CKAN Sparql Interface Extension

Note: The ckanext-sparql_interface extension was tested using Virtuoso sparql instances such as http://dbpedia.org/sparql and http://datos.gob.es/virtuoso/sparql

• Version: 2.0
• Status: Development
• CKAN Version: >= 2.9

This version has been evolved from the original 1.01, to made it work with ckan 2.8 and python 3.9

Description

This is a simple extension, but may be useful for someone that wants to include a Sparql Interface Editor in their CKAN instances. The idea is based on the Sparql Editor of the LODUM project from the University of Munsters Open Data initiative.

Requeriments

The extension use:

• CodeMirror for the code editor in the browser.

• May be extended to use SPARQLWrapper library - SPARQL Endpoint interface to Python

Installation

To install ckanext-sparql_interface:

1. Activate your CKAN virtual environment, for example:

   . /usr/lib/ckan/default/bin/activate

2. Clone the source and install it on the virtualenv

   git clone https://github.com/OpenDataGIS/ckanext-sparql_interface.git
   cd ckanext-sparql_interface
   pip install -e .
   pip install -r requirements.txt
   

3. Add sparql_interface to the ckan.plugins setting in your CKAN config file (by default the config file is located at /etc/ckan/default/ckan.ini).

4. In order to let the English and other languajes profiles work, it is absolutely mandatory to make the directory /ckan/ckan/public/base/i18n writable by the ckan user. CKAN WILL NOT START IF YOU DON'T DO SO!

5. Add configuration to the CKAN configuration file as required. See below.

6. Restart CKAN. For example if you've deployed CKAN with Apache on Ubuntu:

   sudo service apache2 reload

Configuration

In your ckan.ini file set

	ckanext.sparql_interface.endpoint_url = <your default endpoint url>    (defaults to http://dbpedia.org/sparql)
	ckanext.sparql_interface.hide_endpoint_url = (true | false)    (defaults to false)

Use

Go to:

http://[Custom URL]/sparql_interface/

Querys work in:

http://[Custom URL]/sparql_interface/query?query=

To send code through http to the sparql interface:

http://[Custom URL]/sparql_interface/index?view_code=

Notes

To configure your own custom example query in templates/sparql_interface/index.html template

	<!-- Line 57, After-->
	<textarea id="sparql_code" name="sparql_code"  resize="both">
	<!-- Here replace the query-->
	    ...
	</textarea>

To change the default prefixes, edit prefixes in public/ckanext/sparql_interface/public_sparql_interface/base.js

var prefixes = "PREFIX void: <http://rdfs.org/ns/void#> PREFIX geo: <http://www.w3.org/2003/01/geo/wgs84_pos#> PREFIX foaf: <http://xmlns.com/foaf/0.1/> PREFIX vann: <http://purl.org/vocab/vann/> PREFIX teach: <http://linkedscience.org/teach/ns#>"

Changelog

• Version: 1.01: Fix Bugs
• Version: 2.0: Adapted to ckan 2.9 and internacionalized
• Version: 2.0.1: Minor fixes

Example

• http://data.upf.edu/sparql

ToDos

• externalize configuration of default query