feat(upvotes): set GenericForeignKey on UpVote model, manage data mig…

…ration

lacommunaute/forum_upvote/admin.py

@@ -4,18 +4,14 @@
 
 
 class UpVoteAdmin(admin.ModelAdmin):
-    list_display = ("voter", "post", "created_at")
-    raw_id_fields = (
-        "voter",
-        "post",
-    )
+    list_display = ("voter", "created_at")
+    raw_id_fields = ("voter",)
 
 
 class CertifiedPostAdmin(admin.ModelAdmin):
-    list_display = ("topic", "post", "user")
+    list_display = ("topic", "user")
     raw_id_fields = (
         "topic",
-        "post",
         "user",
     )
 

lacommunaute/forum_upvote/migrations/0003_auto_20230718_1509.py

@@ -0,0 +1,79 @@
+import django.db.models.deletion
+from django.contrib.contenttypes.models import ContentType
+from django.db import migrations, models
+
+
+def move_forward_foreign_key_to_generic_foreign_key(apps, schema_editor):
+    UpVote = apps.get_model("forum_upvote", "UpVote")
+    ContentType = apps.get_model("contenttypes", "ContentType")
+
+    UpVote.objects.filter(post__isnull=True).delete()
+
+    for upvote in UpVote.objects.all():
+        upvote.content_object = upvote.post
+        upvote.object_id = upvote.post_id
+        upvote.content_type = ContentType.objects.get_for_model(upvote.post)
+        upvote.save()
+
+
+def move_back_generic_foreign_key_to_foreign_key(apps, schema_editor):
+    UpVote = apps.get_model("forum_upvote", "UpVote")
+    Post = apps.get_model("forum_conversation", "Post")
+
+    post_content_type_id = ContentType.objects.get(model="post", app_label="forum_conversation").id
+    UpVote.objects.exclude(content_type_id=post_content_type_id).delete()
+
+    for upvote in UpVote.objects.all():
+        upvote.post = Post.objects.get(id=upvote.object_id)
+        upvote.save()
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("contenttypes", "0002_remove_content_type_name"),
+        ("forum_upvote", "0002_certifiedpost"),
+    ]
+
+    operations = [
+        migrations.AlterUniqueTogether(
+            name="upvote",
+            unique_together=set(),
+        ),
+        migrations.AddField(
+            model_name="upvote",
+            name="content_type",
+            field=models.ForeignKey(
+                null=True, on_delete=django.db.models.deletion.CASCADE, to="contenttypes.contenttype"
+            ),
+        ),
+        migrations.AddField(
+            model_name="upvote",
+            name="object_id",
+            field=models.PositiveIntegerField(null=True),
+        ),
+        migrations.RunPython(
+            move_forward_foreign_key_to_generic_foreign_key,
+            move_back_generic_foreign_key_to_foreign_key,
+        ),
+        migrations.AlterUniqueTogether(
+            name="upvote",
+            unique_together={("voter", "content_type", "object_id")},
+        ),
+        migrations.AlterField(
+            model_name="upvote",
+            name="content_type",
+            field=models.ForeignKey(
+                on_delete=django.db.models.deletion.CASCADE,
+                to="contenttypes.contenttype",
+            ),
+        ),
+        migrations.AlterField(
+            model_name="upvote",
+            name="object_id",
+            field=models.PositiveIntegerField(),
+        ),
+        migrations.RemoveField(
+            model_name="upvote",
+            name="post",
+        ),
+    ]

lacommunaute/forum_upvote/models.py

@@ -1,4 +1,6 @@
 from django.conf import settings
+from django.contrib.contenttypes.fields import GenericForeignKey
+from django.contrib.contenttypes.models import ContentType
 from django.db import models
 from machina.models.abstract_models import DatedModel
 
@@ -15,20 +17,16 @@ class UpVote(models.Model):
         verbose_name="Voter",
     )
 
-    post = models.ForeignKey(
-        Post,
-        related_name="upvotes",
-        blank=True,
-        null=True,
-        on_delete=models.SET_NULL,
-        verbose_name="Post",
-    )
+    content_type = models.ForeignKey(ContentType, on_delete=models.CASCADE)
+    object_id = models.PositiveIntegerField()
+
+    content_object = GenericForeignKey("content_type", "object_id")
 
     created_at = models.DateTimeField(auto_now_add=True, db_index=True, verbose_name="Creation date")
     objects = models.Manager()
 
     class Meta:
-        unique_together = ["voter", "post"]
+        unique_together = ["voter", "content_type", "object_id"]
         ordering = [
             "-created_at",
         ]