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# $Header: /var/local/cvsroot/4Suite/Ft/Rdf/RdfsHandler.py,v 1.9 2005/03/04 15:03:04 mbrown Exp $
"""
An RDF schema validator for statements in a Model
Copyright 2005 Fourthought, Inc. (USA).
Detailed license and copyright information: http://4suite.org/COPYRIGHT
Project home, documentation, distributions: http://4suite.org/
"""
# Obtained from http://www.w3.org/TR/rdf-schema/rdfs-namespace
# on 2005-03-03. French labels and xml:lang attrs added locally.
# owl:Ontology Class definition added locally, derived from
# http://www.w3.org/2002/07/owl, so that the schema itself will validate
RDFS_XML = """<?xml version="1.0" encoding="utf-8"?>
<rdf:RDF
xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"
xmlns:owl="http://www.w3.org/2002/07/owl#"
xmlns:dc="http://purl.org/dc/elements/1.1/">
<owl:Ontology
rdf:about="http://www.w3.org/2000/01/rdf-schema#"
dc:title="The RDF Schema vocabulary (RDFS)"/>
<rdfs:Class rdf:about="http://www.w3.org/2002/07/owl#Ontology">
<rdfs:label>Ontology</rdfs:label>
</rdfs:Class>
<rdfs:Class rdf:about="http://www.w3.org/2000/01/rdf-schema#Resource">
<rdfs:isDefinedBy rdf:resource="http://www.w3.org/2000/01/rdf-schema#"/>
<rdfs:label xml:lang="en">Resource</rdfs:label>
<rdfs:label xml:lang="fr">Ressource</rdfs:label>
<rdfs:comment>The class resource, everything.</rdfs:comment>
</rdfs:Class>
<rdf:Property rdf:about="http://www.w3.org/1999/02/22-rdf-syntax-ns#type">
<rdfs:isDefinedBy rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#"/>
<rdfs:label xml:lang="en">type</rdfs:label>
<rdfs:label xml:lang="fr">type</rdfs:label>
<rdfs:comment>The subject is an instance of a class.</rdfs:comment>
<rdfs:range rdf:resource="http://www.w3.org/2000/01/rdf-schema#Class"/>
<rdfs:domain rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/>
</rdf:Property>
<rdfs:Class rdf:about="http://www.w3.org/2000/01/rdf-schema#Class">
<rdfs:isDefinedBy rdf:resource="http://www.w3.org/2000/01/rdf-schema#"/>
<rdfs:label xml:lang="en">Class</rdfs:label>
<rdfs:label xml:lang="fr">Classe</rdfs:label>
<rdfs:comment>The class of classes.</rdfs:comment>
<rdfs:subClassOf rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/>
</rdfs:Class>
<rdf:Property rdf:about="http://www.w3.org/2000/01/rdf-schema#subClassOf">
<rdfs:isDefinedBy rdf:resource="http://www.w3.org/2000/01/rdf-schema#"/>
<rdfs:label xml:lang="en">subClassOf</rdfs:label>
<rdfs:label xml:lang="fr">sousClasseDe</rdfs:label>
<rdfs:comment>The subject is a subclass of a class.</rdfs:comment>
<rdfs:range rdf:resource="http://www.w3.org/2000/01/rdf-schema#Class"/>
<rdfs:domain rdf:resource="http://www.w3.org/2000/01/rdf-schema#Class"/>
</rdf:Property>
<rdf:Property rdf:about="http://www.w3.org/2000/01/rdf-schema#subPropertyOf">
<rdfs:isDefinedBy rdf:resource="http://www.w3.org/2000/01/rdf-schema#"/>
<rdfs:label xml:lang="en">subPropertyOf</rdfs:label>
<rdfs:label xml:lang="fr">sousPropriétéDe</rdfs:label>
<rdfs:comment>The subject is a subproperty of a property.</rdfs:comment>
<rdfs:range rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#Property"/>
<rdfs:domain rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#Property"/>
</rdf:Property>
<rdfs:Class rdf:about="http://www.w3.org/1999/02/22-rdf-syntax-ns#Property">
<rdfs:isDefinedBy rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#"/>
<rdfs:label xml:lang="en">Property</rdfs:label>
<rdfs:label xml:lang="fr">Propriété</rdfs:label>
<rdfs:comment>The class of RDF properties.</rdfs:comment>
<rdfs:subClassOf rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/>
</rdfs:Class>
<rdf:Property rdf:about="http://www.w3.org/2000/01/rdf-schema#comment">
<rdfs:isDefinedBy rdf:resource="http://www.w3.org/2000/01/rdf-schema#"/>
<rdfs:label xml:lang="en">comment</rdfs:label>
<rdfs:label xml:lang="fr">commentaire</rdfs:label>
<rdfs:comment>A description of the subject resource.</rdfs:comment>
<rdfs:domain rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/>
<rdfs:range rdf:resource="http://www.w3.org/2000/01/rdf-schema#Literal"/>
</rdf:Property>
<rdf:Property rdf:about="http://www.w3.org/2000/01/rdf-schema#label">
<rdfs:isDefinedBy rdf:resource="http://www.w3.org/2000/01/rdf-schema#"/>
<rdfs:label xml:lang="en">label</rdfs:label>
<rdfs:label xml:lang="fr">libellé</rdfs:label>
<rdfs:comment>A human-readable name for the subject.</rdfs:comment>
<rdfs:domain rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/>
<rdfs:range rdf:resource="http://www.w3.org/2000/01/rdf-schema#Literal"/>
</rdf:Property>
<!-- was: rdfs:ConstraintProperty rdf:ID="domain" -->
<rdf:Property rdf:about="http://www.w3.org/2000/01/rdf-schema#domain">
<rdfs:isDefinedBy rdf:resource="http://www.w3.org/2000/01/rdf-schema#"/>
<rdfs:label xml:lang="en">domain</rdfs:label>
<rdfs:label xml:lang="fr">domaine</rdfs:label>
<rdfs:comment>A domain of the subject property.</rdfs:comment>
<rdfs:range rdf:resource="http://www.w3.org/2000/01/rdf-schema#Class"/>
<rdfs:domain rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#Property"/>
</rdf:Property>
<!-- was: rdfs:ConstraintProperty rdf:ID="range" -->
<rdf:Property rdf:about="http://www.w3.org/2000/01/rdf-schema#range">
<rdfs:isDefinedBy rdf:resource="http://www.w3.org/2000/01/rdf-schema#"/>
<rdfs:label xml:lang="en">range</rdfs:label>
<rdfs:label xml:lang="fr">étendue</rdfs:label>
<rdfs:comment>A range of the subject property.</rdfs:comment>
<rdfs:range rdf:resource="http://www.w3.org/2000/01/rdf-schema#Class"/>
<rdfs:domain rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#Property"/>
</rdf:Property>
<rdf:Property rdf:about="http://www.w3.org/2000/01/rdf-schema#seeAlso">
<rdfs:isDefinedBy rdf:resource="http://www.w3.org/2000/01/rdf-schema#"/>
<rdfs:label xml:lang="en">seeAlso</rdfs:label>
<rdfs:label xml:lang="fr">voirAussi</rdfs:label>
<rdfs:comment>Further information about the subject resource.</rdfs:comment>
<rdfs:range rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/>
<rdfs:domain rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/>
</rdf:Property>
<rdf:Property rdf:about="http://www.w3.org/2000/01/rdf-schema#isDefinedBy">
<rdfs:isDefinedBy rdf:resource="http://www.w3.org/2000/01/rdf-schema#"/>
<rdfs:subPropertyOf rdf:resource="http://www.w3.org/2000/01/rdf-schema#seeAlso"/>
<rdfs:label xml:lang="en">isDefinedBy</rdfs:label>
<rdfs:label xml:lang="fr">estDéfiniPar</rdfs:label>
<rdfs:comment>The defininition of the subject resource.</rdfs:comment>
<rdfs:range rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/>
<rdfs:domain rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/>
</rdf:Property>
<rdfs:Class rdf:about="http://www.w3.org/2000/01/rdf-schema#Literal">
<rdfs:isDefinedBy rdf:resource="http://www.w3.org/2000/01/rdf-schema#"/>
<rdfs:label xml:lang="en">Literal</rdfs:label>
<rdfs:label xml:lang="fr">Littéral</rdfs:label>
<rdfs:comment>The class of literal values, eg. textual strings and integers.</rdfs:comment>
<rdfs:subClassOf rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/>
</rdfs:Class>
<rdfs:Class rdf:about="http://www.w3.org/1999/02/22-rdf-syntax-ns#Statement">
<rdfs:isDefinedBy rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#"/>
<rdfs:label xml:lang="en">Statement</rdfs:label>
<rdfs:label xml:lang="fr">Déclaration</rdfs:label>
<rdfs:subClassOf rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/>
<rdfs:comment>The class of RDF statements.</rdfs:comment>
</rdfs:Class>
<rdf:Property rdf:about="http://www.w3.org/1999/02/22-rdf-syntax-ns#subject">
<rdfs:isDefinedBy rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#"/>
<rdfs:label xml:lang="en">subject</rdfs:label>
<rdfs:label xml:lang="fr">sujet</rdfs:label>
<rdfs:comment>The subject of the subject RDF statement.</rdfs:comment>
<rdfs:domain rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#Statement"/>
<rdfs:range rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/>
</rdf:Property>
<rdf:Property rdf:about="http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate">
<rdfs:isDefinedBy rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#"/>
<rdfs:label xml:lang="en">predicate</rdfs:label>
<rdfs:label xml:lang="fr">prédicat</rdfs:label>
<rdfs:comment>The predicate of the subject RDF statement.</rdfs:comment>
<rdfs:domain rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#Statement"/>
<rdfs:range rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/>
</rdf:Property>
<rdf:Property rdf:about="http://www.w3.org/1999/02/22-rdf-syntax-ns#object">
<rdfs:isDefinedBy rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#"/>
<rdfs:label xml:lang="en">object</rdfs:label>
<rdfs:label xml:lang="fr">objet</rdfs:label>
<rdfs:comment>The object of the subject RDF statement.</rdfs:comment>
<rdfs:domain rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#Statement"/>
<rdfs:range rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/>
</rdf:Property>
<rdfs:Class rdf:about="http://www.w3.org/2000/01/rdf-schema#Container">
<rdfs:isDefinedBy rdf:resource="http://www.w3.org/2000/01/rdf-schema#"/>
<rdfs:label xml:lang="en">Container</rdfs:label>
<rdfs:label xml:lang="fr">Enveloppe</rdfs:label>
<rdfs:subClassOf rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/>
<rdfs:comment>The class of RDF containers.</rdfs:comment>
</rdfs:Class>
<rdfs:Class rdf:about="http://www.w3.org/1999/02/22-rdf-syntax-ns#Bag">
<rdfs:isDefinedBy rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#"/>
<rdfs:label xml:lang="en">Bag</rdfs:label>
<rdfs:label xml:lang="fr">Ensemble</rdfs:label>
<rdfs:comment>The class of unordered containers.</rdfs:comment>
<rdfs:subClassOf rdf:resource="http://www.w3.org/2000/01/rdf-schema#Container"/>
</rdfs:Class>
<rdfs:Class rdf:about="http://www.w3.org/1999/02/22-rdf-syntax-ns#Seq">
<rdfs:isDefinedBy rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#"/>
<rdfs:label xml:lang="en">Sequence</rdfs:label>
<rdfs:label xml:lang="fr">Séquence</rdfs:label>
<rdfs:comment>The class of ordered containers.</rdfs:comment>
<rdfs:subClassOf rdf:resource="http://www.w3.org/2000/01/rdf-schema#Container"/>
</rdfs:Class>
<rdfs:Class rdf:about="http://www.w3.org/1999/02/22-rdf-syntax-ns#Alt">
<rdfs:isDefinedBy rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#"/>
<rdfs:label xml:lang="en">Alt</rdfs:label>
<rdfs:label xml:lang="fr">Choix</rdfs:label>
<rdfs:comment>The class of containers of alternatives.</rdfs:comment>
<rdfs:subClassOf rdf:resource="http://www.w3.org/2000/01/rdf-schema#Container"/>
</rdfs:Class>
<rdfs:Class rdf:about="http://www.w3.org/2000/01/rdf-schema#ContainerMembershipProperty">
<rdfs:isDefinedBy rdf:resource="http://www.w3.org/2000/01/rdf-schema#"/>
<rdfs:label xml:lang="en">ContainerMembershipProperty</rdfs:label>
<rdfs:comment>The class of container membership properties, rdf:_1, rdf:_2, ..., all of which are sub-properties of 'member'.</rdfs:comment>
<rdfs:subClassOf rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#Property"/>
</rdfs:Class>
<rdf:Property rdf:about="http://www.w3.org/2000/01/rdf-schema#member">
<rdfs:isDefinedBy rdf:resource="http://www.w3.org/2000/01/rdf-schema#"/>
<rdfs:label xml:lang="en">member</rdfs:label>
<rdfs:comment>A member of the subject resource.</rdfs:comment>
<rdfs:domain rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/>
<rdfs:range rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/>
</rdf:Property>
<rdf:Property rdf:about="http://www.w3.org/1999/02/22-rdf-syntax-ns#value">
<rdfs:isDefinedBy rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#"/>
<rdfs:label xml:lang="en">value</rdfs:label>
<rdfs:label xml:lang="fr">valuer</rdfs:label>
<rdfs:comment>Idiomatic property used for structured values.</rdfs:comment>
<rdfs:domain rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/>
<rdfs:range rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/>
</rdf:Property>
<!-- the following are new additions, Nov 2002 -->
<rdfs:Class rdf:about="http://www.w3.org/1999/02/22-rdf-syntax-ns#List">
<rdfs:isDefinedBy rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#"/>
<rdfs:label xml:lang="en">List</rdfs:label>
<rdfs:comment>The class of RDF Lists.</rdfs:comment>
<rdfs:subClassOf rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/></rdfs:Class>
<rdf:List rdf:about="http://www.w3.org/1999/02/22-rdf-syntax-ns#nil">
<rdfs:isDefinedBy rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#"/>
<rdfs:label xml:lang="en">nil</rdfs:label>
<rdfs:comment>The empty list, with no items in it. If the rest of a list is nil then the list has no more items in it.</rdfs:comment>
</rdf:List>
<rdf:Property rdf:about="http://www.w3.org/1999/02/22-rdf-syntax-ns#first">
<rdfs:isDefinedBy rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#"/>
<rdfs:label xml:lang="en">first</rdfs:label>
<rdfs:comment>The first item in the subject RDF list.</rdfs:comment>
<rdfs:domain rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#List"/>
<rdfs:range rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/>
</rdf:Property>
<rdf:Property rdf:about="http://www.w3.org/1999/02/22-rdf-syntax-ns#rest">
<rdfs:isDefinedBy rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#"/>
<rdfs:label xml:lang="en">rest</rdfs:label>
<rdfs:comment>The rest of the subject RDF list after the first item.</rdfs:comment>
<rdfs:domain rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#List"/>
<rdfs:range rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#List"/>
</rdf:Property>
<rdfs:Class rdf:about="http://www.w3.org/2000/01/rdf-schema#Datatype">
<rdfs:isDefinedBy rdf:resource="http://www.w3.org/2000/01/rdf-schema#"/>
<rdfs:label xml:lang="en">Datatype</rdfs:label>
<rdfs:comment>The class of RDF datatypes.</rdfs:comment>
<rdfs:subClassOf rdf:resource="http://www.w3.org/2000/01/rdf-schema#Class"/>
</rdfs:Class>
<rdfs:Datatype rdf:about="http://www.w3.org/1999/02/22-rdf-syntax-ns#XMLLiteral">
<rdfs:subClassOf rdf:resource="http://www.w3.org/2000/01/rdf-schema#Literal"/>
<rdfs:isDefinedBy rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#"/>
<rdfs:label xml:lang="en">XMLLiteral</rdfs:label>
<rdfs:comment>The class of XML literal values.</rdfs:comment>
</rdfs:Datatype>
<rdf:Description rdf:about="http://www.w3.org/2000/01/rdf-schema#">
<rdfs:seeAlso rdf:resource="http://www.w3.org/2000/01/rdf-schema-more"/>
</rdf:Description>
</rdf:RDF>"""
from Ft import FtException
from Ft.Lib.Uri import OsPathToUri
from Ft.Rdf import Model, SchemaHandler, RdfException
from Ft.Rdf import RDF_MS_BASE, RDF_SCHEMA_BASE
from Ft.Rdf.Serializers.Dom import Serializer
class RdfsConstraintViolation(FtException):
PROPERTY_HAS_MULTIPLE_RANGES = 1
INVALID_DOMAIN_FOR_PROPERTY = 2
INVALID_RANGE_FOR_PROPERTY = 3
def __init__(self, errorCode, *args):
import MessageSource
FtException.__init__(self, errorCode, MessageSource.RDFS_ERROR_MESSAGES, args)
class RdfsHandler(SchemaHandler):
"""
Processing of RDF schema information on behalf of a model instance.
Note that a RdfsHandler is designed to be associated with
a single model in its lifecycle, which is basically:
init -> initModel -> <user's schema operations> -> reclaim
Do not attempt to reuse a RdfsHandler with multiple models
unless you really know what you're doing
"""
def __init__(self):
"""Initializer for a RdfsHandler. There are no parameters."""
from Ft.Rdf.Drivers import Memory
db = Memory.CreateDb('')
self._coreRdfsModel = Model.Model(db, None)
from Ft.Xml.Domlette import NonvalidatingReader
self._reader = NonvalidatingReader
self._serializer = Serializer()
self._model = None
self._active = False
self._deserialized_URIs = {}
return
def _deserialize(self, model, isrc, scope=None):
"""
Given a model, InputSource, and optional scope,
deserializes the RDF/XML document wrapped by the InputSource
into the model. Caches InputSource URIs so as not to deserialize
the same document twice.
"""
uri = isrc.uri
if uri not in self._deserialized_URIs:
doc = self._reader.parse(isrc)
self._serializer.deserialize(model, doc, scope)
self._deserialized_URIs[uri] = True
return
def initModel(self, model):
"""
Make sure that the core schema statements are in the model
"""
self._model = model
SchemaHandler.initModel(self)
#FIXME: Use faster init method than deserialization
dummy_uri = OsPathToUri(__file__, attemptAbsolute=True)
dummy_uri += '-INTERNAL-RDFS-XML-STRING'
from Ft.Xml.InputSource import DefaultFactory
isrc = DefaultFactory.fromString(RDFS_XML, dummy_uri)
self._deserialize(self._model, isrc, scope=RDF_SCHEMA_BASE)
#Keep around a copy for future reference
isrc = DefaultFactory.fromString(RDFS_XML, dummy_uri)
self._deserialize(self._coreRdfsModel, isrc, scope=RDF_SCHEMA_BASE)
self._active = True
return
def _complete(self, subject, predicate, object, statementUri, scope, flags):
if self._active and predicate:
#FIXME: Deal with statementUri more smartly
#Gather all sub-properties for equivalence in the complete
sub_prop_flags = {}
remain_flags = flags.copy()
if flags.get("predicateFlags"):
sub_prop_flags = {'subjectFlags': flags.get("predicateFlags")}
del remain_flags["predicateFlags"]
props = []
new_props = self._model._complete(
None, RDF_SCHEMA_BASE + 'subPropertyOf',
predicate, statementUri, scope, sub_prop_flags
)
props.extend(new_props)
while new_props:
newer_props = []
for prop in new_props:
newer_props.extend(self._model._complete(
None, RDF_SCHEMA_BASE + 'subPropertyOf',
prop.subject, statementUri, scope, {}))
new_props = newer_props
props.extend(new_props)
matches = self._model._complete(
subject, predicate, object, statementUri, scope, flags
)
for prop in props:
matches.extend(self._model._complete(
subject, prop.subject, object, statementUri, scope,
remain_flags))
return matches
else:
return self._model._complete(subject, predicate, object,
statementUri, scope, flags)
def isCoreRdfs(self, stmt):
"""Checks whether a statement comes from the core RDF meta-model."""
return self._coreRdfsModel.contains(stmt)
def isInstance(self, obj, class_):
"""Checks whether a resource is an instance of a class. Note that this is also true if the resource is an instance of any subclass of the given class."""
class_stmts = self._model.complete(obj, RDF_MS_BASE + 'type', None)
for cs in class_stmts:
if self.isSubClass(cs.object, class_):
return True
return False
def isSubClass(self, class1, class2):
"""Checks whether a class is an instance of another class."""
#Recursive for now. Is it worth moving to iteration?
if class1 == class2: return True
subclass_stmts = self._model.complete(class1, RDF_SCHEMA_BASE + 'subClassOf', None)
if not subclass_stmts: return False
if subclass_stmts[0].object == class2: return True
return self.isSubClass(subclass_stmts[0].object, class2)
def processNewStatements(self, newStmts):
"""Called by the Mode when a new statement is about to be added."""
if self._active and newStmts:
self.checkConstraints(newStmts)
for stmt in newStmts:
self._active = False
if stmt.predicate == RDF_SCHEMA_BASE + 'isDefinedBy':
from Ft.Xml.InputSource import DefaultFactory
isrc = DefaultFactory.fromUri(stmt.object)
self._deserialize(self._model, isrc)
self._active = True
return
def checkConstraints(self, newStmts):
"""
Raises exception if constraint violation found, else returns normally
Does not yet check Extended Constraints (provide hooks?)
"""
domain_uri = RDF_SCHEMA_BASE + 'domain'
range_uri = RDF_SCHEMA_BASE + 'range'
property_uri = RDF_MS_BASE + 'Property'
resource_uri = RDF_SCHEMA_BASE + 'Resource'
literal_uri = RDF_SCHEMA_BASE + 'Literal'
seen_domains = {}
seen_ranges = {}
for newStmt in newStmts:
#First check whether the statement itself
#is the introduction of a constraint
predicate = newStmt.predicate
if self.isSubClass(newStmt.subject, RDF_MS_BASE + 'Property'):
if predicate in (domain_uri, range_uri):
continue
#Now check whether the statement is governed by another constraint
if self.isInstance(predicate, property_uri):
if predicate not in seen_domains:
domains = self._model.complete(predicate, domain_uri, None)
seen_domains[predicate] = domains
else:
domains = seen_domains[predicate]
if predicate not in seen_ranges:
ranges = self._model.complete(predicate, range_uri, None)
if len(ranges) > 1:
raise RdfsConstraintViolation(RdfsConstraintViolation.PROPERTY_HAS_MULTIPLE_RANGES, predicate)
seen_ranges[predicate] = ranges
else:
ranges = seen_ranges[predicate]
if domains:
meets_constraints = False
for domain in domains:
if domain.object == resource_uri:
meets_constraints = True
if self.isInstance(newStmt.subject, domain.object):
meets_constraints = True
if not meets_constraints:
raise RdfsConstraintViolation(RdfsConstraintViolation.INVALID_DOMAIN_FOR_PROPERTY, str(newStmt.subject), str(predicate))
if ranges:
if not self.isInstance(newStmt.object, ranges[0].object) and ranges[0].object not in (resource_uri, literal_uri):
raise RdfsConstraintViolation(RdfsConstraintViolation.INVALID_RANGE_FOR_PROPERTY, str(newStmt.object), str(newStmt.predicate))
return
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