<?php

/**

 * Zend Framework

 *

 * LICENSE

 *

 * This source file is subject to the new BSD license that is bundled

 * with this package in the file LICENSE.txt.

 * It is also available through the world-wide-web at this URL:

 * http://framework.zend.com/license/new-bsd

 * If you did not receive a copy of the license and are unable to

 * obtain it through the world-wide-web, please send an email

 * to license@zend.com so we can send you a copy immediately.

 *

 * @category   Zend

 * @package    Zend_Filter

 * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)

 * @license    http://framework.zend.com/license/new-bsd     New BSD License

 * @version    $Id: Null.php 20096 2010-01-06 02:05:09Z bkarwin $

 */

/**

 * @see Zend_Filter_Interface

 */

require_once 'Zend/Filter/Interface.php';

/**

 * @category   Zend

 * @package    Zend_Filter

 * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)

 * @license    http://framework.zend.com/license/new-bsd     New BSD License

 */

class Zend_Filter_Null implements Zend_Filter_Interface

{

    const BOOLEAN      = 1;

    const INTEGER      = 2;

    const EMPTY_ARRAY  = 4;

    const STRING       = 8;

    const ZERO         = 16;

    const ALL          = 31;

    protected $_constants = array(

        self::BOOLEAN     => 'boolean',

        self::INTEGER     => 'integer',

        self::EMPTY_ARRAY => 'array',

        self::STRING      => 'string',

        self::ZERO        => 'zero',

        self::ALL         => 'all'

    );

    /**

     * Internal type to detect

     *

     * @var integer

     */

    protected $_type = self::ALL;

    /**

     * Constructor

     *

     * @param string|array|Zend_Config $options OPTIONAL

     */

    public function __construct($options = null)

    {

        if ($options instanceof Zend_Config) {

            $options = $options->toArray();

        } else if (!is_array($options)) {

            $options = func_get_args();

            $temp    = array();

            if (!empty($options)) {

                $temp = array_shift($options);

            }

            $options = $temp;

        } else if (is_array($options) && array_key_exists('type', $options)) {

            $options = $options['type'];

        }

        if (!empty($options)) {

            $this->setType($options);

        }

    }

    /**

     * Returns the set null types

     *

     * @return array

     */

    public function getType()

    {

        return $this->_type;

    }

    /**

     * Set the null types

     *

     * @param  integer|array $type

     * @throws Zend_Filter_Exception

     * @return Zend_Filter_Null

     */

    public function setType($type = null)

    {

        if (is_array($type)) {

            $detected = 0;

            foreach($type as $value) {

                if (is_int($value)) {

                    $detected += $value;

                } else if (in_array($value, $this->_constants)) {

                    $detected += array_search($value, $this->_constants);

                }

            }

            $type = $detected;

        } else if (is_string($type)) {

            if (in_array($type, $this->_constants)) {

                $type = array_search($type, $this->_constants);

            }

        }

        if (!is_int($type) || ($type < 0) || ($type > self::ALL)) {

            require_once 'Zend/Filter/Exception.php';

            throw new Zend_Filter_Exception('Unknown type');

        }

        $this->_type = $type;

        return $this;

    }

    /**

     * Defined by Zend_Filter_Interface

     *

     * Returns null representation of $value, if value is empty and matches

     * types that should be considered null.

     *

     * @param  string $value

     * @return string

     */

    public function filter($value)

    {

        $type = $this->getType();

        // STRING ZERO ('0')

        if ($type >= self::ZERO) {

            $type -= self::ZERO;

            if (is_string($value) && ($value == '0')) {

                return null;

            }

        }

        // STRING ('')

        if ($type >= self::STRING) {

            $type -= self::STRING;

            if (is_string($value) && ($value == '')) {

                return null;

            }

        }

        // EMPTY_ARRAY (array())

        if ($type >= self::EMPTY_ARRAY) {

            $type -= self::EMPTY_ARRAY;

            if (is_array($value) && ($value == array())) {

                return null;

            }

        }

        // INTEGER (0)

        if ($type >= self::INTEGER) {

            $type -= self::INTEGER;

            if (is_int($value) && ($value == 0)) {

                return null;

            }

        }

        // BOOLEAN (false)

        if ($type >= self::BOOLEAN) {

            $type -= self::BOOLEAN;

            if (is_bool($value) && ($value == false)) {

                return null;

            }

        }

        return $value;

    }

}