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

100 lines
3.6 KiB
Python

# -*- coding: utf-8 -*-
# Copyright (C) 2014-2017 Andrey Antukh <niwi@niwi.nz>
# Copyright (C) 2014-2017 Jesús Espino <jespinog@gmail.com>
# Copyright (C) 2014-2017 David Barragán <bameda@dbarragan.com>
# Copyright (C) 2014-2017 Alejandro Alonso <alejandro.alonso@kaleidos.net>
# Copyright (C) 2014-2017 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 Like
def add_like(obj, user):
"""Add a like to an object.
If the user has already liked the object nothing happends, so this function can be considered
idempotent.
:param obj: Any Django model instance.
:param user: User adding the like. :class:`~taiga.users.models.User` instance.
"""
obj_type = apps.get_model("contenttypes", "ContentType").objects.get_for_model(obj)
with atomic():
like, created = Like.objects.get_or_create(content_type=obj_type, object_id=obj.id, user=user)
if like.project is not None:
like.project.refresh_totals()
return like
def remove_like(obj, user):
"""Remove an user like from an object.
If the user has not liked the object nothing happens so this function can be considered
idempotent.
:param obj: Any Django model instance.
:param user: User removing her like. :class:`~taiga.users.models.User` instance.
"""
obj_type = apps.get_model("contenttypes", "ContentType").objects.get_for_model(obj)
with atomic():
qs = Like.objects.filter(content_type=obj_type, object_id=obj.id, user=user)
if not qs.exists():
return
like = qs.first()
project = like.project
qs.delete()
if project is not None:
project.refresh_totals()
def get_fans(obj):
"""Get the fans of an object.
:param obj: Any Django model instance.
:return: User queryset object representing the users that liked the object.
"""
obj_type = apps.get_model("contenttypes", "ContentType").objects.get_for_model(obj)
return get_user_model().objects.filter(likes__content_type=obj_type, likes__object_id=obj.id)
def get_liked(user_or_id, model):
"""Get the objects liked 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 likes of the user.
"""
obj_type = apps.get_model("contenttypes", "ContentType").objects.get_for_model(model)
conditions = ('likes_like.content_type_id = %s',
'%s.id = likes_like.object_id' % model._meta.db_table,
'likes_like.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=('likes_like',),
params=(obj_type.id, user_id))