From 0e052f3db87ed0a61b2d5598521bc66b73c76f7c Mon Sep 17 00:00:00 2001
From: Matt Westcott <matt@west.co.tt>
Date: Thu, 1 Sep 2016 15:59:12 +0100
Subject: [PATCH] Optimise (and fix ordering of) submission queries

---
 wagtail/wagtailforms/edit_handlers.py                       | 6 ++++--
 .../wagtailforms/edit_handlers/form_responses_panel.html    | 4 ++--
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/wagtail/wagtailforms/edit_handlers.py b/wagtail/wagtailforms/edit_handlers.py
index fcd0de8dab..93c61531d7 100644
--- a/wagtail/wagtailforms/edit_handlers.py
+++ b/wagtail/wagtailforms/edit_handlers.py
@@ -13,13 +13,15 @@ class BaseFormSubmissionsPanel(EditHandler):
     def render(self):
         from .models import FormSubmission
         submissions = FormSubmission.objects.filter(page=self.instance)
+        submission_count = submissions.count()
 
-        if not submissions:
+        if not submission_count:
             return ''
 
         return mark_safe(render_to_string(self.template, {
             'self': self,
-            'submissions': submissions
+            'submission_count': submission_count,
+            'last_submit_time': submissions.order_by('submit_time').last().submit_time,
         }))
 
 
diff --git a/wagtail/wagtailforms/templates/wagtailforms/edit_handlers/form_responses_panel.html b/wagtail/wagtailforms/templates/wagtailforms/edit_handlers/form_responses_panel.html
index 340e4beef5..b8774cb40f 100644
--- a/wagtail/wagtailforms/templates/wagtailforms/edit_handlers/form_responses_panel.html
+++ b/wagtail/wagtailforms/templates/wagtailforms/edit_handlers/form_responses_panel.html
@@ -9,7 +9,7 @@
                 <label class="label">{{ total }}</label>
                 <div class="field-content">
                     <div class="input">
-                        <a href="{% url 'wagtailforms:list_submissions' self.instance.id %}">{{ submissions.count }}</a>
+                        <a href="{% url 'wagtailforms:list_submissions' self.instance.id %}">{{ submission_count }}</a>
                     </div>
                 </div>
             </div>
@@ -19,7 +19,7 @@
                 <label class="label">{{ latest }}</label>
                 <div class="field-content">
                     <p>
-                        {{ submissions.last.submit_time }}
+                        {{ last_submit_time }}
                     </p>
                 </div>
             </div>