/**
  * Gets a decimal element of the record data array.
  * If the array has not been initialized properly, an empty string is
  * returned instead. If we are a date record, it'll be retrieved from the
  * corresponding topic record.
  *
  * @param string $key the name of the field to retrieve
  *
  * @return string the corresponding element from the record data array
  */
 private function getTopicDecimal($key)
 {
     $result = '';
     if ($this->isTopicOkay()) {
         $result = $this->topic->getRecordPropertyDecimal($key);
     } else {
         $result = $this->getRecordPropertyDecimal($key);
     }
     return $result;
 }