<?php

/**
 * Missing Filter
 *
 * @uses Elastica_Filter_Abstract
 * @category Xodoa
 * @package Elastica
 * @author Maciej Wiercinski <hide@address.com>
 * @link http://www.elasticsearch.org/guide/reference/query-dsl/missing-filter.html
 */
class Elastica_Filter_Missing extends Elastica_Filter_Abstract
{
    /**
     * Construct missing filter
     *
     * @param string $field OPTIONAL
     */
    public function __construct($field = '')
    {
        if (strlen($field)) {
            $this->setField($field);
        }
    }

    /**
     * Set field
     *
     * @param string $field
     */
    public function setField($field)
    {
        return $this->setParam('field', (string) $field);
    }
}