push

lti/urls.py

@@ -14,6 +14,7 @@ urlpatterns = [
     path('jwks/', views.JWKSView.as_view(), name='jwks'),
     path('public-key/', views.PublicKeyPEMView.as_view(), name='public_key_pem'),
     path('select-media/', deep_linking.SelectMediaView.as_view(), name='select_media'),
+    path('media-not-found/', views.MediaNotFoundView.as_view(), name='media_not_found'),
     path('my-media/', views.MyMediaLTIView.as_view(), name='my_media'),
     path('embed/<str:friendly_token>/', views.EmbedMediaLTIView.as_view(), name='embed_media'),
 ]

lti/views.py

@@ -459,7 +459,7 @@ class LaunchView(View):
                 base_url = reverse('lti:embed_media', args=[media.friendly_token])
                 return self.build_url_with_embed_params(base_url, embed_params)
             except Media.DoesNotExist:
-                pass
+                return reverse('lti:media_not_found')
 
         my_media_url = reverse('lti:my_media') + '?mode=lms_embed_mode'
         if custom.get('embed_share_media') == '0':
@@ -677,6 +677,14 @@ class PublicKeyPEMView(View):
         )
 
 
+@method_decorator(xframe_options_exempt, name='dispatch')
+class MediaNotFoundView(View):
+    """Shown when a media token from an LTI launch no longer exists."""
+
+    def get(self, request):
+        return render(request, 'lti/media_not_found.html', status=404)
+
+
 @method_decorator(xframe_options_exempt, name='dispatch')
 class MyMediaLTIView(View):
     """