taiga-back/taiga/projects/votes/services.py

117 lines
4.2 KiB
Python

# -*- coding: utf-8 -*-
# Copyright (C) 2014-2016 Andrey Antukh <niwi@niwi.nz>
# Copyright (C) 2014-2016 Jesús Espino <jespinog@gmail.com>
# Copyright (C) 2014-2016 David Barragán <bameda@dbarragan.com>
# Copyright (C) 2014-2016 Alejandro Alonso <alejandro.alonso@kaleidos.net>
# Copyright (C) 2014-2016 Anler Hernández <hello@anler.me>
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as
# published by the Free Software Foundation, either version 3 of the
# License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
from django.db.models import F
from django.db.transaction import atomic
from django.apps import apps
from django.contrib.auth import get_user_model
from .models import Votes, Vote
def add_vote(obj, user):
"""Add a vote to an object.
If the user has already voted the object nothing happends, so this function can be considered
idempotent.
:param obj: Any Django model instance.
:param user: User adding the vote. :class:`~taiga.users.models.User` instance.
"""
obj_type = apps.get_model("contenttypes", "ContentType").objects.get_for_model(obj)
with atomic():
vote, created = Vote.objects.get_or_create(content_type=obj_type, object_id=obj.id, user=user)
if not created:
return
votes, _ = Votes.objects.get_or_create(content_type=obj_type, object_id=obj.id)
votes.count = F('count') + 1
votes.save()
return vote
def remove_vote(obj, user):
"""Remove an user vote from an object.
If the user has not voted the object nothing happens so this function can be considered
idempotent.
:param obj: Any Django model instance.
:param user: User removing her vote. :class:`~taiga.users.models.User` instance.
"""
obj_type = apps.get_model("contenttypes", "ContentType").objects.get_for_model(obj)
with atomic():
qs = Vote.objects.filter(content_type=obj_type, object_id=obj.id, user=user)
if not qs.exists():
return
qs.delete()
votes, _ = Votes.objects.get_or_create(content_type=obj_type, object_id=obj.id)
votes.count = F('count') - 1
votes.save()
def get_voters(obj):
"""Get the voters of an object.
:param obj: Any Django model instance.
:return: User queryset object representing the users that voted the object.
"""
obj_type = apps.get_model("contenttypes", "ContentType").objects.get_for_model(obj)
return get_user_model().objects.filter(votes__content_type=obj_type, votes__object_id=obj.id)
def get_votes(obj):
"""Get the number of votes an object has.
:param obj: Any Django model instance.
:return: Number of votes or `0` if the object has no votes at all.
"""
obj_type = apps.get_model("contenttypes", "ContentType").objects.get_for_model(obj)
try:
return Votes.objects.get(content_type=obj_type, object_id=obj.id).count
except Votes.DoesNotExist:
return 0
def get_voted(user_or_id, model):
"""Get the objects voted by an user.
:param user_or_id: :class:`~taiga.users.models.User` instance or id.
:param model: Show only objects of this kind. Can be any Django model class.
:return: Queryset of objects representing the votes of the user.
"""
obj_type = apps.get_model("contenttypes", "ContentType").objects.get_for_model(model)
conditions = ('votes_vote.content_type_id = %s',
'%s.id = votes_vote.object_id' % model._meta.db_table,
'votes_vote.user_id = %s')
if isinstance(user_or_id, get_user_model()):
user_id = user_or_id.id
else:
user_id = user_or_id
return model.objects.extra(where=conditions, tables=('votes_vote',),
params=(obj_type.id, user_id))