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 - 2009, 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, $replace);
 113         }
 114
 115         // --------------------------------------------------------------------
 116
 117         /**
 118          * Set HTTP Status Header
 119          * moved to Common procedural functions in 1.7.2
 120          *
 121          * @access      public
 122          * @param       int     the status code
 123          * @param       string
 124          * @return      void
 125          */
 126         function set_status_header($code = '200', $text = '')
 127         {
 128                 set_status_header($code, $text);
 129         }
 130
 131         // --------------------------------------------------------------------
 132
 133         /**
 134          * Enable/disable Profiler
 135          *
 136          * @access      public
 137          * @param       bool
 138          * @return      void
 139          */
 140         function enable_profiler($val = TRUE)
 141         {
 142                 $this->enable_profiler = (is_bool($val)) ? $val : TRUE;
 143         }
 144
 145         // --------------------------------------------------------------------
 146
 147         /**
 148          * Set Cache
 149          *
 150          * @access      public
 151          * @param       integer
 152          * @return      void
 153          */
 154         function cache($time)
 155         {
 156                 $this->cache_expiration = ( ! is_numeric($time)) ? 0 : $time;
 157         }
 158
 159         // --------------------------------------------------------------------
 160
 161         /**
 162          * Display Output
 163          *
 164          * All "view" data is automatically put into this variable by the controller class:
 165          *
 166          * $this->final_output
 167          *
 168          * This function sends the finalized output data to the browser along
 169          * with any server headers and profile data.  It also stops the
 170          * benchmark timer so the page rendering speed and memory usage can be shown.
 171          *
 172          * @access      public
 173          * @return      mixed
 174          */
 175         function _display($output = '')
 176         {
 177                 // Note:  We use globals because we can't use $CI =& get_instance()
 178                 // since this function is sometimes called by the caching mechanism,
 179                 // which happens before the CI super object is available.
 180                 global $BM, $CFG;
 181
 182                 // --------------------------------------------------------------------
 183
 184                 // Set the output data
 185                 if ($output == '')
 186                 {
 187                         $output =& $this->final_output;
 188                 }
 189
 190                 // --------------------------------------------------------------------
 191
 192                 // Do we need to write a cache file?
 193                 if ($this->cache_expiration > 0)
 194                 {
 195                         $this->_write_cache($output);
 196                 }
 197
 198                 // --------------------------------------------------------------------
 199
 200                 // Parse out the elapsed time and memory usage,
 201                 // then swap the pseudo-variables with the data
 202
 203                 $elapsed = $BM->elapsed_time('total_execution_time_start', 'total_execution_time_end');
 204                 $output = str_replace('{elapsed_time}', $elapsed, $output);
 205
 206                 $memory  = ( ! function_exists('memory_get_usage')) ? '0' : round(memory_get_usage()/1024/1024, 2).'MB';
 207                 $output = str_replace('{memory_usage}', $memory, $output);
 208
 209                 // --------------------------------------------------------------------
 210
 211                 // Is compression requested?
 212                 if ($CFG->item('compress_output') === TRUE)
 213                 {
 214                         if (extension_loaded('zlib'))
 215                         {
 216                                 if (isset($_SERVER['HTTP_ACCEPT_ENCODING']) AND strpos($_SERVER['HTTP_ACCEPT_ENCODING'], 'gzip') !== FALSE)
 217                                 {
 218                                         ob_start('ob_gzhandler');
 219                                 }
 220                         }
 221                 }
 222
 223                 // --------------------------------------------------------------------
 224
 225                 // Are there any server headers to send?
 226                 if (count($this->headers) > 0)
 227                 {
 228                         foreach ($this->headers as $header)
 229                         {
 230                                 @header($header[0], $header[1]);
 231                         }
 232                 }
 233
 234                 // --------------------------------------------------------------------
 235
 236                 // Does the get_instance() function exist?
 237                 // If not we know we are dealing with a cache file so we'll
 238                 // simply echo out the data and exit.
 239                 if ( ! function_exists('get_instance'))
 240                 {
 241                         echo $output;
 242                         log_message('debug', "Final output sent to browser");
 243                         log_message('debug', "Total execution time: ".$elapsed);
 244                         return TRUE;
 245                 }
 246
 247                 // --------------------------------------------------------------------
 248
 249                 // Grab the super object.  We'll need it in a moment...
 250                 $CI =& get_instance();
 251
 252                 // Do we need to generate profile data?
 253                 // If so, load the Profile class and run it.
 254                 if ($this->enable_profiler == TRUE)
 255                 {
 256                         $CI->load->library('profiler');
 257
 258                         // If the output data contains closing </body> and </html> tags
 259                         // we will remove them and add them back after we insert the profile data
 260                         if (preg_match("|</body>.*?</html>|is", $output))
 261                         {
 262                                 $output  = preg_replace("|</body>.*?</html>|is", '', $output);
 263                                 $output .= $CI->profiler->run();
 264                                 $output .= '</body></html>';
 265                         }
 266                         else
 267                         {
 268                                 $output .= $CI->profiler->run();
 269                         }
 270                 }
 271
 272                 // --------------------------------------------------------------------
 273
 274                 // Does the controller contain a function named _output()?
 275                 // If so send the output there.  Otherwise, echo it.
 276                 if (method_exists($CI, '_output'))
 277                 {
 278                         $CI->_output($output);
 279                 }
 280                 else
 281                 {
 282                         echo $output;  // Send it to the browser!
 283                 }
 284
 285                 log_message('debug', "Final output sent to browser");
 286                 log_message('debug', "Total execution time: ".$elapsed);
 287         }
 288
 289         // --------------------------------------------------------------------
 290
 291         /**
 292          * Write a Cache File
 293          *
 294          * @access      public
 295          * @return      void
 296          */
 297         function _write_cache($output)
 298         {
 299                 $CI =& get_instance();
 300                 $path = $CI->config->item('cache_path');
 301
 302                 $cache_path = ($path == '') ? BASEPATH.'cache/' : $path;
 303
 304                 if ( ! is_dir($cache_path) OR ! is_really_writable($cache_path))
 305                 {
 306                         return;
 307                 }
 308
 309                 $uri =  $CI->config->item('base_url').
 310                                 $CI->config->item('index_page').
 311                                 $CI->uri->uri_string();
 312
 313                 $cache_path .= md5($uri);
 314
 315                 if ( ! $fp = @fopen($cache_path, FOPEN_WRITE_CREATE_DESTRUCTIVE))
 316                 {
 317                         log_message('error', "Unable to write cache file: ".$cache_path);
 318                         return;
 319                 }
 320
 321                 $expire = time() + ($this->cache_expiration * 60);
 322
 323                 if (flock($fp, LOCK_EX))
 324                 {
 325                         fwrite($fp, $expire.'TS--->'.$output);
 326                         flock($fp, LOCK_UN);
 327                 }
 328                 else
 329                 {
 330                         log_message('error', "Unable to secure a file lock for file at: ".$cache_path);
 331                         return;
 332                 }
 333                 fclose($fp);
 334                 @chmod($cache_path, DIR_WRITE_MODE);
 335
 336                 log_message('debug', "Cache file written: ".$cache_path);
 337         }
 338
 339         // --------------------------------------------------------------------
 340
 341         /**
 342          * Update/serve a cached file
 343          *
 344          * @access      public
 345          * @return      void
 346          */
 347         function _display_cache(&$CFG, &$URI)
 348         {
 349                 $cache_path = ($CFG->item('cache_path') == '') ? BASEPATH.'cache/' : $CFG->item('cache_path');
 350
 351                 if ( ! is_dir($cache_path) OR ! is_really_writable($cache_path))
 352                 {
 353                         return FALSE;
 354                 }
 355
 356                 // Build the file path.  The file name is an MD5 hash of the full URI
 357                 $uri =  $CFG->item('base_url').
 358                                 $CFG->item('index_page').
 359                                 $URI->uri_string;
 360
 361                 $filepath = $cache_path.md5($uri);
 362
 363                 if ( ! @file_exists($filepath))
 364                 {
 365                         return FALSE;
 366                 }
 367
 368                 if ( ! $fp = @fopen($filepath, FOPEN_READ))
 369                 {
 370                         return FALSE;
 371                 }
 372
 373                 flock($fp, LOCK_SH);
 374
 375                 $cache = '';
 376                 if (filesize($filepath) > 0)
 377                 {
 378                         $cache = fread($fp, filesize($filepath));
 379                 }
 380
 381                 flock($fp, LOCK_UN);
 382                 fclose($fp);
 383
 384                 // Strip out the embedded timestamp
 385                 if ( ! preg_match("/(\d+TS--->)/", $cache, $match))
 386                 {
 387                         return FALSE;
 388                 }
 389
 390                 // Has the file expired? If so we'll delete it.
 391                 if (time() >= trim(str_replace('TS--->', '', $match['1'])))
 392                 {
 393                         @unlink($filepath);
 394                         log_message('debug', "Cache file has expired. File deleted");
 395                         return FALSE;
 396                 }
 397
 398                 // Display the cache
 399                 $this->_display(str_replace($match['0'], '', $cache));
 400                 log_message('debug', "Cache file is current. Sending it to browser.");
 401                 return TRUE;
 402         }
 403
 404
 405 }
 406 // END Output Class
 407
 408 /* End of file Output.php */
 409 /* Location: ./system/libraries/Output.php */