Elgg,Triplify and the Semantic Web


Fellow Elggsters, ;)

Many of you know that the current trend for the web has to do with Semantic Services, what people nowadays call web 3.0. Semantic Web is nothing more than an intelligent way for every piece of information to be exchanged and understood between machines without too much fuss for the end-users.

For the people who have't heard anything on the subject  http://en.wikipedia.or/wiki/Semantic_Web and  http://linkeddata.org/  are rich information sources about it.The truth is that the semantic web at the moment after some years of developent is still in early stages.For the battle to be won we need  a critical mass of RDF described resources or LinkedData to flow from almost every site.I have to be honest here and say that this is no easy task and even the "simpler" implementations may prove to be a bit complicated until you get the hang of it.

The elgg engine does provide a small "link" to the semantic world through the FOAF profiles for every user you can produce but that's about it. Many of us have implementations that are rich in data and metadata we would like to share with the rest of the semanic world.

To do so there are mainly 2 ways to go about.

1)For the more technically savvy people SPARQL endpoints like SESAME or ARC can provide solutions for the creation and distribution of RDFs,triples of data and quering via SPARQL.

2)The second way and what we will be showing here is to use some easier tools that do some basic automation by converting your own data from relational databases (like elgg's) into RDF triples  and providing it to the semantic web.

One of the latter tools is called Triplify .  A small definition taken by their site is :

Triplify is based on the definition of relational database queries for a specific Web application in order to retrieve valuable information and to convert the results of these queries into RDF, JSON and Linked Data.

What we have done in order to provide something for the truly wonderful and active Elgg community is to develop a very basic config in order for triplify to work succesfully with Elgg.It only provides triples for the users of your site along with trie Name and SHA1 of their emails (for obvious reasons the unencrypted emails aren't published on the web).This is more of a proof of concept that this really works with Elgg. Please feel welcome to include your own more complex queries and relationships and share it with the community here.

You can find the config file at http://metamorphosis.med.duth.gr/Triplify_config.zip (don't worry the zip only contains the needed config.inc.php) All you have to do is to edit the config file to suit your own database needs ( use the comments in the file to see how and the official documentations on triplify's site as well).

Finally this is working for our own Elgg implementation called MetaMorphosis which is a social environment to share educational resources in health sciences.

Feel free to contact me for any information/help I can provide.

(We have contacted the Triplify people about this config and you probably will be able to get it also from their own site soon)

Nikolas Dovrolis