drupal 7 and rdf

Drupal 7 and RDF

Stéphane Corlosquet, <scorlosquet@gmail.com>- 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

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

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Drupal

● Open & modular architecture

● Extensible by modules● Standards-based● Low resource hosting● Scalable

Building a Drupal site

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Building a Drupal site

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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)

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Building a Drupal site

● Enable the features you want:

Comments, tags, voting/rating, location, translations, revisions, search...

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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

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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

200+ Local user groups

including http://groups.drupal.org/boston

Doubles in size each release

source: http://acko.net/blog/drupal-org-explosion-and-trends source: http://buytaert.net/drupal-site-statistics

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

Who uses Drupal?

Who uses Drupal?

Who uses Drupal?

Who uses Drupal?

http://buytaert.net/tag/drupal-sites

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/

Drupal 7 and RDF

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...

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

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Content types and Fields

Content types and Fields

Node

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.

Mapping to RDF

Mapping to RDF

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)

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

Drupal 7 and RDF

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

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();

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

RDFDB: an RDF Database API

● Connection info:

● Support for master/slave servers● Drivers for ARC2, Virtuoso, 4store● Comes with tests!

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

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

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/

Questions?

Good luck!

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