Search: in
GRDDL in Encyclopedia Encyclopedia
  Tutorials     Encyclopedia     Videos     Books     Software     DVDs  


GRDDL (pronounced 'griddle') is a markup format for Gleaning Resource Descriptions from Dialects of Languages. It is a W3C Recommendation, and enables users to obtain RDF triples out of XML documents, including XHTML. The GRDDL specification shows examples using XSLT, however it was intended to be abstract enough to allow for other implementations as well. It became a Recommendation on September 11, 2007.[1]


How it works

XHTML and transformations

A document specifies associated transformations, using one of a number of ways.

For instance, an XHTML document may contain the following markup:

  profile="">   rel="transformation" href="grokXFN.xsl" /> 

Document consumers are informed that there are GRDDL transformations available in this page, by including the following in the profile attribute of the head element: 

The available transformations are revealed through one or more link elements:

  rel="transformation" href="grokXFN.xsl" /> 

This code is valid for XHTML 1.x only. The profile attribute has been dropped in HTML5, including its XML serialisation.

Microformats and profile transformations

If an XHTML page contains Microformats, there is usually a specific profile.

For instance, a document with hcard information should have:


When fetched has:




Use of this profile licenses RDF data extracted by rel="profileTransformation" href="../vcard/hcard2rdf.xsl">hcard2rdf.xsl from href="">the 2006 vCard/RDF work.

The GRDDL aware agent can then use that profileTransformation to extract all hcard data from pages that reference that link.

XML and transformations

In a similar fashion to XHTML, GRDDL transformations can be attached to XML documents.

XML namespace transformations

Just like a profileTransformation, an XML namespace can have a transformation associated with it.

This allows entire XML dialects (for instance, KML or Atom) to provide meaningful RDF.

An XML document simply points to a namespace


and when fetched, points to a namespaceTransformation.

This also allows very large amounts of the existing XML data in the wild to become RDF/XML with minimal effort from the namespace author.


Once a document has been transformed, there is an RDF representation of that data.

This output is generally put into a database and queried via SPARQL.


GRDDL consumers (also known as GRDDL aware agents)

See also

  • microformats, a simplified approach to semantically annotate data in websites
  • RDFa, a W3C Recommendation for annotating websites with RDF data
  • eRDF, an alternative to RDFa


External links

es:GRDDL fr:Gleaning Resource Descriptions from Dialects of Languages ru:GRDDL

Source: Wikipedia | The above article is available under the GNU FDL. | Edit this article

Search for GRDDL in Tutorials
Search for GRDDL in Encyclopedia
Search for GRDDL in Videos
Search for GRDDL in Books
Search for GRDDL in Software
Search for GRDDL in DVDs
Search for GRDDL in Store


GRDDL in Encyclopedia

Home - Add TutorGig to Your Site - Disclaimer

©2011-2013 All Rights Reserved. Privacy Statement