[#2226,doc/linked-data-and-rdf][s]: add new linked data section (need…

…s more work - @rossjones).

doc/conf.py

@@ -26,7 +26,7 @@
 
 # Add any Sphinx extension module names here, as strings. They can be extensions
 # coming with Sphinx (named 'sphinx.ext.*') or your custom ones.
-extensions = ['sphinx.ext.autodoc']
+extensions = ['sphinx.ext.autodoc', 'sphinx.ext.todo']
 
 # Add any paths that contain templates here, relative to this directory.
 templates_path = ['_templates']

doc/index.rst

@@ -28,10 +28,11 @@ Customizing and Extending
    :maxdepth: 2
 
    theming
+   extensions
    writing-extensions
    forms
    form-integration
-   extensions
+   linked-data-and-rdf
 
 Publishing Datasets
 ===================

doc/linked-data-and-rdf.rst

@@ -0,0 +1,52 @@
+===================
+Linked Data and RDF
+===================
+
+CKAN has extensive support for linked data and RDF. In particular, there is
+complete and functional mapping of the CKAN dataset schema to linked data
+formats.
+
+
+Enabling and Configuring Linked Data Support
+============================================
+
+In CKAN <= 1.6 please install the RDF extension: https://github.com/okfn/ckanext-rdf
+
+In CKAN >= 1.6.1, basic RDF support will be available directly in core.
+
+Configuration
+-------------
+
+.. todo:: fill this in (imagine that config instructions for extension will be
+          in extension but for >= 1.6.1 we have stuff in core)
+
+
+Accessing Linked Data
+=====================
+
+To access linked data versions just access the :doc:`api` in the usual way but
+set the Accept header to the format you would like to be returned. For
+example::
+
+ curl -L -H "Accept: application/rdf+xml" http://thedatahub.org/dataset/gold-prices
+ curl -L -H "Accept: text/n3" http://thedatahub.org/dataset/gold-prices
+
+
+Schema Mapping
+==============
+
+There are various vocabularies that can be used for describing datasets:
+
+* Dublin core: these are the most well-known and basic. Dublin core terms includes the class *dct:Dataset*.
+* DCAT_ - vocabulary for catalogues of datasets
+* VoID_ - vocabulary of interlinked datasets. Specifically designed for describing *rdf* datasets. Perfect except for the fact that it is focused on RDF
+* SCOVO_: this is more oriented to statistical datasets but has a *scovo:Dataset* class.
+
+At the present CKAN uses mostly DCAT and Dublin Core.
+
+.. _DCAT: http://vocab.deri.ie/dcat
+.. _VoID: http://rdfs.org/ns/void
+.. _SCOVO: http://sw.joanneum.at/scovo/schema.html
+
+.. todo:: put in an example of converted data to illustrate the schema
+