includes/actions/HistoryAction.php

   1 <?php
   2 /**
   3  * Page history
   4  *
   5  * Split off from Article.php and Skin.php, 2003-12-22
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License along
  18  * with this program; if not, write to the Free Software Foundation, Inc.,
  19  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  20  * http://www.gnu.org/copyleft/gpl.html
  21  *
  22  * @file
  23  * @ingroup Actions
  24  */
  25
  26 /**
  27  * This class handles printing the history page for an article. In order to
  28  * be efficient, it uses timestamps rather than offsets for paging, to avoid
  29  * costly LIMIT,offset queries.
  30  *
  31  * Construct it by passing in an Article, and call $h->history() to print the
  32  * history.
  33  *
  34  * @ingroup Actions
  35  */
  36 class HistoryAction extends FormlessAction {
  37         const DIR_PREV = 0;
  38         const DIR_NEXT = 1;
  39
  40         /** @var array Array of message keys and strings */
  41         public $message;
  42
  43         public function getName() {
  44                 return 'history';
  45         }
  46
  47         public function requiresWrite() {
  48                 return false;
  49         }
  50
  51         public function requiresUnblock() {
  52                 return false;
  53         }
  54
  55         protected function getPageTitle() {
  56                 return $this->msg( 'history-title', $this->getTitle()->getPrefixedText() )->text();
  57         }
  58
  59         protected function getDescription() {
  60                 // Creation of a subtitle link pointing to [[Special:Log]]
  61                 return Linker::linkKnown(
  62                         SpecialPage::getTitleFor( 'Log' ),
  63                         $this->msg( 'viewpagelogs' )->escaped(),
  64                         array(),
  65                         array( 'page' => $this->getTitle()->getPrefixedText() )
  66                 );
  67         }
  68
  69         /**
  70          * Get the Article object we are working on.
  71          * @return Page
  72          */
  73         public function getArticle() {
  74                 return $this->page;
  75         }
  76
  77         /**
  78          * As we use the same small set of messages in various methods and that
  79          * they are called often, we call them once and save them in $this->message
  80          */
  81         private function preCacheMessages() {
  82                 // Precache various messages
  83                 if ( !isset( $this->message ) ) {
  84                         $msgs = array( 'cur', 'last', 'pipe-separator' );
  85                         foreach ( $msgs as $msg ) {
  86                                 $this->message[$msg] = $this->msg( $msg )->escaped();
  87                         }
  88                 }
  89         }
  90
  91         /**
  92          * Print the history page for an article.
  93          */
  94         function onView() {
  95                 $out = $this->getOutput();
  96                 $request = $this->getRequest();
  97
  98                 /**
  99                  * Allow client caching.
 100                  */
 101                 if ( $out->checkLastModified( $this->page->getTouched() ) ) {
 102                         return; // Client cache fresh and headers sent, nothing more to do.
 103                 }
 104
 105                 wfProfileIn( __METHOD__ );
 106
 107                 $this->preCacheMessages();
 108                 $config = $this->context->getConfig();
 109
 110                 # Fill in the file cache if not set already
 111                 $useFileCache = $config->get( 'UseFileCache' );
 112                 if ( $useFileCache && HTMLFileCache::useFileCache( $this->getContext() ) ) {
 113                         $cache = new HTMLFileCache( $this->getTitle(), 'history' );
 114                         if ( !$cache->isCacheGood( /* Assume up to date */ ) ) {
 115                                 ob_start( array( &$cache, 'saveToFileCache' ) );
 116                         }
 117                 }
 118
 119                 // Setup page variables.
 120                 $out->setFeedAppendQuery( 'action=history' );
 121                 $out->addModules( 'mediawiki.action.history' );
 122                 if ( $config->get( 'UseMediaWikiUIEverywhere' ) ) {
 123                         $out = $this->getOutput();
 124                         $out->addModuleStyles( array(
 125                                 'mediawiki.ui.input',
 126                                 'mediawiki.ui.checkbox',
 127                         ) );
 128                 }
 129
 130                 // Handle atom/RSS feeds.
 131                 $feedType = $request->getVal( 'feed' );
 132                 if ( $feedType ) {
 133                         $this->feed( $feedType );
 134                         wfProfileOut( __METHOD__ );
 135
 136                         return;
 137                 }
 138
 139                 // Fail nicely if article doesn't exist.
 140                 if ( !$this->page->exists() ) {
 141                         $out->addWikiMsg( 'nohistory' );
 142                         # show deletion/move log if there is an entry
 143                         LogEventsList::showLogExtract(
 144                                 $out,
 145                                 array( 'delete', 'move' ),
 146                                 $this->getTitle(),
 147                                 '',
 148                                 array( 'lim' => 10,
 149                                         'conds' => array( "log_action != 'revision'" ),
 150                                         'showIfEmpty' => false,
 151                                         'msgKey' => array( 'moveddeleted-notice' )
 152                                 )
 153                         );
 154                         wfProfileOut( __METHOD__ );
 155
 156                         return;
 157                 }
 158
 159                 /**
 160                  * Add date selector to quickly get to a certain time
 161                  */
 162                 $year = $request->getInt( 'year' );
 163                 $month = $request->getInt( 'month' );
 164                 $tagFilter = $request->getVal( 'tagfilter' );
 165                 $tagSelector = ChangeTags::buildTagFilterSelector( $tagFilter );
 166
 167                 /**
 168                  * Option to show only revisions that have been (partially) hidden via RevisionDelete
 169                  */
 170                 if ( $request->getBool( 'deleted' ) ) {
 171                         $conds = array( 'rev_deleted != 0' );
 172                 } else {
 173                         $conds = array();
 174                 }
 175                 if ( $this->getUser()->isAllowed( 'deletedhistory' ) ) {
 176                         $checkDeleted = Xml::checkLabel( $this->msg( 'history-show-deleted' )->text(),
 177                                 'deleted', 'mw-show-deleted-only', $request->getBool( 'deleted' ) ) . "\n";
 178                 } else {
 179                         $checkDeleted = '';
 180                 }
 181
 182                 // Add the general form
 183                 $action = htmlspecialchars( wfScript() );
 184                 $className = 'historysubmit mw-history-compareselectedversions-button';
 185                 if ( $config->get( 'UseMediaWikiUIEverywhere' ) ) {
 186                         $className .= ' mw-ui-button mw-ui-progressive';
 187                 }
 188                 $out->addHTML(
 189                         "<form action=\"$action\" method=\"get\" id=\"mw-history-searchform\">" .
 190                         Xml::fieldset(
 191                                 $this->msg( 'history-fieldset-title' )->text(),
 192                                 false,
 193                                 array( 'id' => 'mw-history-search' )
 194                         ) .
 195                         Html::hidden( 'title', $this->getTitle()->getPrefixedDBkey() ) . "\n" .
 196                         Html::hidden( 'action', 'history' ) . "\n" .
 197                         Xml::dateMenu(
 198                                 ( $year == null ? MWTimestamp::getLocalInstance()->format( 'Y' ) : $year ),
 199                                 $month
 200                         ) . '&#160;' .
 201                         ( $tagSelector ? ( implode( '&#160;', $tagSelector ) . '&#160;' ) : '' ) .
 202                         $checkDeleted .
 203                         Xml::submitButton(
 204                                 $this->msg( 'allpagessubmit' )->text(),
 205                                 array( 'class' => $className )
 206                         ) . "\n" .
 207                         '</fieldset></form>'
 208                 );
 209
 210                 wfRunHooks( 'PageHistoryBeforeList', array( &$this->page, $this->getContext() ) );
 211
 212                 // Create and output the list.
 213                 $pager = new HistoryPager( $this, $year, $month, $tagFilter, $conds );
 214                 $out->addHTML(
 215                         $pager->getNavigationBar() .
 216                         $pager->getBody() .
 217                         $pager->getNavigationBar()
 218                 );
 219                 $out->preventClickjacking( $pager->getPreventClickjacking() );
 220
 221                 wfProfileOut( __METHOD__ );
 222         }
 223
 224         /**
 225          * Fetch an array of revisions, specified by a given limit, offset and
 226          * direction. This is now only used by the feeds. It was previously
 227          * used by the main UI but that's now handled by the pager.
 228          *
 229          * @param int $limit The limit number of revisions to get
 230          * @param int $offset
 231          * @param int $direction Either self::DIR_PREV or self::DIR_NEXT
 232          * @return ResultWrapper
 233          */
 234         function fetchRevisions( $limit, $offset, $direction ) {
 235                 // Fail if article doesn't exist.
 236                 if ( !$this->getTitle()->exists() ) {
 237                         return new FakeResultWrapper( array() );
 238                 }
 239
 240                 $dbr = wfGetDB( DB_SLAVE );
 241
 242                 if ( $direction === self::DIR_PREV ) {
 243                         list( $dirs, $oper ) = array( "ASC", ">=" );
 244                 } else { /* $direction === self::DIR_NEXT */
 245                         list( $dirs, $oper ) = array( "DESC", "<=" );
 246                 }
 247
 248                 if ( $offset ) {
 249                         $offsets = array( "rev_timestamp $oper " . $dbr->addQuotes( $dbr->timestamp( $offset ) ) );
 250                 } else {
 251                         $offsets = array();
 252                 }
 253
 254                 $page_id = $this->page->getId();
 255
 256                 return $dbr->select( 'revision',
 257                         Revision::selectFields(),
 258                         array_merge( array( 'rev_page' => $page_id ), $offsets ),
 259                         __METHOD__,
 260                         array( 'ORDER BY' => "rev_timestamp $dirs",
 261                                 'USE INDEX' => 'page_timestamp', 'LIMIT' => $limit )
 262                 );
 263         }
 264
 265         /**
 266          * Output a subscription feed listing recent edits to this page.
 267          *
 268          * @param string $type Feed type
 269          */
 270         function feed( $type ) {
 271                 if ( !FeedUtils::checkFeedOutput( $type ) ) {
 272                         return;
 273                 }
 274                 $request = $this->getRequest();
 275
 276                 $feedClasses = $this->context->getConfig()->get( 'FeedClasses' );
 277                 /** @var RSSFeed|AtomFeed $feed */
 278                 $feed = new $feedClasses[$type](
 279                         $this->getTitle()->getPrefixedText() . ' - ' .
 280                         $this->msg( 'history-feed-title' )->inContentLanguage()->text(),
 281                         $this->msg( 'history-feed-description' )->inContentLanguage()->text(),
 282                         $this->getTitle()->getFullURL( 'action=history' )
 283                 );
 284
 285                 // Get a limit on number of feed entries. Provide a sane default
 286                 // of 10 if none is defined (but limit to $wgFeedLimit max)
 287                 $limit = $request->getInt( 'limit', 10 );
 288                 $limit = min(
 289                         max( $limit, 1 ),
 290                         $this->context->getConfig()->get( 'FeedLimit' )
 291                 );
 292
 293                 $items = $this->fetchRevisions( $limit, 0, self::DIR_NEXT );
 294
 295                 // Generate feed elements enclosed between header and footer.
 296                 $feed->outHeader();
 297                 if ( $items->numRows() ) {
 298                         foreach ( $items as $row ) {
 299                                 $feed->outItem( $this->feedItem( $row ) );
 300                         }
 301                 } else {
 302                         $feed->outItem( $this->feedEmpty() );
 303                 }
 304                 $feed->outFooter();
 305         }
 306
 307         function feedEmpty() {
 308                 return new FeedItem(
 309                         $this->msg( 'nohistory' )->inContentLanguage()->text(),
 310                         $this->msg( 'history-feed-empty' )->inContentLanguage()->parseAsBlock(),
 311                         $this->getTitle()->getFullURL(),
 312                         wfTimestamp( TS_MW ),
 313                         '',
 314                         $this->getTitle()->getTalkPage()->getFullURL()
 315                 );
 316         }
 317
 318         /**
 319          * Generate a FeedItem object from a given revision table row
 320          * Borrows Recent Changes' feed generation functions for formatting;
 321          * includes a diff to the previous revision (if any).
 322          *
 323          * @param stdClass|array $row Database row
 324          * @return FeedItem
 325          */
 326         function feedItem( $row ) {
 327                 $rev = new Revision( $row );
 328                 $rev->setTitle( $this->getTitle() );
 329                 $text = FeedUtils::formatDiffRow(
 330                         $this->getTitle(),
 331                         $this->getTitle()->getPreviousRevisionID( $rev->getId() ),
 332                         $rev->getId(),
 333                         $rev->getTimestamp(),
 334                         $rev->getComment()
 335                 );
 336                 if ( $rev->getComment() == '' ) {
 337                         global $wgContLang;
 338                         $title = $this->msg( 'history-feed-item-nocomment',
 339                                 $rev->getUserText(),
 340                                 $wgContLang->timeanddate( $rev->getTimestamp() ),
 341                                 $wgContLang->date( $rev->getTimestamp() ),
 342                                 $wgContLang->time( $rev->getTimestamp() ) )->inContentLanguage()->text();
 343                 } else {
 344                         $title = $rev->getUserText() .
 345                                 $this->msg( 'colon-separator' )->inContentLanguage()->text() .
 346                                 FeedItem::stripComment( $rev->getComment() );
 347                 }
 348
 349                 return new FeedItem(
 350                         $title,
 351                         $text,
 352                         $this->getTitle()->getFullURL( 'diff=' . $rev->getId() . '&oldid=prev' ),
 353                         $rev->getTimestamp(),
 354                         $rev->getUserText(),
 355                         $this->getTitle()->getTalkPage()->getFullURL()
 356                 );
 357         }
 358 }
 359
 360 /**
 361  * @ingroup Pager
 362  * @ingroup Actions
 363  */
 364 class HistoryPager extends ReverseChronologicalPager {
 365         /**
 366          * @var bool|stdClass
 367          */
 368         public $lastRow = false;
 369
 370         public $counter, $historyPage, $buttons, $conds;
 371
 372         protected $oldIdChecked;
 373
 374         protected $preventClickjacking = false;
 375         /**
 376          * @var array
 377          */
 378         protected $parentLens;
 379
 380         /**
 381          * @param HistoryAction $historyPage
 382          * @param string $year
 383          * @param string $month
 384          * @param string $tagFilter
 385          * @param array $conds
 386          */
 387         function __construct( $historyPage, $year = '', $month = '', $tagFilter = '', $conds = array() ) {
 388                 parent::__construct( $historyPage->getContext() );
 389                 $this->historyPage = $historyPage;
 390                 $this->tagFilter = $tagFilter;
 391                 $this->getDateCond( $year, $month );
 392                 $this->conds = $conds;
 393         }
 394
 395         // For hook compatibility...
 396         function getArticle() {
 397                 return $this->historyPage->getArticle();
 398         }
 399
 400         function getSqlComment() {
 401                 if ( $this->conds ) {
 402                         return 'history page filtered'; // potentially slow, see CR r58153
 403                 } else {
 404                         return 'history page unfiltered';
 405                 }
 406         }
 407
 408         function getQueryInfo() {
 409                 $queryInfo = array(
 410                         'tables' => array( 'revision', 'user' ),
 411                         'fields' => array_merge( Revision::selectFields(), Revision::selectUserFields() ),
 412                         'conds' => array_merge(
 413                                 array( 'rev_page' => $this->getWikiPage()->getId() ),
 414                                 $this->conds ),
 415                         'options' => array( 'USE INDEX' => array( 'revision' => 'page_timestamp' ) ),
 416                         'join_conds' => array( 'user' => Revision::userJoinCond() ),
 417                 );
 418                 ChangeTags::modifyDisplayQuery(
 419                         $queryInfo['tables'],
 420                         $queryInfo['fields'],
 421                         $queryInfo['conds'],
 422                         $queryInfo['join_conds'],
 423                         $queryInfo['options'],
 424                         $this->tagFilter
 425                 );
 426                 wfRunHooks( 'PageHistoryPager::getQueryInfo', array( &$this, &$queryInfo ) );
 427
 428                 return $queryInfo;
 429         }
 430
 431         function getIndexField() {
 432                 return 'rev_timestamp';
 433         }
 434
 435         /**
 436          * @param stdClass $row
 437          * @return string
 438          */
 439         function formatRow( $row ) {
 440                 if ( $this->lastRow ) {
 441                         $latest = ( $this->counter == 1 && $this->mIsFirst );
 442                         $firstInList = $this->counter == 1;
 443                         $this->counter++;
 444                         $s = $this->historyLine( $this->lastRow, $row,
 445                                 $this->getTitle()->getNotificationTimestamp( $this->getUser() ), $latest, $firstInList );
 446                 } else {
 447                         $s = '';
 448                 }
 449                 $this->lastRow = $row;
 450
 451                 return $s;
 452         }
 453
 454         function doBatchLookups() {
 455                 # Do a link batch query
 456                 $this->mResult->seek( 0 );
 457                 $batch = new LinkBatch();
 458                 $revIds = array();
 459                 foreach ( $this->mResult as $row ) {
 460                         if ( $row->rev_parent_id ) {
 461                                 $revIds[] = $row->rev_parent_id;
 462                         }
 463                         if ( !is_null( $row->user_name ) ) {
 464                                 $batch->add( NS_USER, $row->user_name );
 465                                 $batch->add( NS_USER_TALK, $row->user_name );
 466                         } else { # for anons or usernames of imported revisions
 467                                 $batch->add( NS_USER, $row->rev_user_text );
 468                                 $batch->add( NS_USER_TALK, $row->rev_user_text );
 469                         }
 470                 }
 471                 $this->parentLens = Revision::getParentLengths( $this->mDb, $revIds );
 472                 $batch->execute();
 473                 $this->mResult->seek( 0 );
 474         }
 475
 476         /**
 477          * Creates begin of history list with a submit button
 478          *
 479          * @return string HTML output
 480          */
 481         function getStartBody() {
 482                 $this->lastRow = false;
 483                 $this->counter = 1;
 484                 $this->oldIdChecked = 0;
 485
 486                 $this->getOutput()->wrapWikiMsg( "<div class='mw-history-legend'>\n$1\n</div>", 'histlegend' );
 487                 $s = Html::openElement( 'form', array( 'action' => wfScript(),
 488                         'id' => 'mw-history-compare' ) ) . "\n";
 489                 $s .= Html::hidden( 'title', $this->getTitle()->getPrefixedDBkey() ) . "\n";
 490                 $s .= Html::hidden( 'action', 'historysubmit' ) . "\n";
 491
 492                 // Button container stored in $this->buttons for re-use in getEndBody()
 493                 $this->buttons = '<div>';
 494                 $className = 'historysubmit mw-history-compareselectedversions-button';
 495                 if ( $this->getConfig()->get( 'UseMediaWikiUIEverywhere' ) ) {
 496                         $className .= ' mw-ui-button';
 497                 }
 498                 $this->buttons .= $this->submitButton( $this->msg( 'compareselectedversions' )->text(),
 499                         array( 'class' => $className )
 500                                 + Linker::tooltipAndAccesskeyAttribs( 'compareselectedversions' )
 501                 ) . "\n";
 502
 503                 if ( $this->getUser()->isAllowed( 'deleterevision' ) ) {
 504                         $this->buttons .= $this->getRevisionButton( 'revisiondelete', 'showhideselectedversions' );
 505                 }
 506                 $this->buttons .= '</div>';
 507
 508                 $s .= $this->buttons;
 509                 $s .= '<ul id="pagehistory">' . "\n";
 510
 511                 return $s;
 512         }
 513
 514         private function getRevisionButton( $name, $msg ) {
 515                 $this->preventClickjacking();
 516                 # Note bug #20966, <button> is non-standard in IE<8
 517                 $element = Html::element(
 518                         'button',
 519                         array(
 520                                 'type' => 'submit',
 521                                 'name' => $name,
 522                                 'value' => '1',
 523                                 'class' => "historysubmit mw-history-$name-button",
 524                         ),
 525                         $this->msg( $msg )->text()
 526                 ) . "\n";
 527                 return $element;
 528         }
 529
 530         function getEndBody() {
 531                 if ( $this->lastRow ) {
 532                         $latest = $this->counter == 1 && $this->mIsFirst;
 533                         $firstInList = $this->counter == 1;
 534                         if ( $this->mIsBackwards ) {
 535                                 # Next row is unknown, but for UI reasons, probably exists if an offset has been specified
 536                                 if ( $this->mOffset == '' ) {
 537                                         $next = null;
 538                                 } else {
 539                                         $next = 'unknown';
 540                                 }
 541                         } else {
 542                                 # The next row is the past-the-end row
 543                                 $next = $this->mPastTheEndRow;
 544                         }
 545                         $this->counter++;
 546                         $s = $this->historyLine( $this->lastRow, $next,
 547                                 $this->getTitle()->getNotificationTimestamp( $this->getUser() ), $latest, $firstInList );
 548                 } else {
 549                         $s = '';
 550                 }
 551                 $s .= "</ul>\n";
 552                 # Add second buttons only if there is more than one rev
 553                 if ( $this->getNumRows() > 2 ) {
 554                         $s .= $this->buttons;
 555                 }
 556                 $s .= '</form>';
 557
 558                 return $s;
 559         }
 560
 561         /**
 562          * Creates a submit button
 563          *
 564          * @param string $message Text of the submit button, will be escaped
 565          * @param array $attributes Attributes
 566          * @return string HTML output for the submit button
 567          */
 568         function submitButton( $message, $attributes = array() ) {
 569                 # Disable submit button if history has 1 revision only
 570                 if ( $this->getNumRows() > 1 ) {
 571                         return Xml::submitButton( $message, $attributes );
 572                 } else {
 573                         return '';
 574                 }
 575         }
 576
 577         /**
 578          * Returns a row from the history printout.
 579          *
 580          * @todo document some more, and maybe clean up the code (some params redundant?)
 581          *
 582          * @param stdClass $row The database row corresponding to the previous line.
 583          * @param mixed $next The database row corresponding to the next line
 584          *   (chronologically previous)
 585          * @param bool|string $notificationtimestamp
 586          * @param bool $latest Whether this row corresponds to the page's latest revision.
 587          * @param bool $firstInList Whether this row corresponds to the first
 588          *   displayed on this history page.
 589          * @return string HTML output for the row
 590          */
 591         function historyLine( $row, $next, $notificationtimestamp = false,
 592                 $latest = false, $firstInList = false ) {
 593                 $rev = new Revision( $row );
 594                 $rev->setTitle( $this->getTitle() );
 595
 596                 if ( is_object( $next ) ) {
 597                         $prevRev = new Revision( $next );
 598                         $prevRev->setTitle( $this->getTitle() );
 599                 } else {
 600                         $prevRev = null;
 601                 }
 602
 603                 $curlink = $this->curLink( $rev, $latest );
 604                 $lastlink = $this->lastLink( $rev, $next );
 605                 $curLastlinks = $curlink . $this->historyPage->message['pipe-separator'] . $lastlink;
 606                 $histLinks = Html::rawElement(
 607                         'span',
 608                         array( 'class' => 'mw-history-histlinks' ),
 609                         $this->msg( 'parentheses' )->rawParams( $curLastlinks )->escaped()
 610                 );
 611
 612                 $diffButtons = $this->diffButtons( $rev, $firstInList );
 613                 $s = $histLinks . $diffButtons;
 614
 615                 $link = $this->revLink( $rev );
 616                 $classes = array();
 617
 618                 $del = '';
 619                 $user = $this->getUser();
 620                 // Show checkboxes for each revision
 621                 if ( $user->isAllowed( 'deleterevision' ) ) {
 622                         $this->preventClickjacking();
 623                         // If revision was hidden from sysops, disable the checkbox
 624                         if ( !$rev->userCan( Revision::DELETED_RESTRICTED, $user ) ) {
 625                                 $del = Xml::check( 'deleterevisions', false, array( 'disabled' => 'disabled' ) );
 626                         // Otherwise, enable the checkbox...
 627                         } else {
 628                                 $del = Xml::check( 'showhiderevisions', false,
 629                                         array( 'name' => 'ids[' . $rev->getId() . ']' ) );
 630                         }
 631                 // User can only view deleted revisions...
 632                 } elseif ( $rev->getVisibility() && $user->isAllowed( 'deletedhistory' ) ) {
 633                         // If revision was hidden from sysops, disable the link
 634                         if ( !$rev->userCan( Revision::DELETED_RESTRICTED, $user ) ) {
 635                                 $del = Linker::revDeleteLinkDisabled( false );
 636                         // Otherwise, show the link...
 637                         } else {
 638                                 $query = array( 'type' => 'revision',
 639                                         'target' => $this->getTitle()->getPrefixedDBkey(), 'ids' => $rev->getId() );
 640                                 $del .= Linker::revDeleteLink( $query,
 641                                         $rev->isDeleted( Revision::DELETED_RESTRICTED ), false );
 642                         }
 643                 }
 644                 if ( $del ) {
 645                         $s .= " $del ";
 646                 }
 647
 648                 $lang = $this->getLanguage();
 649                 $dirmark = $lang->getDirMark();
 650
 651                 $s .= " $link";
 652                 $s .= $dirmark;
 653                 $s .= " <span class='history-user'>" .
 654                         Linker::revUserTools( $rev, true ) . "</span>";
 655                 $s .= $dirmark;
 656
 657                 if ( $rev->isMinor() ) {
 658                         $s .= ' ' . ChangesList::flag( 'minor' );
 659                 }
 660
 661                 # Sometimes rev_len isn't populated
 662                 if ( $rev->getSize() !== null ) {
 663                         # Size is always public data
 664                         $prevSize = isset( $this->parentLens[$row->rev_parent_id] )
 665                                 ? $this->parentLens[$row->rev_parent_id]
 666                                 : 0;
 667                         $sDiff = ChangesList::showCharacterDifference( $prevSize, $rev->getSize() );
 668                         $fSize = Linker::formatRevisionSize( $rev->getSize() );
 669                         $s .= ' <span class="mw-changeslist-separator">. .</span> ' . "$fSize $sDiff";
 670                 }
 671
 672                 # Text following the character difference is added just before running hooks
 673                 $s2 = Linker::revComment( $rev, false, true );
 674
 675                 if ( $notificationtimestamp && ( $row->rev_timestamp >= $notificationtimestamp ) ) {
 676                         $s2 .= ' <span class="updatedmarker">' . $this->msg( 'updatedmarker' )->escaped() . '</span>';
 677                         $classes[] = 'mw-history-line-updated';
 678                 }
 679
 680                 $tools = array();
 681
 682                 # Rollback and undo links
 683                 if ( $prevRev && $this->getTitle()->quickUserCan( 'edit', $user ) ) {
 684                         if ( $latest && $this->getTitle()->quickUserCan( 'rollback', $user ) ) {
 685                                 // Get a rollback link without the brackets
 686                                 $rollbackLink = Linker::generateRollback(
 687                                         $rev,
 688                                         $this->getContext(),
 689                                         array( 'verify', 'noBrackets' )
 690                                 );
 691                                 if ( $rollbackLink ) {
 692                                         $this->preventClickjacking();
 693                                         $tools[] = $rollbackLink;
 694                                 }
 695                         }
 696
 697                         if ( !$rev->isDeleted( Revision::DELETED_TEXT )
 698                                 && !$prevRev->isDeleted( Revision::DELETED_TEXT )
 699                         ) {
 700                                 # Create undo tooltip for the first (=latest) line only
 701                                 $undoTooltip = $latest
 702                                         ? array( 'title' => $this->msg( 'tooltip-undo' )->text() )
 703                                         : array();
 704                                 $undolink = Linker::linkKnown(
 705                                         $this->getTitle(),
 706                                         $this->msg( 'editundo' )->escaped(),
 707                                         $undoTooltip,
 708                                         array(
 709                                                 'action' => 'edit',
 710                                                 'undoafter' => $prevRev->getId(),
 711                                                 'undo' => $rev->getId()
 712                                         )
 713                                 );
 714                                 $tools[] = "<span class=\"mw-history-undo\">{$undolink}</span>";
 715                         }
 716                 }
 717                 // Allow extension to add their own links here
 718                 wfRunHooks( 'HistoryRevisionTools', array( $rev, &$tools ) );
 719
 720                 if ( $tools ) {
 721                         $s2 .= ' ' . $this->msg( 'parentheses' )->rawParams( $lang->pipeList( $tools ) )->escaped();
 722                 }
 723
 724                 # Tags
 725                 list( $tagSummary, $newClasses ) = ChangeTags::formatSummaryRow( $row->ts_tags, 'history' );
 726                 $classes = array_merge( $classes, $newClasses );
 727                 if ( $tagSummary !== '' ) {
 728                         $s2 .= " $tagSummary";
 729                 }
 730
 731                 # Include separator between character difference and following text
 732                 if ( $s2 !== '' ) {
 733                         $s .= ' <span class="mw-changeslist-separator">. .</span> ' . $s2;
 734                 }
 735
 736                 wfRunHooks( 'PageHistoryLineEnding', array( $this, &$row, &$s, &$classes ) );
 737
 738                 $attribs = array();
 739                 if ( $classes ) {
 740                         $attribs['class'] = implode( ' ', $classes );
 741                 }
 742
 743                 return Xml::tags( 'li', $attribs, $s ) . "\n";
 744         }
 745
 746         /**
 747          * Create a link to view this revision of the page
 748          *
 749          * @param Revision $rev
 750          * @return string
 751          */
 752         function revLink( $rev ) {
 753                 $date = $this->getLanguage()->userTimeAndDate( $rev->getTimestamp(), $this->getUser() );
 754                 $date = htmlspecialchars( $date );
 755                 if ( $rev->userCan( Revision::DELETED_TEXT, $this->getUser() ) ) {
 756                         $link = Linker::linkKnown(
 757                                 $this->getTitle(),
 758                                 $date,
 759                                 array( 'class' => 'mw-changeslist-date' ),
 760                                 array( 'oldid' => $rev->getId() )
 761                         );
 762                 } else {
 763                         $link = $date;
 764                 }
 765                 if ( $rev->isDeleted( Revision::DELETED_TEXT ) ) {
 766                         $link = "<span class=\"history-deleted\">$link</span>";
 767                 }
 768
 769                 return $link;
 770         }
 771
 772         /**
 773          * Create a diff-to-current link for this revision for this page
 774          *
 775          * @param Revision $rev
 776          * @param bool $latest This is the latest revision of the page?
 777          * @return string
 778          */
 779         function curLink( $rev, $latest ) {
 780                 $cur = $this->historyPage->message['cur'];
 781                 if ( $latest || !$rev->userCan( Revision::DELETED_TEXT, $this->getUser() ) ) {
 782                         return $cur;
 783                 } else {
 784                         return Linker::linkKnown(
 785                                 $this->getTitle(),
 786                                 $cur,
 787                                 array(),
 788                                 array(
 789                                         'diff' => $this->getWikiPage()->getLatest(),
 790                                         'oldid' => $rev->getId()
 791                                 )
 792                         );
 793                 }
 794         }
 795
 796         /**
 797          * Create a diff-to-previous link for this revision for this page.
 798          *
 799          * @param Revision $prevRev The revision being displayed
 800          * @param stdClass|string|null $next The next revision in list (that is
 801          *        the previous one in chronological order).
 802          *        May either be a row, "unknown" or null.
 803          * @return string
 804          */
 805         function lastLink( $prevRev, $next ) {
 806                 $last = $this->historyPage->message['last'];
 807
 808                 if ( $next === null ) {
 809                         # Probably no next row
 810                         return $last;
 811                 }
 812
 813                 if ( $next === 'unknown' ) {
 814                         # Next row probably exists but is unknown, use an oldid=prev link
 815                         return Linker::linkKnown(
 816                                 $this->getTitle(),
 817                                 $last,
 818                                 array(),
 819                                 array(
 820                                         'diff' => $prevRev->getId(),
 821                                         'oldid' => 'prev'
 822                                 )
 823                         );
 824                 }
 825
 826                 $nextRev = new Revision( $next );
 827
 828                 if ( !$prevRev->userCan( Revision::DELETED_TEXT, $this->getUser() )
 829                         || !$nextRev->userCan( Revision::DELETED_TEXT, $this->getUser() )
 830                 ) {
 831                         return $last;
 832                 }
 833
 834                 return Linker::linkKnown(
 835                         $this->getTitle(),
 836                         $last,
 837                         array(),
 838                         array(
 839                                 'diff' => $prevRev->getId(),
 840                                 'oldid' => $next->rev_id
 841                         )
 842                 );
 843         }
 844
 845         /**
 846          * Create radio buttons for page history
 847          *
 848          * @param Revision $rev
 849          * @param bool $firstInList Is this version the first one?
 850          *
 851          * @return string HTML output for the radio buttons
 852          */
 853         function diffButtons( $rev, $firstInList ) {
 854                 if ( $this->getNumRows() > 1 ) {
 855                         $id = $rev->getId();
 856                         $radio = array( 'type' => 'radio', 'value' => $id );
 857                         /** @todo Move title texts to javascript */
 858                         if ( $firstInList ) {
 859                                 $first = Xml::element( 'input',
 860                                         array_merge( $radio, array(
 861                                                 'style' => 'visibility:hidden',
 862                                                 'name' => 'oldid',
 863                                                 'id' => 'mw-oldid-null' ) )
 864                                 );
 865                                 $checkmark = array( 'checked' => 'checked' );
 866                         } else {
 867                                 # Check visibility of old revisions
 868                                 if ( !$rev->userCan( Revision::DELETED_TEXT, $this->getUser() ) ) {
 869                                         $radio['disabled'] = 'disabled';
 870                                         $checkmark = array(); // We will check the next possible one
 871                                 } elseif ( !$this->oldIdChecked ) {
 872                                         $checkmark = array( 'checked' => 'checked' );
 873                                         $this->oldIdChecked = $id;
 874                                 } else {
 875                                         $checkmark = array();
 876                                 }
 877                                 $first = Xml::element( 'input',
 878                                         array_merge( $radio, $checkmark, array(
 879                                                 'name' => 'oldid',
 880                                                 'id' => "mw-oldid-$id" ) ) );
 881                                 $checkmark = array();
 882                         }
 883                         $second = Xml::element( 'input',
 884                                 array_merge( $radio, $checkmark, array(
 885                                         'name' => 'diff',
 886                                         'id' => "mw-diff-$id" ) ) );
 887
 888                         return $first . $second;
 889                 } else {
 890                         return '';
 891                 }
 892         }
 893
 894         /**
 895          * This is called if a write operation is possible from the generated HTML
 896          * @param bool $enable
 897          */
 898         function preventClickjacking( $enable = true ) {
 899                 $this->preventClickjacking = $enable;
 900         }
 901
 902         /**
 903          * Get the "prevent clickjacking" flag
 904          * @return bool
 905          */
 906         function getPreventClickjacking() {
 907                 return $this->preventClickjacking;
 908         }
 909 }