<?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: Digits.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_Digits implements Zend_Filter_Interface

{

    /**

     * Is PCRE is compiled with UTF-8 and Unicode support

     *

     * @var mixed

     **/

    protected static $_unicodeEnabled;

    /**

     * Class constructor

     *

     * Checks if PCRE is compiled with UTF-8 and Unicode support

     *

     * @return void

     */

    public function __construct()

    {

        if (null === self::$_unicodeEnabled) {

            self::$_unicodeEnabled = (@preg_match('/\pL/u', 'a')) ? true : false;

        }

    }

    /**

     * Defined by Zend_Filter_Interface

     *

     * Returns the string $value, removing all but digit characters

     *

     * @param  string $value

     * @return string

     */

    public function filter($value)

    {

        if (!self::$_unicodeEnabled) {

            // POSIX named classes are not supported, use alternative 0-9 match

            $pattern = '/[^0-9]/';

        } else if (extension_loaded('mbstring')) {

            // Filter for the value with mbstring

            $pattern = '/[^[:digit:]]/';

        } else {

            // Filter for the value without mbstring

            $pattern = '/[\p{^N}]/';

        }

        return preg_replace($pattern, '', (string) $value);

    }

}