Simple Linked Data Deployment using Virtuoso's HTTP Re-write Rules What? Use basic URL pattern as the basis for re-write rules that serve 5-Star Linked Data from a Virtuoso instance.Why? Linked Data offers a powerful mechanism for incorporating the connectivity of hyperlinks (typically HTTP URIs) into the process of actual structured data representation and data access.How? Perquisites: The following example demonstrates the usage of a basic URL pattern as the basis for URL re-write rules. Ensure Virtuoso's native faceted browser is installed so that you can leverage its entity description service via URL pattern: http://{hostname}/describe/?uri={URI}, for powerful HTML based follow-your-nose style of data exploration. URL Pattern: http://{hostname}:8890/id/... Negotiated Data Representation formats to be handled by these rules: text/html via "/page/" path component of the URL.. RDF (text/turtle, application/rdf+xml) via "/data/" path component of the URL . -- Goals -- Use slash terminated HTTP scheme URIs as Object Identifiers (Names) for Data Objects that resolve to Object Representations via a variety of URL patterns aligned to different data representation formats -- Object IDs take the form /id while Object Representation Addresses take the form: /data . -- -- Steps -- Create URL re-write rules: -- rules for HTML based Linked Data graphs DB.DBA.URLREWRITE_CREATE_RULELIST ( 'http_rule_list_1', 1, vector ('http_rule_1', 'http_rule_2')); DB.DBA.URLREWRITE_CREATE_REGEX_RULE ( 'http_rule_2', 1, '/id/(.*)\x24', vector ('par_1'), 1, '/page/%s', vector ('par_1'), NULL, NULL, 2, 303, '' ); -- rules for other Linked Data Graph formats e.g. rdf/xml, n3 DB.DBA.URLREWRITE_CREATE_REGEX_RULE ( 'http_rule_1', 1, '/id/(.*)\x24', vector ('par_1'), 1, '/data/%s', vector ('par_1'), NULL, 'text/n3|application/rdf\\+xml|text/rdf\\+n3', 2, 303, '' ); -- rules for Virtuoso Faceted Linked Data Navigation Service -- rule: unconditionally we redirect "/page" URLs internally to "/describe" which is the default endpoint for the Faceted Navigation Service DB.DBA.URLREWRITE_CREATE_RULELIST ( 'http_rule_list_2', 1, vector ('http_rule_3')); DB.DBA.URLREWRITE_CREATE_REGEX_RULE ( 'http_rule_3', 1, '/page/(.*)\x24', vector ('par_1'), 1, '/fct/rdfdesc/description.vsp?g=http://localhost:8990/id/%s', vector ('par_1'), NULL, NULL, 2, 0, '' ); -- "/SPARQL" URL pattern handling rules that allow use of SPARQL DESCRIBE queries for generating and returning Linked Data Graphs in a variety of formats determined by HTTP request URL patterns. -- query endpoints: http://localhost:8990/id/...> associated with "/data/" patterns DB.DBA.URLREWRITE_CREATE_RULELIST ( 'http_rule_list_3', 1, vector ('http_rule_4')); DB.DBA.URLREWRITE_CREATE_REGEX_RULE ( 'http_rule_4', 1, '/data/(.*)\x24', vector ('par_1'), 1, '/sparql?query=describe%%20%%3Chttp%%3A%%2F%%2Flocalhost%%3A8990%%2Fid%%2F%s%%3E%%20from%%20%%3Chttp%%3A%%2F%%2Flocalhost%%3A8990%%2Fdata%%2F%%3E&format=%U', vector ('par_1', '*accept*'), NULL, NULL, 2, 0, '' ); -- Virtual Directory Setup -- Cleanup DB.DBA.VHOST_REMOVE ( lhost=>'*ini*', vhost=>'*ini*', lpath=>'/id'); -- Create Virtual Directory that's associated with a named URL re-write rule for handling "/id" URL patterns DB.DBA.VHOST_DEFINE ( lhost=>'*ini*', vhost=>'*ini*', lpath=>'/id', ppath=>'/id/', is_dav=>0, def_page=>'', vsp_user=>'dba', opts=>vector ('url_rewrite', 'http_rule_list_1')); -- do the same for "/page" URL patterns with use as Web Service endpoint for Virtuoso's Faceted Navigation Service in mind. DB.DBA.VHOST_REMOVE ( lhost=>'*ini*', vhost=>'*ini*', lpath=>'/page'); DB.DBA.VHOST_DEFINE ( lhost=>'*ini*', vhost=>'*ini*', lpath=>'/page', ppath=>'/page/', is_dav=>0, def_page=>'', vsp_user=>'dba', opts=>vector ('url_rewrite', 'http_rule_list_2')); -- do same for "/data" URL patterns with other Linked Data Graph formats in mind DB.DBA.VHOST_REMOVE ( lhost=>'*ini*', vhost=>'*ini*', lpath=>'/data'); DB.DBA.VHOST_DEFINE ( lhost=>'*ini*', vhost=>'*ini*', lpath=>'/data', ppath=>'/data/', is_dav=>0, def_page=>'', vsp_user=>'dba', opts=>vector ('url_rewrite', 'http_rule_list_3')); Using CURL to verify re-write rules Example 1 curl -L -I http://localhost:8990/id/state/MA HTTP/1.1 303 See Other Server: Virtuoso/06.02.3129 (Win32) i686-generic-win-32 VDB Connection: close Content-Type: text/html; charset=ISO-8859-1 Date: Wed, 04 May 2011 13:44:24 GMT Accept-Ranges: bytes Location: http://localhost:8990/page/state/MA Content-Length: 0 HTTP/1.1 200 OK Server: Virtuoso/06.02.3129 (Win32) i686-generic-win-32 VDB Connection: Keep-Alive Content-Type: text/html; charset=UTF-8 Date: Wed, 04 May 2011 13:44:24 GMT Accept-Ranges: bytes Cache-Control: no-cache, must-revalidate Pragma: no-cache Link: <http://localhost:8990/sparql?query=define%20sql%3Adescribe-mode%20%22LOD%22%20%20DESCRIBE%20%3Chttp%3A%2F%2Flocalhost%3A8 3E&output=application%2Frdf%2Bxml>; rel="alternate"; type="application/rdf+xml"; title="Structured Descriptor Document (RDF/XML host:8990/sparql?query=define%20sql%3Adescribe-mode%20%22LOD%22%20%20DESCRIBE%20%3Chttp%3A%2F%2Flocalhost%3A8990%2Fid%2Fstate%2F >; rel="alternate"; type="text/n3"; title="Structured Descriptor Document (N3/Turtle format)",<http://localhost:8990/sparql?quer ibe-mode%20%22LOD%22%20%20DESCRIBE%20%3Chttp%3A%2F%2Flocalhost%3A8990%2Fid%2Fstate%2FMA%3E&output=application%2Frdf%2Bjson>; rel plication/rdf+json"; title="Structured Descriptor Document (RDF/JSON format)",<http://localhost:8990/sparql?query=define%20sql%3 D%22%20%20DESCRIBE%20%3Chttp%3A%2F%2Flocalhost%3A8990%2Fid%2Fstate%2FMA%3E&output=application%2Fatom%2Bxml>; rel="alternate"; ty ml"; title="Structured Descriptor Document (OData/Atom format)",<http://localhost:8990/sparql?query=define%20sql%3Adescribe-mode RIBE%20%3Chttp%3A%2F%2Flocalhost%3A8990%2Fid%2Fstate%2FMA%3E&output=application%2Fodata%2Bjson>; rel="alternate"; type="applicat ="Structured Descriptor Document (OData/JSON format)",<http://localhost:8990/sparql?query=define%20sql%3Adescribe-mode%20%22LOD% http%3A%2F%2Flocalhost%3A8990%2Fid%2Fstate%2FMA%3E&output=text%2Fcxml>; rel="alternate"; type="text/cxml"; title="Structured Des format)",<http://localhost:8990/sparql?query=define%20sql%3Adescribe-mode%20%22LOD%22%20%20DESCRIBE%20%3Chttp%3A%2F%2Flocalhost FMA%3E&output=text%2Fcsv>; rel="alternate"; type="text/csv"; title="Structured Descriptor Document (CSV format)",<http://localho rel="http://xmlns.com/foaf/0.1/primaryTopic",<http://localhost:8990/id/state/MA>; rev="describedby" Content-Length: 10858 Example 2 curl -L -I -H "Accept: text/n3" http://localhost:8894/id/state/MA HTTP/1.1 303 See Other Server: Virtuoso/06.02.3129 (Win32) i686-generic-win-32 VDB Connection: close Content-Type: text/html; charset=ISO-8859-1 Date: Wed, 04 May 2011 13:46:25 GMT Accept-Ranges: bytes Location: http://localhost:8990/page/state/MA Content-Length: 0 HTTP/1.1 303 See Other Server: Virtuoso/06.02.3129 (Win32) i686-generic-win-32 VDB Connection: Keep-Alive Content-Type: text/html; charset=UTF-8 Date: Wed, 04 May 2011 13:46:25 GMT Accept-Ranges: bytes TCN: choice Vary: negotiate,accept Location: http://localhost:8990/sparql?query=define%20sql%3Adescribe-mode%20%22LOD%22%20%20DESCRIBE%20%3Chttp%3A%2F%2Flocalhost% MA%3E&format=text%2Fn3 Content-Length: 0 HTTP/1.1 200 OK Server: Virtuoso/06.02.3129 (Win32) i686-generic-win-32 VDB Connection: Keep-Alive Date: Wed, 04 May 2011 13:46:25 GMT Accept-Ranges: bytes Content-Type: text/n3; charset=UTF-8 Content-Length: 15 Related Virtuoso Tips and Tricks Collection Virtuoso Faceted Browser Installation and Configuration Guide Virtuoso Faceted Search & Find Engine User Guide Faceted Navigation to Explore Virtuoso hosted Linked Data Usage Guide