W3C home > Mailing lists > Public > www-archive@w3.org > August 2008

Re: GRDDL

From: Henri Sivonen <hsivonen@iki.fi>
Date: Wed, 6 Aug 2008 19:08:06 +0300
Cc: Toby A Inkster <tai@g5n.co.uk>, Justin James <j_james@mindspring.com>, www-archive <www-archive@w3.org>
Message-Id: <99089E87-9D36-4A30-83D7-59C834022904@iki.fi>
To: Julian Reschke <julian.reschke@gmx.de>

Going off-topic for public-html. -public-html +www-archive

On Aug 6, 2008, at 14:28, Julian Reschke wrote:

> Henri Sivonen wrote:
>> ...
>>>> You do this:
>>>>> - Document the mapping between the host language and RDF, do not  
>>>>> touch the host language, and have transformers for each of the  
>>>>> languages, triggered by contenttype/doctype/xmlnamespace.
>>>
>>> That doesn't scale.
>> It scales for the well-known Web markup languages: (X)HTML and SVG  
>> (and perhaps MathML and Atom). It also scales to common image and  
>> timed media formats that XSLT can't handle.
>
> No, it doesn't even scale for them. For instance, in the HTML I  
> produce I could specific conventions (classnames, link relations,  
> whatever) to embed metadata. A generic transformer for HTML wouldn't  
> be able to handle that.

If you use conventions specific to your site, you are venturing  
outside the well-known part. If you serve a program that transforms  
your specific syntax to RDF, you move the point where a well-known  
vocabulary is needed to the RDF layer, but concrete common ground with  
the information consumer has to come somewhere. However, making the  
consumer run a foreign XSLT program has the scalability problem of  
crawlers being able to execute programs in large quantities. With  
Validator.nu, the main scalability program seems to be the ability to  
execute Schematron, which is implemented by compiling the Schematron  
schema into XSLT and running the XSLT program.

Moreover, for class-based syntaxes, a transformer that contains its  
executable parts (whether in XSLT or in another programming language)  
only needs to cover the kind of syntax that a given application is  
interested in consuming. If I'm looking for hCard data and my  
application understands RDF vCard, I only need a transformation from  
hCard to RDF vCard. I don't need a solution that scales to all  
microformats.

>>> It doesn't work with my homegrown vocabulary/markup style  
>>> (remember: distributed extensibility).
>> If you are serving a document in your vocabulary and a program that  
>> makes sense of it, are you really communicating with others by  
>> sending semantic markup or are you communicating by sending  
>> programs? If you made your markup empty and embedded all the data  
>> in the transformation program, would the recipient know any  
>> difference?
>
> I don't see how that is relevant. What's relevant is what the  
> recipient gets. And of course the intent of GRDDL is to have a  
> single transform for a vocabulary, and to reuse that transform for  
> each instance document. You could use it in a different way, but who  
> cares?

http://lists.w3.org/Archives/Public/www-tag/2008Jul/0164.html

-- 
Henri Sivonen
hsivonen@iki.fi
http://hsivonen.iki.fi/
Received on Wednesday, 6 August 2008 16:08:49 UTC

This archive was generated by hypermail 2.4.0 : Friday, 17 January 2020 22:33:31 UTC