<?php
/***************************************************************
*  Copyright notice
*
*  (c) 2008 Patrick Broens (patrick@patrickbroens.nl)
*  All rights reserved
*
*  This script is part of the TYPO3 project. The TYPO3 project is
*  free software; you can redistribute it and/or modify
*  it under the terms of the GNU General Public License as published by
*  the Free Software Foundation; either version 2 of the License, or
*  (at your option) any later version.
*
*  The GNU General Public License can be found at
*  http://www.gnu.org/copyleft/gpl.html.
*
*  This script is distributed in the hope that it will be useful,
*  but WITHOUT ANY WARRANTY; without even the implied warranty of
*  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
*  GNU General Public License for more details.
*
*  This copyright notice MUST APPEAR in all copies of the script!
***************************************************************/

/**
 * Alphanumeric filter
 *
 * @author Patrick Broens <patrick@patrickbroens.nl>
 * @package TYPO3
 * @subpackage form
 */
class tx_form_System_Filter_Alphanumeric implements tx_form_System_Filter_Interface {

	/**
	 * Allow whitespace
	 *
	 * @var boolean
	 */
	protected $allowWhiteSpace;

	/**
	 * Constructor
	 *
	 * @param array $arguments Filter configuration
	 */
	public function __construct($arguments = array()) {
		$this->setAllowWhiteSpace($arguments['allowWhiteSpace']);
	}

	/**
	 * Allow white space in the submitted value
	 *
	 * @param boolean $allowWhiteSpace True if allowed
	 * @return void
	 */
	public function setAllowWhiteSpace($allowWhiteSpace = TRUE) {
		$this->allowWhiteSpace = (boolean) $allowWhiteSpace;
	}

	/**
	 * Return filtered value
	 * Remove all but alphabetic and numeric characters
	 * Allow whitespace by choice
	 *
	 * @param  string $value
	 * @return string
	 */
	public function filter($value) {
		$whiteSpace = $this->allowWhiteSpace ? '\s' : '';

		$pattern = '/[^a-zA-Z0-9'  . $whiteSpace . ']/u';

		return preg_replace($pattern, '', (string) $value);
	}
}
?>