This gem allows you to use a Talis platform meta store as a backend for RDF.rb.

RDF.rb is only concerned with RDF, and Talis stores provide a wide range of functionality beyond its scope. The Pho library has programmatic access to a wider range of features, which this library will not attempt to cover on its own.

Synopsis:

require 'rdf'
require 'rdf/talis'

repo = RDF::Talis::Repository.new('bhuga-dev1')
puts RDF::Writer.for(:ntriples).dump repo

Or on your own repo (take care):

repo = RDF::Talis::Repository.new('store-name', :user => user, :pass => pass)

repo.load 'http://datagraph.org/jhacker/foaf.nt'
repo.count
# => 10
# 12 triples in Talis, but we're ignoring the etags (see below)

subject = repo.first.subject
subject_statements = repo.query(:subject => subject)
subject_statements.size
# => 7

repo.delete(*subject_statements)
repo.count
# => 3

This RDF::Talis::Repositories work pretty much as any RDF::Repository does, with some things to note:

• #clear uses a reset job. This will not just remove all RDF, but also all of the other goodies associated with your Talis repo. Use with care!
• #load does not support contexts, which are done with private graphs at different URLs with Talis stores.
• Talis stores insert an etag statement for each inserted subject. These etags are ignored by RDF::Talis::Repository: you only get out what you put in. This means that you might not get quite the same graph back as with other tools.

As an example:

repo.load 'http://datagraph.org/jhacker/foaf.nt'
subject = repo.first.subject
subject_statements = repo.query(:subject => subject)
repo.delete(*subject_statements)
repo.has_subject?(subject)
# => false

Note, however, that an etag with the subject still exists in the repository (shown here as an NTriple):

<http://datagraph.org/jhacker/#self> <http://schemas.talis.com/2005/dir/schema#etag> "1c219cb8-bfd9-4cb8-b717-3f9deb03b32a" .

The recommended method of installation is via RubyGems.

$ sudo gem install rdf-talis

• {RDF::Talis::Repository}
• http://rdf.rubyforge.org - RDF.rb's home page
• http://rdf.rubyforge.org/RDF/Repository.html
• http://rubyforge.org/projects/pho/
• http://n2.talis.com/wiki/Main_Page

Please post questions or feedback to the W3C-ruby-rdf mailing list.

• Ben Lavender | [email protected] | http://github.com/bhuga | http://bhuga.net | http://blog.datagraph.org

This is free and unemcumbered software released into the public domain. For more information, see the accompanying UNLICENSE file.

If you're unfamiliar with public domain, that means it's perfectly fine to start with this skeleton and code away, later relicensing as you see fit.