CI_Output::_display PHP Method

    public function _display($output = '')
    {
        // Note:  We use load_class() because we can't use $CI =& get_instance()
        // since this function is sometimes called by the caching mechanism,
        // which happens before the CI super object is available.
        $BM =& load_class('Benchmark', 'core');
        $CFG =& load_class('Config', 'core');
        // Grab the super object if we can.
        if (class_exists('CI_Controller', FALSE)) {
            $CI =& get_instance();
        }
        // --------------------------------------------------------------------
        // Set the output data
        if ($output === '') {
            $output =& $this->final_output;
        }
        // --------------------------------------------------------------------
        // Do we need to write a cache file? Only if the controller does not have its
        // own _output() method and we are not dealing with a cache file, which we
        // can determine by the existence of the $CI object above
        if ($this->cache_expiration > 0 && isset($CI) && !method_exists($CI, '_output')) {
            $this->_write_cache($output);
        }
        // --------------------------------------------------------------------
        // Parse out the elapsed time and memory usage,
        // then swap the pseudo-variables with the data
        $elapsed = $BM->elapsed_time('total_execution_time_start', 'total_execution_time_end');
        if ($this->parse_exec_vars === TRUE) {
            $memory = round(memory_get_usage() / 1024 / 1024, 2) . 'MB';
            $output = str_replace(array('{elapsed_time}', '{memory_usage}'), array($elapsed, $memory), $output);
        }
        // --------------------------------------------------------------------
        // Is compression requested?
        if (isset($CI) && $this->_compress_output === TRUE && isset($_SERVER['HTTP_ACCEPT_ENCODING']) && strpos($_SERVER['HTTP_ACCEPT_ENCODING'], 'gzip') !== FALSE) {
            ob_start('ob_gzhandler');
        }
        // --------------------------------------------------------------------
        // Are there any server headers to send?
        if (count($this->headers) > 0) {
            foreach ($this->headers as $header) {
                @header($header[0], $header[1]);
            }
        }
        // --------------------------------------------------------------------
        // Does the $CI object exist?
        // If not we know we are dealing with a cache file so we'll
        // simply echo out the data and exit.
        if (!isset($CI)) {
            if ($this->_compress_output === TRUE) {
                if (isset($_SERVER['HTTP_ACCEPT_ENCODING']) && strpos($_SERVER['HTTP_ACCEPT_ENCODING'], 'gzip') !== FALSE) {
                    header('Content-Encoding: gzip');
                    header('Content-Length: ' . strlen($output));
                } else {
                    // User agent doesn't support gzip compression,
                    // so we'll have to decompress our cache
                    $output = gzinflate(substr($output, 10, -8));
                }
            }
            echo $output;
            log_message('info', 'Final output sent to browser');
            log_message('debug', 'Total execution time: ' . $elapsed);
            return;
        }
        // --------------------------------------------------------------------
        // Do we need to generate profile data?
        // If so, load the Profile class and run it.
        if ($this->enable_profiler === TRUE) {
            $CI->load->library('profiler');
            if (!empty($this->_profiler_sections)) {
                $CI->profiler->set_sections($this->_profiler_sections);
            }
            // If the output data contains closing </body> and </html> tags
            // we will remove them and add them back after we insert the profile data
            $output = preg_replace('|</body>.*?</html>|is', '', $output, -1, $count) . $CI->profiler->run();
            if ($count > 0) {
                $output .= '</body></html>';
            }
        }
        // Does the controller contain a function named _output()?
        // If so send the output there.  Otherwise, echo it.
        if (method_exists($CI, '_output')) {
            $CI->_output($output);
        } else {
            echo $output;
            // Send it to the browser!
        }
        log_message('info', 'Final output sent to browser');
        log_message('debug', 'Total execution time: ' . $elapsed);
    }

 function _display($output = '')
 {
     if (ENVIRONMENT !== 'development') {
         $this->final_output = str_replace('> <', '><', preg_replace("/\\s+|\n+|\r/", ' ', $this->final_output));
     }
     parent::_display($output);
 }