purge minutes (details, list, rss) pages on save/delete

apps/minutes/models.py

@@ -1,12 +1,15 @@
 """Models for PSF board meeting minutes."""
 
 from django.conf import settings
-from django.db import models
+from django.db import models, transaction
+from django.db.models.signals import post_delete, post_save, pre_save
+from django.dispatch import receiver
 from django.urls import reverse
 from markupfield.fields import MarkupField
 
 from apps.cms.models import ContentManageable
 from apps.minutes.managers import MinutesQuerySet
+from fastly.utils import purge_url
 
 DEFAULT_MARKUP_TYPE = getattr(settings, "DEFAULT_MARKUP_TYPE", "restructuredtext")
 
@@ -53,3 +56,39 @@ def get_date_month(self):
     def get_date_day(self):
         """Return the meeting date's zero-padded day string."""
         return self.date.strftime("%d").zfill(2)
+
+
+@receiver(pre_save, sender=Minutes)
+def remember_previous_url(sender, instance, **kwargs):
+    """Remember the stored detail URL so a changed meeting date also purges the old page."""
+    instance.previous_url = None
+    if kwargs.get("raw", False) or instance.pk is None:
+        return
+    previous = Minutes.objects.filter(pk=instance.pk).only("date").first()
+    if previous is not None:
+        instance.previous_url = previous.get_absolute_url()
+
+
+@receiver(post_save, sender=Minutes)
+@receiver(post_delete, sender=Minutes)
+def purge_fastly_cache(sender, instance, **kwargs):
+    """Purge the minutes detail, list, and feed pages once the change is committed.
+
+    Purges regardless of publish state so unpublished or deleted minutes disappear too.
+    Deferred to commit so a request racing the admin transaction can't re-cache stale content.
+    """
+    # Skip in fixtures
+    if kwargs.get("raw", False):
+        return
+
+    current_url = instance.get_absolute_url()
+    urls = [current_url, reverse("minutes_list"), reverse("minutes_feed")]
+    previous_url = getattr(instance, "previous_url", None)
+    if previous_url and previous_url != current_url:
+        urls.append(previous_url)
+
+    def purge():
+        for url in urls:
+            purge_url(url)
+
+    transaction.on_commit(purge, using=kwargs["using"])

apps/minutes/tests/test_models.py

@@ -1,4 +1,5 @@
 import datetime
+from unittest import mock
 
 from django.test import TestCase
 
@@ -29,3 +30,41 @@ def test_date_methods(self):
         self.assertEqual(self.m1.get_date_year(), "2012")
         self.assertEqual(self.m1.get_date_month(), "01")
         self.assertEqual(self.m1.get_date_day(), "01")
+
+
+@mock.patch("apps.minutes.models.purge_url")
+class MinutesPurgeTests(TestCase):
+    def purged(self, purge_url):
+        return {c.args[0] for c in purge_url.call_args_list}
+
+    def test_save_purges_detail_list_and_feed(self, purge_url):
+        with self.captureOnCommitCallbacks(execute=True):
+            Minutes.objects.create(date=datetime.date(2024, 3, 5), content="x", is_published=True)
+        self.assertEqual(
+            self.purged(purge_url),
+            {
+                "/psf/records/board/minutes/2024-03-05/",
+                "/psf/records/board/minutes/",
+                "/psf/records/board/minutes/feed/",
+            },
+        )
+
+    def test_no_purge_before_commit(self, purge_url):
+        with self.captureOnCommitCallbacks(execute=False) as callbacks:
+            Minutes.objects.create(date=datetime.date(2024, 3, 5), content="x", is_published=True)
+        purge_url.assert_not_called()
+        self.assertEqual(len(callbacks), 1)
+
+    def test_changing_date_purges_old_and_new_detail(self, purge_url):
+        minutes = Minutes.objects.create(date=datetime.date(2024, 3, 5), content="x", is_published=True)
+        minutes.date = datetime.date(2024, 3, 6)
+        with self.captureOnCommitCallbacks(execute=True):
+            minutes.save()
+        self.assertIn("/psf/records/board/minutes/2024-03-05/", self.purged(purge_url))
+        self.assertIn("/psf/records/board/minutes/2024-03-06/", self.purged(purge_url))
+
+    def test_delete_purges_detail(self, purge_url):
+        minutes = Minutes.objects.create(date=datetime.date(2024, 3, 5), content="x", is_published=True)
+        with self.captureOnCommitCallbacks(execute=True):
+            minutes.delete()
+        self.assertIn("/psf/records/board/minutes/2024-03-05/", self.purged(purge_url))