class LiteralStatement(models.Model):
"""
Statement where the object is a literal.
"""
id = UUIDField("ID", primary_key=True)
subject = fields.URIField(verbose_name=_("Subject"), db_index=True)
predicate = fields.URIField(_("Predicate"), db_index=True)
object = fields.LiteralField(_("Object"), db_index=True)
context = models.ForeignKey(NamedGraph, verbose_name=_("Context"))
class Meta: # pylint: disable=C1001
unique_together = ('subject', 'predicate', 'object', 'context')
def __unicode__(self):
return u"{0}, {1}".format(self.as_triple(), self.context.identifier) # pylint: disable=E1101
def as_triple(self):
"""
Converts this predicate to a triple.
"""
return self.subject, self.predicate, self.object
class NamedGraph(models.Model):
"""
Models a context which represents a named graph.
"""
identifier = fields.URIField(verbose_name=_("Identifier"), unique=True)
class Meta: # pylint: disable=C1001
verbose_name = _("named graph")
verbose_name_plural = _("named graphs")
def __unicode__(self):
return u"{0}".format(self.identifier)
class URIStatement(models.Model):
"""
Statement where the object is a URI.
"""
id = models.UUIDField("ID", default=uuid.uuid4, primary_key=True)
subject = fields.URIField(verbose_name=_("Subject"), db_index=True)
predicate = fields.URIField(_("Predicate"), db_index=True)
object = fields.URIField(_("Object"), db_index=True)
context = models.ForeignKey(NamedGraph,
verbose_name=_("Context"),
on_delete=models.CASCADE)
class Meta:
unique_together = ('subject', 'predicate', 'object', 'context')
def __str__(self):
return "{}, {}".format(self.as_triple(), self.context.identifier)
def as_triple(self):
"""
Converts this predicate to a triple.
"""
return self.subject, self.predicate, self.object
class NamedGraph(models.Model):
"""
Models a context which represents a named graph.
"""
identifier = fields.URIField(verbose_name=_("Identifier"), db_index=True)
store = models.ForeignKey(Store,
verbose_name=_("Store"),
on_delete=models.CASCADE,
db_index=True)
class Meta:
verbose_name = _("named graph")
verbose_name_plural = _("named graphs")
unique_together = [
("identifier", "store"),
]
def __str__(self):
return "{}-{}".format(self.identifier, "identifier")
