DCAT validation results

[stijngoedertier]

Now that the OGC API DCAT feed can export an entire catalog (see also #59), it would be great to pick up the work left on the DCAT converter.

The opendata.vlaanderen.be/validator DCAT Validator gave me the following suggestions:

• URLs as resources: now URLs are literals <dcat:accessURL>https://example.com/download</dcat:accessURL> but should be resources <dcat:accessURL rdf:resource="https://example.com/download"/>

• email addresses with mailto://: also email addresses should become resources. <vcard:hasEmail>noreply@example.com</vcard:hasEmail> should be resources with mailto-protocol indicated <vcard:hasEmail rdf:resource="mailto://noreply@example.com"/>

• language tags: dct:title and dct:description literals need a language tag. Ideally this also works with multilingual records.

• dcat:Catalog: include a catalog description in the DCAT output. Catalog properties such as dct:license should ideally be made configurable.

• dct:publisher: dcat:contactPoint is already provided with various roles, but DCAT also requires a dct:publisher property.

• dct:accessRights: the DCAT converter does not seem to map it.

Additionally, also this deserves some further thought:

• URIs for blank nodes: Now resources like dcat:Dataset, dcat:CatalogRecord, skos:Concept do not have a URI. For dcat:Dataset and dcat:CatalogRecord the URI could perhaps be made configurable. For skos:Concept, the URI could be taken from the link (gmx:Anchor) if available.