developers

technical items of interest to linked data developers

Driving the bathing water quality API from JavaScript

screenshot of demo

Simple Security for Fuseki

This entry describes an interim solution for providing a minimal level of access control to a Fuseki server.

Fuseki, a part of the Jena family of linked data tools, is an Open Source SPARQL server. It provides the REST-style SPARQL HTTP Update, and SPARQL Query and SPARQL Update using the SPARQL protocol over HTTP.

Though a security model is expected to be developed in future, Fuseki currently has no means of restricting access to the server.

Linked data API slide set

I recently gave a lightning talk on the Linked Data API at the Open Government Data Camp.

It was a very high level summary (only had 10 mins in total) but a couple of people asked for a pointer to the slides so they are: here.

Using Interval Set URIs in Statistical Data

Statistical publications generally include at least one dimension comprised of the time intervals over which data has been aggregated. Linked data vocabularies for representing statistical information, such as SCOVO and current SDMX/Linked-Data collaborative activities refer to time intervals as 'things' or 'objects' rather than as literal values. This will typically involves the assignment of a URI so that multiple references can be made to the same interval.

An RDF to JSON converter on Google App Engine

As part of our work on the SDX project we felt one requirement was to enable typical web developers to exploit the RDF linked data in a simpler, more developer friendly form. In particular it would be nice to be able to access an RDF model of a resource as JSON to simply using it from ajax clients.

Generating RDF from CSV - example using xlwrap

Although there is a dump of the RDF data from CKAN available on-line, it's the full CKAN dataset and not the UK Government-specific set. For some ongoing experiments, I want some CKAN data in RDF for the published government data listed on data.hmg.gov.uk. The source data is published, however, in CSV and JSON format.

RDF Result sets

[This entry is a cross-post of an earlier personal blog post.]

In some recent semantic web applications, where we’ve been creating user interfaces over REST style interfaces over RDF data sets, we found a common pattern emerging – ResultSets. The approach we took has been documented but it’s buried in other details so I’d like to pull out the essential pattern in this post.

Situation

OWL 2 for RDF Vocabularies

[This entry is a cross-post of an earlier personal blog post.]

Investigating VoID and CKAN

For some experiments we're doing at the moment, I need some datasets from CKAN that also include VoID markup. Fortunately, the metadata from CKAN has been translated to RDF: there's no official reference that I can find, but this thread describes the main points. Sadly, the CKAN RDF does not include any elements from VoID.