🗃️ Make AbstractDocument.updated_at an auto_now field

src/filingcabinet/migrations/0029_alter_document_updated_at.py

@@ -0,0 +1,17 @@
+# Generated by Django 4.2.4 on 2023-12-18 17:14
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("filingcabinet", "0028_alter_collectiondirectory_depth_and_more"),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name="document",
+            name="updated_at",
+            field=models.DateTimeField(auto_now=True, null=True),
+        ),
+    ]

src/filingcabinet/models.py

@@ -191,7 +191,9 @@ class AbstractDocument(models.Model):
     )
 
     created_at = models.DateTimeField(default=timezone.now, null=True)
-    updated_at = models.DateTimeField(default=timezone.now, null=True)
+    updated_at = models.DateTimeField(
+        auto_now=True, null=True
+    )  # Allow null for old values
     published_at = models.DateTimeField(default=None, null=True, blank=True)
 
     num_pages = models.PositiveIntegerField(default=0)
@@ -460,6 +462,12 @@ def has_format(self, format):
     def has_format_webp(self):
         return self.has_format("webp")
 
+    def save(self, *args, **kwargs):
+        if "update_fields" in kwargs:
+            kwargs["update_fields"] = {"last_modified_at"}.union("update_fields")
+
+        super().save(*args, **kwargs)
+
 
 class Document(AbstractDocument):
     class Meta(AbstractDocument.Meta):