def traverse_one(self, attribute, source, target, visitor):
"""
:param source: source data proxy
:type source: instance of `DataTraversalProxy` or None
:param target: target data proxy
:type target: instance of `DataTraversalProxy` or None
"""
if __debug__:
self.__log_traverse_one(self.__trv_path, attribute, source, target)
prx = source or target
if prx.do_traverse():
rel_op = RELATION_OPERATIONS.check(source, target)
for attr in prx.get_relationship_attributes():
# Check cascade settings.
if not bool(attr.cascade & rel_op):
continue
if not source is None:
try:
attr_source = source.get_attribute_proxy(attr)
except AttributeError:
# If the source does not have the attribute set, we
# do nothing (as opposed to when the value is None).
continue
else:
attr_source = None
if not target is None:
attr_target = target.get_attribute_proxy(attr)
else:
attr_target = None
attr_rel_op = RELATION_OPERATIONS.check(attr_source,
attr_target)
if attr_rel_op == RELATION_OPERATIONS.ADD:
if rel_op == RELATION_OPERATIONS.ADD:
parent = source
else:
parent = target
elif attr_rel_op == RELATION_OPERATIONS.REMOVE:
parent = target
else: # UPDATE
parent = target
card = get_attribute_cardinality(attr)
if card == CARDINALITY_CONSTANTS.ONE:
if attr_source is None and attr_target is None:
# If both source and target have None values, there is
# nothing to do.
continue
if attr_rel_op == RELATION_OPERATIONS.ADD:
# if not attr_source.get_id() is None:
# # We only ADD new items.
# continue
src_items = [attr_source]
tgt_items = None
elif attr_rel_op == RELATION_OPERATIONS.REMOVE:
src_items = None
tgt_items = [attr_target]
else: # UPDATE
src_items = [attr_source]
tgt_items = [attr_target]
src_id = attr_source.get_id()
tgt_id = attr_target.get_id()
if src_id != tgt_id:
if not src_id is None:
# If the source ID is None, this is a replace
# operation (ADD source, REMOVE target).
src_target = attr_target.get_matching(src_id)
if not src_target is None:
tgt_items.append(src_target)
else:
src_items = attr_source
tgt_items = attr_target
self.__trv_path.push(parent, (source, target), attr, rel_op)
self.traverse_many(attr, src_items, tgt_items, visitor)
self.__trv_path.pop() # path.pop()
visitor.visit(self.__trv_path, attribute, source, target)
def test_get_attribute_cardinality(self):
self.assert_equal(get_attribute_cardinality(self.member_attr),
CARDINALITY_CONSTANTS.ONE)
self.assert_raises(ValueError, get_attribute_cardinality,
self.terminal_attr)
def test_get_attribute_cardinality(self, attr_name):
mb_attr = member_attribute(Member, attr_name)
assert get_attribute_cardinality(mb_attr) == CARDINALITY_CONSTANTS.ONE
t_attr = terminal_attribute(int, attr_name)
with pytest.raises(ValueError):
get_attribute_cardinality(t_attr)
def test_get_attribute_cardinality(self, attr_name):
mb_attr = member_attribute(Member, attr_name)
assert get_attribute_cardinality(mb_attr) == CARDINALITY_CONSTANTS.ONE
t_attr = terminal_attribute(int, attr_name)
with pytest.raises(ValueError):
get_attribute_cardinality(t_attr)
def traverse_one(self, attribute, source, target, visitor):
"""
:param source: source data proxy
:type source: instance of `DataTraversalProxy` or None
:param target: target data proxy
:type target: instance of `DataTraversalProxy` or None
"""
if __debug__:
self.__log_traverse_one(self.__trv_path, attribute, source, target)
prx = source or target
rel_op = RELATION_OPERATIONS.check(source, target)
if prx.do_traverse() \
and (rel_op == prx.relation_operation or attribute is None):
for attr in prx.get_relationship_attributes():
# Check cascade settings.
if not bool(attr.cascade & rel_op):
continue
if not source is None:
try:
attr_source = source.get_attribute_proxy(attr)
except AttributeError:
# If the source does not have the attribute set, we
# do nothing (as opposed to when the value is None).
continue
else:
attr_source = None
if not target is None:
attr_target = target.get_attribute_proxy(attr)
else:
attr_target = None
attr_rel_op = RELATION_OPERATIONS.check(
attr_source, attr_target)
if attr_rel_op == RELATION_OPERATIONS.ADD:
if rel_op == RELATION_OPERATIONS.ADD:
parent = source
else:
parent = target
elif attr_rel_op == RELATION_OPERATIONS.REMOVE:
parent = target
else: # UPDATE
parent = target
card = get_attribute_cardinality(attr)
if card == CARDINALITY_CONSTANTS.ONE:
if attr_source is None and attr_target is None:
# If both source and target have None values, there is
# nothing to do.
continue
if attr_rel_op == RELATION_OPERATIONS.ADD:
# if not attr_source.get_id() is None:
# # We only ADD new items.
# continue
src_items = [attr_source]
tgt_items = None
elif attr_rel_op == RELATION_OPERATIONS.REMOVE:
src_items = None
tgt_items = [attr_target]
else: # UPDATE
src_items = [attr_source]
tgt_items = [attr_target]
src_id = attr_source.get_id()
tgt_id = attr_target.get_id()
if src_id != tgt_id:
if not src_id is None:
# If the source ID is None, this is a replace
# operation (ADD source, REMOVE target).
src_target = attr_target.get_matching(src_id)
if not src_target is None:
tgt_items.append(src_target)
else:
src_items = attr_source
tgt_items = attr_target
self.__trv_path.push(parent, (source, target), attr, rel_op)
self.traverse_many(attr, src_items, tgt_items, visitor)
self.__trv_path.pop() # path.pop()
visitor.visit(self.__trv_path, attribute, source, target)