Raptor RDF Parser Wrapper for RDF.rb

This is an RDF.rb plugin that adds support for parsing/serializing RDF/XML, Turtle and RDFa data using the Raptor RDF Parser library.

• http://github.com/bendiken/rdf-raptor
• http://blog.datagraph.org/2010/04/parsing-rdf-with-ruby

Features

• Requires the Raptor library and utilities to be available.
• Based on the rapper command-line utility bundled with Raptor.
• Parses and serializes RDF data from/into the RDF/XML or Turtle formats.
• Extracts RDF statements from XHTML+RDFa documents.
• Provides serialization format autodetection for RDF/XML, Turtle and RDFa.
• Compatible with any operating system supported by Raptor and Ruby.
• Compatible with MRI 1.8.x, 1.9.x and JRuby (tested with JRuby 1.4).

Examples

require 'rdf/raptor'

Ensuring Raptor is installed and obtaining the version number

RDF::Raptor.available?         #=> true
RDF::Raptor.version            #=> "1.4.21"

Parsing RDF statements from an RDF/XML file

RDF::Reader.open("http://datagraph.org/jhacker/foaf.rdf") do |reader|
  reader.each_statement do |statement|
    puts statement.inspect
  end
end

Parsing RDF statements from a Turtle file

RDF::Reader.open("http://datagraph.org/jhacker/foaf.ttl") do |reader|
  reader.each_statement do |statement|
    puts statement.inspect
  end
end

Extracting RDF statements from an XHTML+RDFa document

RDF::Reader.open(url = "http://bblfish.net/", :format => :rdfa, :base_uri => url) do |reader|
  reader.each_statement do |statement|
    puts statement.inspect
  end
end

Serializing RDF statements into an RDF/XML file

data = RDF::Repository.load("http://datagraph.org/jhacker/foaf.nt")

RDF::Writer.open("output.rdf") do |writer|
  data.each_statement do |statement|
    writer << statement
  end
end

Serializing RDF statements into a Turtle file

data = RDF::Repository.load("http://datagraph.org/jhacker/foaf.nt")

RDF::Writer.open("output.ttl") do |writer|
  data.each_statement do |statement|
    writer << statement
  end
end

Obtaining the RDF/XML format specification class

RDF::Format.for(:rdfxml)       #=> RDF::Raptor::RDFXML::Format
RDF::Format.for("input.rdf")
RDF::Format.for(:file_name      => "input.rdf")
RDF::Format.for(:file_extension => "rdf")
RDF::Format.for(:content_type   => "application/rdf+xml")

Obtaining the Turtle format specification class

RDF::Format.for(:turtle)       #=> RDF::Raptor::Turtle::Format
RDF::Format.for("input.ttl")
RDF::Format.for(:file_name      => "input.ttl")
RDF::Format.for(:file_extension => "ttl")
RDF::Format.for(:content_type   => "text/turtle")

Obtaining the RDFa format specification class

RDF::Format.for(:rdfa)         #=> RDF::Raptor::RDFa::Format
RDF::Format.for("input.html")
RDF::Format.for(:file_name      => "input.html")
RDF::Format.for(:file_extension => "html")
RDF::Format.for(:content_type   => "application/xhtml+xml")

Documentation

http://rdf.rubyforge.org/raptor/

• {RDF::Raptor}
  • {RDF::Raptor::RDFXML}
  • {RDF::Raptor::Turtle}
  • {RDF::Raptor::RDFa}
  • {RDF::Raptor::Graphviz}

Dependencies

• RDF.rb (>= 0.2.0)
• Raptor (>= 1.4.16), specifically the rapper binary

Installation

The recommended installation method is via RubyGems. To install the latest official release of the RDF::Raptor gem, do:

% [sudo] gem install rdf-raptor

To install the required Raptor command-line tools themselves, look for a raptor or raptor-utils package in your platform's package management system. Here follow installation instructions for the Mac and the most common Linux and BSD distributions:

% [sudo] port install raptor             # Mac OS X with MacPorts
% [sudo] fink install raptor-bin         # Mac OS X with Fink
% [sudo] aptitude install raptor-utils   # Ubuntu / Debian
% [sudo] yum install raptor              # Fedora / CentOS / RHEL
% [sudo] zypper install raptor           # openSUSE
% [sudo] emerge raptor                   # Gentoo Linux
% [sudo] pacman -S raptor                # Arch Linux
% [sudo] pkg_add -r raptor               # FreeBSD
% [sudo] pkg_add raptor                  # OpenBSD / NetBSD

Download

To get a local working copy of the development repository, do:

% git clone git://github.com/bendiken/rdf-raptor.git

Alternatively, you can download the latest development version as a tarball as follows:

% wget http://github.com/bendiken/rdf-raptor/tarball/master

Author

• Arto Bendiken - http://ar.to/
• John Fieber - http://github.com/jfieber

Contributors

• Ben Lavender - http://bhuga.net/

License

RDF::Raptor is free and unencumbered public domain software. For more information, see http://unlicense.org/ or the accompanying UNLICENSE file.