Ajax Timelines and the Semantic Web

Explore anything that has a time component with a little Timeline Ajax code.

The SPARQL query is shown in Listing 19. The sparql2timeline.xsl can be reused from any of the above examples. The commands also are very similar, as shown in Listing 20. The evolution.html can be copied to filesystem.html and modified to include filesystem.json, and we have a new Timeline.


Using RDF and SPARQL can be a great advantage when creating Timelines for new data sources. The sparql2timeline.xsl file can be reused to convert SPARQL query results to JSON. The two main things required are getting the data into RDF and the SPARQL query itself. I've touched on only some possibilities of SPARQL in this article. With SPARQL, it's easy to ensure that a value in the results matches a regular expression or has some other property, such as being between two dates. Results can come from multiple data sources using the UNION keyword. For example, it is easy to combine any of the above SPARQL queries into a single query to show multiple types of time events on a single Timeline.

Resources for this article: /article/9463.

Ben Martin has been working on filesystems for more than ten years. He is currently working toward a PhD at the University of Wollongong, Australia, combining Semantic Filesystems with Formal Concept Analysis to improve human-filesystem interaction.