Since the publication of version 1.1 of the DCAT application profile for data portals in Europe in October 2015, discussions with implementers identified an interest among the community members to create an OWL expression of the application profile.
Around the same time, work was underway at W3C to develop a language for validating RDF graphs against a set of conditions, known as the SHACL Shapes Constraint Language.
In the context of work that was undertaken to develop further guidelines for the implementation of DCAT-AP v1.1, implementers of DCAT-AP v1.1 also expressed their interest in the application of SHACL to validate DCAT-AP-compliant data, for example in cases where DCAT-AP data is harvested into portals.
In response to the interest expressed by the implementer community, the ISA² Programme of the European Commission undertook a project to develop an OWL/SHACL expression of DCAT-AP v1.1 under its action on promoting semantic interoperability amongst the EU Member States.
SHACL/OWL applied to DCAT-AP v1.1
The outcome as of the date of publication of this news item is available in two folders on GitHub:
- https://github.com/SEMICeu/dcat-ap_shacl/tree/master/shacl-201608 contains the source code based on the August 2016 version of the SHACL specification. This version can be used for validation using the Free version of TopBraid Composer.
- https://github.com/SEMICeu/dcat-ap_shacl/tree/master/shacl-latest contains the source code based on the June 2017 version of the SHACL specification, based on the June 2017 version of the SHACL specification which is essentially identical to the W3C Recommendation published on 20 July 2017. This version currently cannot be used with the Free version of Topbraid Composer until the tool is upgraded to comply with the latest SHACL specification.
The sources in both folders are structured in a similar way:
- A file that contains the shapes to validate the presence of the mandatory classes: dcat-ap-mandatory-classes.shapes.ttl.
- A file that contains the shapes to validate the mandatory properties: dcat-ap.shapes.ttl
- A file that contains the shapes to validate the use of the vocabularies mandated by the DCAT-AP specification: dcat-ap-mdr-vocabularies.shapes.ttl
All the details are available on: https://joinup.ec.europa.eu/release/dcat-ap-v11
The results of the work are available for download at https://joinup.ec.europa.eu/node/146653/ (the two files at the bottom of the Distributions table), while the actual development history, the issues raised and their resolutions can be viewed at https://github.com/semiceu/dcat-ap_shacl.