core: cleanup

passbook/core/views/access.py

@@ -1,6 +1,10 @@
 """passbook access helper classes"""
 from logging import getLogger
 
+from django.http import Http404
+
+from passbook.core.models import Application
+
 LOGGER = getLogger(__name__)
 
 class AccessMixin:
@@ -9,7 +13,12 @@ class AccessMixin:
 
     def provider_to_application(self, provider):
         """Lookup application assigned to provider, throw error if no application assigned"""
-        return provider.application
+        try:
+            return provider.application
+        except Application.DoesNotExist as exc:
+            # TODO: Log that no provider has no application assigned
+            LOGGER.warning('Provider "%s" has no application assigned...', provider)
+            raise Http404 from exc
 
     def user_has_access(self, application, user):
         """Check if user has access to application."""