Hi again, We did some more tests against DBpedia resources on our framework, it looks like DBpedia does not do content negotiation properly in case it does not support the client requested MIME-type:
curl -v -H "Accept: text/turtle" http://dbpedia.org/resource/Tim_Berners-Lee * About to connect() to dbpedia.org port 80 (#0) * Trying 194.109.129.58... * connected * Connected to dbpedia.org (194.109.129.58) port 80 (#0) > GET /resource/Tim_Berners-Lee HTTP/1.1 > User-Agent: curl/7.25.0 (x86_64-apple-darwin11.3.0) libcurl/7.25.0 OpenSSL/1.0.1b zlib/1.2.7 libidn/1.22 > Host: dbpedia.org > Accept: text/turtle > < HTTP/1.1 303 See Other < Date: Wed, 30 May 2012 20:03:31 GMT < Content-Type: text/html; charset=UTF-8 < Connection: keep-alive < Server: Virtuoso/06.04.3132 (Linux) x86_64-generic-linux-glibc25-64 VDB < Location: http://dbpedia.org/page/Tim_Berners-Lee < Content-Length: 0 < * Connection #0 to host dbpedia.org left intact * Closing connection #0 The "303 see other" is wrong in this case, it should instead return a "406 not acceptable". Otherwise the client expects that he gets the requested MIME-type at the other location. With 406 it could return the HTML type as "alternates", that would be correct. see: https://developer.mozilla.org/en/HTTP/Content_negotiation https://developer.mozilla.org/en/HTTP/HTTP_response_codes#406 If I do it with a list of supported MIME-types (including one which is returned by DBpedia) it is correct: % curl -v -H "Accept: text/turtle,application/rdf+xml" http://dbpedia.org/resource/Tim_Berners-Lee * About to connect() to dbpedia.org port 80 (#0) * Trying 194.109.129.58... * connected * Connected to dbpedia.org (194.109.129.58) port 80 (#0) > GET /resource/Tim_Berners-Lee HTTP/1.1 > User-Agent: curl/7.25.0 (x86_64-apple-darwin11.3.0) libcurl/7.25.0 OpenSSL/1.0.1b zlib/1.2.7 libidn/1.22 > Host: dbpedia.org > Accept: text/turtle,application/rdf+xml > < HTTP/1.1 303 See Other < Date: Wed, 30 May 2012 20:15:07 GMT < Content-Type: application/rdf+xml; qs=0.95 < Connection: keep-alive < Server: Virtuoso/06.04.3132 (Linux) x86_64-generic-linux-glibc25-64 VDB < Accept-Ranges: bytes < TCN: choice < Vary: negotiate,accept < Content-Location: /data/Tim_Berners-Lee.xml < Link: <http://mementoarchive.lanl.gov/dbpedia/timegate/http://dbpedia.org/resource/Tim_Berners-Lee>; rel="timegate" < Location: http://dbpedia.org/data/Tim_Berners-Lee.xml < Content-Length: 0 < * Connection #0 to host dbpedia.org left intact * Closing connection #0 So now it redirects me with 303 to the rdf+xml version, which is an accepted MIME-type from the client. BTW I found it correctly described on a Virtuoso page ;) http://virtuoso.openlinksw.com/whitepapers/VirtDeployingLinkedDataGuide_Introduction.html BTW2 any reasons that turtle is not supported? IMHO rdf+xml has to become extinct and replaced by turtle. Today someone asked me if they have to learn XML first to understand RDF because many samples in RDF books are in RDF/XML. That does not help adoption of RDF in the real world ;) cu Adrian ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Dbpedia-discussion mailing list Dbpedia-discussion@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/dbpedia-discussion
