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         function getArticle() {
  45                 return $this->mArticle;
  46         }
  47
  48         function getTitle() {
  49                 return $this->mTitle;
  50         }
  51
  52         /**
  53          * As we use the same small set of messages in various methods and that
  54          * they are called often, we call them once and save them in $this->message
  55          */
  56         function preCacheMessages() {
  57                 // Precache various messages
  58                 if( !isset( $this->message ) ) {
  59                         foreach( explode(' ', 'cur last rev-delundel' ) as $msg ) {
  60                                 $this->message[$msg] = wfMsgExt( $msg, array( 'escape') );
  61                         }
  62                 }
  63         }
  64
  65         /**
  66          * Print the history page for an article.
  67          *
  68          * @returns nothing
  69          */
  70         function history() {
  71                 global $wgOut, $wgRequest, $wgTitle, $wgScript;
  72
  73                 /*
  74                  * Allow client caching.
  75                  */
  76                 if( $wgOut->checkLastModified( $this->mArticle->getTouched() ) )
  77                         /* Client cache fresh and headers sent, nothing more to do. */
  78                         return;
  79
  80                 wfProfileIn( __METHOD__ );
  81
  82                 /*
  83                  * Setup page variables.
  84                  */
  85                 $wgOut->setPageTitle( wfMsg( 'history-title', $this->mTitle->getPrefixedText() ) );
  86                 $wgOut->setPageTitleActionText( wfMsg( 'history_short' ) );
  87                 $wgOut->setArticleFlag( false );
  88                 $wgOut->setArticleRelated( true );
  89                 $wgOut->setRobotPolicy( 'noindex,nofollow' );
  90                 $wgOut->setSyndicated( true );
  91                 $wgOut->setFeedAppendQuery( 'action=history' );
  92                 $wgOut->addScriptFile( 'history.js' );
  93
  94                 $logPage = SpecialPage::getTitleFor( 'Log' );
  95                 $logLink = $this->mSkin->makeKnownLinkObj( $logPage, wfMsgHtml( 'viewpagelogs' ), 'page=' . $this->mTitle->getPrefixedUrl() );
  96                 $wgOut->setSubtitle( $logLink );
  97
  98                 $feedType = $wgRequest->getVal( 'feed' );
  99                 if( $feedType ) {
 100                         wfProfileOut( __METHOD__ );
 101                         return $this->feed( $feedType );
 102                 }
 103
 104                 /*
 105                  * Fail if article doesn't exist.
 106                  */
 107                 if( !$this->mTitle->exists() ) {
 108                         $wgOut->addWikiMsg( 'nohistory' );
 109                         wfProfileOut( __METHOD__ );
 110                         return;
 111                 }
 112
 113                 /*
 114                  * "go=first" means to jump to the last (earliest) history page.
 115                  * This is deprecated, it no longer appears in the user interface
 116                  */
 117                 if ( $wgRequest->getText("go") == 'first' ) {
 118                         $limit = $wgRequest->getInt( 'limit', 50 );
 119                         global $wgFeedLimit;
 120                         if( $limit > $wgFeedLimit ) {
 121                                 $limit = $wgFeedLimit;
 122                         }
 123                         $wgOut->redirect( $wgTitle->getLocalURL( "action=history&limit={$limit}&dir=prev" ) );
 124                         return;
 125                 }
 126
 127                 /**
 128                  * Add date selector to quickly get to a certain time
 129                  */
 130                 $year = $wgRequest->getInt( 'year' );
 131                 $month = $wgRequest->getInt( 'month' );
 132
 133                 $action = htmlspecialchars( $wgScript );
 134                 $wgOut->addHTML(
 135                         Xml::fieldset( wfMsg( 'history-search' ) ) .
 136                         "<form action=\"$action\" method=\"get\"><div>" .
 137                         Xml::hidden( 'title', $this->mTitle->getPrefixedDBKey() ) . "\n" .
 138                         Xml::hidden( 'action', 'history' ) . "\n" .
 139                         $this->getDateMenu( $year, $month ) . '&nbsp;' .
 140                         Xml::submitButton( wfMsg( 'allpagessubmit' ) ) . "\n" .
 141                         '</div></form></fieldset>'
 142                 );
 143
 144                 wfRunHooks( 'PageHistoryBeforeList', array( &$this->mArticle ) );
 145
 146                 /**
 147                  * Do the list
 148                  */
 149                 $pager = new PageHistoryPager( $this, $year, $month );
 150                 $this->linesonpage = $pager->getNumRows();
 151                 $wgOut->addHTML(
 152                         $pager->getNavigationBar() .
 153                         $this->beginHistoryList() .
 154                         $pager->getBody() .
 155                         $this->endHistoryList() .
 156                         $pager->getNavigationBar()
 157                 );
 158                 wfProfileOut( __METHOD__ );
 159         }
 160
 161         /**
 162          * @return string Formatted HTML
 163          * @param int $year
 164          * @param int $month
 165          */
 166         private function getDateMenu( $year, $month ) {
 167                 # Offset overrides year/month selection
 168                 if( $month && $month !== -1 ) {
 169                         $encMonth = intval( $month );
 170                 } else {
 171                         $encMonth = '';
 172                 }
 173                 if ( $year ) {
 174                         $encYear = intval( $year );
 175                 } else if( $encMonth ) {
 176                         $thisMonth = intval( gmdate( 'n' ) );
 177                         $thisYear = intval( gmdate( 'Y' ) );
 178                         if( intval($encMonth) > $thisMonth ) {
 179                                 $thisYear--;
 180                         }
 181                         $encYear = $thisYear;
 182                 } else {
 183                         $encYear = '';
 184                 }
 185                 return Xml::label( wfMsg( 'year' ), 'year' ) . ' '.
 186                         Xml::input( 'year', 4, $encYear, array('id' => 'year', 'maxlength' => 4) ) .
 187                         ' '.
 188                         Xml::label( wfMsg( 'month' ), 'month' ) . ' '.
 189                         Xml::monthSelector( $encMonth, -1 );
 190         }
 191
 192         /**
 193          * Creates begin of history list with a submit button
 194          *
 195          * @return string HTML output
 196          */
 197         function beginHistoryList() {
 198                 global $wgTitle, $wgScript;
 199                 $this->lastdate = '';
 200                 $s = wfMsgExt( 'histlegend', array( 'parse') );
 201                 $s .= Xml::openElement( 'form', array( 'action' => $wgScript ) );
 202                 $s .= Xml::hidden( 'title', $wgTitle->getPrefixedDbKey() );
 203                 $s .= $this->submitButton();
 204                 $s .= '<ul id="pagehistory">' . "\n";
 205                 return $s;
 206         }
 207
 208         /**
 209          * Creates end of history list with a submit button
 210          *
 211          * @return string HTML output
 212          */
 213         function endHistoryList() {
 214                 $s = '</ul>';
 215                 $s .= $this->submitButton( array( 'id' => 'historysubmit' ) );
 216                 $s .= '</form>';
 217                 return $s;
 218         }
 219
 220         /**
 221          * Creates a submit button
 222          *
 223          * @param array $bits optional CSS ID
 224          * @return string HTML output for the submit button
 225          */
 226         function submitButton( $bits = array() ) {
 227                 # Disable submit button if history has 1 revision only
 228                 if ( $this->linesonpage > 1 ) {
 229                         return Xml::submitButton( wfMsg( 'compareselectedversions' ),
 230                                 $bits + array(
 231                                         'class'     => 'historysubmit',
 232                                         'accesskey' => wfMsg( 'accesskey-compareselectedversions' ),
 233                                         'title'     => wfMsg( 'tooltip-compareselectedversions' ),
 234                                         )
 235                                 );
 236                 } else {
 237                         return '';
 238                 }
 239         }
 240
 241         /**
 242          * Returns a row from the history printout.
 243          *
 244          * @todo document some more, and maybe clean up the code (some params redundant?)
 245          *
 246          * @param Row $row The database row corresponding to the previous line.
 247          * @param mixed $next The database row corresponding to the next line.
 248          * @param int $counter Apparently a counter of what row number we're at, counted from the top row = 1.
 249          * @param $notificationtimestamp
 250          * @param bool $latest Whether this row corresponds to the page's latest revision.
 251          * @param bool $firstInList Whether this row corresponds to the first displayed on this history page.
 252          * @return string HTML output for the row
 253          */
 254         function historyLine( $row, $next, $counter = '', $notificationtimestamp = false, $latest = false, $firstInList = false ) {
 255                 global $wgUser, $wgLang;
 256                 $rev = new Revision( $row );
 257                 $rev->setTitle( $this->mTitle );
 258
 259                 $s = '';
 260                 $curlink = $this->curLink( $rev, $latest );
 261                 $lastlink = $this->lastLink( $rev, $next, $counter );
 262                 $arbitrary = $this->diffButtons( $rev, $firstInList, $counter );
 263                 $link = $this->revLink( $rev );
 264
 265                 $s .= "($curlink) ($lastlink) $arbitrary";
 266
 267                 if( $wgUser->isAllowed( 'deleterevision' ) ) {
 268                         $revdel = SpecialPage::getTitleFor( 'Revisiondelete' );
 269                         if( $firstInList ) {
 270                         // We don't currently handle well changing the top revision's settings
 271                                 $del = $this->message['rev-delundel'];
 272                         } else if( !$rev->userCan( Revision::DELETED_RESTRICTED ) ) {
 273                         // If revision was hidden from sysops
 274                                 $del = $this->message['rev-delundel'];
 275                         } else {
 276                                 $del = $this->mSkin->makeKnownLinkObj( $revdel,
 277                                         $this->message['rev-delundel'],
 278                                         'target=' . urlencode( $this->mTitle->getPrefixedDbkey() ) .
 279                                         '&oldid=' . urlencode( $rev->getId() ) );
 280                                 // Bolden oversighted content
 281                                 if( $rev->isDeleted( Revision::DELETED_RESTRICTED ) )
 282                                         $del = "<strong>$del</strong>";
 283                         }
 284                         $s .= " <tt>(<small>$del</small>)</tt> ";
 285                 }
 286
 287                 $s .= " $link";
 288                 $s .= " <span class='history-user'>" . $this->mSkin->revUserTools( $rev, true ) . "</span>";
 289
 290                 if( $row->rev_minor_edit ) {
 291                         $s .= ' ' . Xml::element( 'span', array( 'class' => 'minor' ), wfMsg( 'minoreditletter') );
 292                 }
 293
 294                 if ( !is_null( $size = $rev->getSize() ) && $rev->userCan( Revision::DELETED_TEXT ) ) {
 295                         $s .= ' ' . $this->mSkin->formatRevisionSize( $size );
 296                 }
 297
 298                 $s .= $this->mSkin->revComment( $rev, false, true );
 299
 300                 if ($notificationtimestamp && ($row->rev_timestamp >= $notificationtimestamp)) {
 301                         $s .= ' <span class="updatedmarker">' .  wfMsgHtml( 'updatedmarker' ) . '</span>';
 302                 }
 303                 #add blurb about text having been deleted
 304                 if( $rev->isDeleted( Revision::DELETED_TEXT ) ) {
 305                         $s .= ' <tt>' . wfMsgHtml( 'deletedrev' ) . '</tt>';
 306                 }
 307
 308                 $tools = array();
 309
 310                 if ( !is_null( $next ) && is_object( $next ) ) {
 311                         if( !$this->mTitle->getUserPermissionsErrors( 'rollback', $wgUser )
 312                         && !$this->mTitle->getUserPermissionsErrors( 'edit', $wgUser )
 313                         && $latest ) {
 314                                 $tools[] = '<span class="mw-rollback-link">'
 315                                         . $this->mSkin->buildRollbackLink( $rev )
 316                                         . '</span>';
 317                         }
 318
 319                         if( $this->mTitle->quickUserCan( 'edit' ) &&
 320                                 !$rev->isDeleted( Revision::DELETED_TEXT ) &&
 321                                 !$next->rev_deleted & Revision::DELETED_TEXT ) {
 322                                 $undolink = $this->mSkin->makeKnownLinkObj(
 323                                         $this->mTitle,
 324                                         wfMsgHtml( 'editundo' ),
 325                                         'action=edit&undoafter=' . $next->rev_id . '&undo=' . $rev->getId()
 326                                 );
 327                                 $tools[] = "<span class=\"mw-history-undo\">{$undolink}</span>";
 328                         }
 329                 }
 330
 331                 if( $tools ) {
 332                         $s .= ' (' . implode( ' | ', $tools ) . ')';
 333                 }
 334
 335                 wfRunHooks( 'PageHistoryLineEnding', array( $this, &$row , &$s ) );
 336
 337                 return "<li>$s</li>\n";
 338         }
 339
 340         /**
 341         * Create a link to view this revision of the page
 342         * @param Revision $rev
 343         * @returns string
 344         */
 345         function revLink( $rev ) {
 346                 global $wgLang;
 347                 $date = $wgLang->timeanddate( wfTimestamp(TS_MW, $rev->getTimestamp()), true );
 348                 if( $rev->userCan( Revision::DELETED_TEXT ) ) {
 349                         $link = $this->mSkin->makeKnownLinkObj(
 350                                 $this->mTitle, $date, "oldid=" . $rev->getId() );
 351                 } else {
 352                         $link = $date;
 353                 }
 354                 if( $rev->isDeleted( Revision::DELETED_TEXT ) ) {
 355                         return '<span class="history-deleted">' . $link . '</span>';
 356                 }
 357                 return $link;
 358         }
 359
 360         /**
 361         * Create a diff-to-current link for this revision for this page
 362         * @param Revision $rev
 363         * @param Bool $latest, this is the latest revision of the page?
 364         * @returns string
 365         */
 366         function curLink( $rev, $latest ) {
 367                 $cur = $this->message['cur'];
 368                 if( $latest || !$rev->userCan( Revision::DELETED_TEXT ) ) {
 369                         return $cur;
 370                 } else {
 371                         return $this->mSkin->makeKnownLinkObj(
 372                                 $this->mTitle, $cur,
 373                                 'diff=' . $this->getLatestID() .
 374                                 "&oldid=" . $rev->getId() );
 375                 }
 376         }
 377
 378         /**
 379         * Create a diff-to-previous link for this revision for this page.
 380         * @param Revision $prevRev, the previous revision
 381         * @param mixed $next, the newer revision
 382         * @param int $counter, what row on the history list this is
 383         * @returns string
 384         */
 385         function lastLink( $prevRev, $next, $counter ) {
 386                 $last = $this->message['last'];
 387                 # $next may either be a Row, null, or "unkown"
 388                 $nextRev = is_object($next) ? new Revision( $next ) : $next;
 389                 if( is_null($next) ) {
 390                         # Probably no next row
 391                         return $last;
 392                 } elseif( $next === 'unknown' ) {
 393                         # Next row probably exists but is unknown, use an oldid=prev link
 394                         return $this->mSkin->makeKnownLinkObj(
 395                                 $this->mTitle,
 396                                 $last,
 397                                 "diff=" . $prevRev->getId() . "&oldid=prev" );
 398                 } elseif( !$prevRev->userCan(Revision::DELETED_TEXT) || !$nextRev->userCan(Revision::DELETED_TEXT) ) {
 399                         return $last;
 400                 } else {
 401                         return $this->mSkin->makeKnownLinkObj(
 402                                 $this->mTitle,
 403                                 $last,
 404                                 "diff=" . $prevRev->getId() . "&oldid={$next->rev_id}"
 405                                 /*,
 406                                 '',
 407                                 '',
 408                                 "tabindex={$counter}"*/ );
 409                 }
 410         }
 411
 412         /**
 413          * Create radio buttons for page history
 414          *
 415          * @param object $rev Revision
 416          * @param bool $firstInList Is this version the first one?
 417          * @param int $counter A counter of what row number we're at, counted from the top row = 1.
 418          * @return string HTML output for the radio buttons
 419          */
 420         function diffButtons( $rev, $firstInList, $counter ) {
 421                 if( $this->linesonpage > 1) {
 422                         $radio = array(
 423                                 'type'  => 'radio',
 424                                 'value' => $rev->getId(),
 425                         );
 426
 427                         if( !$rev->userCan( Revision::DELETED_TEXT ) ) {
 428                                 $radio['disabled'] = 'disabled';
 429                         }
 430
 431                         /** @todo: move title texts to javascript */
 432                         if ( $firstInList ) {
 433                                 $first = Xml::element( 'input', array_merge(
 434                                         $radio,
 435                                         array(
 436                                                 'style' => 'visibility:hidden',
 437                                                 'name'  => 'oldid' ) ) );
 438                                 $checkmark = array( 'checked' => 'checked' );
 439                         } else {
 440                                 if( $counter == 2 ) {
 441                                         $checkmark = array( 'checked' => 'checked' );
 442                                 } else {
 443                                         $checkmark = array();
 444                                 }
 445                                 $first = Xml::element( 'input', array_merge(
 446                                         $radio,
 447                                         $checkmark,
 448                                         array( 'name'  => 'oldid' ) ) );
 449                                 $checkmark = array();
 450                         }
 451                         $second = Xml::element( 'input', array_merge(
 452                                 $radio,
 453                                 $checkmark,
 454                                 array( 'name'  => 'diff' ) ) );
 455                         return $first . $second;
 456                 } else {
 457                         return '';
 458                 }
 459         }
 460
 461         /** @todo document */
 462         function getLatestId() {
 463                 if( is_null( $this->mLatestId ) ) {
 464                         $id = $this->mTitle->getArticleID();
 465                         $db = wfGetDB( DB_SLAVE );
 466                         $this->mLatestId = $db->selectField( 'page',
 467                                 "page_latest",
 468                                 array( 'page_id' => $id ),
 469                                 __METHOD__ );
 470                 }
 471                 return $this->mLatestId;
 472         }
 473
 474         /**
 475          * Fetch an array of revisions, specified by a given limit, offset and
 476          * direction. This is now only used by the feeds. It was previously
 477          * used by the main UI but that's now handled by the pager.
 478          */
 479         function fetchRevisions($limit, $offset, $direction) {
 480                 $dbr = wfGetDB( DB_SLAVE );
 481
 482                 if ($direction == PageHistory::DIR_PREV)
 483                         list($dirs, $oper) = array("ASC", ">=");
 484                 else /* $direction == PageHistory::DIR_NEXT */
 485                         list($dirs, $oper) = array("DESC", "<=");
 486
 487                 if ($offset)
 488                         $offsets = array("rev_timestamp $oper '$offset'");
 489                 else
 490                         $offsets = array();
 491
 492                 $page_id = $this->mTitle->getArticleID();
 493
 494                 return $dbr->select(
 495                         'revision',
 496                         Revision::selectFields(),
 497                         array_merge(array("rev_page=$page_id"), $offsets),
 498                         __METHOD__,
 499                         array('ORDER BY' => "rev_timestamp $dirs",
 500                                 'USE INDEX' => 'page_timestamp', 'LIMIT' => $limit)
 501                 );
 502         }
 503
 504         /** @todo document */
 505         function getNotificationTimestamp() {
 506                 global $wgUser, $wgShowUpdatedMarker;
 507
 508                 if ($this->mNotificationTimestamp !== NULL)
 509                         return $this->mNotificationTimestamp;
 510
 511                 if ($wgUser->isAnon() || !$wgShowUpdatedMarker)
 512                         return $this->mNotificationTimestamp = false;
 513
 514                 $dbr = wfGetDB(DB_SLAVE);
 515
 516                 $this->mNotificationTimestamp = $dbr->selectField(
 517                         'watchlist',
 518                         'wl_notificationtimestamp',
 519                         array(  'wl_namespace' => $this->mTitle->getNamespace(),
 520                                 'wl_title' => $this->mTitle->getDBkey(),
 521                                 'wl_user' => $wgUser->getId()
 522                         ),
 523                         __METHOD__ );
 524
 525                 // Don't use the special value reserved for telling whether the field is filled
 526                 if ( is_null( $this->mNotificationTimestamp ) ) {
 527                         $this->mNotificationTimestamp = false;
 528                 }
 529
 530                 return $this->mNotificationTimestamp;
 531         }
 532
 533         /**
 534          * Output a subscription feed listing recent edits to this page.
 535          * @param string $type
 536          */
 537         function feed( $type ) {
 538                 global $wgFeedClasses, $wgRequest, $wgFeedLimit;
 539                 if ( !FeedUtils::checkFeedOutput($type) ) {
 540                         return;
 541                 }
 542
 543                 $feed = new $wgFeedClasses[$type](
 544                         $this->mTitle->getPrefixedText() . ' - ' .
 545                                 wfMsgForContent( 'history-feed-title' ),
 546                         wfMsgForContent( 'history-feed-description' ),
 547                         $this->mTitle->getFullUrl( 'action=history' ) );
 548
 549                 // Get a limit on number of feed entries. Provide a sane default
 550                 // of 10 if none is defined (but limit to $wgFeedLimit max)
 551                 $limit = $wgRequest->getInt( 'limit', 10 );
 552                 if( $limit > $wgFeedLimit || $limit < 1 ) {
 553                         $limit = 10;
 554                 }
 555                 $items = $this->fetchRevisions($limit, 0, PageHistory::DIR_NEXT);
 556
 557                 $feed->outHeader();
 558                 if( $items ) {
 559                         foreach( $items as $row ) {
 560                                 $feed->outItem( $this->feedItem( $row ) );
 561                         }
 562                 } else {
 563                         $feed->outItem( $this->feedEmpty() );
 564                 }
 565                 $feed->outFooter();
 566         }
 567
 568         function feedEmpty() {
 569                 global $wgOut;
 570                 return new FeedItem(
 571                         wfMsgForContent( 'nohistory' ),
 572                         $wgOut->parse( wfMsgForContent( 'history-feed-empty' ) ),
 573                         $this->mTitle->getFullUrl(),
 574                         wfTimestamp( TS_MW ),
 575                         '',
 576                         $this->mTitle->getTalkPage()->getFullUrl() );
 577         }
 578
 579         /**
 580          * Generate a FeedItem object from a given revision table row
 581          * Borrows Recent Changes' feed generation functions for formatting;
 582          * includes a diff to the previous revision (if any).
 583          *
 584          * @param $row
 585          * @return FeedItem
 586          */
 587         function feedItem( $row ) {
 588                 $rev = new Revision( $row );
 589                 $rev->setTitle( $this->mTitle );
 590                 $text = FeedUtils::formatDiffRow( $this->mTitle,
 591                         $this->mTitle->getPreviousRevisionID( $rev->getId() ),
 592                         $rev->getId(),
 593                         $rev->getTimestamp(),
 594                         $rev->getComment() );
 595
 596                 if( $rev->getComment() == '' ) {
 597                         global $wgContLang;
 598                         $title = wfMsgForContent( 'history-feed-item-nocomment',
 599                                 $rev->getUserText(),
 600                                 $wgContLang->timeanddate( $rev->getTimestamp() ) );
 601                 } else {
 602                         $title = $rev->getUserText() . ": " . $this->stripComment( $rev->getComment() );
 603                 }
 604
 605                 return new FeedItem(
 606                         $title,
 607                         $text,
 608                         $this->mTitle->getFullUrl( 'diff=' . $rev->getId() . '&oldid=prev' ),
 609                         $rev->getTimestamp(),
 610                         $rev->getUserText(),
 611                         $this->mTitle->getTalkPage()->getFullUrl() );
 612         }
 613
 614         /**
 615          * Quickie hack... strip out wikilinks to more legible form from the comment.
 616          */
 617         function stripComment( $text ) {
 618                 return preg_replace( '/\[\[([^]]*\|)?([^]]+)\]\]/', '\2', $text );
 619         }
 620 }
 621
 622
 623 /**
 624  * @ingroup Pager
 625  */
 626 class PageHistoryPager extends ReverseChronologicalPager {
 627         public $mLastRow = false, $mPageHistory;
 628
 629         function __construct( $pageHistory, $year='', $month='' ) {
 630                 parent::__construct();
 631                 $this->mPageHistory = $pageHistory;
 632                 $this->getDateCond( $year, $month );
 633         }
 634
 635         function getQueryInfo() {
 636                 $queryInfo = array(
 637                         'tables'  => array('revision'),
 638                         'fields'  => Revision::selectFields(),
 639                         'conds'   => array('rev_page' => $this->mPageHistory->mTitle->getArticleID() ),
 640                         'options' => array( 'USE INDEX' => array('revision' => 'page_timestamp') )
 641                 );
 642                 wfRunHooks( 'PageHistoryPager::getQueryInfo', array( &$this, &$queryInfo ) );
 643                 return $queryInfo;
 644         }
 645
 646         function getIndexField() {
 647                 return 'rev_timestamp';
 648         }
 649
 650         function formatRow( $row ) {
 651                 if ( $this->mLastRow ) {
 652                         $latest = $this->mCounter == 1 && $this->mIsFirst;
 653                         $firstInList = $this->mCounter == 1;
 654                         $s = $this->mPageHistory->historyLine( $this->mLastRow, $row, $this->mCounter++,
 655                                 $this->mPageHistory->getNotificationTimestamp(), $latest, $firstInList );
 656                 } else {
 657                         $s = '';
 658                 }
 659                 $this->mLastRow = $row;
 660                 return $s;
 661         }
 662
 663         function getStartBody() {
 664                 $this->mLastRow = false;
 665                 $this->mCounter = 1;
 666                 return '';
 667         }
 668
 669         function getEndBody() {
 670                 if ( $this->mLastRow ) {
 671                         $latest = $this->mCounter == 1 && $this->mIsFirst;
 672                         $firstInList = $this->mCounter == 1;
 673                         if ( $this->mIsBackwards ) {
 674                                 # Next row is unknown, but for UI reasons, probably exists if an offset has been specified
 675                                 if ( $this->mOffset == '' ) {
 676                                         $next = null;
 677                                 } else {
 678                                         $next = 'unknown';
 679                                 }
 680                         } else {
 681                                 # The next row is the past-the-end row
 682                                 $next = $this->mPastTheEndRow;
 683                         }
 684                         $s = $this->mPageHistory->historyLine( $this->mLastRow, $next, $this->mCounter++,
 685                                 $this->mPageHistory->getNotificationTimestamp(), $latest, $firstInList );
 686                 } else {
 687                         $s = '';
 688                 }
 689                 return $s;
 690         }
 691 }