Implemented db relationship

ldap3_mapper_new/dbutils.py

+from collections.abc import MutableSet
+
+class DBRelationshipSet(MutableSet):
+	def __init__(self, dbobj, relattr, ldapcls):
+		self.__dbobj = dbobj
+		self.__relattr = relattr
+		self.__ldapcls = ldapcls
+
+	def __get_dns(self):
+		return [mapobj.dn for mapobj in getattr(self.__dbobj, self.__relattr)]
+
+	def __repr__(self):
+		return repr(set(self))
+
+	def __contains__(self, value):
+		if value is None or not isinstance(value, self.__ldapcls):
+			return False
+		return value.ldap_object.dn in self.__get_dns()
+
+	def __iter__(self):
+		return iter(filter(lambda obj: obj is not None, [self.__ldapcls.query.get(dn) for dn in self.__get_dns()]))
+
+	def __len__(self):
+		return len(set(self))
+
+	def add(self, value):
+		if not isinstance(value, self.__ldapcls):
+			raise TypeError()
+		if value.ldap_object.session is not None:
+			self.__ldapcls.ldap_mapper.session.add(value)
+		if value.ldap_object.dn not in self.__get_dns():
+			getattr(self.__dbobj, self.__relattr).append(self.__ldapcls(dn=value.ldap_object.dn))
+
+	def discard(self, value):
+		if not isinstance(value, self.__ldapcls):
+			raise TypeError()
+		rel = getattr(self.__dbobj, self.__relattr)
+		for mapobj in list(rel):
+			if mapobj.dn == value.ldap_object.dn:
+				rel.remove(mapobj)
+
+class DBRelationship:
+	def __init__(self, relattr, ldapcls, mapcls, backref=None, backattr=None):
+		self.relattr = relattr
+		self.ldapcls = ldapcls
+		self.mapcls = mapcls
+		self.backref = backref
+		self.backattr = backattr
+
+	def __set_name__(self, cls, name):
+		if self.backref:
+			assert self.backattr
+			setattr(self.ldapcls, self.backref, DBBackreference(cls, self.relattr, self.mapcls, self.backattr))
+
+	def __get__(self, obj, objtype=None):
+		if obj is None:
+			return self
+		return DBRelationshipSet(obj, self.relattr, self.ldapcls)
+
+	def __set__(self, obj, values):
+		tmp = self.__get__(obj)
+		tmp.clear()
+		for value in values:
+			tmp.add(value)
+
+class DBBackreferenceSet(MutableSet):
+	def __init__(self, ldapobj, dbcls, relattr, mapcls, backattr):
+		self.__ldapobj = ldapobj
+		self.__dbcls = dbcls
+		self.__relattr, = relattr
+		self.__mapcls = mapcls
+		self.__backattr = backattr
+
+	@property
+	def __dn(self):
+		return self.__ldapobj.ldap_object.dn
+
+	def __get(self):
+		return {getattr(mapobj, self.__backattr) for mapobj in self.__mapcls.query.filter_by(dn=self.__dn)}
+
+	def __repr__(self):
+		return repr(self.__get())
+
+	def __contains__(self, value):
+		return value in self.__get()
+
+	def __iter__(self):
+		return iter(self.__get())
+
+	def __len__(self):
+		return len(self.__get())
+
+	def add(self, value):
+		# TODO: add value to db session if necessary
+		if not isinstance(value, self.__dbcls):
+			raise TypeError()
+		rel = getattr(value, self.__relattr)
+		if self.__dn not in {mapobj.dn for mapobj in rel}:
+			rel.append(self.__mapcls(dn=self.__dn))
+
+	def discard(self, value):
+		if not isinstance(value, self.__dbcls):
+			raise TypeError()
+		rel = getattr(value, self.__relattr)
+		for mapobj in list(rel):
+			if mapobj.dn == self.__dn:
+				rel.remove(mapobj)
+
+class DBBackreference:
+	def __init__(self, dbcls, relattr, mapcls, backattr):
+		self.dbcls = dbcls
+		self.relattr = relattr
+		self.mapcls = mapcls
+		self.backattr = backattr
+
+	def __get__(self, obj, objtype=None):
+		if obj is None:
+			return self
+		return DBBackreferenceSet(obj, self.dbcls, self.relattr, self.mapcls, self.backattr)
+
+	def __set__(self, obj, values):
+		tmp = self.__get__(obj)
+		tmp.clear()
+		for value in values:
+			tmp.add(value)