system/core/Utf8.php

<?php
/**
 * CodeIgniter
 *
 * An open source application development framework for PHP 5.2.4 or newer
 *
 * NOTICE OF LICENSE
 *
 * Licensed under the Open Software License version 3.0
 *
 * This source file is subject to the Open Software License (OSL 3.0) that is
 * bundled with this package in the files license.txt / license.rst.  It is
 * also available through the world wide web at this URL:
 * http://opensource.org/licenses/OSL-3.0
 * 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
 * licensing@ellislab.com so we can send you a copy immediately.
 *
 * @package		CodeIgniter
 * @author		EllisLab Dev Team
 * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
 * @license		http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
 * @link		http://codeigniter.com
 * @since		Version 2.0
 * @filesource
 */
defined('BASEPATH') OR exit('No direct script access allowed');

/**
 * Utf8 Class
 *
 * Provides support for UTF-8 environments
 *
 * @package		CodeIgniter
 * @subpackage	Libraries
 * @category	UTF-8
 * @author		EllisLab Dev Team
 * @link		http://codeigniter.com/user_guide/libraries/utf8.html
 */
class CI_Utf8 {

	/**
	 * Class constructor
	 *
	 * Determines if UTF-8 support is to be enabled.
	 *
	 * @return	void
	 */
	public function __construct()
	{
		log_message('debug', 'Utf8 Class Initialized');

		$charset = strtoupper(config_item('charset'));

		// set internal encoding for multibyte string functions if necessary
		// and set a flag so we don't have to repeatedly use extension_loaded()
		// or function_exists()
		if (extension_loaded('mbstring'))
		{
			define('MB_ENABLED', TRUE);
			mb_internal_encoding($charset);
			// This is required for mb_convert_encoding() to strip invalid characters
			ini_set('mbstring.substitute_character', 'none');
		}
		else
		{
			define('MB_ENABLED', FALSE);
		}

		// Do the same for iconv, which actually has more easy to remember
		// predefined constants (such as ICONV_IMPL), but the iconv PHP
		// manual page says that using them is "strongly discouraged".
		if (extension_loaded('iconv'))
		{
			define('ICONV_ENABLED', TRUE);
			iconv_set_encoding('internal_encoding', $charset);
		}
		else
		{
			define('ICONV_ENABLED', FALSE);
		}

		if (
			defined('PREG_BAD_UTF8_ERROR')				// PCRE must support UTF-8
			&& (ICONV_ENABLED === TRUE OR MB_ENABLED === TRUE)	// iconv or mbstring must be installed
			&& $charset === 'UTF-8'					// Application charset must be UTF-8
			)
		{
			define('UTF8_ENABLED', TRUE);
			log_message('debug', 'UTF-8 Support Enabled');
		}
		else
		{
			define('UTF8_ENABLED', FALSE);
			log_message('debug', 'UTF-8 Support Disabled');
		}
	}

	// --------------------------------------------------------------------

	/**
	 * Clean UTF-8 strings
	 *
	 * Ensures strings contain only valid UTF-8 characters.
	 *
	 * @uses	CI_Utf8::_is_ascii()	Decide whether a conversion is needed
	 *
	 * @param	string	$str	String to clean
	 * @return	string
	 */
	public function clean_string($str)
	{
		if ($this->_is_ascii($str) === FALSE)
		{
			if (ICONV_ENABLED)
			{
				$str = @iconv('UTF-8', 'UTF-8//IGNORE', $str);
			}
			elseif (MB_ENABLED)
			{
				$str = mb_convert_encoding($str, 'UTF-8', 'UTF-8');
			}
		}

		return $str;
	}

	// --------------------------------------------------------------------

	/**
	 * Remove ASCII control characters
	 *
	 * Removes all ASCII control characters except horizontal tabs,
	 * line feeds, and carriage returns, as all others can cause
	 * problems in XML.
	 *
	 * @param	string	$str	String to clean
	 * @return	string
	 */
	public function safe_ascii_for_xml($str)
	{
		return remove_invisible_characters($str, FALSE);
	}

	// --------------------------------------------------------------------

	/**
	 * Convert to UTF-8
	 *
	 * Attempts to convert a string to UTF-8.
	 *
	 * @param	string	$str		Input string
	 * @param	string	$encoding	Input encoding
	 * @return	string	$str encoded in UTF-8 or FALSE on failure
	 */
	public function convert_to_utf8($str, $encoding)
	{
		if (ICONV_ENABLED)
		{
			return @iconv($encoding, 'UTF-8', $str);
		}
		elseif (MB_ENABLED === TRUE)
		{
			return @mb_convert_encoding($str, 'UTF-8', $encoding);
		}

		return FALSE;
	}

	// --------------------------------------------------------------------

	/**
	 * Is ASCII?
	 *
	 * Tests if a string is standard 7-bit ASCII or not.
	 *
	 * @param	string	$str	String to check
	 * @return	bool
	 */
	protected function _is_ascii($str)
	{
		return (preg_match('/[^\x00-\x7F]/S', $str) === 0);
	}

}

/* End of file Utf8.php */
/* Location: ./system/core/Utf8.php */