class ManifestHelper(object):
def __init__(self, uri=None):
self.uri = None
if uri:
self.uri = uri
self.reset()
def reset(self):
self.g = None
if self.uri:
self.g = ConjunctiveGraph(identifier=self.uri)
else:
self.g = ConjunctiveGraph()
self.namespaces = {}
self.urihelper = URIHelper(self.namespaces)
#add defaults
for prefix, ns in NAMESPACES.iteritems():
self.add_namespace(prefix, ns)
def from_string(self, textfile, format="xml", encoding="utf-8"):
self.reset()
self.g.parse(textfile, format)
return
def triple_exists(self, s, p, o):
if not type(self.g).__name__ in ['ConjunctiveGraph', 'Graph']:
return False
if s == '*':
s = None
if p == '*':
p = None
if o == '*':
o = None
if not isinstance(s, URIRef) and not isinstance(s, BNode) and not s == None:
s = self.urihelper.get_uriref(s)
if not isinstance(p, URIRef) and not p == None:
p = self.urihelper.parse_uri(p)
if not isinstance(o, URIRef) and not isinstance(o, Literal) and not isinstance(o, BNode) and not o == None:
if not isinstance(o, basestring):
o = unicode(o)
o = self.urihelper.parse_uri(o, return_Literal_not_Exception=True)
count = 0
for ans_s, ans_p, ans_o in self.g.triples((s, p, o)):
count += 1
if count > 0:
return True
else:
return False
def list_objects(self, s, p):
objects = []
if not type(self.g).__name__ in ['ConjunctiveGraph', 'Graph']:
return objects
if s == '*':
s = None
if p == '*':
p = None
if not isinstance(s, URIRef) and not isinstance(s, BNode) and not s == None:
s = self.urihelper.get_uriref(s)
if not isinstance(p, URIRef) and not p == None:
p = self.urihelper.parse_uri(p)
for o in self.g.objects(s, p):
objects.append(o)
return objects
def add_triple(self, s, p, o):
if not isinstance(s, URIRef) and not isinstance(s, BNode):
s = self.urihelper.get_uriref(s)
if not isinstance(p, URIRef):
p = self.urihelper.parse_uri(p)
if not isinstance(o, URIRef) and not isinstance(o, Literal) and not isinstance(o, BNode):
if not isinstance(o, basestring):
o = unicode(o)
o = self.urihelper.parse_uri(o, return_Literal_not_Exception=True)
self.g.add((s, p, o))
self.g.commit()
return
def add_namespace(self, prefix, uri):
if not isinstance (prefix, basestring):
raise TypeError('Add namespace: prefix is not of type string or unicode')
if not isinstance(uri, (URIRef, Namespace)):
if not isinstance(uri, basestring):
raise TypeError('Add namespace: namespace is not of type string or unicode')
if not isinstance(prefix, unicode):
prefix = unicode(prefix)
if isinstance(uri, basestring) and not isinstance(uri, unicode):
uri = unicode(uri)
self.namespaces[prefix] = self.urihelper.get_namespace(uri)
if prefix not in self.urihelper.namespaces:
self.urihelper.namespaces[prefix] = self.urihelper.get_namespace(uri)
self.g.bind(prefix, self.namespaces[prefix])
return
def del_namespace(self, prefix, ns):
if prefix in self.namespaces:
del self.namespaces[prefix]
return
def del_triple(self, s, p, o=None):
if not type(self.g).__name__ in ['ConjunctiveGraph', 'Graph']:
return
if s == '*':
s = None
if p == '*':
p = None
if o == '*':
o = None
if not isinstance(s, URIRef) and not isinstance(s, BNode) and not s == None:
s = self.urihelper.get_uriref(s)
if not isinstance(p, URIRef) and not p == None:
p = self.urihelper.parse_uri(p)
if not isinstance(o, URIRef) and not isinstance(o, Literal) and not isinstance(o, BNode) and not o == None:
if not isinstance(o, basestring):
o = unicode(o)
o = self.urihelper.parse_uri(o, return_Literal_not_Exception=True)
self.g.remove((s, p, o))
return
def get_graph(self):
return self.g
def to_string(self, format="xml"):
if type(self.g).__name__ in ['ConjunctiveGraph', 'Graph'] and len(self.g)>0:
self.g.commit()
ans_str = self.g.serialize(format=format, encoding="utf-8")+"\n"
return ans_str
else:
return u'<?xml version="1.0" encoding="UTF-8"?>\n'
