52 lines
1.8 KiB
Python
52 lines
1.8 KiB
Python
# Licensed under the Apache License, Version 2.0 (the "License"); you may
|
|
# not use this file except in compliance with the License. You may obtain
|
|
# a copy of the License at
|
|
#
|
|
# http://www.apache.org/licenses/LICENSE-2.0
|
|
#
|
|
# Unless required by applicable law or agreed to in writing, software
|
|
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
|
|
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
|
|
# License for the specific language governing permissions and limitations
|
|
# under the License.
|
|
|
|
"""Implementation of paginate query."""
|
|
|
|
from manila import exception
|
|
import sqlalchemy
|
|
|
|
|
|
def paginate_query(query, model, limit, sort_key='created_at',
|
|
sort_dir='desc', offset=None):
|
|
"""Returns a query with sorting / pagination criteria added.
|
|
|
|
:param query: the query object to which we should add paging/sorting
|
|
:param model: the ORM model class
|
|
:param limit: maximum number of items to return
|
|
:param sort_key: attributes by which results should be sorted, default is
|
|
created_at
|
|
:param sort_dir: direction in which results should be sorted (asc, desc)
|
|
:param offset: the number of items to skip from the marker or from the
|
|
first element.
|
|
|
|
:rtype: sqlalchemy.orm.query.Query
|
|
:return: The query with sorting/pagination added.
|
|
"""
|
|
|
|
try:
|
|
sort_key_attr = getattr(model, sort_key)
|
|
except AttributeError:
|
|
raise exception.InvalidInput(reason='Invalid sort key %s' % sort_key)
|
|
if sort_dir == 'desc':
|
|
query = query.order_by(sqlalchemy.desc(sort_key_attr))
|
|
else:
|
|
query = query.order_by(sqlalchemy.asc(sort_key_attr))
|
|
|
|
if limit is not None:
|
|
query = query.limit(limit)
|
|
|
|
if offset:
|
|
query = query.offset(offset)
|
|
|
|
return query
|