/**
  * Function that creates a value record for all artifact last changeset 
  * @param integer $tracker_id
  * @param integer $field_id
  * @return mixed array of changeset_value_id or false if nothing inserted
  */
 public function createNoneChangesetValue($tracker_id, $field_id)
 {
     $changesetValueDao = new Tracker_Artifact_Changeset_ValueDao();
     $changeset_value_ids = $changesetValueDao->createFromLastChangesetByTrackerId($tracker_id, $field_id, 1);
     if (empty($changeset_value_ids)) {
         return false;
     }
     return $changeset_value_ids;
 }
 /**
  * Display the field for CSV export
  * Used in CSV data export
  *
  * @param int $artifact_id the corresponding artifact id
  * @param int $changeset_id the corresponding changeset
  * @param mixed $value the value of the field
  *
  * @return string
  */
 public function fetchCSVChangesetValue($artifact_id, $changeset_id, $value, $report)
 {
     $values = array();
     $artifact = Tracker_ArtifactFactory::instance()->getArtifactById($artifact_id);
     if ($artifact->useArtifactPermissions()) {
         $dao = new Tracker_Artifact_Changeset_ValueDao();
         $row = $dao->searchByFieldId($changeset_id, $this->id)->getRow();
         $changeset_value_id = $row['id'];
         foreach ($this->getValueDao()->searchByChangesetValueId($changeset_value_id) as $value) {
             $name = $this->getUGroupDao()->searchByUGroupId($value['ugroup_id'])->getRow();
             $values[] = util_translate_name_ugroup($name['name']);
         }
         return implode(',', $values);
     }
     return '';
 }