"""A relationship defined in the ontology."""
import logging
import rdflib
from osp.core.ontology.entity import OntologyEntity
logger = logging.getLogger(__name__)
# TODO characteristics
BLACKLIST = {rdflib.OWL.bottomObjectProperty, rdflib.OWL.topObjectProperty}
[docs]class OntologyRelationship(OntologyEntity):
"""A relationship defined in the ontology."""
def __init__(self, namespace_registry, namespace_iri, name, iri_suffix):
"""Initialize the ontology relationship.
Args:
namespace_registry (OntologyNamespaceRegistry): The namespace
registry where all namespaces are stored.
namespace_iri (rdflib.URIRef): The IRI of the namespace.
name (str): The name of the relationship.
iri_suffix (str): namespace_iri + namespace_registry make up the
namespace of this entity.
"""
super().__init__(namespace_registry, namespace_iri, name, iri_suffix)
logger.debug("Create ontology object property %s" % self)
@property
def inverse(self):
"""Get the inverse of this relationship.
If it doesn't exist, add one to the graph.
Returns:
OntologyRelationship: The inverse relationship.
"""
triple1 = (self.iri, rdflib.OWL.inverseOf, None)
triple2 = (None, rdflib.OWL.inverseOf, self.iri)
for _, _, o in self.namespace._graph.triples(triple1):
if not isinstance(o, rdflib.BNode):
return self.namespace._namespace_registry.from_iri(o)
for s, _, _ in self.namespace._graph.triples(triple2):
if not isinstance(s, rdflib.BNode):
return self.namespace._namespace_registry.from_iri(s)
return self._add_inverse()
def _direct_superclasses(self):
"""Get all the direct subclasses of this relationship.
Returns:
OntologyRelationship: The direct subrelationships
"""
return self._directly_connected(
rdflib.RDFS.subPropertyOf, blacklist=BLACKLIST
)
def _direct_subclasses(self):
"""Get all the direct subclasses of this relationship.
Returns:
OntologyRelationship: The direct subrelationships
"""
return self._directly_connected(
rdflib.RDFS.subPropertyOf, inverse=True, blacklist=BLACKLIST
)
def _superclasses(self):
"""Get all the superclasses of this relationship.
Yields:
OntologyRelationship: The superrelationships.
"""
yield self
yield from self._transitive_hull(
rdflib.RDFS.subPropertyOf, blacklist=BLACKLIST
)
def _subclasses(self):
"""Get all the subclasses of this relationship.
Yields:
OntologyRelationship: The subrelationships.
"""
yield self
yield from self._transitive_hull(
rdflib.RDFS.subPropertyOf, inverse=True, blacklist=BLACKLIST
)
def _add_inverse(self):
"""Add the inverse of this relationship to the path.
Returns:
OntologyRelationship: The inverse relationship.
"""
o = rdflib.URIRef(self.namespace.get_iri() + "INVERSE_OF_" + self.name)
x = (self.iri, rdflib.OWL.inverseOf, o)
y = (o, rdflib.RDF.type, rdflib.OWL.ObjectProperty)
z = (
o,
rdflib.SKOS.prefLabel,
rdflib.Literal("INVERSE_OF_" + self.name, lang="en"),
)
self.namespace._graph.add(x)
self.namespace._graph.add(y)
self.namespace._graph.add(z)
for superclass in self.direct_superclasses:
self.namespace._graph.add(
(o, rdflib.RDFS.subPropertyOf, superclass.inverse.iri)
)
return self._namespace_registry.from_iri(o)
