Create separate class for acdh:hasSubject range

[zozlak]

Having a separate class for the acdh:hasSubject range will allow us to define separate doorkeeper check rules for the values.

acdh-oeaw/arche-doorkeeper#32
acdh-oeaw/arche-ref-sources#13

[bellerophons-pegasus]

Could you please explain why?

We are aiming for a dedicated vocabulary for acdh:hasSubject and then we would have something similar to acdh:hasLanguage or acdh:hasLicense, which make use of skos:Concept. What would be different in the case with acdh:hasSubject?

Btw: We had a class 'Concept' in the early days of the ontology and decided to kick it out at some point

[zozlak]

We were thinking with Seta about a different way of defining vocabularies for properties. Now we need:

• A single vocabulary defined all allowed values. So if we want to combine few existing vocabularies, we need to do it by hand and publish on our own and then maintain it (track changes in source vocabularies and backport them to ours) which is quite inconvenient.
• Which has to be fully imported into ARCHE. Which is quite an overkill for large vocabularies we use sparsely (among existing ones e.g. ISO languages or field of science which have thousands of concepts making thousands of ARCHE resources but we in practice use only a few values).

On the other hand we already have in place an URI checking mechanism where for a given ARCHE class we define a set of allowed external authority files (e.g. a Person can be identified by an URI in the acdhi, viaf, gnd, etc. namespace). This method allows to easily combine multiple sources and it doesn't require to materialize all possible values as ARCHE resources. Just as the rules system is based on ARCHE class being a range of a given property, a distinct set of rules requires a dedicated class to be defined. What's worth noting it would be just a helper class like dozens we have already for defining property inheritance and cardinality constrains.

[zozlak]

Anyway, at the moment acdh:hasSubject is a datatype property and this will affect us only when we will switch it to an object one.