Hi everyone,

in latest days I’ve created a local Drupal instance to begin developing an agrovoc-Drupal alpha release. I think that subsequent steps are the right way and should be performed:

Define a CCK content type suitable for an Agrovoc node (initially only for the EN instance; other languages are further extendable through  i18n module)

Map CCK to RDF (it’s a sort of “reversal engineering”, I know), through the SKOS vocabulary.

With the help of Node Import module, define a mapping between an Agrovoc instance and CCK-RDF. I think that the MySQL downloadable version is the best solution for its record type characteristics. In fact as I must tie together Agrovoc nodes via broader/narrower/related/…  relationships, I need to find a simple manner to find links immediately, and not only when two nodes are fully instantiated in the graph.

In the mysql instance, ‘agrovocterm’ table has 32.000 records for each language with a ‘termcode’ field that is usable as an immediate link between nodes to accomplish their relations.

The output of a run of node import is a partial instance (only English language is produced) of an entire Agrovoc graph, but fully accessible.

Further step is the integration of this nodes collection with an Apache Solr instance.

RDF related – modules

These Drupal 6.x modules should be used mostly in –dev version. A number of issue has been opened but until now without a response. Their installation sequence should be strictly followed because of their reciprocal dependences not properly defined.

RDF       (so-called "rdf API") – [remember to load ARC 2 library]

Enables the use of Resource Description Framework (RDF) metadata.

SPARQL API

Enables the use of SPARQL queries with the RDF API.

External RDF Vocabulary Importer (so-called "evoc"; install latest -dev with a minor modification into Sparql Endpoint, see row 190)

Allows to import external Vocabularies in order to map them to Drupal data objects.

[after installation, go to ‘evoc/import’ and go further with SKOS import]

Evoc Reference (submodule of evoc)

Defines a field type for referencing an RDF class or property from a node.

RDF CCK             

Allows to define mappings between CCK fields and RDF and export nodes as RDF. 

 

Until now, the latest module (RDF Proxy) seems not working (.module file has a number of structural “holes” to be filled).  

It should allows to mirror distant RDF resources which can be cached locally via SPARQL queries.

It’s all. I hope this can help you to investigate further on this proposal and perhaps help me to find another (and best) way to instantiate the Agrovoc graph.

Alessandro