feat: Support targets which don't use integers as their primary keys (closes #18)

Author: kevinrenskers

CLAUDE.md

@@ -25,6 +25,9 @@ uv run .
 # Linting and formatting
 uv run ruff check .
 uv run ruff format .
+
+# Creating migrations
+uv run django-admin makemigrations generic_notifications --settings=tests.settings
 ```
 
 ## Architecture Overview

generic_notifications/migrations/0005_alter_notificationfrequency_options_and_more.py

@@ -0,0 +1,28 @@
+# Generated by Django 5.2.5 on 2025-10-20 09:35
+
+from django.conf import settings
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("contenttypes", "0002_remove_content_type_name"),
+        ("generic_notifications", "0004_rename_emailfrequency_notificationfrequency"),
+        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
+    ]
+
+    operations = [
+        migrations.AlterModelOptions(
+            name="notificationfrequency",
+            options={"verbose_name_plural": "Notification frequencies"},
+        ),
+        migrations.AlterField(
+            model_name="notification",
+            name="object_id",
+            field=models.CharField(blank=True, max_length=36, null=True),
+        ),
+        migrations.AddIndex(
+            model_name="notification",
+            index=models.Index(fields=["content_type", "object_id"], name="notification_target_idx"),
+        ),
+    ]

generic_notifications/models.py

@@ -49,7 +49,7 @@ class Notification(models.Model):
 
     # Generic relation to link to any object (article, comment, etc)
     content_type = models.ForeignKey(ContentType, on_delete=models.CASCADE, null=True, blank=True)
-    object_id = models.PositiveIntegerField(null=True, blank=True)
+    object_id = models.CharField(max_length=36, null=True, blank=True)
     target = GenericForeignKey("content_type", "object_id")
 
     # Flexible metadata for any extra data
@@ -61,6 +61,7 @@ class Meta:
         indexes = [
             models.Index(fields=["recipient", "read"], name="notification_unread_idx"),
             models.Index(fields=["recipient", "added"], name="notification_recipient_idx"),
+            models.Index(fields=["content_type", "object_id"], name="notification_target_idx"),
         ]
         ordering = ["-added"]