View file application/libraries/Engine/Filter/Censor.php

<?php
/**
 * SocialEngine
 *
 * @category   Engine
 * @package    Engine_Filter
 * @copyright  Copyright 2006-2010 Webligo Developments
 * @license    http://www.socialengine.com/license/
 * @version    $Id: Censor.php 9747 2012-07-26 02:08:08Z john $
 */

/**
 * @category   Engine
 * @package    Engine_Filter
 * @copyright  Copyright 2006-2010 Webligo Developments
 * @license    http://www.socialengine.com/license/
 */
class Engine_Filter_Censor implements Zend_Filter_Interface
{
    protected static $_defaultForbiddenWords;

    protected $_forbiddenWords;

    protected $_replaceString = '*';

    public function __construct($options = array())
    {
        if (!empty($options['forbiddenWords'])) {
            $this->_forbiddenWords = $options['forbiddenWords'];
        } else {
            $this->_forbiddenWords = self::getDefaultForbiddenWords();
        }
        if (is_string($this->_forbiddenWords)) {
            $this->_forbiddenWords = preg_split('/\s*,\s*/', $this->_forbiddenWords);
            $this->_forbiddenWords = array_map('trim', $this->_forbiddenWords);
            $this->_forbiddenWords = array_filter($this->_forbiddenWords);
        }
        if (!is_array($this->_forbiddenWords)) {
            $this->_forbiddenWords = null;
        }

        if (!empty($options['replaceString'])) {
            $this->_replaceString = $options['replaceString'];
        }
    }

    public function filter($value)
    {
        $value = Engine_Text_Emoji::encode($value);

        if (empty($value) || empty($this->_forbiddenWords) || !is_array($this->_forbiddenWords)) {
            return $value;
        }

        foreach ($this->_forbiddenWords as $word) {
            // periods and slashes need to be escaped otherwise they become
            // part of the regular expression which can result in strange errors
            $expr = preg_quote($word, '/');
            $expr = str_replace('\\*', '.*?', $expr);
            $replace = str_pad('', strlen(str_replace('*', '', $word)), $this->_replaceString);
            $value = preg_replace('/\b' . $expr. '\b/i', $replace, $value);
        }

        return $value;
    }

    // Static stuff

    public static function getDefaultForbiddenWords()
    {
        if (null === self::$_defaultForbiddenWords) {
            if (Zend_Registry::isRegistered('Censor')) {
                $forbiddenWords = Zend_Registry::get('Censor');
                if (is_string($forbiddenWords) || is_array($forbiddenWords)) {
                    return $forbiddenWords;
                }
            }
        } else {
            return self::$_defaultForbiddenWords;
        }
    }

    public static function setDefaultForbiddenWords($words)
    {
        self::$_defaultForbiddenWords = $words;
    }
}