Source code for rdflib.plugins.serializers.trig
"""
Trig RDF graph serializer for RDFLib.
See <http://www.w3.org/TR/trig/> for syntax specification.
"""
from collections import defaultdict
from rdflib.plugins.serializers.turtle import TurtleSerializer, _GEN_QNAME_FOR_DT, VERB
from rdflib.term import BNode, Literal
__all__ = ['TrigSerializer']
[docs]class TrigSerializer(TurtleSerializer):
short_name = "trig"
indentString = 4 * u' '
[docs] def __init__(self, store):
if store.context_aware:
self.contexts = list(store.contexts())
self.default_context = store.default_context.identifier
if store.default_context:
self.contexts.append(store.default_context)
else:
self.contexts = [store]
self.default_context = None
super(TrigSerializer, self).__init__(store)
[docs] def preprocess(self):
for context in self.contexts:
self.store = context
self.getQName(context.identifier)
self._references = defaultdict(int)
self._subjects = {}
for triple in context:
self.preprocessTriple(triple)
self._contexts[context]=(self.orderSubjects(), self._subjects, self._references)
[docs] def reset(self):
super(TrigSerializer, self).reset()
self._contexts = {}
[docs] def serialize(self, stream, base=None, encoding=None,
spacious=None, **args):
self.reset()
self.stream = stream
self.base = base
if spacious is not None:
self._spacious = spacious
self.preprocess()
self.startDocument()
firstTime = True
for store, (ordered_subjects, subjects, ref) in self._contexts.items():
if not ordered_subjects: continue
self._references = ref
self._serialized = {}
self.store = store
self._subjects = subjects
if self.default_context and store.identifier==self.default_context:
self.write(self.indent() + '\n{')
else:
if isinstance(store.identifier, BNode):
iri = store.identifier.n3()
else:
iri = self.getQName(store.identifier)
if iri is None:
iri = store.identifier.n3()
self.write(self.indent() + '\n%s {' % iri)
self.depth += 1
for subject in ordered_subjects:
if self.isDone(subject):
continue
if firstTime:
firstTime = False
if self.statement(subject) and not firstTime:
self.write('\n')
self.depth -= 1
self.write('}\n')
self.endDocument()
stream.write(u"\n".encode('ascii'))