includes/logging/LogFormatter.php

   1 <?php
   2 /**
   3  * Contains classes for formatting log entries
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @author Niklas Laxström
  22  * @license http://www.gnu.org/copyleft/gpl.html GNU General Public License 2.0 or later
  23  * @since 1.19
  24  */
  25
  26 /**
  27  * Implements the default log formatting.
  28  * Can be overridden by subclassing and setting
  29  * $wgLogActionsHandlers['type/subtype'] = 'class'; or
  30  * $wgLogActionsHandlers['type/*'] = 'class';
  31  * @since 1.19
  32  */
  33 class LogFormatter {
  34         // Audience options for viewing usernames, comments, and actions
  35         const FOR_PUBLIC = 1;
  36         const FOR_THIS_USER = 2;
  37
  38         // Static->
  39
  40         /**
  41          * Constructs a new formatter suitable for given entry.
  42          * @param LogEntry $entry
  43          * @return LogFormatter
  44          */
  45         public static function newFromEntry( LogEntry $entry ) {
  46                 global $wgLogActionsHandlers;
  47                 $fulltype = $entry->getFullType();
  48                 $wildcard = $entry->getType() . '/*';
  49                 $handler = '';
  50
  51                 if ( isset( $wgLogActionsHandlers[$fulltype] ) ) {
  52                         $handler = $wgLogActionsHandlers[$fulltype];
  53                 } elseif ( isset( $wgLogActionsHandlers[$wildcard] ) ) {
  54                         $handler = $wgLogActionsHandlers[$wildcard];
  55                 }
  56
  57                 if ( $handler !== '' && is_string( $handler ) && class_exists( $handler ) ) {
  58                         return new $handler( $entry );
  59                 }
  60
  61                 return new LegacyLogFormatter( $entry );
  62         }
  63
  64         /**
  65          * Handy shortcut for constructing a formatter directly from
  66          * database row.
  67          * @param object $row
  68          * @see DatabaseLogEntry::getSelectQueryData
  69          * @return LogFormatter
  70          */
  71         public static function newFromRow( $row ) {
  72                 return self::newFromEntry( DatabaseLogEntry::newFromRow( $row ) );
  73         }
  74
  75         // Nonstatic->
  76
  77         /** @var LogEntryBase */
  78         protected $entry;
  79
  80         /** @var int Constant for handling log_deleted */
  81         protected $audience = self::FOR_PUBLIC;
  82
  83         /** @var bool Whether to output user tool links */
  84         protected $linkFlood = false;
  85
  86         /**
  87          * Set to true if we are constructing a message text that is going to
  88          * be included in page history or send to IRC feed. Links are replaced
  89          * with plaintext or with [[pagename]] kind of syntax, that is parsed
  90          * by page histories and IRC feeds.
  91          * @var string
  92          */
  93         protected $plaintext = false;
  94
  95         /** @var string */
  96         protected $irctext = false;
  97
  98         protected function __construct( LogEntry $entry ) {
  99                 $this->entry = $entry;
 100                 $this->context = RequestContext::getMain();
 101         }
 102
 103         /**
 104          * Replace the default context
 105          * @param IContextSource $context
 106          */
 107         public function setContext( IContextSource $context ) {
 108                 $this->context = $context;
 109         }
 110
 111         /**
 112          * Set the visibility restrictions for displaying content.
 113          * If set to public, and an item is deleted, then it will be replaced
 114          * with a placeholder even if the context user is allowed to view it.
 115          * @param int $audience Const self::FOR_THIS_USER or self::FOR_PUBLIC
 116          */
 117         public function setAudience( $audience ) {
 118                 $this->audience = ( $audience == self::FOR_THIS_USER )
 119                         ? self::FOR_THIS_USER
 120                         : self::FOR_PUBLIC;
 121         }
 122
 123         /**
 124          * Check if a log item can be displayed
 125          * @param int $field LogPage::DELETED_* constant
 126          * @return bool
 127          */
 128         protected function canView( $field ) {
 129                 if ( $this->audience == self::FOR_THIS_USER ) {
 130                         return LogEventsList::userCanBitfield(
 131                                 $this->entry->getDeleted(), $field, $this->context->getUser() );
 132                 } else {
 133                         return !$this->entry->isDeleted( $field );
 134                 }
 135         }
 136
 137         /**
 138          * If set to true, will produce user tool links after
 139          * the user name. This should be replaced with generic
 140          * CSS/JS solution.
 141          * @param bool $value
 142          */
 143         public function setShowUserToolLinks( $value ) {
 144                 $this->linkFlood = $value;
 145         }
 146
 147         /**
 148          * Ugly hack to produce plaintext version of the message.
 149          * Usually you also want to set extraneous request context
 150          * to avoid formatting for any particular user.
 151          * @see getActionText()
 152          * @return string Plain text
 153          */
 154         public function getPlainActionText() {
 155                 $this->plaintext = true;
 156                 $text = $this->getActionText();
 157                 $this->plaintext = false;
 158
 159                 return $text;
 160         }
 161
 162         /**
 163          * Even uglier hack to maintain backwards compatibilty with IRC bots
 164          * (bug 34508).
 165          * @see getActionText()
 166          * @return string Text
 167          */
 168         public function getIRCActionComment() {
 169                 $actionComment = $this->getIRCActionText();
 170                 $comment = $this->entry->getComment();
 171
 172                 if ( $comment != '' ) {
 173                         if ( $actionComment == '' ) {
 174                                 $actionComment = $comment;
 175                         } else {
 176                                 $actionComment .= wfMessage( 'colon-separator' )->inContentLanguage()->text() . $comment;
 177                         }
 178                 }
 179
 180                 return $actionComment;
 181         }
 182
 183         /**
 184          * Even uglier hack to maintain backwards compatibilty with IRC bots
 185          * (bug 34508).
 186          * @see getActionText()
 187          * @return string Text
 188          */
 189         public function getIRCActionText() {
 190                 $this->plaintext = true;
 191                 $this->irctext = true;
 192
 193                 $entry = $this->entry;
 194                 $parameters = $entry->getParameters();
 195                 // @see LogPage::actionText()
 196                 // Text of title the action is aimed at.
 197                 $target = $entry->getTarget()->getPrefixedText();
 198                 $text = null;
 199                 switch ( $entry->getType() ) {
 200                         case 'move':
 201                                 switch ( $entry->getSubtype() ) {
 202                                         case 'move':
 203                                                 $movesource = $parameters['4::target'];
 204                                                 $text = wfMessage( '1movedto2' )
 205                                                         ->rawParams( $target, $movesource )->inContentLanguage()->escaped();
 206                                                 break;
 207                                         case 'move_redir':
 208                                                 $movesource = $parameters['4::target'];
 209                                                 $text = wfMessage( '1movedto2_redir' )
 210                                                         ->rawParams( $target, $movesource )->inContentLanguage()->escaped();
 211                                                 break;
 212                                         case 'move-noredirect':
 213                                                 break;
 214                                         case 'move_redir-noredirect':
 215                                                 break;
 216                                 }
 217                                 break;
 218
 219                         case 'delete':
 220                                 switch ( $entry->getSubtype() ) {
 221                                         case 'delete':
 222                                                 $text = wfMessage( 'deletedarticle' )
 223                                                         ->rawParams( $target )->inContentLanguage()->escaped();
 224                                                 break;
 225                                         case 'restore':
 226                                                 $text = wfMessage( 'undeletedarticle' )
 227                                                         ->rawParams( $target )->inContentLanguage()->escaped();
 228                                                 break;
 229                                         // @codingStandardsIgnoreStart Long line
 230                                         //case 'revision': // Revision deletion
 231                                         //case 'event': // Log deletion
 232                                         // see https://svn.wikimedia.org/viewvc/mediawiki/trunk/phase3/includes/LogPage.php?&pathrev=97044&r1=97043&r2=97044
 233                                         //default:
 234                                         // @codingStandardsIgnoreEnd
 235                                 }
 236                                 break;
 237
 238                         case 'patrol':
 239                                 // @codingStandardsIgnoreStart Long line
 240                                 // https://svn.wikimedia.org/viewvc/mediawiki/trunk/phase3/includes/PatrolLog.php?&pathrev=97495&r1=97494&r2=97495
 241                                 // @codingStandardsIgnoreEnd
 242                                 // Create a diff link to the patrolled revision
 243                                 if ( $entry->getSubtype() === 'patrol' ) {
 244                                         $diffLink = htmlspecialchars(
 245                                                 wfMessage( 'patrol-log-diff', $parameters['4::curid'] )
 246                                                         ->inContentLanguage()->text() );
 247                                         $text = wfMessage( 'patrol-log-line', $diffLink, "[[$target]]", "" )
 248                                                 ->inContentLanguage()->text();
 249                                 } else {
 250                                         // broken??
 251                                 }
 252                                 break;
 253
 254                         case 'protect':
 255                                 switch ( $entry->getSubtype() ) {
 256                                         case 'protect':
 257                                                 $text = wfMessage( 'protectedarticle' )
 258                                                         ->rawParams( $target . ' ' . $parameters[0] )->inContentLanguage()->escaped();
 259                                                 break;
 260                                         case 'unprotect':
 261                                                 $text = wfMessage( 'unprotectedarticle' )
 262                                                         ->rawParams( $target )->inContentLanguage()->escaped();
 263                                                 break;
 264                                         case 'modify':
 265                                                 $text = wfMessage( 'modifiedarticleprotection' )
 266                                                         ->rawParams( $target . ' ' . $parameters[0] )->inContentLanguage()->escaped();
 267                                                 break;
 268                                 }
 269                                 break;
 270
 271                         case 'newusers':
 272                                 switch ( $entry->getSubtype() ) {
 273                                         case 'newusers':
 274                                         case 'create':
 275                                                 $text = wfMessage( 'newuserlog-create-entry' )
 276                                                         ->inContentLanguage()->escaped();
 277                                                 break;
 278                                         case 'create2':
 279                                         case 'byemail':
 280                                                 $text = wfMessage( 'newuserlog-create2-entry' )
 281                                                         ->rawParams( $target )->inContentLanguage()->escaped();
 282                                                 break;
 283                                         case 'autocreate':
 284                                                 $text = wfMessage( 'newuserlog-autocreate-entry' )
 285                                                         ->inContentLanguage()->escaped();
 286                                                 break;
 287                                 }
 288                                 break;
 289
 290                         case 'upload':
 291                                 switch ( $entry->getSubtype() ) {
 292                                         case 'upload':
 293                                                 $text = wfMessage( 'uploadedimage' )
 294                                                         ->rawParams( $target )->inContentLanguage()->escaped();
 295                                                 break;
 296                                         case 'overwrite':
 297                                                 $text = wfMessage( 'overwroteimage' )
 298                                                         ->rawParams( $target )->inContentLanguage()->escaped();
 299                                                 break;
 300                                 }
 301                                 break;
 302
 303                         case 'rights':
 304                                 if ( count( $parameters['4::oldgroups'] ) ) {
 305                                         $oldgroups = implode( ', ', $parameters['4::oldgroups'] );
 306                                 } else {
 307                                         $oldgroups = wfMessage( 'rightsnone' )->inContentLanguage()->escaped();
 308                                 }
 309                                 if ( count( $parameters['5::newgroups'] ) ) {
 310                                         $newgroups = implode( ', ', $parameters['5::newgroups'] );
 311                                 } else {
 312                                         $newgroups = wfMessage( 'rightsnone' )->inContentLanguage()->escaped();
 313                                 }
 314                                 switch ( $entry->getSubtype() ) {
 315                                         case 'rights':
 316                                                 $text = wfMessage( 'rightslogentry' )
 317                                                         ->rawParams( $target, $oldgroups, $newgroups )->inContentLanguage()->escaped();
 318                                                 break;
 319                                         case 'autopromote':
 320                                                 $text = wfMessage( 'rightslogentry-autopromote' )
 321                                                         ->rawParams( $target, $oldgroups, $newgroups )->inContentLanguage()->escaped();
 322                                                 break;
 323                                 }
 324                                 break;
 325
 326                         case 'merge':
 327                                 $text = wfMessage( 'pagemerge-logentry' )
 328                                         ->rawParams( $target, $parameters['4::dest'], $parameters['5::mergepoint'] )
 329                                         ->inContentLanguage()->escaped();
 330                                 break;
 331                         // case 'suppress' --private log -- aaron  (so we know who to blame in a few years :-D)
 332                         // default:
 333                 }
 334                 if ( is_null( $text ) ) {
 335                         $text = $this->getPlainActionText();
 336                 }
 337
 338                 $this->plaintext = false;
 339                 $this->irctext = false;
 340
 341                 return $text;
 342         }
 343
 344         /**
 345          * Gets the log action, including username.
 346          * @return string HTML
 347          */
 348         public function getActionText() {
 349                 if ( $this->canView( LogPage::DELETED_ACTION ) ) {
 350                         $element = $this->getActionMessage();
 351                         if ( $element instanceof Message ) {
 352                                 $element = $this->plaintext ? $element->text() : $element->escaped();
 353                         }
 354                         if ( $this->entry->isDeleted( LogPage::DELETED_ACTION ) ) {
 355                                 $element = $this->styleRestricedElement( $element );
 356                         }
 357                 } else {
 358                         $performer = $this->getPerformerElement() . $this->msg( 'word-separator' )->text();
 359                         $element = $performer . $this->getRestrictedElement( 'rev-deleted-event' );
 360                 }
 361
 362                 return $element;
 363         }
 364
 365         /**
 366          * Returns a sentence describing the log action. Usually
 367          * a Message object is returned, but old style log types
 368          * and entries might return pre-escaped HTML string.
 369          * @return Message|string Pre-escaped HTML
 370          */
 371         protected function getActionMessage() {
 372                 $message = $this->msg( $this->getMessageKey() );
 373                 $message->params( $this->getMessageParameters() );
 374
 375                 return $message;
 376         }
 377
 378         /**
 379          * Returns a key to be used for formatting the action sentence.
 380          * Default is logentry-TYPE-SUBTYPE for modern logs. Legacy log
 381          * types will use custom keys, and subclasses can also alter the
 382          * key depending on the entry itself.
 383          * @return string Message key
 384          */
 385         protected function getMessageKey() {
 386                 $type = $this->entry->getType();
 387                 $subtype = $this->entry->getSubtype();
 388
 389                 return "logentry-$type-$subtype";
 390         }
 391
 392         /**
 393          * Returns extra links that comes after the action text, like "revert", etc.
 394          *
 395          * @return string
 396          */
 397         public function getActionLinks() {
 398                 return '';
 399         }
 400
 401         /**
 402          * Extracts the optional extra parameters for use in action messages.
 403          * The array indexes start from number 3.
 404          * @return array
 405          */
 406         protected function extractParameters() {
 407                 $entry = $this->entry;
 408                 $params = array();
 409
 410                 if ( $entry->isLegacy() ) {
 411                         foreach ( $entry->getParameters() as $index => $value ) {
 412                                 $params[$index + 3] = $value;
 413                         }
 414                 }
 415
 416                 // Filter out parameters which are not in format #:foo
 417                 foreach ( $entry->getParameters() as $key => $value ) {
 418                         if ( strpos( $key, ':' ) === false ) {
 419                                 continue;
 420                         }
 421                         list( $index, $type, ) = explode( ':', $key, 3 );
 422                         $params[$index - 1] = $this->formatParameterValue( $type, $value );
 423                 }
 424
 425                 /* Message class doesn't like non consecutive numbering.
 426                  * Fill in missing indexes with empty strings to avoid
 427                  * incorrect renumbering.
 428                  */
 429                 if ( count( $params ) ) {
 430                         $max = max( array_keys( $params ) );
 431                         for ( $i = 4; $i < $max; $i++ ) {
 432                                 if ( !isset( $params[$i] ) ) {
 433                                         $params[$i] = '';
 434                                 }
 435                         }
 436                 }
 437
 438                 return $params;
 439         }
 440
 441         /**
 442          * Formats parameters intented for action message from
 443          * array of all parameters. There are three hardcoded
 444          * parameters (array is zero-indexed, this list not):
 445          *  - 1: user name with premade link
 446          *  - 2: usable for gender magic function
 447          *  - 3: target page with premade link
 448          * @return array
 449          */
 450         protected function getMessageParameters() {
 451                 if ( isset( $this->parsedParameters ) ) {
 452                         return $this->parsedParameters;
 453                 }
 454
 455                 $entry = $this->entry;
 456                 $params = $this->extractParameters();
 457                 $params[0] = Message::rawParam( $this->getPerformerElement() );
 458                 $params[1] = $this->canView( LogPage::DELETED_USER ) ? $entry->getPerformer()->getName() : '';
 459                 $params[2] = Message::rawParam( $this->makePageLink( $entry->getTarget() ) );
 460
 461                 // Bad things happens if the numbers are not in correct order
 462                 ksort( $params );
 463
 464                 $this->parsedParameters = $params;
 465                 return $this->parsedParameters;
 466         }
 467
 468         /**
 469          * Formats parameters values dependent to their type
 470          * @param string $type The type of the value.
 471          *   Valid are currently:
 472          *     * - (empty) or plain: The value is returned as-is
 473          *     * raw: The value will be added to the log message
 474          *            as raw parameter (e.g. no escaping)
 475          *            Use this only if there is no other working
 476          *            type like user-link or title-link
 477          *     * msg: The value is a message-key, the output is
 478          *            the message in user language
 479          *     * msg-content: The value is a message-key, the output
 480          *                    is the message in content language
 481          *     * user: The value is a user name, e.g. for GENDER
 482          *     * user-link: The value is a user name, returns a
 483          *                  link for the user
 484          *     * title: The value is a page title,
 485          *              returns name of page
 486          *     * title-link: The value is a page title,
 487          *                   returns link to this page
 488          *     * number: Format value as number
 489          * @param string $value The parameter value that should
 490          *                      be formated
 491          * @return string|array Formated value
 492          * @since 1.21
 493          */
 494         protected function formatParameterValue( $type, $value ) {
 495                 $saveLinkFlood = $this->linkFlood;
 496
 497                 switch ( strtolower( trim( $type ) ) ) {
 498                         case 'raw':
 499                                 $value = Message::rawParam( $value );
 500                                 break;
 501                         case 'msg':
 502                                 $value = $this->msg( $value )->text();
 503                                 break;
 504                         case 'msg-content':
 505                                 $value = $this->msg( $value )->inContentLanguage()->text();
 506                                 break;
 507                         case 'number':
 508                                 $value = Message::numParam( $value );
 509                                 break;
 510                         case 'user':
 511                                 $user = User::newFromName( $value );
 512                                 $value = $user->getName();
 513                                 break;
 514                         case 'user-link':
 515                                 $this->setShowUserToolLinks( false );
 516
 517                                 $user = User::newFromName( $value );
 518                                 $value = Message::rawParam( $this->makeUserLink( $user ) );
 519
 520                                 $this->setShowUserToolLinks( $saveLinkFlood );
 521                                 break;
 522                         case 'title':
 523                                 $title = Title::newFromText( $value );
 524                                 $value = $title->getPrefixedText();
 525                                 break;
 526                         case 'title-link':
 527                                 $title = Title::newFromText( $value );
 528                                 $value = Message::rawParam( $this->makePageLink( $title ) );
 529                                 break;
 530                         case 'plain':
 531                                 // Plain text, nothing to do
 532                         default:
 533                                 // Catch other types and use the old behavior (return as-is)
 534                 }
 535
 536                 return $value;
 537         }
 538
 539         /**
 540          * Helper to make a link to the page, taking the plaintext
 541          * value in consideration.
 542          * @param Title $title The page
 543          * @param array $parameters Query parameters
 544          * @throws MWException
 545          * @return string
 546          */
 547         protected function makePageLink( Title $title = null, $parameters = array() ) {
 548                 if ( !$this->plaintext ) {
 549                         $link = Linker::link( $title, null, array(), $parameters );
 550                 } else {
 551                         if ( !$title instanceof Title ) {
 552                                 throw new MWException( "Expected title, got null" );
 553                         }
 554                         $link = '[[' . $title->getPrefixedText() . ']]';
 555                 }
 556
 557                 return $link;
 558         }
 559
 560         /**
 561          * Provides the name of the user who performed the log action.
 562          * Used as part of log action message or standalone, depending
 563          * which parts of the log entry has been hidden.
 564          * @return string
 565          */
 566         public function getPerformerElement() {
 567                 if ( $this->canView( LogPage::DELETED_USER ) ) {
 568                         $performer = $this->entry->getPerformer();
 569                         $element = $this->makeUserLink( $performer );
 570                         if ( $this->entry->isDeleted( LogPage::DELETED_USER ) ) {
 571                                 $element = $this->styleRestricedElement( $element );
 572                         }
 573                 } else {
 574                         $element = $this->getRestrictedElement( 'rev-deleted-user' );
 575                 }
 576
 577                 return $element;
 578         }
 579
 580         /**
 581          * Gets the user provided comment
 582          * @return string HTML
 583          */
 584         public function getComment() {
 585                 if ( $this->canView( LogPage::DELETED_COMMENT ) ) {
 586                         $comment = Linker::commentBlock( $this->entry->getComment() );
 587                         // No hard coded spaces thanx
 588                         $element = ltrim( $comment );
 589                         if ( $this->entry->isDeleted( LogPage::DELETED_COMMENT ) ) {
 590                                 $element = $this->styleRestricedElement( $element );
 591                         }
 592                 } else {
 593                         $element = $this->getRestrictedElement( 'rev-deleted-comment' );
 594                 }
 595
 596                 return $element;
 597         }
 598
 599         /**
 600          * Helper method for displaying restricted element.
 601          * @param string $message
 602          * @return string HTML or wiki text
 603          */
 604         protected function getRestrictedElement( $message ) {
 605                 if ( $this->plaintext ) {
 606                         return $this->msg( $message )->text();
 607                 }
 608
 609                 $content = $this->msg( $message )->escaped();
 610                 $attribs = array( 'class' => 'history-deleted' );
 611
 612                 return Html::rawElement( 'span', $attribs, $content );
 613         }
 614
 615         /**
 616          * Helper method for styling restricted element.
 617          * @param string $content
 618          * @return string HTML or wiki text
 619          */
 620         protected function styleRestricedElement( $content ) {
 621                 if ( $this->plaintext ) {
 622                         return $content;
 623                 }
 624                 $attribs = array( 'class' => 'history-deleted' );
 625
 626                 return Html::rawElement( 'span', $attribs, $content );
 627         }
 628
 629         /**
 630          * Shortcut for wfMessage which honors local context.
 631          * @param string $key
 632          * @return Message
 633          */
 634         protected function msg( $key ) {
 635                 return $this->context->msg( $key );
 636         }
 637
 638         protected function makeUserLink( User $user ) {
 639                 if ( $this->plaintext ) {
 640                         $element = $user->getName();
 641                 } else {
 642                         $element = Linker::userLink(
 643                                 $user->getId(),
 644                                 $user->getName()
 645                         );
 646
 647                         if ( $this->linkFlood ) {
 648                                 $element .= Linker::userToolLinksRedContribs(
 649                                         $user->getId(),
 650                                         $user->getName(),
 651                                         $user->getEditCount()
 652                                 );
 653                         }
 654                 }
 655
 656                 return $element;
 657         }
 658
 659         /**
 660          * @return array Array of titles that should be preloaded with LinkBatch
 661          */
 662         public function getPreloadTitles() {
 663                 return array();
 664         }
 665
 666         /**
 667          * @return array Output of getMessageParameters() for testing
 668          */
 669         public function getMessageParametersForTesting() {
 670                 // This function was added because getMessageParameters() is
 671                 // protected and a change from protected to public caused
 672                 // problems with extensions
 673                 return $this->getMessageParameters();
 674         }
 675 }
 676
 677 /**
 678  * This class formats all log entries for log types
 679  * which have not been converted to the new system.
 680  * This is not about old log entries which store
 681  * parameters in a different format - the new
 682  * LogFormatter classes have code to support formatting
 683  * those too.
 684  * @since 1.19
 685  */
 686 class LegacyLogFormatter extends LogFormatter {
 687         /**
 688          * Backward compatibility for extension changing the comment from
 689          * the LogLine hook. This will be set by the first call on getComment(),
 690          * then it might be modified by the hook when calling getActionLinks(),
 691          * so that the modified value will be returned when calling getComment()
 692          * a second time.
 693          *
 694          * @var string|null
 695          */
 696         private $comment = null;
 697
 698         /**
 699          * Cache for the result of getActionLinks() so that it does not need to
 700          * run multiple times depending on the order that getComment() and
 701          * getActionLinks() are called.
 702          *
 703          * @var string|null
 704          */
 705         private $revert = null;
 706
 707         public function getComment() {
 708                 if ( $this->comment === null ) {
 709                         $this->comment = parent::getComment();
 710                 }
 711
 712                 // Make sure we execute the LogLine hook so that we immediately return
 713                 // the correct value.
 714                 if ( $this->revert === null ) {
 715                         $this->getActionLinks();
 716                 }
 717
 718                 return $this->comment;
 719         }
 720
 721         protected function getActionMessage() {
 722                 $entry = $this->entry;
 723                 $action = LogPage::actionText(
 724                         $entry->getType(),
 725                         $entry->getSubtype(),
 726                         $entry->getTarget(),
 727                         $this->plaintext ? null : $this->context->getSkin(),
 728                         (array)$entry->getParameters(),
 729                         !$this->plaintext // whether to filter [[]] links
 730                 );
 731
 732                 $performer = $this->getPerformerElement();
 733                 if ( !$this->irctext ) {
 734                         $action = $performer . $this->msg( 'word-separator' )->text() . $action;
 735                 }
 736
 737                 return $action;
 738         }
 739
 740         public function getActionLinks() {
 741                 if ( $this->revert !== null ) {
 742                         return $this->revert;
 743                 }
 744
 745                 if ( $this->entry->isDeleted( LogPage::DELETED_ACTION ) ) {
 746                         $this->revert = '';
 747                         return $this->revert;
 748                 }
 749
 750                 $title = $this->entry->getTarget();
 751                 $type = $this->entry->getType();
 752                 $subtype = $this->entry->getSubtype();
 753
 754                 // Show unblock/change block link
 755                 if ( ( $type == 'block' || $type == 'suppress' )
 756                         && ( $subtype == 'block' || $subtype == 'reblock' )
 757                 ) {
 758                         if ( !$this->context->getUser()->isAllowed( 'block' ) ) {
 759                                 return '';
 760                         }
 761
 762                         $links = array(
 763                                 Linker::linkKnown(
 764                                         SpecialPage::getTitleFor( 'Unblock', $title->getDBkey() ),
 765                                         $this->msg( 'unblocklink' )->escaped()
 766                                 ),
 767                                 Linker::linkKnown(
 768                                         SpecialPage::getTitleFor( 'Block', $title->getDBkey() ),
 769                                         $this->msg( 'change-blocklink' )->escaped()
 770                                 )
 771                         );
 772
 773                         return $this->msg( 'parentheses' )->rawParams(
 774                                 $this->context->getLanguage()->pipeList( $links ) )->escaped();
 775                 // Show change protection link
 776                 } elseif ( $type == 'protect'
 777                         && ( $subtype == 'protect' || $subtype == 'modify' || $subtype == 'unprotect' )
 778                 ) {
 779                         $links = array(
 780                                 Linker::link( $title,
 781                                         $this->msg( 'hist' )->escaped(),
 782                                         array(),
 783                                         array(
 784                                                 'action' => 'history',
 785                                                 'offset' => $this->entry->getTimestamp()
 786                                         )
 787                                 )
 788                         );
 789                         if ( $this->context->getUser()->isAllowed( 'protect' ) ) {
 790                                 $links[] = Linker::linkKnown(
 791                                         $title,
 792                                         $this->msg( 'protect_change' )->escaped(),
 793                                         array(),
 794                                         array( 'action' => 'protect' )
 795                                 );
 796                         }
 797
 798                         return $this->msg( 'parentheses' )->rawParams(
 799                                 $this->context->getLanguage()->pipeList( $links ) )->escaped();
 800                 }
 801
 802                 // Do nothing. The implementation is handled by the hook modifiying the
 803                 // passed-by-ref parameters. This also changes the default value so that
 804                 // getComment() and getActionLinks() do not call them indefinitely.
 805                 $this->revert = '';
 806
 807                 // This is to populate the $comment member of this instance so that it
 808                 // can be modified when calling the hook just below.
 809                 if ( $this->comment === null ) {
 810                         $this->getComment();
 811                 }
 812
 813                 $params = $this->entry->getParameters();
 814
 815                 wfRunHooks( 'LogLine', array( $type, $subtype, $title, $params,
 816                         &$this->comment, &$this->revert, $this->entry->getTimestamp() ) );
 817
 818                 return $this->revert;
 819         }
 820 }