private function getFieldValuesIndexedByName(PFUser $user, Tracker_Artifact $artifact)
 {
     $changeset = $artifact->getLastChangeset();
     $values = array();
     foreach ($this->formelement_factory->getUsedFieldsForREST($artifact->getTracker()) as $field) {
         if (!$field->userCanRead($user) || !$field instanceof Tracker_FormElement_Field_Alphanum) {
             continue;
         }
         $field_value = $field->getRESTValue($user, $changeset);
         $values[$field->getName()] = $field_value;
     }
     return $values;
 }
 private function getFieldsValues(PFUser $user, Tracker_Artifact $artifact)
 {
     $changeset = $artifact->getLastChangeset();
     return $this->mapAndFilter($this->formelement_factory->getUsedFieldsForREST($artifact->getTracker()), $this->getFieldsValuesFilter($user, $changeset));
 }