includes/exception/MWException.php

   1 <?php
   2 /**
   3  * This program is free software; you can redistribute it and/or modify
   4  * it under the terms of the GNU General Public License as published by
   5  * the Free Software Foundation; either version 2 of the License, or
   6  * (at your option) any later version.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  16  * http://www.gnu.org/copyleft/gpl.html
  17  *
  18  * @file
  19  */
  20
  21 /**
  22  * MediaWiki exception
  23  *
  24  * @ingroup Exception
  25  */
  26 class MWException extends Exception {
  27         /**
  28          * Should the exception use $wgOut to output the error?
  29          *
  30          * @return bool
  31          */
  32         public function useOutputPage() {
  33                 return $this->useMessageCache() &&
  34                 !empty( $GLOBALS['wgFullyInitialised'] ) &&
  35                 !empty( $GLOBALS['wgOut'] ) &&
  36                 !defined( 'MEDIAWIKI_INSTALL' );
  37         }
  38
  39         /**
  40          * Whether to log this exception in the exception debug log.
  41          *
  42          * @since 1.23
  43          * @return bool
  44          */
  45         public function isLoggable() {
  46                 return true;
  47         }
  48
  49         /**
  50          * Can the extension use the Message class/wfMessage to get i18n-ed messages?
  51          *
  52          * @return bool
  53          */
  54         public function useMessageCache() {
  55                 global $wgLang;
  56
  57                 foreach ( $this->getTrace() as $frame ) {
  58                         if ( isset( $frame['class'] ) && $frame['class'] === LocalisationCache::class ) {
  59                                 return false;
  60                         }
  61                 }
  62
  63                 return $wgLang instanceof Language;
  64         }
  65
  66         /**
  67          * Get a message from i18n
  68          *
  69          * @param string $key Message name
  70          * @param string $fallback Default message if the message cache can't be
  71          *                  called by the exception
  72          * The function also has other parameters that are arguments for the message
  73          * @return string Message with arguments replaced
  74          */
  75         public function msg( $key, $fallback /*[, params...] */ ) {
  76                 $args = array_slice( func_get_args(), 2 );
  77
  78                 if ( $this->useMessageCache() ) {
  79                         try {
  80                                 return wfMessage( $key, $args )->text();
  81                         } catch ( Exception $e ) {
  82                         }
  83                 }
  84                 return wfMsgReplaceArgs( $fallback, $args );
  85         }
  86
  87         /**
  88          * If $wgShowExceptionDetails is true, return a HTML message with a
  89          * backtrace to the error, otherwise show a message to ask to set it to true
  90          * to show that information.
  91          *
  92          * @return string Html to output
  93          */
  94         public function getHTML() {
  95                 global $wgShowExceptionDetails;
  96
  97                 if ( $wgShowExceptionDetails ) {
  98                         return '<p>' . nl2br( htmlspecialchars( MWExceptionHandler::getLogMessage( $this ) ) ) .
  99                         '</p><p>Backtrace:</p><p>' .
 100                         nl2br( htmlspecialchars( MWExceptionHandler::getRedactedTraceAsString( $this ) ) ) .
 101                         "</p>\n";
 102                 } else {
 103                         $logId = WebRequest::getRequestId();
 104                         $type = static::class;
 105                         return Html::errorBox(
 106                         htmlspecialchars(
 107                                 '[' . $logId . '] ' .
 108                                 gmdate( 'Y-m-d H:i:s' ) . ": " .
 109                                 $this->msg( "internalerror-fatal-exception",
 110                                         "Fatal exception of type $1",
 111                                         $type,
 112                                         $logId,
 113                                         MWExceptionHandler::getURL( $this )
 114                                 )
 115                         ) ) .
 116                         "<!-- Set \$wgShowExceptionDetails = true; " .
 117                         "at the bottom of LocalSettings.php to show detailed " .
 118                         "debugging information. -->";
 119                 }
 120         }
 121
 122         /**
 123          * Get the text to display when reporting the error on the command line.
 124          * If $wgShowExceptionDetails is true, return a text message with a
 125          * backtrace to the error.
 126          *
 127          * @return string
 128          */
 129         public function getText() {
 130                 global $wgShowExceptionDetails;
 131
 132                 if ( $wgShowExceptionDetails ) {
 133                         return MWExceptionHandler::getLogMessage( $this ) .
 134                         "\nBacktrace:\n" . MWExceptionHandler::getRedactedTraceAsString( $this ) . "\n";
 135                 } else {
 136                         return "Set \$wgShowExceptionDetails = true; " .
 137                         "in LocalSettings.php to show detailed debugging information.\n";
 138                 }
 139         }
 140
 141         /**
 142          * Return the title of the page when reporting this error in a HTTP response.
 143          *
 144          * @return string
 145          */
 146         public function getPageTitle() {
 147                 return $this->msg( 'internalerror', 'Internal error' );
 148         }
 149
 150         /**
 151          * Output the exception report using HTML.
 152          */
 153         public function reportHTML() {
 154                 global $wgOut, $wgSitename;
 155                 if ( $this->useOutputPage() ) {
 156                         $wgOut->prepareErrorPage( $this->getPageTitle() );
 157
 158                         $wgOut->addHTML( $this->getHTML() );
 159
 160                         $wgOut->output();
 161                 } else {
 162                         self::header( 'Content-Type: text/html; charset=utf-8' );
 163                         echo "<!DOCTYPE html>\n" .
 164                                 '<html><head>' .
 165                                 // Mimick OutputPage::setPageTitle behaviour
 166                                 '<title>' .
 167                                 htmlspecialchars( $this->msg( 'pagetitle', "$1 - $wgSitename", $this->getPageTitle() ) ) .
 168                                 '</title>' .
 169                                 '<style>body { font-family: sans-serif; margin: 0; padding: 0.5em 2em; }</style>' .
 170                                 "</head><body>\n";
 171
 172                         echo $this->getHTML();
 173
 174                         echo "</body></html>\n";
 175                 }
 176         }
 177
 178         /**
 179          * Output a report about the exception and takes care of formatting.
 180          * It will be either HTML or plain text based on isCommandLine().
 181          */
 182         public function report() {
 183                 global $wgMimeType;
 184
 185                 if ( defined( 'MW_API' ) ) {
 186                         // Unhandled API exception, we can't be sure that format printer is alive
 187                         self::header( 'MediaWiki-API-Error: internal_api_error_' . static::class );
 188                         wfHttpError( 500, 'Internal Server Error', $this->getText() );
 189                 } elseif ( self::isCommandLine() ) {
 190                         $message = $this->getText();
 191                         // T17602: STDERR may not be available
 192                         if ( !defined( 'MW_PHPUNIT_TEST' ) && defined( 'STDERR' ) ) {
 193                                 fwrite( STDERR, $message );
 194                         } else {
 195                                 echo $message;
 196                         }
 197                 } else {
 198                         self::statusHeader( 500 );
 199                         self::header( "Content-Type: $wgMimeType; charset=utf-8" );
 200
 201                         $this->reportHTML();
 202                 }
 203         }
 204
 205         /**
 206          * Check whether we are in command line mode or not to report the exception
 207          * in the correct format.
 208          *
 209          * @return bool
 210          */
 211         public static function isCommandLine() {
 212                 return !empty( $GLOBALS['wgCommandLineMode'] );
 213         }
 214
 215         /**
 216          * Send a header, if we haven't already sent them. We shouldn't,
 217          * but sometimes we might in a weird case like Export
 218          * @param string $header
 219          */
 220         private static function header( $header ) {
 221                 if ( !headers_sent() ) {
 222                         header( $header );
 223                 }
 224         }
 225         private static function statusHeader( $code ) {
 226                 if ( !headers_sent() ) {
 227                         HttpStatus::header( $code );
 228                 }
 229         }
 230 }