lodcloud diagram ckan metadata
This page describes how to assert the metadata that the lodcould diagram requires. It is intended to help address outstanding issues.
- This page has the same intent as validator.lod-cloud.net/levels and a W3C wiki page, i.e., to describe what metadata should be provided (and how).
- validator.lod-cloud.net/validate will check a datahub.io dataset for the metadata expected by the LODCloud diagram.
- I ramble at length about my less-than-awesome experiences using CKAN.
- lift-ckan.py is a SADI service (or command line) that will return an RDF description of any CKAN dataset. Its results are much nicer than that provided by default CKAN installations and by datahub.io; it uses best-practice vocabularies and "unpacks" the CKAN-y incantations that this page shows you how to make.
This list is incomplete and will develop as the need arises.
A URI that is a common string prefix of all the entity URIs in a void:Dataset [VoID]. For example, http://data.example.org/id/person/joe and http://data.example.org/id/farm/sunnydale-fresh are two URIs that share the namespace http://data.example.org/id/.
Edit the CKAN entry to add a "key"=namespace and "value" of, e.g., http://data.example.org/id/. For example, the following screen shot shows adding a namespace at http://datahub.io/dataset/edit/bio2rdf-chebi :
An appropriate RDF expression of the same information would look like the following:
@prefix void: <http://rdfs.org/ns/void#> .
@prefix datafaqs: <http://purl.org/twc/vocab/datafaqs#> .
<http://datahub.io/dataset/bio2rdf-chebi>
a void:Dataset, datafaqs:CKANDataset;
void:uriSpace <http://data.example.org/id/>;
.
Add a [ckan] Resource with "format"=api/sparql and "name"=SPARQL Endpoint and "URL" of the SPARQL endpoint.