diff --git a/visualizer/tests/testSimple.py b/visualizer/tests/testSimple.py
index f5df1319..139cb4d4 100644
--- a/visualizer/tests/testSimple.py
+++ b/visualizer/tests/testSimple.py
@@ -293,6 +293,15 @@ def test_embedly_translation(self):
response = self.client.get(visualizeUrl)
self.assertRedirects(response, expectedBaseURL + 'barchart-interactive', status_code=301)
+ def test_embedded_404_returns_friendly_page(self):
+ """
+ When an embedded visualization slug doesn't exist, return a friendly
+ HTML page with a 404 status, so it displays nicely in iframes.
+ """
+ response = self.client.get('/ve/nonexistent-slug')
+ self.assertEqual(response.status_code, 404)
+ self.assertIn(b'Visualization Not Found', response.content)
+
@patch('visualizer.wikipedia.wikipedia.WikipediaExport._get_todays_date_string')
def test_wikicode(self, mockGetDateString):
""" Validate that the wikicode can be generated and hasn't inadvertently changed """
diff --git a/visualizer/views.py b/visualizer/views.py
index d1b51011..2059b8fd 100644
--- a/visualizer/views.py
+++ b/visualizer/views.py
@@ -12,12 +12,13 @@
from django.contrib.auth import get_user_model
from django.contrib.auth.mixins import LoginRequiredMixin
from django.core.cache import cache
-from django.http import JsonResponse, HttpResponse
+from django.http import Http404, JsonResponse, HttpResponse
from django.shortcuts import render
from django.templatetags.static import static
from django.urls import Resolver404
from django.urls import resolve
from django.urls import reverse
+from django.utils.cache import patch_cache_control
from django.utils.decorators import method_decorator
from django.views import View
from django.views.decorators.clickjacking import xframe_options_exempt
@@ -207,6 +208,24 @@ class VisualizeEmbedded(DetailView):
model = JsonConfig
template_name = 'visualizer/visualize-embedded.html'
+ def get(self, request, *args, **kwargs):
+ try:
+ return super().get(request, *args, **kwargs)
+ except Http404:
+ response = HttpResponse(
+ ''
+ ''
+ 'Visualization Not Found
'
+ 'This visualization is no longer available.
'
+ 'Please re-send the election data to generate a new visualization.
'
+ '',
+ content_type='text/html',
+ status=404,
+ )
+ patch_cache_control(response, no_store=True, no_cache=True, max_age=0)
+ return response
+
def get_context_data(self, **kwargs):
config = super().get_context_data(**kwargs)