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Drupal 7 and RDF
Stéphane Corlosquet, <[email protected] >- Software engineer, MGH- Drupal 7 core RDF maintainer- SemWeb geek
Linked Data Ventures, MIT, Oct 2010
This work is licensed under a Creative Commons Attribution 3.0 License, with attribution to Stéphane Corlosquet
Slides: http://files.openspring.net/2010/10/drupal7-rdf-mit-lod-ventures-oct-2010.pdf
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Drupal
● Dries Buytaert - small news site in 2000● Open Source - 2001● Content Management System● LAMP stack● Non-developers can build sites
and publish content● Control panels instead of code
http://www.flickr.com/photos/funkyah/2400889778/
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Drupal
● Open & modular architecture
● Extensible by modules● Standards-based● Low resource hosting● Scalable
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Building a Drupal site
http://www.flickr.com/photos/toomuchdew/3792159077/
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Building a Drupal site
http://www.flickr.com/photos/georgivar/4795856532/
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Building a Drupal site
● Create the content types you need: Blog, article, wiki, forum, polls, image, video, podcast, e-commerce... (be creative)
http://www.flickr.com/photos/georgivar/4795856532/
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Building a Drupal site
● Enable the features you want:
Comments, tags, voting/rating, location, translations, revisions, search...
http://www.flickr.com/photos/skip/42288941/
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Building a Drupal site
● Place links in the navigation bars and blocks
● Build Views over your data
● Skin your site: theming
http://www.flickr.com/photos/skip/42288887/
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Building a Drupal site
6000 free contributed modules ● Google Analytics● Wysiwyg● Captcha● Calendar● XML sitemap● Five stars● Twitter● ...
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Drupal inside
● Database storage (PDO)
● Cron
● Queue / batch API
● File management
● User management
● Form API
● Security
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User experience
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The Drupal Community
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The Drupal Community
http://webchick.net/node/80
“It’s really the Drupal community and not so much the software that makes the Drupal project what it
is. So fostering the Drupal community is actually more important than just managing the code base.” -
Dries Buytaert
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200+ Local user groups
including http://groups.drupal.org/boston
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Doubles in size each release
source: http://acko.net/blog/drupal-org-explosion-and-trends source: http://buytaert.net/drupal-site-statistics
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Doubles in size each release
● Drupal 6 (stable) - 325,145+ sites● Drupal 7 (beta 1) - 20,000+ sites
● Total estimation 500,000 sites (1% of the Web)
http://buytaert.net/20000-drupal-gardens-siteshttp://drupal.org/project/usage/drupal
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Who uses Drupal?
http://buytaert.net/tag/drupal-sites
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Try Drupal 7
● Download and Install Drupal 7
● Grab latest release http://drupal.org/project/drupal● Mac OS: MAMP http://www.mamp.info/● Acquia Stack http://acquia.com/downloads
● Drupal Gardens: free Drupal 7 site http://www.drupalgardens.com/
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History of RDF in Drupal
● rdf.php (2000, Dries)● FOAF, vCard (2004, walkah)● Relationship (2005, dman)● Semantic Search (2006, hendler)● RDF (2007, Arto)● OpenCalais (febbraro, 2008)● RDF CCK (2008, scor)● and more...
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Experiment prior Drupal 7
● Expose Drupal's data in RDF
● Automatically● No RDF expertise
required● Module based
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Architecture
● User driven data model● Content type = RDF class● Field = RDF property● Node = RDF resource
http://www.flickr.com/photos/docman/2216568210
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Content types and Fields
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Content types and Fields
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Mapping to RDF
● site:Person a rdfs:Class;
rdfs:subClassOf foaf:Person.
● site:first_name a rdf:Property;
rdfs:subPropertyOf foaf:firstName.
● site:colleague rdfs:domain site:Person.
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Experiment continued
● 1. Automatic site vocabulary generation● 2. Mapping Content Models to existing
ontologies● 3. Data endpoint for SPARQL querying● 4. Lazy loading of external data (data import)
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Drupal 7 and RDF
● Drupal 7 core is RDFa enabled!● RDFa output by default on blogs, forums,
comments, etc. using FOAF, SIOC, DC, SKOS
● Beta1 released a few days ago
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Drupal 7 contributed modules
● http://drupal.org/project/rdf● Import vocabularies● Interface for mappings
● http://drupal.org/project/sparql_ep● SPARQL endpoint on Drupal data
● PHP ARC2 library http://github.com/semsol/arc2
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RDFDB: an RDF Database API
● Access RDF stores via a consistent API● SPARQL 1.1● Vendor agnostic● Similar to Drupal 7 Database abstraction layer
● rdfdb_insert_data($graph, $triples)->execute();● rdfdb_select('?g ?s ?p ?o')->where('GRAPH ?g { ?
s ?p ?o . }')->limit(1000)->execute();
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RDFDB: an RDF Database API
● Similar to Drupal 7 Database abstraction layer● rdfdb_insert_data($graph, $triples)->execute();● rdfdb_select('?s ?p ?o')->where('?s ?p ?o')-
>limit(10)->execute();● rdfdb_clear($graph)->execute()
● Do not worry about what RDF store the SPARQL endpoint is running on
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RDFDB: an RDF Database API
● Connection info:
● Support for master/slave servers● Drivers for ARC2, Virtuoso, 4store● Comes with tests!
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RDFDB: an RDF Database API
● Why an abstraction layer?● Every store has its own way to implement SPARQL
updates, some are RESTful, some others have their own SPARQL update syntax.
● ARC2: SPARQL+ via POST requests● 4store: POST, PUT and DELETE requests
● Download● http://github.com/scor/rdfdb
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How to get involved● So many ways... code, documentation, support,
translations, graphic design
● http://drupal.org/getting-involved● Watch video http://webchick.net/node/80
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How to get involved● Subscribe to the Semantic Web group at
http://groups.drupal.org/semantic-web
● Semantic Drupal news at http://semantic-drupal.com/
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Questions?
Good luck!
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