How to tag nodes with RDF terms

At the moment you have two options for attaching RDF tuples to nodes: You can do it manually, or you can do it in code. Taxonomy, meanwhile, has an entire user interface built up for a variety of tasks.

Manually, you can use the form at admin/content/rdf/add. The subject is the URI of your node, the predicate is your "tag type," and the object is another URI, or some other content as specified by your RDF schema.

The API call to insert a new rdf statement is rdf_insert, and the API call to remove an existing rdf statement is rdf_delete. They work about the same as the manual form. With taxonomy, the equivalent functions would be a bit harder to find on your first try.

To find the tuples attached to a given node, the easiest API call for that seems to be rdf_query.

I'm working on a UI to allow for relating nodes to RDF metadata that is based on the relations module. I have something preliminary working, and if it looks like it would be generally useful I'm going to submit it as a patch to that module. I'll be sure to post back is if/when that happens.

I've written a proof-of-concept module to which lets you store a relationship between a node on your drupal site and a URI that has a dc:title statement in the RDF module's tables.

The module is here http://svn3.cvsdude.com/devseed/sandbox/drupal-6/relations_rdf/ I'm looking to suggestions as the best way to move forward with it and feedback as to how useful it would be.

(subscribing)

I wrote the RDF CCK module which allows CCK fields to be mapped to RDF properties. In your case you would use nodereference field, though the RDF CCK module is generic and applies to any type of CCK field. It features an autocomplete mapping mechanism which makes it easier to choose the right mappings from imported vocabularies (via the evoc module).

subscribing... i've found the relations module to be... incomplete at best.

AutoRDF is a new project for automatically tagging content.