public function setFormatter($field, $formatter, $options = null)
    {
        // support for field names as array
        if (is_array($field)) {
            foreach ($field as $f) {
                $this->setFormatter($f, $formatter, $options);
            }

            return $this;
        }

        if (!isset($this->columns[$field])) {
            throw new BaseException('Cannot format nonexistant field '.$field);
        }

        $this->columns[$field]['type'] = '';
        $this->addFormatter($field, $formatter, $options);
        $this->last_column = $field;

        return $this;
    }