Skip to content
Branch: develop
Go to file

Latest commit


Failed to load latest commit information.
Latest commit message
Commit time

RDF::Microdata reader/writer

Microdata parser for RDF.rb.

Gem Version Build Status


RDF::Microdata is a Microdata reader for Ruby using the RDF.rb library suite.


RDF::Microdata parses Microdata into statements or triples using the rules defined in Microdata RDF.

  • Microdata parser.
  • Uses Nokogiri for parsing HTML
  • If available, uses Nokogumbo gem for are pure-HTML5 parser with better error detection.

Install with 'gem install rdf-microdata'

Living implementation

Microdata to RDF transformation is undergoing active development. This implementation attempts to be up-to-date as of the time of release, and is being used in developing the Microdata RDF specification.

This implementation includes support for the proposed @itemprop-reverse attribute.

Microdata Registry

The parser uses a build-in version of the Microdata RDF registry.


Reading RDF data in the Microdata format

require 'rdf/microdata'
graph = RDF::Graph.load("etc/doap.html", format: :microdata)

Reading using content-negotation

require 'rdf/microdata'
graph = RDF::Graph.load("etc/doap.html", content_type: "text/html")


This spec is based on the W3C HTML Data Task Force specification and does not support GRDDL-type triple generation, such as for html>head>title anchor tags.

If the RDFa parser is available, {RDF::Microdata::Format} will not assert content type text/html or file extension .html, as this is also asserted by RDFa. Instead, the RDFa reader will invoke the microdata reader if an @itemscope attribute is detected.



Full documentation available on

Principle Classes

  • {RDF::Microdata::Format} Asserts :html format, text/html mime-type and .html file extension.
  • {RDF::Microdata::Reader}
    • {RDF::Microdata::Reader::Nokogiri}

RDFa-based Reader

There is an experimental reader based on transforming Microdata to RDFa within the DOM. To invoke this, add the rdfa: true option to the {}, or use {RDF::Microdata::RdfaReader} directly.

The reader exposes a #rdfa method, which can be used to retrieve the transformed HTML+RDFa




  • Do your best to adhere to the existing coding conventions and idioms.
  • Don't use hard tabs, and don't leave trailing whitespace on any line.
  • Do document every method you add using YARD annotations. Read the tutorial or just look at the existing code for examples.
  • Don't touch the .gemspec, VERSION or AUTHORS files. If you need to change them, do so on your private branch only.
  • Do feel free to add yourself to the CREDITS file and the corresponding list in the the README. Alphabetical order applies.
  • Do note that in order for us to merge any non-trivial changes (as a rule of thumb, additions larger than about 15 lines of code), we need an explicit public domain dedication on record from you.


This is free and unencumbered public domain software. For more information, see or the accompanying {file:UNLICENSE} file.


You can’t perform that action at this time.