shapes-ISSUE-47 (sparqling-shape-graph): Can SPARQL-based constraints access the shape graph, and how? [SHACL Spec]

shapes-ISSUE-47 (sparqling-shape-graph): Can SPARQL-based constraints access the shape graph, and how? [SHACL Spec]

http://www.w3.org/2014/data-shapes/track/issues/47

Raised by: Richard Cyganiak
On product: SHACL Spec

SHACL constraints are themselves encoded as RDF graphs.

The WG will likely define a SPARQL-based extension mechanism.

When writing constraints using this SPARQL-based extension mechanism, one may want access to certain information from the SHACL constraint graph. Possible mechanisms for such access include:

1. The SHACL processor substitutes magic variables in the SPARQL query with values from the shape graph (a form of template instantiation)
2. SHACL defines additional SPARQL functions that allow access to the SHACL graph and can be used in the query in BIND/FILTER expressions
3a. The RDF dataset under validation is overlaid with an additional named graph that contains the SHACL graph, and can be used in the query with the GRAPH keyword
3b. Like 3a, but instead of a hardcoded graph name in the dataset, we have a magic variable that contains the name of the SHACL graph
4. Provide no access and require that the query be self-contained (except for passing in the focus node via ?this)

Multiple mechanisms could be supported.

This is a narrower phrasing of the now closed ISSUE-30.

Received on Thursday, 23 April 2015 19:42:28 UTC