filter/algebra/pix.php

   1 <?php
   2       // This function fetches math. images from the data directory
   3       // If not, it obtains the corresponding TeX expression from the cache_tex db table
   4       // and uses mimeTeX to create the image file
   5
   6 // disable moodle specific debug messages and any errors in output
   7 define('NO_DEBUG_DISPLAY', true);
   8 define('NO_MOODLE_COOKIES', true); // Because it interferes with caching
   9
  10     require_once('../../config.php');
  11
  12     if (!filter_is_enabled('algebra')) {
  13         print_error('filternotenabled');
  14     }
  15
  16     require_once($CFG->libdir.'/filelib.php');
  17     require_once($CFG->dirroot.'/filter/tex/lib.php');
  18
  19     $cmd    = '';               // Initialise these variables
  20     $status = '';
  21
  22     $relativepath = get_file_argument();
  23
  24     $args = explode('/', trim($relativepath, '/'));
  25
  26     if (count($args) == 1) {
  27         $image    = $args[0];
  28         $pathname = $CFG->dataroot.'/filter/algebra/'.$image;
  29     } else {
  30         print_error('invalidarguments', 'error');
  31     }
  32
  33     if (!file_exists($pathname)) {
  34         $md5 = str_replace('.gif','',$image);
  35         if ($texcache = $DB->get_record('cache_filters', array('filter'=>'algebra', 'md5key'=>$md5))) {
  36             if (!file_exists($CFG->dataroot.'/filter/algebra')) {
  37                 make_upload_directory('filter/algebra');
  38             }
  39
  40             $texexp = $texcache->rawtext;
  41             $texexp = str_replace('&lt;','<',$texexp);
  42             $texexp = str_replace('&gt;','>',$texexp);
  43             $texexp = preg_replace('!\r\n?!',' ',$texexp);
  44             $texexp = '\Large ' . $texexp;
  45             $cmd = filter_tex_get_cmd($pathname, $texexp);
  46             system($cmd, $status);
  47         }
  48     }
  49
  50     if (file_exists($pathname)) {
  51         send_file($pathname, $image);
  52     } else {
  53         if (debugging()) {
  54             echo "The shell command<br />$cmd<br />returned status = $status<br />\n";
  55             echo "Image not found!<br />";
  56             echo "Please try the <a href=\"$CFG->wwwroot/filter/algebra/algebradebug.php\">debugging script</a>";
  57         } else {
  58             echo "Image not found!<br />";
  59             echo "Please try the <a href=\"$CFG->wwwroot/filter/algebra/algebradebug.php\">debugging script</a><br />";
  60             echo "Please turn on debug mode in site configuration to see more info here.";
  61         }
  62     }
  63