Hide last updated data until date is populated.

Tools/GardeningServer/ui/ct-last-updated.html

 <!--
 Copyright 2014 The Chromium Authors. All rights reserved.
 Use of this source code is governed by a BSD-style license that can be
 found in the LICENSE file.
 -->
 
 <polymer-element name="ct-last-updated" attributes="date">
   <template>
-    Updated {{ date | _deltaMinutes }} min ago @ {{ date | _hours }}:{{ date | _minutes }}
+    <template if="{{ visible }}">

[ojan, 2014/08/12 21:27:05]

How about instead of adding a separate property, you make the default value of
date be null instead of new Date(0)? That way you can just check if="{{ date }}"
here and if the date is removed, then we stop displaying it again. Also you then
wouldn't need the dateChanged handler.

[teravest, 2014/08/12 21:30:04]

Much better, thanks.

+      Updated {{ date | _deltaMinutes }} min ago @ {{ date | _hours }}:{{ date | _minutes }}
+    </template>
   </template>
   <script>
   (function() {
     Polymer({
       date: new Date(0),
+      visible: false,
+
+      dateChanged: function() {
+        this.visible = true;
+      },
 
       _deltaMinutes: function(date) {
         return date.minutesAgo();
       },
       _hours: function(date) {
         return date.getHours();
       },
       _minutes: function(date) {
-        return date.getMinutes();
+        var s = date.getMinutes() + "";

[ojan, 2014/08/12 21:27:05]

Nit: date.getMinutes().toString() is more idiomatic JS I think.

[teravest, 2014/08/12 21:30:04]

Done.

+        if (s.length == 1)
+          s = "0" + s;
+        return s;
       },
     });
   })();
 
   </script>
 </polymer-element>