<?php
/**
 * Encoding functions
 *
 * Contains HTML and Unicode conversion functions
 *
 * @package Core
 * @author  Andreas Goetz   <hide@address.com>
 * @version $Id: encoding.php,v 1.3 2008/02/10 17:03:06 andig2 Exp $
 */

/**
 * Like html_entity_decode() but also supports numeric entities. 
 * Output encoding is ISO-8852-1.
 *
 * @author www.php.net
 * @param  string   $string  html entity loaded string
 * @return string            html entity free string 
 */
function html_entity_decode_all($string) 
{
    // replace numeric entities
    $string = preg_replace('~&#x([0-9a-f]+);~ei', 'chr(hexdec("\\1"))', $string);
    $string = preg_replace('~&#([0-9]+);~e', 'chr(\\1)', $string);
#   utf8 version commented out
#    $string = preg_replace('~&#x([0-9a-f]+);~ei', 'code2utf(hexdec("\\1"))', $string);
#    $string = preg_replace('~&#([0-9]+);~e', 'code2utf(\\1)', $string);
    
    // replace literal entities
    $trans_tbl = get_html_translation_table(HTML_ENTITIES);    
    $trans_tbl = array_flip($trans_tbl);
#   utf8 version commented out
#    foreach (get_html_translation_table(HTML_ENTITIES) as $val=>$key) $trans_tbl[$key] = utf8_encode($val);
    
    return strtr($string, $trans_tbl);
}

/**
 * Like html_entity_decode() but also supports numeric entities. 
 * Output encoding is UTF-8.
 *
 * @author www.php.net
 * @param  string   $string  html entity loaded string
 * @return string            html entity free string 
 */
function html_entity_decode_all_utf8($string) 
{
    // replace numeric entities
#   non-utf8 version commented out
#    $string = preg_replace('~&#x([0-9a-f]+);~ei', 'chr(hexdec("\\1"))', $string);
#    $string = preg_replace('~&#([0-9]+);~e', 'chr(\\1)', $string);
    $string = preg_replace('~&#x([0-9a-f]+);~ei', 'code2utf(hexdec("\\1"))', $string);
    $string = preg_replace('~&#([0-9]+);~e', 'code2utf(\\1)', $string);
    
    // replace literal entities
#   non-utf8 version commented out
#    $trans_tbl = get_html_translation_table(HTML_ENTITIES);    
#    $trans_tbl = array_flip($trans_tbl);
    foreach (get_html_translation_table(HTML_ENTITIES) as $val=>$key) $trans_tbl[$key] = utf8_encode($val);
    
    return strtr($string, $trans_tbl);
}

/**
 * Returns the utf-8 encoding corresponding to the unicode character value 
 * @author  from php.net, courtesy - hide@address.com
 */
function code2utf($num)
{
    if ($num < 128) return chr($num);
    if ($num < 2048) return chr(($num >> 6) + 192) . chr(($num & 63) + 128);
    if ($num < 65536) return chr(($num >> 12) + 224) . chr((($num >> 6) & 63) + 128) . chr(($num & 63) + 128);
    if ($num < 2097152) return chr(($num >> 18) + 240) . chr((($num >> 12) & 63) + 128) . chr((($num >> 6) & 63) + 128) . chr(($num & 63) + 128);
    return '';
}

/**
 * Clean HTML entities and replace &nbsp; special spaces
 *
 * @author Andreas Goetz	<hide@address.com>
 * @param  string   $string  html entity loaded string
 * @return string            html entity free string 
 */
function html_clean($str) 
{
    return trim(str_replace(chr(160), ' ', html_entity_decode_all($str)));
}
        
/**
 * Clean HTML entities, tags and replace &nbsp; special spaces
 * Output encoding is UTF-8.
 *
 * @author Andreas Goetz	<hide@address.com>
 * @param  string   $str    html entity loaded string
 * @return string           html entity free string 
 */
function html_clean_utf8($str) 
{
#   this replacement breaks unicode enitity encoding as A0 might occor as part of any character
#   $str    = str_replace(chr(160), ' ', $str);
    $str    = html_entity_decode_all_utf8(strip_tags($str));
    return trim($str);
}

/**
 * Chance character set encoding for hierarchical array
 *
 * @param  mixed    $data   string or hierarchical array to convert
 * @return mixed    data in target encoding
 */
function iconv_array($source_encoding, $target_encoding, $data)
{
    if (is_array($data))
    {
        // recursive call for array conversion
        foreach ($data as $key => $val)
        {
            $data[$key] = iconv_array($source_encoding, $target_encoding, $val);
        }
    }
    else
    {
        // finally convert string value
        $data = iconv($source_encoding, $target_encoding, $data);
        if ($data === FALSE) errorpage('Character set conversion error', "Error converting from $source_encoding to $target_encoding.");
    }
    
    return $data;
}

/**
 * Convert HTML to plain text for some common entities
 */
function html_to_text($str)
{
    // create list items
    $str = preg_replace("#<li.*?>#i", "\n-", $str);

    // de-html line breaks
    $str = preg_replace('#<(br|p).*?>#i', "\n", $str);
    
    // avoid double line breaks
    $str = preg_replace("#\n+#", "\n", $str);
    
    return $str;
}

?>