fixes #471, launch check for new version on page_tail

include/config_default.inc.php

@@ -276,6 +276,16 @@ $conf['ext_imagick_dir'] = '';
 // are array(5,10,20,50,'all') but you can set any other numeric value.
 $conf['comments_page_nb_comments'] = 10;
 
+// how often should we check for new versions of Piwigo on piwigo.org? In
+// seconds. The check is made only if there are visits on Piwigo.
+// 0 to disable.
+$conf['update_notify_check_period'] = 24*60*60;
+
+// how often should be remind of new versions available? For example a first
+// notification was sent on May 5th 2017 for 2.9.1, after how many seconds
+// we send it again? 0 to disable.
+$conf['update_notify_reminder_period'] = 7*24*60*60;
+
 // +-----------------------------------------------------------------------+
 // |                                 email                                 |
 // +-----------------------------------------------------------------------+

include/page_tail.php

@@ -39,6 +39,31 @@ if (!is_a_guest())
     );
 }
 
+//--------------------------------------------------------- update notification
+if ($conf['update_notify_check_period'] > 0)
+{
+  $check_for_updates = false;
+  if (isset($conf['update_notify_last_check']))
+  {
+    if (strtotime($conf['update_notify_last_check']) < strtotime($conf['update_notify_check_period'].' seconds ago'))
+    {
+      $check_for_updates = true;
+    }
+  }
+  else
+  {
+    $check_for_updates = true;
+  }
+
+  if ($check_for_updates)
+  {
+    include_once(PHPWG_ROOT_PATH.'admin/include/functions.php');
+    include_once(PHPWG_ROOT_PATH.'admin/include/updates.class.php');
+    $updates = new updates();
+    $updates->notify_piwigo_new_versions();
+  }
+}
+
 //------------------------------------------------------------- generation time
 $debug_vars = array();