New W3C GRDDL service
To celebrate the progress of GRDDL towards its final stage, and to replace the aging and somewhat unreliable XSLT-based GRDDL demonstrator, I’ve just released a brand new W3C GRDDL service.
It simply takes a Web page and extracts the RDF statements it can find in there using GRDDL.
I have made its source code available on W3C Public CVS server, but the gist the work is done by the underlying library, python-librdf, the Python binding for Redland. Particular thanks to Dave Beckett who provided amazing user support to help setting this up!
August 28th, 2007 at 16:10
So for the average Joe developer, what does this mean to them? Will this take my microformatted data and turn it into RDF? If so, once the data is in RDF what would we do with it?
August 28th, 2007 at 16:22
I fear it would be too long to answer that question in a single blog comment but hopefully the GRDDL primer answers some of it already:
To make a long story short, a microformat that uses a profile URI can be made GRDDL-friendly very easily, and thus provide a wealth of data to the semantic Web; these data can then be used and re-used, typically in mash-ups services.
August 29th, 2007 at 03:15
So for me as the end-user I don’t really have to worry about GRDDL or RDF, I just have to make sure that my blogroll is marked up using the XFN microformat? Someone else is going to screen scrape my blog to gather my relationships data and translate that into something more Semantic Web friendly?
August 29th, 2007 at 08:47
Indeed (with the caveat that not all microformats are GRDDL-friendly).
September 4th, 2007 at 04:59
Hi, nice to see new service.
Unfortunately, this doesn’t seem to work well with a profile based GRDDL whose encoding is not UTF-8 (OK for link based GRDDL). For example, I can get a proper result from http://www.kanzaki.com/docs/sw/ using XSLT service, but “Input is not proper UTF-8” error from new service.
Could you check for this issue ?
thank you.
September 4th, 2007 at 15:14
Indeed, that’s a bug; I’m looking into it, but haven’t found a straightforward workaround yet…
September 4th, 2007 at 15:29
Looking at it more closely, it happens because the profile document http://www.kanzaki.com/ns/metaprof has its encoding only declared in the HTTP header, not in the XML encoding declaration.
Of course, this is acceptable per the spec, so I have reported a bug in the underlying library:
http://bugs.librdf.org/mantis/view.php?id=231
(it ties back to a bug I had reported a while back in libxml2 I fear:
http://bugzilla.gnome.org/show_bug.cgi?id=104790 )
September 5th, 2007 at 02:53
OK, I added an XML declaration to my profile, and got proper result.
thank you for quick response!
September 7th, 2007 at 20:30
Turns out that due to the way I use libxml as a push parser, there is no way to pass in an external
encoding: xmlCreatePushParserCtxt:
xmlParserCtxtPtr
xmlCreatePushParserCtxt(xmlSAXHandlerPtr sax, void *user_data,
const char *chunk, int size, const char *filename);
It would either need libxml to add a new API, I would have to call it a different way
with knowledge of it’s internals (yuck) or it would need internal changes to libxml.
September 16th, 2007 at 21:27
This service seems fabulous, but i get the utf-8 error two when trying the service on 3 sites i’ve tested.
And when trying to parse this very blog, i get a blank page on Mac-Firefox2 (scripts are enabled)
I still have the encoding stipulated though.
??
April 17th, 2008 at 19:01
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