private function checkIfUpdateIsAvailable($date)
 {
     $losungen = new HerrnhuterLosungenPlugin_Xml();
     if (!$losungen->checkIfLosungenAvailable($date)) {
         if ($this->checkIfUpdateAvailable($date)) {
             return true;
         }
     }
     return false;
 }
 function checkIfInstalled($dates)
 {
     $losungReader = new HerrnhuterLosungenPlugin_Xml();
     $ret = array();
     foreach ($dates as $date) {
         $installed = $losungReader->checkIfLosungenAvailable($date);
         $ret[] = array('date' => $date, 'installed' => $installed);
     }
     return $ret;
 }