/TR/xslt20/#media-type-registration 
(XSLT v2.0 Working Draft, 4 April 2005)

...this says that the registration is for the current, previous and 
future versions of XSLT.



Maybe we've been over this before and I forgot the answer, but 
I don't see quite how XSLT v1 and v2 stylesheets should be made 
available... (eg. for the XHTML2 case).

>* but indeed, there would be a need to explain how to produce RDF using
>a document and javascript; if you have any particular suggestions, I
>think we could link it from the specification next time it is published.
>  
>
Good point...

Dan
Received on Wednesday, 6 July 2005 14:33:18 GMT

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