libraries/Output.php

   1 <?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');
   2 /**
   3  * CodeIgniter
   4  *
   5  * An open source application development framework for PHP 4.3.2 or newer
   6  *
   7  * @package             CodeIgniter
   8  * @author              ExpressionEngine Dev Team
   9  * @copyright   Copyright (c) 2008, EllisLab, Inc.
  10  * @license             http://codeigniter.com/user_guide/license.html
  11  * @link                http://codeigniter.com
  12  * @since               Version 1.0
  13  * @filesource
  14  */
  15
  16 // ------------------------------------------------------------------------
  17
  18 /**
  19  * Output Class
  20  *
  21  * Responsible for sending final output to browser
  22  *
  23  * @package             CodeIgniter
  24  * @subpackage  Libraries
  25  * @category    Output
  26  * @author              ExpressionEngine Dev Team
  27  * @link                http://codeigniter.com/user_guide/libraries/output.html
  28  */
  29 class CI_Output {
  30
  31         var $final_output;
  32         var $cache_expiration   = 0;
  33         var $headers                    = array();
  34         var $enable_profiler    = FALSE;
  35
  36
  37         function CI_Output()
  38         {
  39                 log_message('debug', "Output Class Initialized");
  40         }
  41
  42         // --------------------------------------------------------------------
  43
  44         /**
  45          * Get Output
  46          *
  47          * Returns the current output string
  48          *
  49          * @access      public
  50          * @return      string
  51          */
  52         function get_output()
  53         {
  54                 return $this->final_output;
  55         }
  56
  57         // --------------------------------------------------------------------
  58
  59         /**
  60          * Set Output
  61          *
  62          * Sets the output string
  63          *
  64          * @access      public
  65          * @param       string
  66          * @return      void
  67          */
  68         function set_output($output)
  69         {
  70                 $this->final_output = $output;
  71         }
  72
  73         // --------------------------------------------------------------------
  74
  75         /**
  76          * Append Output
  77          *
  78          * Appends data onto the output string
  79          *
  80          * @access      public
  81          * @param       string
  82          * @return      void
  83          */
  84         function append_output($output)
  85         {
  86                 if ($this->final_output == '')
  87                 {
  88                         $this->final_output = $output;
  89                 }
  90                 else
  91                 {
  92                         $this->final_output .= $output;
  93                 }
  94         }
  95
  96         // --------------------------------------------------------------------
  97
  98         /**
  99          * Set Header
 100          *
 101          * Lets you set a server header which will be outputted with the final display.
 102          *
 103          * Note:  If a file is cached, headers will not be sent.  We need to figure out
 104          * how to permit header data to be saved with the cache data...
 105          *
 106          * @access      public
 107          * @param       string
 108          * @return      void
 109          */
 110         function set_header($header, $replace = TRUE)
 111         {
 112                 $this->headers[] = array($header, $replace);
 113         }
 114
 115         // --------------------------------------------------------------------
 116
 117         /**
 118          * Set HTTP Status Header
 119          *
 120          * @access      public
 121          * @param       int     the status code
 122          * @param       string
 123          * @return      void
 124          */
 125         function set_status_header($code = '200', $text = '')
 126         {
 127                 $stati = array(
 128                                                         '200'   => 'OK',
 129                                                         '201'   => 'Created',
 130                                                         '202'   => 'Accepted',
 131                                                         '203'   => 'Non-Authoritative Information',
 132                                                         '204'   => 'No Content',
 133                                                         '205'   => 'Reset Content',
 134                                                         '206'   => 'Partial Content',
 135
 136                                                         '300'   => 'Multiple Choices',
 137                                                         '301'   => 'Moved Permanently',
 138                                                         '302'   => 'Found',
 139                                                         '304'   => 'Not Modified',
 140                                                         '305'   => 'Use Proxy',
 141                                                         '307'   => 'Temporary Redirect',
 142
 143                                                         '400'   => 'Bad Request',
 144                                                         '401'   => 'Unauthorized',
 145                                                         '403'   => 'Forbidden',
 146                                                         '404'   => 'Not Found',
 147                                                         '405'   => 'Method Not Allowed',
 148                                                         '406'   => 'Not Acceptable',
 149                                                         '407'   => 'Proxy Authentication Required',
 150                                                         '408'   => 'Request Timeout',
 151                                                         '409'   => 'Conflict',
 152                                                         '410'   => 'Gone',
 153                                                         '411'   => 'Length Required',
 154                                                         '412'   => 'Precondition Failed',
 155                                                         '413'   => 'Request Entity Too Large',
 156                                                         '414'   => 'Request-URI Too Long',
 157                                                         '415'   => 'Unsupported Media Type',
 158                                                         '416'   => 'Requested Range Not Satisfiable',
 159                                                         '417'   => 'Expectation Failed',
 160
 161                                                         '500'   => 'Internal Server Error',
 162                                                         '501'   => 'Not Implemented',
 163                                                         '502'   => 'Bad Gateway',
 164                                                         '503'   => 'Service Unavailable',
 165                                                         '504'   => 'Gateway Timeout',
 166                                                         '505'   => 'HTTP Version Not Supported'
 167                                                 );
 168
 169                 if ($code == '' OR ! is_numeric($code))
 170                 {
 171                         show_error('Status codes must be numeric');
 172                 }
 173
 174                 if (isset($stati[$code]) AND $text == '')
 175                 {
 176                         $text = $stati[$code];
 177                 }
 178
 179                 if ($text == '')
 180                 {
 181                         show_error('No status text available.  Please check your status code number or supply your own message text.');
 182                 }
 183
 184                 $server_protocol = (isset($_SERVER['SERVER_PROTOCOL'])) ? $_SERVER['SERVER_PROTOCOL'] : FALSE;
 185
 186                 if (substr(php_sapi_name(), 0, 3) == 'cgi')
 187                 {
 188                         header("Status: {$code} {$text}", TRUE);
 189                 }
 190                 elseif ($server_protocol == 'HTTP/1.1' OR $server_protocol == 'HTTP/1.0')
 191                 {
 192                         header($server_protocol." {$code} {$text}", TRUE, $code);
 193                 }
 194                 else
 195                 {
 196                         header("HTTP/1.1 {$code} {$text}", TRUE, $code);
 197                 }
 198         }
 199
 200         // --------------------------------------------------------------------
 201
 202         /**
 203          * Enable/disable Profiler
 204          *
 205          * @access      public
 206          * @param       bool
 207          * @return      void
 208          */
 209         function enable_profiler($val = TRUE)
 210         {
 211                 $this->enable_profiler = (is_bool($val)) ? $val : TRUE;
 212         }
 213
 214         // --------------------------------------------------------------------
 215
 216         /**
 217          * Set Cache
 218          *
 219          * @access      public
 220          * @param       integer
 221          * @return      void
 222          */
 223         function cache($time)
 224         {
 225                 $this->cache_expiration = ( ! is_numeric($time)) ? 0 : $time;
 226         }
 227
 228         // --------------------------------------------------------------------
 229
 230         /**
 231          * Display Output
 232          *
 233          * All "view" data is automatically put into this variable by the controller class:
 234          *
 235          * $this->final_output
 236          *
 237          * This function sends the finalized output data to the browser along
 238          * with any server headers and profile data.  It also stops the
 239          * benchmark timer so the page rendering speed and memory usage can be shown.
 240          *
 241          * @access      public
 242          * @return      mixed
 243          */
 244         function _display($output = '')
 245         {
 246                 // Note:  We use globals because we can't use $CI =& get_instance()
 247                 // since this function is sometimes called by the caching mechanism,
 248                 // which happens before the CI super object is available.
 249                 global $BM, $CFG;
 250
 251                 // --------------------------------------------------------------------
 252
 253                 // Set the output data
 254                 if ($output == '')
 255                 {
 256                         $output =& $this->final_output;
 257                 }
 258
 259                 // --------------------------------------------------------------------
 260
 261                 // Do we need to write a cache file?
 262                 if ($this->cache_expiration > 0)
 263                 {
 264                         $this->_write_cache($output);
 265                 }
 266
 267                 // --------------------------------------------------------------------
 268
 269                 // Parse out the elapsed time and memory usage,
 270                 // then swap the pseudo-variables with the data
 271
 272                 $elapsed = $BM->elapsed_time('total_execution_time_start', 'total_execution_time_end');
 273                 $output = str_replace('{elapsed_time}', $elapsed, $output);
 274
 275                 $memory  = ( ! function_exists('memory_get_usage')) ? '0' : round(memory_get_usage()/1024/1024, 2).'MB';
 276                 $output = str_replace('{memory_usage}', $memory, $output);
 277
 278                 // --------------------------------------------------------------------
 279
 280                 // Is compression requested?
 281                 if ($CFG->item('compress_output') === TRUE)
 282                 {
 283                         if (extension_loaded('zlib'))
 284                         {
 285                                 if (isset($_SERVER['HTTP_ACCEPT_ENCODING']) AND strpos($_SERVER['HTTP_ACCEPT_ENCODING'], 'gzip') !== FALSE)
 286                                 {
 287                                         ob_start('ob_gzhandler');
 288                                 }
 289                         }
 290                 }
 291
 292                 // --------------------------------------------------------------------
 293
 294                 // Are there any server headers to send?
 295                 if (count($this->headers) > 0)
 296                 {
 297                         foreach ($this->headers as $header)
 298                         {
 299                                 @header($header[0], $header[1]);
 300                         }
 301                 }
 302
 303                 // --------------------------------------------------------------------
 304
 305                 // Does the get_instance() function exist?
 306                 // If not we know we are dealing with a cache file so we'll
 307                 // simply echo out the data and exit.
 308                 if ( ! function_exists('get_instance'))
 309                 {
 310                         echo $output;
 311                         log_message('debug', "Final output sent to browser");
 312                         log_message('debug', "Total execution time: ".$elapsed);
 313                         return TRUE;
 314                 }
 315
 316                 // --------------------------------------------------------------------
 317
 318                 // Grab the super object.  We'll need it in a moment...
 319                 $CI =& get_instance();
 320
 321                 // Do we need to generate profile data?
 322                 // If so, load the Profile class and run it.
 323                 if ($this->enable_profiler == TRUE)
 324                 {
 325                         $CI->load->library('profiler');
 326
 327                         // If the output data contains closing </body> and </html> tags
 328                         // we will remove them and add them back after we insert the profile data
 329                         if (preg_match("|</body>.*?</html>|is", $output))
 330                         {
 331                                 $output  = preg_replace("|</body>.*?</html>|is", '', $output);
 332                                 $output .= $CI->profiler->run();
 333                                 $output .= '</body></html>';
 334                         }
 335                         else
 336                         {
 337                                 $output .= $CI->profiler->run();
 338                         }
 339                 }
 340
 341                 // --------------------------------------------------------------------
 342
 343                 // Does the controller contain a function named _output()?
 344                 // If so send the output there.  Otherwise, echo it.
 345                 if (method_exists($CI, '_output'))
 346                 {
 347                         $CI->_output($output);
 348                 }
 349                 else
 350                 {
 351                         echo $output;  // Send it to the browser!
 352                 }
 353
 354                 log_message('debug', "Final output sent to browser");
 355                 log_message('debug', "Total execution time: ".$elapsed);
 356         }
 357
 358         // --------------------------------------------------------------------
 359
 360         /**
 361          * Write a Cache File
 362          *
 363          * @access      public
 364          * @return      void
 365          */
 366         function _write_cache($output)
 367         {
 368                 $CI =& get_instance();
 369                 $path = $CI->config->item('cache_path');
 370
 371                 $cache_path = ($path == '') ? BASEPATH.'cache/' : $path;
 372
 373                 if ( ! is_dir($cache_path) OR ! is_really_writable($cache_path))
 374                 {
 375                         return;
 376                 }
 377
 378                 $uri =  $CI->config->item('base_url').
 379                                 $CI->config->item('index_page').
 380                                 $CI->uri->uri_string();
 381
 382                 $cache_path .= md5($uri);
 383
 384                 if ( ! $fp = @fopen($cache_path, FOPEN_WRITE_CREATE_DESTRUCTIVE))
 385                 {
 386                         log_message('error', "Unable to write cache file: ".$cache_path);
 387                         return;
 388                 }
 389
 390                 $expire = time() + ($this->cache_expiration * 60);
 391
 392                 if (flock($fp, LOCK_EX))
 393                 {
 394                         fwrite($fp, $expire.'TS--->'.$output);
 395                         flock($fp, LOCK_UN);
 396                 }
 397                 else
 398                 {
 399                         log_message('error', "Unable to secure a file lock for file at: ".$cache_path);
 400                         return;
 401                 }
 402                 fclose($fp);
 403                 @chmod($cache_path, DIR_WRITE_MODE);
 404
 405                 log_message('debug', "Cache file written: ".$cache_path);
 406         }
 407
 408         // --------------------------------------------------------------------
 409
 410         /**
 411          * Update/serve a cached file
 412          *
 413          * @access      public
 414          * @return      void
 415          */
 416         function _display_cache(&$CFG, &$URI)
 417         {
 418                 $cache_path = ($CFG->item('cache_path') == '') ? BASEPATH.'cache/' : $CFG->item('cache_path');
 419
 420                 if ( ! is_dir($cache_path) OR ! is_really_writable($cache_path))
 421                 {
 422                         return FALSE;
 423                 }
 424
 425                 // Build the file path.  The file name is an MD5 hash of the full URI
 426                 $uri =  $CFG->item('base_url').
 427                                 $CFG->item('index_page').
 428                                 $URI->uri_string;
 429
 430                 $filepath = $cache_path.md5($uri);
 431
 432                 if ( ! @file_exists($filepath))
 433                 {
 434                         return FALSE;
 435                 }
 436
 437                 if ( ! $fp = @fopen($filepath, FOPEN_READ))
 438                 {
 439                         return FALSE;
 440                 }
 441
 442                 flock($fp, LOCK_SH);
 443
 444                 $cache = '';
 445                 if (filesize($filepath) > 0)
 446                 {
 447                         $cache = fread($fp, filesize($filepath));
 448                 }
 449
 450                 flock($fp, LOCK_UN);
 451                 fclose($fp);
 452
 453                 // Strip out the embedded timestamp
 454                 if ( ! preg_match("/(\d+TS--->)/", $cache, $match))
 455                 {
 456                         return FALSE;
 457                 }
 458
 459                 // Has the file expired? If so we'll delete it.
 460                 if (time() >= trim(str_replace('TS--->', '', $match['1'])))
 461                 {
 462                         @unlink($filepath);
 463                         log_message('debug', "Cache file has expired. File deleted");
 464                         return FALSE;
 465                 }
 466
 467                 // Display the cache
 468                 $this->_display(str_replace($match['0'], '', $cache));
 469                 log_message('debug', "Cache file is current. Sending it to browser.");
 470                 return TRUE;
 471         }
 472
 473
 474 }
 475 // END Output Class
 476
 477 /* End of file Output.php */
 478 /* Location: ./system/libraries/Output.php */