Swappable Vote model

.github/workflows/ci.yml

@@ -22,7 +22,7 @@ jobs:
       - name: Install dependencies
         run: |
           python -m pip install --upgrade pip
-          pip install -q Django==${{ matrix.django-version }} flake8 coverage djangorestframework
+          pip install -q Django==${{ matrix.django-version }} flake8 coverage djangorestframework swapper tox
       - name: Lint with flake8
         run: |
           flake8 --exclude vote/migrations/* vote

.gitignore

@@ -10,3 +10,4 @@ __pycache__/
 htmlcov
 .coverage
 .eggs/
+.tox/

README.md

@@ -87,3 +87,75 @@ POST /api/comments/{id}/vote/
 POST /api/comments/{id}/vote/ {"action":"down"}
 DELETE /api/comments/{id}/vote/
 ```
+
+### Swapping Vote Model
+
+To swap Vote model with your own model:
+
+1. Declare your own Vote model:
+
+    ```
+    # myvote/models.py
+
+    from vote.base_models import AbstractVote
+    from vote.models import VoteModel
+
+    class MyVote(AbstractVote):
+        '''To test model swapping'''
+        modified = models.DateTimeField(auto_now=True)
+
+        class Meta:
+            abstract = False
+            unique_together = ('user_id', 'content_type', 'object_id', 'action')
+            index_together = ('content_type', 'object_id')
+    ```
+
+2. In your votable model:
+
+    ```
+    from vote.models import VotableManager
+    from myvote.models import MyVote
+
+    class Comment(VoteModel):
+        user_id = models.BigIntegerField()
+        content = models.TextField()
+        num_vote = models.IntegerField(default=0)
+        create_at = models.DateTimeField(auto_now_add=True)
+        update_at = models.DateTimeField(auto_now=True)
+
+        votes = VotableManager(MyVote)    
+    ```
+
+3. Update settings, swapping the Vote model with yours:
+
+    ```
+    VOTE_VOTE_MODEL = 'myvote.MyVote
+    ```
+
+Alternatively, declare your own VotableManager, which overrides the constructor
+specifying `MyVote` as the `through` argument.
+
+```
+class MyVotableManager(VotableMangaer):
+    def __init__(self, **kwargs):
+        super().__init__(MyVote, **kwargs)
+
+
+class MyVoteModel(VoteModel):
+    votes = MyVotableManager()
+
+    class Meta:
+        abstract = True
+```
+
+Then you can use `MyVoteModel` instead of the default `VoteModel` in your 
+votable models:
+
+```
+class Comment(MyVoteModel):
+    user_id = models.BigIntegerField()
+    content = models.TextField()
+    num_vote = models.IntegerField(default=0)
+    create_at = models.DateTimeField(auto_now_add=True)
+    update_at = models.DateTimeField(auto_now=True)
+```

runtests.py

@@ -3,8 +3,12 @@
 
 from django.conf import settings
 from django.core.management import execute_from_command_line
+from django.utils.functional import empty
 
-if not settings.configured:
+
+def configure(**options):
+    if settings._wrapped is not empty:
+        settings._wrapped = empty
     settings.configure(
         SECRET_KEY="secret key",
         DATABASES={
@@ -40,8 +44,12 @@
                 },
             },
         ],
+        **options
     )
 
+if not settings.configured:
+    configure()
+
 
 def runtests():
     argv = sys.argv[:1] + ["test"] + sys.argv[1:]

runtests_swapped.py

@@ -0,0 +1,27 @@
+#!/usr/bin/env python
+import sys
+
+from django.conf import settings
+from django.core.management import execute_from_command_line
+from runtests import configure
+
+if not settings.configured:
+    configure()
+
+
+def runtests_swapped():
+    argv = sys.argv[:1] + ["test", "test.tests.VoteTest.test_vote_up"] + sys.argv[1:]
+    execute_from_command_line(argv)
+    configure(VOTE_VOTE_MODEL='test.MyVote')
+    from test.models import Comment, MyVote
+    from vote.models import VotableManager
+    from vote.utils import _reset_vote_model
+    _reset_vote_model()
+    # The VoteModel's votes manager has to be updated for the new Vote model
+    Comment.votes = VotableManager(MyVote)
+    argv = sys.argv[:1] + ["test"] + sys.argv[1:]
+    execute_from_command_line(argv)
+
+
+if __name__ == "__main__":
+    runtests_swapped()

test/models.py

@@ -1,8 +1,19 @@
 from django.db import models
+from vote.base_models import AbstractVote
 from vote.models import VoteModel
 
 
 # Create your models here.
+class MyVote(AbstractVote):
+    '''To test model swapping'''
+    modified = models.DateTimeField(auto_now=True)
+
+    class Meta:
+        abstract = False
+        unique_together = ('user_id', 'content_type', 'object_id', 'action')
+        index_together = ('content_type', 'object_id')
+
+
 class Comment(VoteModel):
     user_id = models.BigIntegerField()
     content = models.TextField()

test/tests.py

@@ -1,8 +1,10 @@
 from __future__ import absolute_import
 from django.test import TestCase
 from django.contrib.auth.models import User
-from vote.models import Vote, UP, DOWN
-from test.models import Comment
+from vote.base_models import UP, DOWN
+from vote.models import Vote
+from test.models import Comment, MyVote
+from vote.utils import _get_vote_model
 
 
 class VoteTest(TestCase):
@@ -23,7 +25,8 @@ def setUp(self):
 
     def tearDown(self):
         self.model.objects.all().delete()
-        self.through.objects.all().delete()
+        vote_model = _get_vote_model()
+        vote_model.objects.all().delete()
         User.objects.all().delete()
 
     def call_api(self, api_name, model=None, *args, **kwargs):
@@ -81,7 +84,8 @@ def test_vote_get(self):
                                             content="I'm a comment")
         self.assertIsNone(self.call_api('get', comment, self.user2.pk))
         self.call_api('up', comment, self.user2.pk)
-        vote = Vote.objects.first()
+        vote_model = _get_vote_model()
+        vote = vote_model.objects.first()
         self.assertEqual(vote, self.call_api('get', comment, self.user2.pk))
 
     def test_vote_all(self):

tox.ini

@@ -0,0 +1,19 @@
+[tox]
+envlist = py39-django{22,32,40},py39-django{22,32,40}-swapper
+
+[testenv-django{22,32,40}]
+deps =
+    django22: Django==2.2
+    django32: Django==3.2
+    django40: Django==4.0
+    djangorestframework
+commands = ./runtests.py
+
+[testenv:py39-django{22,32,40}-swapper]
+deps =
+    django22: Django==2.2
+    django32: Django==3.2
+    django40: Django==4.0
+    djangorestframework
+    swapper: swapper==1.3.0
+commands = ./runtests_swapped.py

vote/base_models.py

@@ -0,0 +1,56 @@
+from django.db import models
+from django.contrib.contenttypes.models import ContentType
+from django.contrib.contenttypes.fields import GenericForeignKey
+
+UP = 0
+DOWN = 1
+
+
+class VoteManager(models.Manager):
+
+    def filter(self, *args, **kwargs):
+        if 'content_object' in kwargs:
+            content_object = kwargs.pop('content_object')
+            content_type = ContentType.objects.get_for_model(content_object)
+            kwargs.update({
+                'content_type': content_type,
+                'object_id': content_object.pk
+            })
+
+        return super(VoteManager, self).filter(*args, **kwargs)
+
+
+class AbstractVote(models.Model):
+    ACTION_FIELD = {
+        UP: 'num_vote_up',
+        DOWN: 'num_vote_down'
+    }
+
+    user_id = models.BigIntegerField()
+    content_type = models.ForeignKey(
+        ContentType,
+        related_name='+',
+        on_delete=models.CASCADE
+    )
+    object_id = models.PositiveIntegerField()
+    content_object = GenericForeignKey()
+    action = models.PositiveSmallIntegerField(default=UP)
+    create_at = models.DateTimeField(auto_now_add=True)
+
+    objects = VoteManager()
+
+    class Meta:
+        abstract = True
+        index_together = ('content_type', 'object_id')
+
+    @classmethod
+    def votes_for(cls, model, instance=None, action=UP):
+        ct = ContentType.objects.get_for_model(model)
+        kwargs = {
+            "content_type": ct,
+            "action": action
+        }
+        if instance is not None:
+            kwargs["object_id"] = instance.pk
+
+        return cls.objects.filter(**kwargs)

vote/managers.py

@@ -53,7 +53,9 @@ def __init__(self, through, model, instance, field_name='votes'):
         self.field_name = field_name
 
     def vote(self, user_id, action):
+        '''Returns the Vote object on success. None on failure.'''
         try:
+            vote = None
             with transaction.atomic():
                 self.instance = self.model.objects.select_for_update().get(
                     pk=self.instance.pk)
@@ -75,20 +77,22 @@ def vote(self, user_id, action):
                     setattr(self.instance, voted_field,
                             getattr(self.instance, voted_field) - 1)
                 except self.through.DoesNotExist:
-                    self.through.objects.create(user_id=user_id,
-                                                content_type=content_type,
-                                                object_id=self.instance.pk,
-                                                action=action)
+                    vote = self.through.objects.create(
+                        user_id=user_id,
+                        content_type=content_type,
+                        object_id=self.instance.pk,
+                        action=action
+                    )
 
                 statistics_field = self.through.ACTION_FIELD.get(action)
                 setattr(self.instance, statistics_field,
                         getattr(self.instance, statistics_field) + 1)
 
                 self.instance.save()
 
-            return True
+            return vote
         except (OperationalError, IntegrityError):
-            return False
+            return None
 
     @instance_required
     def up(self, user_id):

vote/models.py

@@ -1,56 +1,21 @@
 from django.db import models
-from django.contrib.contenttypes.models import ContentType
-from django.contrib.contenttypes.fields import GenericForeignKey
+from vote.base_models import AbstractVote
 from vote.managers import VotableManager
+try:
+    from swapper import swappable_setting
+except ImportError:
+    swappable_setting = None
 
-UP = 0
-DOWN = 1
 
-
-class VoteManager(models.Manager):
-
-    def filter(self, *args, **kwargs):
-        if 'content_object' in kwargs:
-            content_object = kwargs.pop('content_object')
-            content_type = ContentType.objects.get_for_model(content_object)
-            kwargs.update({
-                'content_type': content_type,
-                'object_id': content_object.pk
-            })
-
-        return super(VoteManager, self).filter(*args, **kwargs)
-
-
-class Vote(models.Model):
-    ACTION_FIELD = {
-        UP: 'num_vote_up',
-        DOWN: 'num_vote_down'
-    }
-
-    user_id = models.BigIntegerField()
-    content_type = models.ForeignKey(ContentType, on_delete=models.CASCADE)
-    object_id = models.PositiveIntegerField()
-    content_object = GenericForeignKey()
-    action = models.PositiveSmallIntegerField(default=UP)
-    create_at = models.DateTimeField(auto_now_add=True)
-
-    objects = VoteManager()
+class Vote(AbstractVote):
 
     class Meta:
+        abstract = False
         unique_together = ('user_id', 'content_type', 'object_id', 'action')
         index_together = ('content_type', 'object_id')
-
-    @classmethod
-    def votes_for(cls, model, instance=None, action=UP):
-        ct = ContentType.objects.get_for_model(model)
-        kwargs = {
-            "content_type": ct,
-            "action": action
-        }
-        if instance is not None:
-            kwargs["object_id"] = instance.pk
-
-        return cls.objects.filter(**kwargs)
+        swappable = None
+        if swappable_setting:
+            swappable = swappable_setting('vote', 'Vote')
 
 
 class VoteModel(models.Model):

vote/templatetags/vote.py

@@ -3,7 +3,7 @@
 from django import template
 from django.contrib.auth.models import AnonymousUser
 
-from vote.models import UP
+from vote.base_models import UP
 
 register = template.Library()