Auto redirect if available before countdown on state change

data/interfaces/default/shutdown.html

@@ -35,8 +35,9 @@
         </div>
     </div>
 </%def>
+
 <%def name="javascriptIncludes()">
-    <script>
+<script>
     // Use p.countdown as container, pass redirect, duration, and optional message
     $(".countdown").countdown(reloadPage, ${timer}, "");
     $('#state-change-modal').modal({
@@ -49,5 +50,35 @@
     function reloadPage() {
         window.location.href = "${new_http_root}index";
     }
-    </script>
+
+    // Redirect to home page if page is available.
+    var checkOnline = setInterval(checkPageOffline, 1000);
+
+    function checkPageOffline() {
+        $.ajax({
+            type: 'HEAD',
+            url: 'index',
+            timeout: 1000,
+            error: function () {
+                % if signal != 'shutdown':
+                clearInterval(checkOnline);
+                setInterval(checkPageOnline, 1000);
+                % else:
+                reloadPage();
+                % endif
+            }
+        });
+    }
+    function checkPageOnline() {
+        $.ajax({
+            type: 'HEAD',
+            url: 'index',
+            timeout: 1000,
+            success: function () {
+                reloadPage();
+            }
+        });
+    }
+</script>
+
 </%def>

plexpy/webserve.py

@@ -3324,7 +3324,7 @@ class WebInterface(object):
         else:
             new_http_root = '/'
 
-        return serve_template(templatename="shutdown.html", title=title,
+        return serve_template(templatename="shutdown.html", signal=signal, title=title,
                               new_http_root=new_http_root, message=message, timer=timer, quote=quote)
 
     @cherrypy.expose