protected function getJoinCswFields($reference)
{
$fields = array();
foreach ($reference as $k => $v) {
if ($k === 'LOGIC') {
continue;
}
if (is_numeric($k)) {
$fields = array_merge($fields, $this->getJoinCswFields($v));
} else {
// key
$csw_result = \CSQLWhere::makeOperation($k);
list($field, ) = array_values($csw_result);
$fields[$field] = array('TABLE_ALIAS' => 'alias', 'FIELD_NAME' => $field, 'FIELD_TYPE' => 'string', 'MULTIPLE' => '', 'JOIN' => '');
// no need to add values as csw fields
}
}
return $fields;
}