Zebra_Form::_extract_values PHP Method

    private function _extract_values($array)
    {
        $result = array();
        // iterate through the array's values
        foreach ($array as $index => $value) {
            // if entry is an array, flatten array recursively
            if (is_array($value)) {
                $result = array_merge($result, $this->_extract_values($value));
            } else {
                $result[] = $index;
            }
        }
        // return found values
        return $result;
    }