def delete_branch(cls, resource_id=None, db_session=None, *args, **kwargs):
"""
This deletes whole branch with children starting from resource_id
:param resource_id:
:param db_session:
:return:
"""
tablename = cls.model.__table__.name
# lets lock rows to prevent bad tree states
resource = ResourceService.lock_resource_for_update(
resource_id=resource_id, db_session=db_session)
parent_id = resource.parent_id
ordering = resource.ordering
raw_q = """
WITH RECURSIVE subtree AS (
SELECT res.resource_id
FROM {tablename} AS res WHERE res.resource_id = :resource_id
UNION ALL
SELECT res_u.resource_id
FROM {tablename} res_u, subtree st
WHERE res_u.parent_id = st.resource_id
)
DELETE FROM resources where resource_id in (select * from subtree);
""".format(tablename=tablename)
db_session = get_db_session(db_session)
text_obj = sa.text(raw_q)
db_session.execute(text_obj, params={'resource_id': resource_id})
cls.shift_ordering_down(parent_id, ordering, db_session=db_session)
return True
def set_position(cls,
resource_id,
to_position,
db_session=None,
*args,
**kwargs):
"""
Sets node position for new node in the tree
:param resource_id: resource to move
:param to_position: new position
:param db_session:
:return:def count_children(cls, resource_id, db_session=None):
"""
db_session = get_db_session(db_session)
# lets lock rows to prevent bad tree states
resource = ResourceService.lock_resource_for_update(
resource_id=resource_id, db_session=db_session)
cls.check_node_position(resource.parent_id,
to_position,
on_same_branch=True,
db_session=db_session)
cls.shift_ordering_up(resource.parent_id,
to_position,
db_session=db_session)
db_session.flush()
db_session.expire(resource)
resource.ordering = to_position
return True
def check_node_parent(cls,
resource_id,
new_parent_id,
db_session=None,
*args,
**kwargs):
"""
Checks if parent destination is valid for node
:param resource_id:
:param new_parent_id:
:param db_session:
:return:
"""
db_session = get_db_session(db_session)
new_parent = ResourceService.lock_resource_for_update(
resource_id=new_parent_id, db_session=db_session)
# we are not moving to "root" so parent should be found
if not new_parent and new_parent_id is not None:
raise ZigguratResourceTreeMissingException(
'New parent node not found')
else:
result = cls.path_upper(new_parent_id, db_session=db_session)
path_ids = [r.resource_id for r in result]
if resource_id in path_ids:
raise ZigguratResourceTreePathException(
'Trying to insert node into itself')
def check_node_parent(cls, resource_id, new_parent_id, db_session=None,
*args, **kwargs):
"""
Checks if parent destination is valid for node
:param resource_id:
:param new_parent_id:
:param db_session:
:return:
"""
db_session = get_db_session(db_session)
new_parent = ResourceService.lock_resource_for_update(
resource_id=new_parent_id,
db_session=db_session)
# we are not moving to "root" so parent should be found
if not new_parent and new_parent_id is not None:
raise ZigguratResourceTreeMissingException(
'New parent node not found')
else:
result = cls.path_upper(new_parent_id,
db_session=db_session)
path_ids = [r.resource_id for r in result]
if resource_id in path_ids:
raise ZigguratResourceTreePathException(
'Trying to insert node into itself')
def delete_branch(cls, resource_id=None, db_session=None, *args, **kwargs):
"""
This deletes whole branch with children starting from resource_id
:param resource_id:
:param db_session:
:return:
"""
tablename = cls.model.__table__.name
# lets lock rows to prevent bad tree states
resource = ResourceService.lock_resource_for_update(
resource_id=resource_id,
db_session=db_session)
parent_id = resource.parent_id
ordering = resource.ordering
raw_q = """
WITH RECURSIVE subtree AS (
SELECT res.resource_id
FROM {tablename} AS res WHERE res.resource_id = :resource_id
UNION ALL
SELECT res_u.resource_id
FROM {tablename} res_u, subtree st
WHERE res_u.parent_id = st.resource_id
)
DELETE FROM resources where resource_id in (select * from subtree);
""".format(tablename=tablename)
db_session = get_db_session(db_session)
text_obj = sa.text(raw_q)
db_session.execute(text_obj, params={'resource_id': resource_id})
cls.shift_ordering_down(parent_id, ordering, db_session=db_session)
return True
def set_position(cls, resource_id, to_position, db_session=None, *args,
**kwargs):
"""
Sets node position for new node in the tree
:param resource_id: resource to move
:param to_position: new position
:param db_session:
:return:def count_children(cls, resource_id, db_session=None):
"""
db_session = get_db_session(db_session)
# lets lock rows to prevent bad tree states
resource = ResourceService.lock_resource_for_update(
resource_id=resource_id,
db_session=db_session)
cls.check_node_position(
resource.parent_id, to_position, on_same_branch=True,
db_session=db_session)
cls.shift_ordering_up(resource.parent_id, to_position,
db_session=db_session)
db_session.flush()
db_session.expire(resource)
resource.ordering = to_position
return True
def move_to_position(cls,
resource_id,
to_position,
new_parent_id=noop,
db_session=None,
*args,
**kwargs):
"""
Moves node to new location in the tree
:param resource_id: resource to move
:param to_position: new position
:param new_parent_id: new parent id
:param db_session:
:return:
"""
db_session = get_db_session(db_session)
# lets lock rows to prevent bad tree states
resource = ResourceService.lock_resource_for_update(
resource_id=resource_id, db_session=db_session)
parent = ResourceService.lock_resource_for_update(
resource_id=resource.parent_id, db_session=db_session)
same_branch = False
# reset if parent is same as old
if new_parent_id == resource.parent_id:
new_parent_id = noop
if new_parent_id is not noop:
cls.check_node_parent(resource_id,
new_parent_id,
db_session=db_session)
else:
same_branch = True
if new_parent_id is noop:
# it is not guaranteed that parent exists
parent_id = resource.parent_id if resource else None
else:
parent_id = new_parent_id
cls.check_node_position(parent_id,
to_position,
on_same_branch=same_branch,
db_session=db_session)
# move on same branch
if new_parent_id is noop:
order_range = list(sorted((resource.ordering, to_position)))
move_down = resource.ordering > to_position
query = db_session.query(cls.model)
query = query.filter(cls.model.parent_id == parent_id)
query = query.filter(cls.model.ordering.between(*order_range))
if move_down:
query.update({cls.model.ordering: cls.model.ordering + 1},
synchronize_session=False)
else:
query.update({cls.model.ordering: cls.model.ordering - 1},
synchronize_session=False)
db_session.flush()
db_session.expire(resource)
resource.ordering = to_position
# move between branches
else:
cls.shift_ordering_down(resource.parent_id,
resource.ordering,
db_session=db_session)
cls.shift_ordering_up(new_parent_id,
to_position,
db_session=db_session)
db_session.expire(resource)
resource.parent_id = new_parent_id
resource.ordering = to_position
db_session.flush()
return True
def move_to_position(cls, resource_id, to_position,
new_parent_id=noop, db_session=None, *args,
**kwargs):
"""
Moves node to new location in the tree
:param resource_id: resource to move
:param to_position: new position
:param new_parent_id: new parent id
:param db_session:
:return:
"""
db_session = get_db_session(db_session)
# lets lock rows to prevent bad tree states
resource = ResourceService.lock_resource_for_update(
resource_id=resource_id,
db_session=db_session)
parent = ResourceService.lock_resource_for_update(
resource_id=resource.parent_id,
db_session=db_session)
same_branch = False
# reset if parent is same as old
if new_parent_id == resource.parent_id:
new_parent_id = noop
if new_parent_id is not noop:
cls.check_node_parent(resource_id, new_parent_id,
db_session=db_session)
else:
same_branch = True
if new_parent_id is noop:
# it is not guaranteed that parent exists
parent_id = resource.parent_id if resource else None
else:
parent_id = new_parent_id
cls.check_node_position(
parent_id, to_position, on_same_branch=same_branch,
db_session=db_session)
# move on same branch
if new_parent_id is noop:
order_range = list(sorted((resource.ordering, to_position)))
move_down = resource.ordering > to_position
query = db_session.query(cls.model)
query = query.filter(cls.model.parent_id == parent_id)
query = query.filter(cls.model.ordering.between(*order_range))
if move_down:
query.update({cls.model.ordering: cls.model.ordering + 1},
synchronize_session=False)
else:
query.update({cls.model.ordering: cls.model.ordering - 1},
synchronize_session=False)
db_session.flush()
db_session.expire(resource)
resource.ordering = to_position
# move between branches
else:
cls.shift_ordering_down(resource.parent_id, resource.ordering,
db_session=db_session)
cls.shift_ordering_up(new_parent_id, to_position,
db_session=db_session)
db_session.expire(resource)
resource.parent_id = new_parent_id
resource.ordering = to_position
db_session.flush()
return True