HTMLPurifier_Encoder::convertFromUTF8 PHP Method

    public static function convertFromUTF8($str, $config, $context)
    {
        $encoding = $config->get('Core.Encoding');
        if ($escape = $config->get('Core.EscapeNonASCIICharacters')) {
            $str = self::convertToASCIIDumbLossless($str);
        }
        if ($encoding === 'utf-8') {
            return $str;
        }
        static $iconv = null;
        if ($iconv === null) {
            $iconv = self::iconvAvailable();
        }
        if ($iconv && !$config->get('Test.ForceNoIconv')) {
            // Undo our previous fix in convertToUTF8, otherwise iconv will barf
            $ascii_fix = self::testEncodingSupportsASCII($encoding);
            if (!$escape && !empty($ascii_fix)) {
                $clear_fix = array();
                foreach ($ascii_fix as $utf8 => $native) {
                    $clear_fix[$utf8] = '';
                }
                $str = strtr($str, $clear_fix);
            }
            $str = strtr($str, array_flip($ascii_fix));
            // Normal stuff
            $str = self::iconv('utf-8', $encoding . '//IGNORE', $str);
            return $str;
        } elseif ($encoding === 'iso-8859-1') {
            $str = utf8_decode($str);
            return $str;
        }
        trigger_error('Encoding not supported', E_USER_ERROR);
        // You might be tempted to assume that the ASCII representation
        // might be OK, however, this is *not* universally true over all
        // encodings.  So we take the conservative route here, rather
        // than forcibly turn on %Core.EscapeNonASCIICharacters
    }

 public function purify($html, $config = null)
 {
     $config = $config ? HTMLPurifier_Config::create($config) : $this->config;
     $lexer = HTMLPurifier_Lexer::create($config);
     $context = new HTMLPurifier_Context();
     $this->generator = new HTMLPurifier_Generator($config, $context);
     $context->register('Generator', $this->generator);
     if ($config->get('Core.CollectErrors')) {
         $language_factory = HTMLPurifier_LanguageFactory::instance();
         $language = $language_factory->create($config, $context);
         $context->register('Locale', $language);
         $error_collector = new HTMLPurifier_ErrorCollector($context);
         $context->register('ErrorCollector', $error_collector);
     }
     $id_accumulator = HTMLPurifier_IDAccumulator::build($config, $context);
     $context->register('IDAccumulator', $id_accumulator);
     $html = HTMLPurifier_Encoder::convertToUTF8($html, $config, $context);
     $filter_flags = $config->getBatch('Filter');
     $custom_filters = $filter_flags['Custom'];
     unset($filter_flags['Custom']);
     $filters = array();
     foreach ($filter_flags as $filter => $flag) {
         if (!$flag) {
             continue;
         }
         if (strpos($filter, '.') !== false) {
             continue;
         }
         $class = "HTMLPurifier_Filter_{$filter}";
         $filters[] = new $class();
     }
     foreach ($custom_filters as $filter) {
         $filters[] = $filter;
     }
     $filters = array_merge($filters, $this->filters);
     for ($i = 0, $filter_size = count($filters); $i < $filter_size; $i++) {
         $html = $filters[$i]->preFilter($html, $config, $context);
     }
     $html = $this->generator->generateFromTokens($this->strategy->execute($lexer->tokenizeHTML($html, $config, $context), $config, $context));
     for ($i = $filter_size - 1; $i >= 0; $i--) {
         $html = $filters[$i]->postFilter($html, $config, $context);
     }
     $html = HTMLPurifier_Encoder::convertFromUTF8($html, $config, $context);
     $this->context =& $context;
     return $html;
 }