Viewing file:  XMLSerializer.py (3.99 KB) -rw-r--r--
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from __future__ import generators
from rdflib.syntax.serializers import Serializer
from rdflib.URIRef import URIRef
from rdflib.Literal import Literal
from rdflib.BNode import BNode
from rdflib.util import uniq
from rdflib.exceptions import Error
from rdflib.syntax.xml_names import split_uri
from xml.sax.saxutils import quoteattr, escape
class XMLSerializer(Serializer):
def __init__(self, store):
super(XMLSerializer, self).__init__(store)
def __bindings(self):
store = self.store
nm = store.namespace_manager
bindings = {}
for predicate in uniq(store.predicates()):
prefix, namespace, name = nm.compute_qname(predicate)
bindings[prefix] = URIRef(namespace)
RDFNS = URIRef("http://www.w3.org/1999/02/22-rdf-syntax-ns#")
if "rdf" in bindings:
assert bindings["rdf"]==RDFNS
else:
bindings["rdf"] = RDFNS
for prefix, namespace in bindings.iteritems():
yield prefix, namespace
def serialize(self, stream, base=None, encoding=None, **args):
self.base = base
self.__stream = stream
self.__serialized = {}
encoding = self.encoding
self.write = write = lambda uni: stream.write(uni.encode(encoding, 'replace'))
# startDocument
write('<?xml version="1.0" encoding="%s"?>\n' % self.encoding)
# startRDF
write('<rdf:RDF\n')
if args.get('include_base', None)==True:
write(' xml:base="%s"\n' % base)
# TODO: assert(namespaces["http://www.w3.org/1999/02/22-rdf-syntax-ns#"]=='rdf')
bindings = list(self.__bindings())
bindings.sort()
for prefix, namespace in bindings:
if prefix:
write(' xmlns:%s="%s"\n' % (prefix, namespace))
else:
write(' xmlns="%s"\n' % namespace)
write('>\n')
# write out triples by subject
for subject in self.store.subjects():
self.subject(subject, 1)
# endRDF
write( "</rdf:RDF>\n" )
# Set to None so that the memory can get garbage collected.
#self.__serialized = None
del self.__serialized
def subject(self, subject, depth=1):
if not subject in self.__serialized:
self.__serialized[subject] = 1
if isinstance(subject, (BNode,URIRef)):
write = self.write
indent = " " * depth
element_name = "rdf:Description"
if isinstance(subject, BNode):
write( '%s<%s rdf:nodeID="%s"' %
(indent, element_name, subject))
else:
uri = quoteattr(self.relativize(subject))
write( "%s<%s rdf:about=%s" % (indent, element_name, uri))
if (subject, None, None) in self.store:
write( ">\n" )
for predicate, object in self.store.predicate_objects(subject):
self.predicate(predicate, object, depth+1)
write( "%s</%s>\n" % (indent, element_name))
else:
write( "/>\n" )
def predicate(self, predicate, object, depth=1):
write = self.write
indent = " " * depth
qname = self.store.namespace_manager.qname(predicate)
if isinstance(object, Literal):
attributes = ""
if object.language:
attributes += ' xml:lang="%s"'%object.language
if object.datatype:
attributes += ' rdf:datatype="%s"'%object.datatype
write("%s<%s%s>%s</%s>\n" %
(indent, qname, attributes,
escape(object), qname) )
else:
if isinstance(object, BNode):
write('%s<%s rdf:nodeID="%s"/>\n' %
(indent, qname, object))
else:
write("%s<%s rdf:resource=%s/>\n" %
(indent, qname, quoteattr(self.relativize(object))))
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