includes/Exception.php

   1 <?php
   2
   3 /**
   4  * MediaWiki exception
   5  * @addtogroup Exception
   6  */
   7 class MWException extends Exception
   8 {
   9         function useOutputPage() {
  10                 return !empty( $GLOBALS['wgFullyInitialised'] ) &&
  11                         !empty( $GLOBALS['wgArticle'] ) && !empty( $GLOBALS['wgTitle'] );
  12         }
  13
  14         function useMessageCache() {
  15                 global $wgLang;
  16                 return is_object( $wgLang );
  17         }
  18
  19         /** Get a message from i18n */
  20         function msg( $key, $fallback /*[, params...] */ ) {
  21                 $args = array_slice( func_get_args(), 2 );
  22                 if ( $this->useMessageCache() ) {
  23                         return wfMsgReal( $key, $args );
  24                 } else {
  25                         return wfMsgReplaceArgs( $fallback, $args );
  26                 }
  27         }
  28
  29         /* If wgShowExceptionDetails, return a HTML message with a backtrace to the error. */
  30         function getHTML() {
  31                 global $wgShowExceptionDetails;
  32                 if( $wgShowExceptionDetails ) {
  33                         return '<p>' . htmlspecialchars( $this->getMessage() ) .
  34                                 '</p><p>Backtrace:</p><p>' . nl2br( htmlspecialchars( $this->getTraceAsString() ) ) .
  35                                 "</p>\n";
  36                 } else {
  37                         return "<p>Set <b><tt>\$wgShowExceptionDetails = true;</tt></b> " .
  38                                 "at the bottom of LocalSettings.php to show detailed " .
  39                                 "debugging information.</p>";
  40                 }
  41         }
  42
  43         /* If wgShowExceptionDetails, return a text message with a backtrace to the error */
  44         function getText() {
  45                 global $wgShowExceptionDetails;
  46                 if( $wgShowExceptionDetails ) {
  47                         return $this->getMessage() .
  48                                 "\nBacktrace:\n" . $this->getTraceAsString() . "\n";
  49                 } else {
  50                         return "<p>Set <tt>\$wgShowExceptionDetails = true;</tt> " .
  51                                 "in LocalSettings.php to show detailed debugging information.</p>";
  52                 }
  53         }
  54
  55         /* Return titles of this error page */
  56         function getPageTitle() {
  57                 if ( $this->useMessageCache() ) {
  58                         return wfMsg( 'internalerror' );
  59                 } else {
  60                         global $wgSitename;
  61                         return "$wgSitename error";
  62                 }
  63         }
  64
  65         /** Return the requested URL and point to file and line number from which the
  66          * exception occured
  67          */
  68         function getLogMessage() {
  69                 global $wgRequest;
  70                 $file = $this->getFile();
  71                 $line = $this->getLine();
  72                 $message = $this->getMessage();
  73                 return $wgRequest->getRequestURL() . " Exception from line $line of $file: $message";
  74         }
  75
  76         /** Output the exception report using HTML */
  77         function reportHTML() {
  78                 global $wgOut;
  79                 if ( $this->useOutputPage() ) {
  80                         $wgOut->setPageTitle( $this->getPageTitle() );
  81                         $wgOut->setRobotpolicy( "noindex,nofollow" );
  82                         $wgOut->setArticleRelated( false );
  83                         $wgOut->enableClientCache( false );
  84                         $wgOut->redirect( '' );
  85                         $wgOut->clearHTML();
  86                         $wgOut->addHTML( $this->getHTML() );
  87                         $wgOut->output();
  88                 } else {
  89                         echo $this->htmlHeader();
  90                         echo $this->getHTML();
  91                         echo $this->htmlFooter();
  92                 }
  93         }
  94
  95         /* Output a report about the exception and takes care of formatting.
  96          * It will be either HTML or plain text based on $wgCommandLineMode.
  97          */
  98         function report() {
  99                 global $wgCommandLineMode;
 100                 if ( $wgCommandLineMode ) {
 101                         fwrite( STDERR, $this->getText() );
 102                 } else {
 103                         $log = $this->getLogMessage();
 104                         if ( $log ) {
 105                                 wfDebugLog( 'exception', $log );
 106                         }
 107                         $this->reportHTML();
 108                 }
 109         }
 110
 111         function htmlHeader() {
 112                 global $wgLogo, $wgSitename, $wgOutputEncoding;
 113
 114                 if ( !headers_sent() ) {
 115                         header( 'HTTP/1.0 500 Internal Server Error' );
 116                         header( 'Content-type: text/html; charset='.$wgOutputEncoding );
 117                         /* Don't cache error pages!  They cause no end of trouble... */
 118                         header( 'Cache-control: none' );
 119                         header( 'Pragma: nocache' );
 120                 }
 121                 $title = $this->getPageTitle();
 122                 echo "<html>
 123                 <head>
 124                 <title>$title</title>
 125                 </head>
 126                 <body>
 127                 <h1><img src='$wgLogo' style='float:left;margin-right:1em' alt=''>$title</h1>
 128                 ";
 129         }
 130
 131         function htmlFooter() {
 132                 echo "</body></html>";
 133         }
 134
 135 }
 136
 137 /**
 138  * Exception class which takes an HTML error message, and does not
 139  * produce a backtrace. Replacement for OutputPage::fatalError().
 140  * @addtogroup Exception
 141  */
 142 class FatalError extends MWException {
 143         function getHTML() {
 144                 return $this->getMessage();
 145         }
 146
 147         function getText() {
 148                 return $this->getMessage();
 149         }
 150 }
 151
 152 /**
 153  * @addtogroup Exception
 154  */
 155 class ErrorPageError extends MWException {
 156         public $title, $msg;
 157
 158         /**
 159          * Note: these arguments are keys into wfMsg(), not text!
 160          */
 161         function __construct( $title, $msg ) {
 162                 $this->title = $title;
 163                 $this->msg = $msg;
 164                 parent::__construct( wfMsg( $msg ) );
 165         }
 166
 167         function report() {
 168                 global $wgOut;
 169                 $wgOut->showErrorPage( $this->title, $this->msg );
 170                 $wgOut->output();
 171         }
 172 }
 173
 174 /**
 175  * Install an exception handler for MediaWiki exception types.
 176  */
 177 function wfInstallExceptionHandler() {
 178         set_exception_handler( 'wfExceptionHandler' );
 179 }
 180
 181 /**
 182  * Report an exception to the user
 183  */
 184 function wfReportException( Exception $e ) {
 185          if ( $e instanceof MWException ) {
 186                  try {
 187                          $e->report();
 188                  } catch ( Exception $e2 ) {
 189                          // Exception occurred from within exception handler
 190                          // Show a simpler error message for the original exception,
 191                          // don't try to invoke report()
 192                          $message = "MediaWiki internal error.\n\n" .
 193                          "Original exception: " . $e->__toString() .
 194                          "\n\nException caught inside exception handler: " .
 195                          $e2->__toString() . "\n";
 196
 197                          if ( !empty( $GLOBALS['wgCommandLineMode'] ) ) {
 198                                  fwrite( STDERR, $message );
 199                          } else {
 200                                  echo nl2br( htmlspecialchars( $message ) ). "\n";
 201                          }
 202                  }
 203          } else {
 204                  echo $e->__toString();
 205          }
 206 }
 207
 208 /**
 209  * Exception handler which simulates the appropriate catch() handling:
 210  *
 211  *   try {
 212  *       ...
 213  *   } catch ( MWException $e ) {
 214  *       $e->report();
 215  *   } catch ( Exception $e ) {
 216  *       echo $e->__toString();
 217  *   }
 218  */
 219 function wfExceptionHandler( $e ) {
 220         global $wgFullyInitialised;
 221         wfReportException( $e );
 222
 223         // Final cleanup, similar to wfErrorExit()
 224         if ( $wgFullyInitialised ) {
 225                 try {
 226                         wfLogProfilingData(); // uses $wgRequest, hence the $wgFullyInitialised condition
 227                 } catch ( Exception $e ) {}
 228         }
 229
 230         // Exit value should be nonzero for the benefit of shell jobs
 231         exit( 1 );
 232 }
 233
 234