handle deletion stale cache for homepage and electionpage

templates/visualizer/confirmDeleteUpload.html

@@ -23,6 +23,11 @@ <h1 class="page-section-heading text-center">Delete this visualization?</h1>
     Note: this visualization is updated automatically from an official data source. Deleting it will stop those updates.
   </p>
   {% endif %}
+  {% if isOnElectionPage %}
+  <p class="text-center">
+    Note: this visualization appears on an election results page. Deleting it will remove it from that page.
+  </p>
+  {% endif %}
 
   <form method="post" class="text-center">
     {% csrf_token %}

visualizer/tests/testUserDashboard.py

@@ -161,3 +161,6 @@ def test_delete(self):
         self.assertEqual(response.url, reverse('userDashboard'))
         self.assertFalse(JsonConfig.objects.filter(pk=config.pk).exists())
         mockCloudflare.purge_vis_cache.assert_called_once_with(config.slug)
+        # The homepage recent list and the sitemap linked to it, too
+        mockCloudflare.purge_paths_cache.assert_called_once_with(
+            ['/', '/index.html', '/sitemap.xml'])

visualizer/views.py

@@ -35,6 +35,7 @@
 from accounts.permissions import IsOwnerOrReadOnly, HasAPIAccess
 from common import viewUtils
 from common.cloudflare import CloudflareAPI
+from electionpage.models import ElectionPage
 from scraper.models import Scraper, MultiScraper
 from visualizer import validators
 from visualizer.common import make_complete_url, intify
@@ -215,14 +216,23 @@ def get_context_data(self, **kwargs):
             jsonConfig=self.object).exists()
         context['hasScraper'] = Scraper.objects.filter(jsonConfig=self.object).exists() or \
             MultiScraper.objects.filter(jsonConfig=self.object).exists()
+        context['isOnElectionPage'] = ElectionPage.objects.filter(
+            listOfElections=self.object).exists()
         return context
 
     def form_valid(self, form):
         # Cloudflare purging only happens in JsonConfig.save() - on deletion,
         # we must purge here to avoid serving cached copies of a deleted page
         slug = self.object.slug
+        electionPagePaths = [
+            reverse('electionPage', args=(page.slug,))
+            for page in ElectionPage.objects.filter(listOfElections=self.object)]
         response = super().form_valid(form)
         CloudflareAPI.purge_vis_cache(slug)
+        # The homepage's recent list, the sitemap, and any election pages that
+        # included this visualization would otherwise keep linking to it
+        CloudflareAPI.purge_paths_cache(
+            ['/', '/index.html', '/sitemap.xml'] + electionPagePaths)
         return response