<?php
/**
* CodeIgniter
*
* An open source application development framework for PHP
*
* This content is released under the MIT License (MIT)
*
* Copyright (c) 2014 - 2015, British Columbia Institute of Technology
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*
* @package CodeIgniter
* @author EllisLab Dev Team
* @copyright Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
* @copyright Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
* @license http://opensource.org/licenses/MIT MIT License
* @link http://codeigniter.com
* @since Version 2.0.0
* @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()
{
if (
defined('PREG_BAD_UTF8_ERROR') // PCRE must support UTF-8
&& (ICONV_ENABLED === TRUE OR MB_ENABLED === TRUE) // iconv or mbstring must be installed
&& strtoupper(config_item('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');
}

log_message('info', 'Utf8 Class Initialized');
}

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

/**
* Clean UTF-8 strings
*
* Ensures strings contain only valid UTF-8 characters.
*
* @param string $str String to clean
* @return string
*/
public function clean_string($str)
{
if ($this->is_ascii($str) === FALSE)
{
if (MB_ENABLED)
{
$str = mb_convert_encoding($str, 'UTF-8', 'UTF-8');
}
elseif (ICONV_ENABLED)
{
$str = @iconv('UTF-8', 'UTF-8//IGNORE', $str);
}
}

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, $encoding)
{
if (MB_ENABLED)
{
return mb_convert_encoding($str, 'UTF-8', $encoding);
}
elseif (ICONV_ENABLED)
{
return @iconv($encoding, 'UTF-8', $str);
}

return FALSE;
}

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

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

}