includes/Math.php

   1 <?php
   2
   3 function linkToMathImage ( $tex, $outputhash )
   4 {
   5         global $wgMathPath;
   6         $url = htmlspecialchars( "$wgMathPath/$outputhash.png" );
   7         $alt = htmlspecialchars( $tex );
   8         return "<img class='tex' src=\"$url\" alt=\"$alt\" />";
   9 }
  10
  11 function renderMath( $tex )
  12 {
  13         global $wgUser, $wgMathDirectory, $wgTmpDirectory, $wgInputEncoding;
  14         global $wgTexvc;
  15         $mf   = wfMsg( "math_failure" );
  16         $munk = wfMsg( "math_unknown_error" );
  17
  18         $fname = "renderMath";
  19
  20         $math = $wgUser->getOption("math");
  21         if( $math == 3 ) {
  22                 return ('$ '.wfEscapeHTML($tex).' $');
  23         }
  24
  25         $md5 = md5($tex);
  26         $md5_sql = mysql_escape_string(pack("H32", $md5));
  27         if ($math == 0) {
  28                 $sql = "SELECT math_outputhash FROM math WHERE math_inputhash = '$md5_sql'";
  29         } else {
  30                 $sql = "SELECT math_outputhash,math_html_conservativeness,math_html FROM math WHERE math_inputhash = '$md5_sql'";
  31         }
  32
  33         $res = wfQuery( $sql, DB_READ, $fname );
  34
  35         if( $rpage = wfFetchObject ( $res ) ) {
  36                 $outputhash = unpack( "H32md5", $rpage->math_outputhash . "                " );
  37                 $outputhash = $outputhash ['md5'];
  38                 if( file_exists( "$wgMathDirectory/$outputhash.png" ) ) {
  39                         if (($math == 0) || ($rpage->math_html == '') || (($math == 1) && ($rpage->math_html_conservativeness != 2)) || (($math == 4) && ($rpage->math_html_conservativeness == 0))) {
  40                                 return linkToMathImage ( $tex, $outputhash );
  41                         } else {
  42                                 return $rpage->math_html;
  43                         }
  44                 }
  45         }
  46
  47         # Ensure that the temp and output directories are available before continuing...
  48         if( !file_exists( $wgMathDirectory ) ) {
  49                 if( !@mkdir( $wgMathDirectory ) ) {
  50                         return "<b>$mf (" . wfMsg( "math_bad_output" ) . ")</b>";
  51                 }
  52         } elseif( !is_dir( $wgMathDirectory ) || !is_writable( $wgMathDirectory ) ) {
  53                 return "<b>$mf (" . wfMsg( "math_bad_output" ) . ")</b>";
  54         }
  55         if( !file_exists( $wgTmpDirectory ) ) {
  56                 if( !@mkdir( $wgTmpDirectory ) ) {
  57                         return "<b>$mf (" . wfMsg( "math_bad_tmpdir" ) . ")</b>";
  58                 }
  59         } elseif( !is_dir( $wgTmpDirectory ) || !is_writable( $wgTmpDirectory ) ) {
  60                 return "<b>$mf (" . wfMsg( "math_bad_tmpdir" ) . ")</b>";
  61         }
  62
  63         if( !is_executable( $wgTexvc ) ) {
  64                 return "<b>$mf (" . wfMsg( "math_notexvc" ) . ")</b>";
  65         }
  66         $cmd = $wgTexvc." ".
  67                 escapeshellarg($wgTmpDirectory)." ".
  68                 escapeshellarg($wgMathDirectory)." ".
  69                 escapeshellarg($tex)." ".
  70                 escapeshellarg($wgInputEncoding);
  71         wfDebug( "TeX: $cmd" );
  72         $contents = `$cmd`;
  73
  74         if (strlen($contents) == 0) {
  75                 return "<b>".$mf." (".$munk."): ".wfEscapeHTML($tex)."</b>";
  76         }
  77
  78         $retval = substr ($contents, 0, 1);
  79         if (($retval == "C") || ($retval == "M") || ($retval == "L")) {
  80             if ($retval == "C")
  81                 $conservativeness = 2;
  82             else if ($retval == "M")
  83                 $conservativeness = 1;
  84             else
  85                 $conservativeness = 0;
  86             $outdata = substr ($contents, 33);
  87
  88             $i = strpos($outdata, "\000");
  89
  90             $outhtml = substr($outdata, 0, $i);
  91             $mathml = substr($outdata, $i+1);
  92
  93             $sql_html = "'".mysql_escape_string($outhtml)."'";
  94             $sql_mathml = "'".mysql_escape_string($mathml)."'";
  95         } else if (($retval == "c") || ($retval == "m") || ($retval == "l"))  {
  96             $outhtml = substr ($contents, 33);
  97             if ($retval == "c")
  98                 $conservativeness = 2;
  99             else if ($retval == "m")
 100                 $conservativeness = 1;
 101             else
 102                 $conservativeness = 0;
 103             $sql_html = "'".mysql_escape_string($outhtml)."'";
 104             $mathml = '';
 105             $sql_mathml = 'NULL';
 106         } else if ($retval == "X") {
 107             $outhtml = '';
 108             $mathml = substr ($contents, 33);
 109             $sql_html = 'NULL';
 110             $sql_mathml = "'".mysql_escape_string($mathml)."'";
 111             $conservativeness = 0;
 112         } else if ($retval == "+") {
 113             $outhtml = '';
 114             $mathml = '';
 115             $sql_html = 'NULL';
 116             $sql_mathml = 'NULL';
 117             $conservativeness = 0;
 118         } else {
 119             if ($retval == "E")
 120                 $errmsg = wfMsg( "math_lexing_error" );
 121             else if ($retval == "S")
 122                 $errmsg = wfMsg( "math_syntax_error" );
 123             else if ($retval == "F")
 124                 $errmsg = wfMsg( "math_unknown_function" );
 125             else
 126                 $errmsg = $munk;
 127             return "<h3>".$mf." (".$errmsg.substr($contents, 1)."): ".wfEscapeHTML($tex)."</h3>";
 128         }
 129
 130         $outmd5 = substr ($contents, 1, 32);
 131         if (!preg_match("/^[a-f0-9]{32}$/", $outmd5)) {
 132                 return "<b>".$mf." (".$munk."): ".wfEscapeHTML($tex)."</b>";
 133         }
 134
 135         if( !file_exists( "$wgMathDirectory/$outmd5.png" ) ) {
 136                 $errmsg = wfMsg( "math_image_error" );
 137                 return "<h3>$mf ($errmsg): " . wfEscapeHTML($tex) . "</h3>";
 138         }
 139
 140         $outmd5_sql = mysql_escape_string(pack("H32", $outmd5));
 141
 142         $sql = "REPLACE INTO math VALUES ('".$md5_sql."', '".$outmd5_sql."', ".$conservativeness.", ".$sql_html.", ".$sql_mathml.")";
 143
 144         $res = wfQuery( $sql, DB_READ, $fname );
 145         # we don't really care if it fails
 146
 147         if (($math == 0) || ($rpage->math_html == '') || (($math == 1) && ($conservativeness != 2)) || (($math == 4) && ($conservativeness == 0)))
 148             return linkToMathImage($tex, $outmd5);
 149         else
 150             return $outhtml;
 151 }
 152
 153 ?>