includes/PageHistory.php

   1 <?php
   2 /**
   3  * Page history
   4  *
   5  * Split off from Article.php and Skin.php, 2003-12-22
   6  * @file
   7  */
   8
   9 /**
  10  * This class handles printing the history page for an article.  In order to
  11  * be efficient, it uses timestamps rather than offsets for paging, to avoid
  12  * costly LIMIT,offset queries.
  13  *
  14  * Construct it by passing in an Article, and call $h->history() to print the
  15  * history.
  16  *
  17  */
  18 class PageHistory {
  19         const DIR_PREV = 0;
  20         const DIR_NEXT = 1;
  21
  22         var $mArticle, $mTitle, $mSkin;
  23         var $lastdate;
  24         var $linesonpage;
  25         var $mNotificationTimestamp;
  26         var $mLatestId = null;
  27
  28         /**
  29          * Construct a new PageHistory.
  30          *
  31          * @param Article $article
  32          * @returns nothing
  33          */
  34         function __construct($article) {
  35                 global $wgUser;
  36
  37                 $this->mArticle =& $article;
  38                 $this->mTitle =& $article->mTitle;
  39                 $this->mNotificationTimestamp = NULL;
  40                 $this->mSkin = $wgUser->getSkin();
  41                 $this->preCacheMessages();
  42         }
  43
  44         /**
  45          * As we use the same small set of messages in various methods and that
  46          * they are called often, we call them once and save them in $this->message
  47          */
  48         function preCacheMessages() {
  49                 // Precache various messages
  50                 if( !isset( $this->message ) ) {
  51                         foreach( explode(' ', 'cur last rev-delundel' ) as $msg ) {
  52                                 $this->message[$msg] = wfMsgExt( $msg, array( 'escape') );
  53                         }
  54                 }
  55         }
  56
  57         /**
  58          * Print the history page for an article.
  59          *
  60          * @returns nothing
  61          */
  62         function history() {
  63                 global $wgOut, $wgRequest, $wgTitle;
  64
  65                 /*
  66                  * Allow client caching.
  67                  */
  68
  69                 if( $wgOut->checkLastModified( $this->mArticle->getTouched() ) )
  70                         /* Client cache fresh and headers sent, nothing more to do. */
  71                         return;
  72
  73                 wfProfileIn( __METHOD__ );
  74
  75                 /*
  76                  * Setup page variables.
  77                  */
  78                 $wgOut->setPageTitle( wfMsg( 'history-title', $this->mTitle->getPrefixedText() ) );
  79                 $wgOut->setPageTitleActionText( wfMsg( 'history_short' ) );
  80                 $wgOut->setArticleFlag( false );
  81                 $wgOut->setArticleRelated( true );
  82                 $wgOut->setRobotpolicy( 'noindex,nofollow' );
  83                 $wgOut->setSyndicated( true );
  84                 $wgOut->setFeedAppendQuery( 'action=history' );
  85                 $wgOut->addScriptFile( 'history.js' );
  86
  87                 $logPage = SpecialPage::getTitleFor( 'Log' );
  88                 $logLink = $this->mSkin->makeKnownLinkObj( $logPage, wfMsgHtml( 'viewpagelogs' ), 'page=' . $this->mTitle->getPrefixedUrl() );
  89                 $wgOut->setSubtitle( $logLink );
  90
  91                 $feedType = $wgRequest->getVal( 'feed' );
  92                 if( $feedType ) {
  93                         wfProfileOut( __METHOD__ );
  94                         return $this->feed( $feedType );
  95                 }
  96
  97                 /*
  98                  * Fail if article doesn't exist.
  99                  */
 100                 if( !$this->mTitle->exists() ) {
 101                         $wgOut->addWikiMsg( 'nohistory' );
 102                         wfProfileOut( __METHOD__ );
 103                         return;
 104                 }
 105
 106                 /*
 107                  * "go=first" means to jump to the last (earliest) history page.
 108                  * This is deprecated, it no longer appears in the user interface
 109                  */
 110                 if ( $wgRequest->getText("go") == 'first' ) {
 111                         $limit = $wgRequest->getInt( 'limit', 50 );
 112                         global $wgFeedLimit;
 113                         if( $limit > $wgFeedLimit ) {
 114                                 $limit = $wgFeedLimit;
 115                         }
 116                         $wgOut->redirect( $wgTitle->getLocalURL( "action=history&limit={$limit}&dir=prev" ) );
 117                         return;
 118                 }
 119
 120                 wfRunHooks( 'PageHistoryBeforeList', array( &$this->mArticle ) );
 121
 122                 /**
 123                  * Do the list
 124                  */
 125                 $pager = new PageHistoryPager( $this );
 126                 $this->linesonpage = $pager->getNumRows();
 127                 $wgOut->addHTML(
 128                         $pager->getNavigationBar() .
 129                         $this->beginHistoryList() .
 130                         $pager->getBody() .
 131                         $this->endHistoryList() .
 132                         $pager->getNavigationBar()
 133                 );
 134                 wfProfileOut( __METHOD__ );
 135         }
 136
 137         /**
 138          * Creates begin of history list with a submit button
 139          *
 140          * @return string HTML output
 141          */
 142         function beginHistoryList() {
 143                 global $wgTitle, $wgScript;
 144                 $this->lastdate = '';
 145                 $s = wfMsgExt( 'histlegend', array( 'parse') );
 146                 $s .= Xml::openElement( 'form', array( 'action' => $wgScript ) );
 147                 $s .= Xml::hidden( 'title', $wgTitle->getPrefixedDbKey() );
 148                 $s .= $this->submitButton();
 149                 $s .= '<ul id="pagehistory">' . "\n";
 150                 return $s;
 151         }
 152
 153         /**
 154          * Creates end of history list with a submit button
 155          *
 156          * @return string HTML output
 157          */
 158         function endHistoryList() {
 159                 $s = '</ul>';
 160                 $s .= $this->submitButton( array( 'id' => 'historysubmit' ) );
 161                 $s .= '</form>';
 162                 return $s;
 163         }
 164
 165         /**
 166          * Creates a submit button
 167          *
 168          * @param array $bits optional CSS ID
 169          * @return string HTML output for the submit button
 170          */
 171         function submitButton( $bits = array() ) {
 172                 # Disable submit button if history has 1 revision only
 173                 if ( $this->linesonpage > 1 ) {
 174                         return Xml::submitButton( wfMsg( 'compareselectedversions' ),
 175                                 $bits + array(
 176                                         'class'     => 'historysubmit',
 177                                         'accesskey' => wfMsg( 'accesskey-compareselectedversions' ),
 178                                         'title'     => wfMsg( 'tooltip-compareselectedversions' ),
 179                                         )
 180                                 );
 181                 } else {
 182                         return '';
 183                 }
 184         }
 185
 186         /**
 187          * Returns a row from the history printout.
 188          *
 189          * @todo document some more, and maybe clean up the code (some params redundant?)
 190          *
 191          * @param Row $row The database row corresponding to the previous line.
 192          * @param mixed $next The database row corresponding to the next line.
 193          * @param int $counter Apparently a counter of what row number we're at, counted from the top row = 1.
 194          * @param $notificationtimestamp
 195          * @param bool $latest Whether this row corresponds to the page's latest revision.
 196          * @param bool $firstInList Whether this row corresponds to the first displayed on this history page.
 197          * @return string HTML output for the row
 198          */
 199         function historyLine( $row, $next, $counter = '', $notificationtimestamp = false, $latest = false, $firstInList = false ) {
 200                 global $wgUser, $wgLang;
 201                 $rev = new Revision( $row );
 202                 $rev->setTitle( $this->mTitle );
 203
 204                 $s = '';
 205                 $curlink = $this->curLink( $rev, $latest );
 206                 $lastlink = $this->lastLink( $rev, $next, $counter );
 207                 $arbitrary = $this->diffButtons( $rev, $firstInList, $counter );
 208                 $link = $this->revLink( $rev );
 209
 210                 $s .= "($curlink) ($lastlink) $arbitrary";
 211
 212                 if( $wgUser->isAllowed( 'deleterevision' ) ) {
 213                         $revdel = SpecialPage::getTitleFor( 'Revisiondelete' );
 214                         if( $firstInList ) {
 215                         // We don't currently handle well changing the top revision's settings
 216                                 $del = $this->message['rev-delundel'];
 217                         } else if( !$rev->userCan( Revision::DELETED_RESTRICTED ) ) {
 218                         // If revision was hidden from sysops
 219                                 $del = $this->message['rev-delundel'];
 220                         } else {
 221                                 $del = $this->mSkin->makeKnownLinkObj( $revdel,
 222                                         $this->message['rev-delundel'],
 223                                         'target=' . urlencode( $this->mTitle->getPrefixedDbkey() ) .
 224                                         '&oldid=' . urlencode( $rev->getId() ) );
 225                                 // Bolden oversighted content
 226                                 if( $rev->isDeleted( Revision::DELETED_RESTRICTED ) )
 227                                         $del = "<strong>$del</strong>";
 228                         }
 229                         $s .= " <tt>(<small>$del</small>)</tt> ";
 230                 }
 231
 232                 $s .= " $link";
 233                 $s .= " <span class='history-user'>" . $this->mSkin->revUserTools( $rev, true ) . "</span>";
 234
 235                 if( $row->rev_minor_edit ) {
 236                         $s .= ' ' . Xml::element( 'span', array( 'class' => 'minor' ), wfMsg( 'minoreditletter') );
 237                 }
 238
 239                 if ( !is_null( $size = $rev->getSize() ) && $rev->userCan( Revision::DELETED_TEXT ) ) {
 240                         if ( $size == 0 )
 241                                 $stxt = wfMsgHtml( 'historyempty' );
 242                         else
 243                                 $stxt = wfMsgExt( 'historysize', array( 'parsemag' ), $wgLang->formatNum( $size ) );
 244                         $s .= " <span class=\"history-size\">$stxt</span>";
 245                 }
 246
 247                 $s .= $this->mSkin->revComment( $rev, false, true );
 248
 249                 if ($notificationtimestamp && ($row->rev_timestamp >= $notificationtimestamp)) {
 250                         $s .= ' <span class="updatedmarker">' .  wfMsgHtml( 'updatedmarker' ) . '</span>';
 251                 }
 252                 #add blurb about text having been deleted
 253                 if( $rev->isDeleted( Revision::DELETED_TEXT ) ) {
 254                         $s .= ' <tt>' . wfMsgHtml( 'deletedrev' ) . '</tt>';
 255                 }
 256
 257                 $tools = array();
 258
 259                 if ( !is_null( $next ) && is_object( $next ) ) {
 260                         if( !$this->mTitle->getUserPermissionsErrors( 'rollback', $wgUser )
 261                         && !$this->mTitle->getUserPermissionsErrors( 'edit', $wgUser )
 262                         && $latest ) {
 263                                 $tools[] = '<span class="mw-rollback-link">'
 264                                         . $this->mSkin->buildRollbackLink( $rev )
 265                                         . '</span>';
 266                         }
 267
 268                         if( $this->mTitle->quickUserCan( 'edit' ) &&
 269                                 !$rev->isDeleted( Revision::DELETED_TEXT ) &&
 270                                 !$next->rev_deleted & Revision::DELETED_TEXT ) {
 271                                 $undolink = $this->mSkin->makeKnownLinkObj(
 272                                         $this->mTitle,
 273                                         wfMsgHtml( 'editundo' ),
 274                                         'action=edit&undoafter=' . $next->rev_id . '&undo=' . $rev->getId()
 275                                 );
 276                                 $tools[] = "<span class=\"mw-history-undo\">{$undolink}</span>";
 277                         }
 278                 }
 279
 280                 if( $tools ) {
 281                         $s .= ' (' . implode( ' | ', $tools ) . ')';
 282                 }
 283
 284                 wfRunHooks( 'PageHistoryLineEnding', array( &$row , &$s ) );
 285
 286                 return "<li>$s</li>\n";
 287         }
 288
 289         /**
 290         * Create a link to view this revision of the page
 291         * @param Revision $rev
 292         * @returns string
 293         */
 294         function revLink( $rev ) {
 295                 global $wgLang;
 296                 $date = $wgLang->timeanddate( wfTimestamp(TS_MW, $rev->getTimestamp()), true );
 297                 if( $rev->userCan( Revision::DELETED_TEXT ) ) {
 298                         $link = $this->mSkin->makeKnownLinkObj(
 299                                 $this->mTitle, $date, "oldid=" . $rev->getId() );
 300                 } else {
 301                         $link = $date;
 302                 }
 303                 if( $rev->isDeleted( Revision::DELETED_TEXT ) ) {
 304                         return '<span class="history-deleted">' . $link . '</span>';
 305                 }
 306                 return $link;
 307         }
 308
 309         /**
 310         * Create a diff-to-current link for this revision for this page
 311         * @param Revision $rev
 312         * @param Bool $latest, this is the latest revision of the page?
 313         * @returns string
 314         */
 315         function curLink( $rev, $latest ) {
 316                 $cur = $this->message['cur'];
 317                 if( $latest || !$rev->userCan( Revision::DELETED_TEXT ) ) {
 318                         return $cur;
 319                 } else {
 320                         return $this->mSkin->makeKnownLinkObj(
 321                                 $this->mTitle, $cur,
 322                                 'diff=' . $this->getLatestID() .
 323                                 "&oldid=" . $rev->getId() );
 324                 }
 325         }
 326
 327         /**
 328         * Create a diff-to-previous link for this revision for this page.
 329         * @param Revision $prevRev, the previous revision
 330         * @param mixed $next, the newer revision
 331         * @param int $counter, what row on the history list this is
 332         * @returns string
 333         */
 334         function lastLink( $prevRev, $next, $counter ) {
 335                 $last = $this->message['last'];
 336                 # $next may either be a Row, null, or "unkown"
 337                 $nextRev = is_object($next) ? new Revision( $next ) : $next;
 338                 if( is_null($next) ) {
 339                         # Probably no next row
 340                         return $last;
 341                 } elseif( $next === 'unknown' ) {
 342                         # Next row probably exists but is unknown, use an oldid=prev link
 343                         return $this->mSkin->makeKnownLinkObj(
 344                                 $this->mTitle,
 345                                 $last,
 346                                 "diff=" . $prevRev->getId() . "&oldid=prev" );
 347                 } elseif( !$prevRev->userCan(Revision::DELETED_TEXT) || !$nextRev->userCan(Revision::DELETED_TEXT) ) {
 348                         return $last;
 349                 } else {
 350                         return $this->mSkin->makeKnownLinkObj(
 351                                 $this->mTitle,
 352                                 $last,
 353                                 "diff=" . $prevRev->getId() . "&oldid={$next->rev_id}"
 354                                 /*,
 355                                 '',
 356                                 '',
 357                                 "tabindex={$counter}"*/ );
 358                 }
 359         }
 360
 361         /**
 362          * Create radio buttons for page history
 363          *
 364          * @param object $rev Revision
 365          * @param bool $firstInList Is this version the first one?
 366          * @param int $counter A counter of what row number we're at, counted from the top row = 1.
 367          * @return string HTML output for the radio buttons
 368          */
 369         function diffButtons( $rev, $firstInList, $counter ) {
 370                 if( $this->linesonpage > 1) {
 371                         $radio = array(
 372                                 'type'  => 'radio',
 373                                 'value' => $rev->getId(),
 374                         );
 375
 376                         if( !$rev->userCan( Revision::DELETED_TEXT ) ) {
 377                                 $radio['disabled'] = 'disabled';
 378                         }
 379
 380                         /** @todo: move title texts to javascript */
 381                         if ( $firstInList ) {
 382                                 $first = Xml::element( 'input', array_merge(
 383                                         $radio,
 384                                         array(
 385                                                 'style' => 'visibility:hidden',
 386                                                 'name'  => 'oldid' ) ) );
 387                                 $checkmark = array( 'checked' => 'checked' );
 388                         } else {
 389                                 if( $counter == 2 ) {
 390                                         $checkmark = array( 'checked' => 'checked' );
 391                                 } else {
 392                                         $checkmark = array();
 393                                 }
 394                                 $first = Xml::element( 'input', array_merge(
 395                                         $radio,
 396                                         $checkmark,
 397                                         array( 'name'  => 'oldid' ) ) );
 398                                 $checkmark = array();
 399                         }
 400                         $second = Xml::element( 'input', array_merge(
 401                                 $radio,
 402                                 $checkmark,
 403                                 array( 'name'  => 'diff' ) ) );
 404                         return $first . $second;
 405                 } else {
 406                         return '';
 407                 }
 408         }
 409
 410         /** @todo document */
 411         function getLatestId() {
 412                 if( is_null( $this->mLatestId ) ) {
 413                         $id = $this->mTitle->getArticleID();
 414                         $db = wfGetDB( DB_SLAVE );
 415                         $this->mLatestId = $db->selectField( 'page',
 416                                 "page_latest",
 417                                 array( 'page_id' => $id ),
 418                                 __METHOD__ );
 419                 }
 420                 return $this->mLatestId;
 421         }
 422
 423         /**
 424          * Fetch an array of revisions, specified by a given limit, offset and
 425          * direction. This is now only used by the feeds. It was previously
 426          * used by the main UI but that's now handled by the pager.
 427          */
 428         function fetchRevisions($limit, $offset, $direction) {
 429                 $dbr = wfGetDB( DB_SLAVE );
 430
 431                 if ($direction == PageHistory::DIR_PREV)
 432                         list($dirs, $oper) = array("ASC", ">=");
 433                 else /* $direction == PageHistory::DIR_NEXT */
 434                         list($dirs, $oper) = array("DESC", "<=");
 435
 436                 if ($offset)
 437                         $offsets = array("rev_timestamp $oper '$offset'");
 438                 else
 439                         $offsets = array();
 440
 441                 $page_id = $this->mTitle->getArticleID();
 442
 443                 $res = $dbr->select(
 444                         'revision',
 445                         Revision::selectFields(),
 446                         array_merge(array("rev_page=$page_id"), $offsets),
 447                         __METHOD__,
 448                         array('ORDER BY' => "rev_timestamp $dirs",
 449                                 'USE INDEX' => 'page_timestamp', 'LIMIT' => $limit)
 450                         );
 451
 452                 $result = array();
 453                 while (($obj = $dbr->fetchObject($res)) != NULL)
 454                         $result[] = $obj;
 455
 456                 return $result;
 457         }
 458
 459         /** @todo document */
 460         function getNotificationTimestamp() {
 461                 global $wgUser, $wgShowUpdatedMarker;
 462
 463                 if ($this->mNotificationTimestamp !== NULL)
 464                         return $this->mNotificationTimestamp;
 465
 466                 if ($wgUser->isAnon() || !$wgShowUpdatedMarker)
 467                         return $this->mNotificationTimestamp = false;
 468
 469                 $dbr = wfGetDB(DB_SLAVE);
 470
 471                 $this->mNotificationTimestamp = $dbr->selectField(
 472                         'watchlist',
 473                         'wl_notificationtimestamp',
 474                         array(  'wl_namespace' => $this->mTitle->getNamespace(),
 475                                 'wl_title' => $this->mTitle->getDBkey(),
 476                                 'wl_user' => $wgUser->getId()
 477                         ),
 478                         __METHOD__ );
 479
 480                 // Don't use the special value reserved for telling whether the field is filled
 481                 if ( is_null( $this->mNotificationTimestamp ) ) {
 482                         $this->mNotificationTimestamp = false;
 483                 }
 484
 485                 return $this->mNotificationTimestamp;
 486         }
 487
 488         /**
 489          * Output a subscription feed listing recent edits to this page.
 490          * @param string $type
 491          */
 492         function feed( $type ) {
 493                 require_once 'SpecialRecentchanges.php';
 494
 495                 global $wgFeed, $wgFeedClasses;
 496
 497                 if ( !$wgFeed ) {
 498                         global $wgOut;
 499                         $wgOut->addWikiMsg( 'feed-unavailable' );
 500                         return;
 501                 }
 502
 503                 if( !isset( $wgFeedClasses[$type] ) ) {
 504                         global $wgOut;
 505                         $wgOut->addWikiMsg( 'feed-invalid' );
 506                         return;
 507                 }
 508
 509                 $feed = new $wgFeedClasses[$type](
 510                         $this->mTitle->getPrefixedText() . ' - ' .
 511                                 wfMsgForContent( 'history-feed-title' ),
 512                         wfMsgForContent( 'history-feed-description' ),
 513                         $this->mTitle->getFullUrl( 'action=history' ) );
 514
 515                 $items = $this->fetchRevisions(10, 0, PageHistory::DIR_NEXT);
 516                 $feed->outHeader();
 517                 if( $items ) {
 518                         foreach( $items as $row ) {
 519                                 $feed->outItem( $this->feedItem( $row ) );
 520                         }
 521                 } else {
 522                         $feed->outItem( $this->feedEmpty() );
 523                 }
 524                 $feed->outFooter();
 525         }
 526
 527         function feedEmpty() {
 528                 global $wgOut;
 529                 return new FeedItem(
 530                         wfMsgForContent( 'nohistory' ),
 531                         $wgOut->parse( wfMsgForContent( 'history-feed-empty' ) ),
 532                         $this->mTitle->getFullUrl(),
 533                         wfTimestamp( TS_MW ),
 534                         '',
 535                         $this->mTitle->getTalkPage()->getFullUrl() );
 536         }
 537
 538         /**
 539          * Generate a FeedItem object from a given revision table row
 540          * Borrows Recent Changes' feed generation functions for formatting;
 541          * includes a diff to the previous revision (if any).
 542          *
 543          * @param $row
 544          * @return FeedItem
 545          */
 546         function feedItem( $row ) {
 547                 $rev = new Revision( $row );
 548                 $rev->setTitle( $this->mTitle );
 549                 $text = rcFormatDiffRow( $this->mTitle,
 550                         $this->mTitle->getPreviousRevisionID( $rev->getId() ),
 551                         $rev->getId(),
 552                         $rev->getTimestamp(),
 553                         $rev->getComment() );
 554
 555                 if( $rev->getComment() == '' ) {
 556                         global $wgContLang;
 557                         $title = wfMsgForContent( 'history-feed-item-nocomment',
 558                                 $rev->getUserText(),
 559                                 $wgContLang->timeanddate( $rev->getTimestamp() ) );
 560                 } else {
 561                         $title = $rev->getUserText() . ": " . $this->stripComment( $rev->getComment() );
 562                 }
 563
 564                 return new FeedItem(
 565                         $title,
 566                         $text,
 567                         $this->mTitle->getFullUrl( 'diff=' . $rev->getId() . '&oldid=prev' ),
 568                         $rev->getTimestamp(),
 569                         $rev->getUserText(),
 570                         $this->mTitle->getTalkPage()->getFullUrl() );
 571         }
 572
 573         /**
 574          * Quickie hack... strip out wikilinks to more legible form from the comment.
 575          */
 576         function stripComment( $text ) {
 577                 return preg_replace( '/\[\[([^]]*\|)?([^]]+)\]\]/', '\2', $text );
 578         }
 579 }
 580
 581
 582 /**
 583  * @ingroup Pager
 584  */
 585 class PageHistoryPager extends ReverseChronologicalPager {
 586         public $mLastRow = false, $mPageHistory;
 587
 588         function __construct( $pageHistory ) {
 589                 parent::__construct();
 590                 $this->mPageHistory = $pageHistory;
 591         }
 592
 593         function getQueryInfo() {
 594                 return array(
 595                         'tables' => 'revision',
 596                         'fields' => Revision::selectFields(),
 597                         'conds' => array('rev_page' => $this->mPageHistory->mTitle->getArticleID() ),
 598                         'options' => array( 'USE INDEX' => 'page_timestamp' )
 599                 );
 600         }
 601
 602         function getIndexField() {
 603                 return 'rev_timestamp';
 604         }
 605
 606         function formatRow( $row ) {
 607                 if ( $this->mLastRow ) {
 608                         $latest = $this->mCounter == 1 && $this->mIsFirst;
 609                         $firstInList = $this->mCounter == 1;
 610                         $s = $this->mPageHistory->historyLine( $this->mLastRow, $row, $this->mCounter++,
 611                                 $this->mPageHistory->getNotificationTimestamp(), $latest, $firstInList );
 612                 } else {
 613                         $s = '';
 614                 }
 615                 $this->mLastRow = $row;
 616                 return $s;
 617         }
 618
 619         function getStartBody() {
 620                 $this->mLastRow = false;
 621                 $this->mCounter = 1;
 622                 return '';
 623         }
 624
 625         function getEndBody() {
 626                 if ( $this->mLastRow ) {
 627                         $latest = $this->mCounter == 1 && $this->mIsFirst;
 628                         $firstInList = $this->mCounter == 1;
 629                         if ( $this->mIsBackwards ) {
 630                                 # Next row is unknown, but for UI reasons, probably exists if an offset has been specified
 631                                 if ( $this->mOffset == '' ) {
 632                                         $next = null;
 633                                 } else {
 634                                         $next = 'unknown';
 635                                 }
 636                         } else {
 637                                 # The next row is the past-the-end row
 638                                 $next = $this->mPastTheEndRow;
 639                         }
 640                         $s = $this->mPageHistory->historyLine( $this->mLastRow, $next, $this->mCounter++,
 641                                 $this->mPageHistory->getNotificationTimestamp(), $latest, $firstInList );
 642                 } else {
 643                         $s = '';
 644                 }
 645                 return $s;
 646         }
 647 }