A Faceted Browser over SPARQL Endpoints

Posted: February 8, 2012 | Author: | Filed under: Uncategorized | Tags: , , | 15 Comments

I have recently been working on (yet another?) faceted browser over RDF data… more precisely RDF data loaded in a SPARQL endpoint that support COUNT and GROUP BY queries. I have successfully used it against Fuseki, Talis platform(tested against http://api.talis.com/stores/bbc-backstage/services/sparql) and Virtuoso (tested against http://dbpedia.org/sparql)

Main characteristics:

  1. Configurable: most aspects of the browser is configurable through two JSON files (configuration.json and facets.json). This includes basic templating & styling ability. To change the style, add a facet or browse a completely different data; just edit the json files accordingly and reload the page
  2. No preprocessing required: as all request are standard SPARQL queries… nothing is required a priori neither on the publisher nor on the consumer end
  3. Facets are defined as triple patterns (see example) therefore facets values don’t need to be necessarily directly associated with the items browsed i.e. they can be a few hops of the browsed items

see the screenshot below to get a feeling of the browser…

If you have used Google Refine before, the resemblance is probably clear. Indeed, I am reusing the JavaScript and CSS code that makes the facets part of Google Refine (they are gratefully under New BSD License.. how much I love open source!!!)

Having it running

The code is shared on github. grab it, deploy it to a Java application server and then play with the configuration files  (a number of examples are provided with the source)

Outlook and //TODO

The most exciting part to me (thanks to the Google Refine inspiration) is that all the needed knowledge about the endpoint and the facets are maintained as JSON on the client side and communicated with the server upon each request. If a user somehow update this configuration and submit to the server, she can customise her view (as an example I added a change button to each facet which allow the user to change only the facet she sees… potentially an add facet button can be added)

Additionally, a list of issues and features to add is on the github repository.

comments/feedback are very warmly welcomed 🙂

 

Update 19/03/2012:  support for fulltext search facets added. Currently supports Virtuoso and standard SPARQL (using regex). See example