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 $mLatestId = null;
  26
  27         /**
  28          * Construct a new PageHistory.
  29          *
  30          * @param Article $article
  31          * @returns nothing
  32          */
  33         function __construct( $article ) {
  34                 global $wgUser;
  35                 $this->mArticle =& $article;
  36                 $this->mTitle =& $article->mTitle;
  37                 $this->mSkin = $wgUser->getSkin();
  38                 $this->preCacheMessages();
  39         }
  40
  41         function getArticle() {
  42                 return $this->mArticle;
  43         }
  44
  45         function getTitle() {
  46                 return $this->mTitle;
  47         }
  48
  49         /**
  50          * As we use the same small set of messages in various methods and that
  51          * they are called often, we call them once and save them in $this->message
  52          */
  53         function preCacheMessages() {
  54                 // Precache various messages
  55                 if( !isset( $this->message ) ) {
  56                         foreach( explode(' ', 'cur last rev-delundel' ) as $msg ) {
  57                                 $this->message[$msg] = wfMsgExt( $msg, array( 'escape') );
  58                         }
  59                 }
  60         }
  61
  62         /**
  63          * Print the history page for an article.
  64          *
  65          * @returns nothing
  66          */
  67         function history() {
  68                 global $wgOut, $wgRequest, $wgTitle, $wgScript;
  69
  70                 /*
  71                  * Allow client caching.
  72                  */
  73                 if( $wgOut->checkLastModified( $this->mArticle->getTouched() ) )
  74                         return; // Client cache fresh and headers sent, nothing more to do.
  75
  76                 wfProfileIn( __METHOD__ );
  77
  78                 /*
  79                  * Setup page variables.
  80                  */
  81                 $wgOut->setPageTitle( wfMsg( 'history-title', $this->mTitle->getPrefixedText() ) );
  82                 $wgOut->setPageTitleActionText( wfMsg( 'history_short' ) );
  83                 $wgOut->setArticleFlag( false );
  84                 $wgOut->setArticleRelated( true );
  85                 $wgOut->setRobotPolicy( 'noindex,nofollow' );
  86                 $wgOut->setSyndicated( true );
  87                 $wgOut->setFeedAppendQuery( 'action=history' );
  88                 $wgOut->addScriptFile( 'history.js' );
  89
  90                 $logPage = SpecialPage::getTitleFor( 'Log' );
  91                 $logLink = $this->mSkin->makeKnownLinkObj( $logPage, wfMsgHtml( 'viewpagelogs' ),
  92                         'page=' . $this->mTitle->getPrefixedUrl() );
  93                 $wgOut->setSubtitle( $logLink );
  94
  95                 $feedType = $wgRequest->getVal( 'feed' );
  96                 if( $feedType ) {
  97                         wfProfileOut( __METHOD__ );
  98                         return $this->feed( $feedType );
  99                 }
 100
 101                 /*
 102                  * Fail if article doesn't exist.
 103                  */
 104                 if( !$this->mTitle->exists() ) {
 105                         $wgOut->addWikiMsg( 'nohistory' );
 106                         wfProfileOut( __METHOD__ );
 107                         return;
 108                 }
 109
 110                 /**
 111                  * Add date selector to quickly get to a certain time
 112                  */
 113                 $year = $wgRequest->getInt( 'year' );
 114                 $month = $wgRequest->getInt( 'month' );
 115                 $tagFilter = $wgRequest->getVal( 'tagfilter' );
 116
 117                 $action = htmlspecialchars( $wgScript );
 118                 $wgOut->addHTML(
 119                         "<form action=\"$action\" method=\"get\" id=\"mw-history-searchform\">" .
 120                         Xml::fieldset( wfMsg( 'history-fieldset-title' ), false, array( 'id' => 'mw-history-search' ) ) .
 121                         Xml::hidden( 'title', $this->mTitle->getPrefixedDBKey() ) . "\n" .
 122                         Xml::hidden( 'action', 'history' ) . "\n" .
 123                         $this->getDateMenu( $year, $month ) . '&nbsp;' .
 124                         implode( '&nbsp;', ChangeTags::buildTagFilterSelector( $tagFilter ) ) . '&nbsp;' .
 125                         Xml::submitButton( wfMsg( 'allpagessubmit' ) ) . "\n" .
 126                         '</fieldset></form>'
 127                 );
 128
 129                 wfRunHooks( 'PageHistoryBeforeList', array( &$this->mArticle ) );
 130
 131                 /**
 132                  * Do the list
 133                  */
 134                 $pager = new PageHistoryPager( $this, $year, $month, $tagFilter );
 135                 $this->linesonpage = $pager->getNumRows();
 136                 $wgOut->addHTML(
 137                         $pager->getNavigationBar() .
 138                         $this->beginHistoryList() .
 139                         $pager->getBody() .
 140                         $this->endHistoryList() .
 141                         $pager->getNavigationBar()
 142                 );
 143
 144                 wfProfileOut( __METHOD__ );
 145         }
 146
 147         /**
 148          * @return string Formatted HTML
 149          * @param int $year
 150          * @param int $month
 151          */
 152         private function getDateMenu( $year, $month ) {
 153                 # Offset overrides year/month selection
 154                 if( $month && $month !== -1 ) {
 155                         $encMonth = intval( $month );
 156                 } else {
 157                         $encMonth = '';
 158                 }
 159                 if( $year ) {
 160                         $encYear = intval( $year );
 161                 } else if( $encMonth ) {
 162                         $thisMonth = intval( gmdate( 'n' ) );
 163                         $thisYear = intval( gmdate( 'Y' ) );
 164                         if( intval($encMonth) > $thisMonth ) {
 165                                 $thisYear--;
 166                         }
 167                         $encYear = $thisYear;
 168                 } else {
 169                         $encYear = '';
 170                 }
 171                 return Xml::label( wfMsg( 'year' ), 'year' ) . ' '.
 172                         Xml::input( 'year', 4, $encYear, array('id' => 'year', 'maxlength' => 4) ) .
 173                                 ' '.
 174                         Xml::label( wfMsg( 'month' ), 'month' ) . ' '.
 175                         Xml::monthSelector( $encMonth, -1 );
 176         }
 177
 178         /**
 179          * Creates begin of history list with a submit button
 180          *
 181          * @return string HTML output
 182          */
 183         function beginHistoryList() {
 184                 global $wgTitle, $wgScript, $wgEnableHtmlDiff;
 185                 $this->lastdate = '';
 186                 $s = wfMsgExt( 'histlegend', array( 'parse') );
 187                 $s .= Xml::openElement( 'form', array( 'action' => $wgScript, 'id' => 'mw-history-compare' ) );
 188                 $s .= Xml::hidden( 'title', $wgTitle->getPrefixedDbKey() );
 189                 if( $wgEnableHtmlDiff ) {
 190                         $s .= $this->submitButton( wfMsg( 'visualcomparison'),
 191                                 array(
 192                                                 'name' => 'htmldiff',
 193                                                 'class'     => 'historysubmit',
 194                                                 'accesskey' => wfMsg( 'accesskey-visualcomparison' ),
 195                                                 'title'     => wfMsg( 'tooltip-compareselectedversions' ),
 196                                 )
 197                         );
 198                         $s .= $this->submitButton( wfMsg( 'wikicodecomparison'),
 199                                 array(
 200                                                 'class'     => 'historysubmit',
 201                                                 'accesskey' => wfMsg( 'accesskey-compareselectedversions' ),
 202                                                 'title'     => wfMsg( 'tooltip-compareselectedversions' ),
 203                                 )
 204                         );
 205                 } else {
 206                         $s .= $this->submitButton( wfMsg( 'compareselectedversions'),
 207                                 array(
 208                                                 'class'     => 'historysubmit',
 209                                                 'accesskey' => wfMsg( 'accesskey-compareselectedversions' ),
 210                                                 'title'     => wfMsg( 'tooltip-compareselectedversions' ),
 211                                 )
 212                         );
 213                 }
 214                 $s .= '<ul id="pagehistory">' . "\n";
 215                 return $s;
 216         }
 217
 218         /**
 219          * Creates end of history list with a submit button
 220          *
 221          * @return string HTML output
 222          */
 223         function endHistoryList() {
 224                 global $wgEnableHtmlDiff;
 225                 $s = '</ul>';
 226                 if( $wgEnableHtmlDiff ) {
 227                         $s .= $this->submitButton( wfMsg( 'visualcomparison'),
 228                                 array(
 229                                                 'name' => 'htmldiff',
 230                                                 'class'     => 'historysubmit',
 231                                                 'accesskey' => wfMsg( 'accesskey-visualcomparison' ),
 232                                                 'title'     => wfMsg( 'tooltip-compareselectedversions' ),
 233                                 )
 234                         );
 235                         $s .= $this->submitButton( wfMsg( 'wikicodecomparison'),
 236                                 array(
 237                                                 'class'     => 'historysubmit',
 238                                                 'accesskey' => wfMsg( 'accesskey-compareselectedversions' ),
 239                                                 'title'     => wfMsg( 'tooltip-compareselectedversions' ),
 240                                 )
 241                         );
 242                 } else {
 243                         $s .= $this->submitButton( wfMsg( 'compareselectedversions'),
 244                                 array(
 245                                                 'class'     => 'historysubmit',
 246                                                 'accesskey' => wfMsg( 'accesskey-compareselectedversions' ),
 247                                                 'title'     => wfMsg( 'tooltip-compareselectedversions' ),
 248                                 )
 249                         );
 250                 }
 251                 $s .= '</form>';
 252                 return $s;
 253         }
 254
 255         /**
 256          * Creates a submit button
 257          *
 258          * @param array $attributes attributes
 259          * @return string HTML output for the submit button
 260          */
 261         function submitButton($message, $attributes = array() ) {
 262                 # Disable submit button if history has 1 revision only
 263                 if( $this->linesonpage > 1 ) {
 264                         return Xml::submitButton( $message , $attributes );
 265                 } else {
 266                         return '';
 267                 }
 268         }
 269
 270         /**
 271          * Returns a row from the history printout.
 272          *
 273          * @todo document some more, and maybe clean up the code (some params redundant?)
 274          *
 275          * @param Row $row The database row corresponding to the previous line.
 276          * @param mixed $next The database row corresponding to the next line.
 277          * @param int $counter Apparently a counter of what row number we're at, counted from the top row = 1.
 278          * @param $notificationtimestamp
 279          * @param bool $latest Whether this row corresponds to the page's latest revision.
 280          * @param bool $firstInList Whether this row corresponds to the first displayed on this history page.
 281          * @return string HTML output for the row
 282          */
 283         function historyLine( $row, $next, $counter = '', $notificationtimestamp = false, $latest = false, $firstInList = false ) {
 284                 global $wgUser, $wgLang;
 285                 $rev = new Revision( $row );
 286                 $rev->setTitle( $this->mTitle );
 287
 288                 $curlink = $this->curLink( $rev, $latest );
 289                 $lastlink = $this->lastLink( $rev, $next, $counter );
 290                 $arbitrary = $this->diffButtons( $rev, $firstInList, $counter );
 291                 $link = $this->revLink( $rev );
 292                 $classes = array();
 293
 294                 $s = "($curlink) ($lastlink) $arbitrary";
 295
 296                 if( $wgUser->isAllowed( 'deleterevision' ) ) {
 297                         if( $firstInList ) {
 298                                 // We don't currently handle well changing the top revision's settings
 299                                 $del = Xml::tags( 'span', array( 'class'=>'mw-revdelundel-link' ), '('.$this->message['rev-delundel'].')' );
 300                         } else if( !$rev->userCan( Revision::DELETED_RESTRICTED ) ) {
 301                                 // If revision was hidden from sysops
 302                                 $del = Xml::tags( 'span', array( 'class'=>'mw-revdelundel-link' ), '('.$this->message['rev-delundel'].')' );
 303                         } else {
 304                                 $query = array( 'target' => $this->mTitle->getPrefixedDbkey(),
 305                                         'oldid' => $rev->getId()
 306                                 );
 307                                 $del = $this->mSkin->revDeleteLink( $query, $rev->isDeleted( Revision::DELETED_RESTRICTED ) );
 308                         }
 309                         $s .= " $del ";
 310                 }
 311
 312                 $s .= " $link";
 313                 $s .= " <span class='history-user'>" . $this->mSkin->revUserTools( $rev, true ) . "</span>";
 314
 315                 if( $row->rev_minor_edit ) {
 316                         $s .= ' ' . Xml::element( 'span', array( 'class' => 'minor' ), wfMsg( 'minoreditletter') );
 317                 }
 318
 319                 if( !is_null( $size = $rev->getSize() ) && $rev->userCan( Revision::DELETED_TEXT ) ) {
 320                         $s .= ' ' . $this->mSkin->formatRevisionSize( $size );
 321                 }
 322
 323                 $s .= $this->mSkin->revComment( $rev, false, true );
 324
 325                 if( $notificationtimestamp && ($row->rev_timestamp >= $notificationtimestamp) ) {
 326                         $s .= ' <span class="updatedmarker">' .  wfMsgHtml( 'updatedmarker' ) . '</span>';
 327                 }
 328                 if( $rev->isDeleted( Revision::DELETED_TEXT ) ) {
 329                         $s .= ' <tt>' . wfMsgHtml( 'deletedrev' ) . '</tt>';
 330                 }
 331
 332                 $tools = array();
 333
 334                 if( !is_null( $next ) && is_object( $next ) ) {
 335                         if( $latest && $this->mTitle->userCan( 'rollback' ) && $this->mTitle->userCan( 'edit' ) ) {
 336                                 $tools[] = '<span class="mw-rollback-link">'.$this->mSkin->buildRollbackLink( $rev ).'</span>';
 337                         }
 338
 339                         if( $this->mTitle->quickUserCan( 'edit' ) && !$rev->isDeleted( Revision::DELETED_TEXT ) &&
 340                                 !$next->rev_deleted & Revision::DELETED_TEXT )
 341                         {
 342                                 # Create undo tooltip for the first (=latest) line only
 343                                 $undoTooltip = $latest
 344                                         ? array( 'title' => wfMsg( 'tooltip-undo' ) )
 345                                         : array();
 346                                 $undolink = $this->mSkin->link(
 347                                         $this->mTitle,
 348                                         wfMsgHtml( 'editundo' ),
 349                                         $undoTooltip,
 350                                         array( 'action' => 'edit', 'undoafter' => $next->rev_id, 'undo' => $rev->getId() ),
 351                                         array( 'known', 'noclasses' )
 352                                 );
 353                                 $tools[] = "<span class=\"mw-history-undo\">{$undolink}</span>";
 354                         }
 355                 }
 356
 357                 if( $tools ) {
 358                         $s .= ' (' . implode( ' | ', $tools ) . ')';
 359                 }
 360
 361                 # Tags
 362                 list($tagSummary, $newClasses) = ChangeTags::formatSummaryRow( $row->ts_tags, 'history' );
 363                 $classes = array_merge( $classes, $newClasses );
 364                 $s .= " $tagSummary";
 365
 366                 wfRunHooks( 'PageHistoryLineEnding', array( $this, &$row , &$s ) );
 367
 368                 $classes = implode( ' ', $classes );
 369
 370                 return "<li class=\"$classes\">$s</li>\n";
 371         }
 372
 373         /**
 374          * Create a link to view this revision of the page
 375          * @param Revision $rev
 376          * @returns string
 377          */
 378         function revLink( $rev ) {
 379                 global $wgLang;
 380                 $date = $wgLang->timeanddate( wfTimestamp(TS_MW, $rev->getTimestamp()), true );
 381                 if( $rev->userCan( Revision::DELETED_TEXT ) ) {
 382                         $link = $this->mSkin->makeKnownLinkObj(
 383                         $this->mTitle, $date, "oldid=" . $rev->getId() );
 384                 } else {
 385                         $link = $date;
 386                 }
 387                 if( $rev->isDeleted( Revision::DELETED_TEXT ) ) {
 388                         return '<span class="history-deleted">' . $link . '</span>';
 389                 }
 390                 return $link;
 391         }
 392
 393         /**
 394          * Create a diff-to-current link for this revision for this page
 395          * @param Revision $rev
 396          * @param Bool $latest, this is the latest revision of the page?
 397          * @returns string
 398          */
 399         function curLink( $rev, $latest ) {
 400                 $cur = $this->message['cur'];
 401                 if( $latest || !$rev->userCan( Revision::DELETED_TEXT ) ) {
 402                         return $cur;
 403                 } else {
 404                         return $this->mSkin->makeKnownLinkObj( $this->mTitle, $cur,
 405                                 'diff=' . $this->mTitle->getLatestRevID() . "&oldid=" . $rev->getId() );
 406                 }
 407         }
 408
 409         /**
 410          * Create a diff-to-previous link for this revision for this page.
 411          * @param Revision $prevRev, the previous revision
 412          * @param mixed $next, the newer revision
 413          * @param int $counter, what row on the history list this is
 414          * @returns string
 415          */
 416         function lastLink( $prevRev, $next, $counter ) {
 417                 $last = $this->message['last'];
 418                 # $next may either be a Row, null, or "unkown"
 419                 $nextRev = is_object($next) ? new Revision( $next ) : $next;
 420                 if( is_null($next) ) {
 421                         # Probably no next row
 422                         return $last;
 423                 } elseif( $next === 'unknown' ) {
 424                         # Next row probably exists but is unknown, use an oldid=prev link
 425                         return $this->mSkin->makeKnownLinkObj( $this->mTitle, $last,
 426                                 "diff=" . $prevRev->getId() . "&oldid=prev" );
 427                 } elseif( !$prevRev->userCan(Revision::DELETED_TEXT) || !$nextRev->userCan(Revision::DELETED_TEXT) ) {
 428                         return $last;
 429                 } else {
 430                         return $this->mSkin->makeKnownLinkObj( $this->mTitle, $last,
 431                                 "diff=" . $prevRev->getId() . "&oldid={$next->rev_id}" );
 432                 }
 433         }
 434
 435         /**
 436          * Create radio buttons for page history
 437          *
 438          * @param object $rev Revision
 439          * @param bool $firstInList Is this version the first one?
 440          * @param int $counter A counter of what row number we're at, counted from the top row = 1.
 441          * @return string HTML output for the radio buttons
 442          */
 443         function diffButtons( $rev, $firstInList, $counter ) {
 444                 if( $this->linesonpage > 1) {
 445                         $radio = array(
 446                                 'type'  => 'radio',
 447                                 'value' => $rev->getId(),
 448                         );
 449
 450                         if( !$rev->userCan( Revision::DELETED_TEXT ) ) {
 451                                 $radio['disabled'] = 'disabled';
 452                         }
 453
 454                         /** @todo: move title texts to javascript */
 455                         if( $firstInList ) {
 456                                 $first = Xml::element( 'input', array_merge(
 457                                 $radio,
 458                                 array(
 459                                                 'style' => 'visibility:hidden',
 460                                                 'name'  => 'oldid' ) ) );
 461                                 $checkmark = array( 'checked' => 'checked' );
 462                         } else {
 463                                 if( $counter == 2 ) {
 464                                         $checkmark = array( 'checked' => 'checked' );
 465                                 } else {
 466                                         $checkmark = array();
 467                                 }
 468                                 $first = Xml::element( 'input', array_merge(
 469                                 $radio,
 470                                 $checkmark,
 471                                 array( 'name'  => 'oldid' ) ) );
 472                                 $checkmark = array();
 473                         }
 474                         $second = Xml::element( 'input', array_merge(
 475                         $radio,
 476                         $checkmark,
 477                         array( 'name'  => 'diff' ) ) );
 478                         return $first . $second;
 479                 } else {
 480                         return '';
 481                 }
 482         }
 483
 484         /**
 485          * Fetch an array of revisions, specified by a given limit, offset and
 486          * direction. This is now only used by the feeds. It was previously
 487          * used by the main UI but that's now handled by the pager.
 488          */
 489         function fetchRevisions($limit, $offset, $direction) {
 490                 $dbr = wfGetDB( DB_SLAVE );
 491
 492                 if( $direction == PageHistory::DIR_PREV )
 493                         list($dirs, $oper) = array("ASC", ">=");
 494                 else /* $direction == PageHistory::DIR_NEXT */
 495                         list($dirs, $oper) = array("DESC", "<=");
 496
 497                 if( $offset )
 498                         $offsets = array("rev_timestamp $oper '$offset'");
 499                 else
 500                         $offsets = array();
 501
 502                 $page_id = $this->mTitle->getArticleID();
 503
 504                 return $dbr->select( 'revision',
 505                         Revision::selectFields(),
 506                         array_merge(array("rev_page=$page_id"), $offsets),
 507                         __METHOD__,
 508                         array( 'ORDER BY' => "rev_timestamp $dirs",
 509                                 'USE INDEX' => 'page_timestamp', 'LIMIT' => $limit)
 510                 );
 511         }
 512
 513         /**
 514          * Output a subscription feed listing recent edits to this page.
 515          * @param string $type
 516          */
 517         function feed( $type ) {
 518                 global $wgFeedClasses, $wgRequest, $wgFeedLimit;
 519                 if( !FeedUtils::checkFeedOutput($type) ) {
 520                         return;
 521                 }
 522
 523                 $feed = new $wgFeedClasses[$type](
 524                 $this->mTitle->getPrefixedText() . ' - ' .
 525                 wfMsgForContent( 'history-feed-title' ),
 526                 wfMsgForContent( 'history-feed-description' ),
 527                 $this->mTitle->getFullUrl( 'action=history' ) );
 528
 529                 // Get a limit on number of feed entries. Provide a sane default
 530                 // of 10 if none is defined (but limit to $wgFeedLimit max)
 531                 $limit = $wgRequest->getInt( 'limit', 10 );
 532                 if( $limit > $wgFeedLimit || $limit < 1 ) {
 533                         $limit = 10;
 534                 }
 535                 $items = $this->fetchRevisions($limit, 0, PageHistory::DIR_NEXT);
 536
 537                 $feed->outHeader();
 538                 if( $items ) {
 539                         foreach( $items as $row ) {
 540                                 $feed->outItem( $this->feedItem( $row ) );
 541                         }
 542                 } else {
 543                         $feed->outItem( $this->feedEmpty() );
 544                 }
 545                 $feed->outFooter();
 546         }
 547
 548         function feedEmpty() {
 549                 global $wgOut;
 550                 return new FeedItem(
 551                         wfMsgForContent( 'nohistory' ),
 552                         $wgOut->parse( wfMsgForContent( 'history-feed-empty' ) ),
 553                         $this->mTitle->getFullUrl(),
 554                         wfTimestamp( TS_MW ),
 555                                 '',
 556                         $this->mTitle->getTalkPage()->getFullUrl() );
 557         }
 558
 559         /**
 560          * Generate a FeedItem object from a given revision table row
 561          * Borrows Recent Changes' feed generation functions for formatting;
 562          * includes a diff to the previous revision (if any).
 563          *
 564          * @param $row
 565          * @return FeedItem
 566          */
 567         function feedItem( $row ) {
 568                 $rev = new Revision( $row );
 569                 $rev->setTitle( $this->mTitle );
 570                 $text = FeedUtils::formatDiffRow( $this->mTitle,
 571                 $this->mTitle->getPreviousRevisionID( $rev->getId() ),
 572                 $rev->getId(),
 573                 $rev->getTimestamp(),
 574                 $rev->getComment() );
 575
 576                 if( $rev->getComment() == '' ) {
 577                         global $wgContLang;
 578                         $title = wfMsgForContent( 'history-feed-item-nocomment',
 579                         $rev->getUserText(),
 580                         $wgContLang->timeanddate( $rev->getTimestamp() ) );
 581                 } else {
 582                         $title = $rev->getUserText() . wfMsgForContent( 'colon-separator' ) . FeedItem::stripComment( $rev->getComment() );
 583                 }
 584
 585                 return new FeedItem(
 586                         $title,
 587                         $text,
 588                         $this->mTitle->getFullUrl( 'diff=' . $rev->getId() . '&oldid=prev' ),
 589                         $rev->getTimestamp(),
 590                         $rev->getUserText(),
 591                         $this->mTitle->getTalkPage()->getFullUrl() );
 592         }
 593 }
 594
 595
 596 /**
 597  * @ingroup Pager
 598  */
 599 class PageHistoryPager extends ReverseChronologicalPager {
 600         public $mLastRow = false, $mPageHistory, $mTitle;
 601
 602         function __construct( $pageHistory, $year='', $month='', $tagFilter = '' ) {
 603                 parent::__construct();
 604                 $this->mPageHistory = $pageHistory;
 605                 $this->mTitle =& $this->mPageHistory->mTitle;
 606                 $this->tagFilter = $tagFilter;
 607                 $this->getDateCond( $year, $month );
 608         }
 609
 610         function getQueryInfo() {
 611                 $queryInfo = array(
 612                         'tables'  => array('revision'),
 613                         'fields'  => array_merge( Revision::selectFields(), array('ts_tags') ),
 614                         'conds'   => array('rev_page' => $this->mPageHistory->mTitle->getArticleID() ),
 615                         'options' => array( 'USE INDEX' => array('revision' => 'page_timestamp') ),
 616                         'join_conds' => array( 'tag_summary' => array( 'LEFT JOIN', 'ts_rev_id=rev_id' ) ),
 617                 );
 618                 ChangeTags::modifyDisplayQuery( $queryInfo['tables'], $queryInfo['fields'], $queryInfo['conds'], $queryInfo['join_conds'], $this->tagFilter );
 619                 wfRunHooks( 'PageHistoryPager::getQueryInfo', array( &$this, &$queryInfo ) );
 620                 return $queryInfo;
 621         }
 622
 623         function getIndexField() {
 624                 return 'rev_timestamp';
 625         }
 626
 627         function formatRow( $row ) {
 628                 if( $this->mLastRow ) {
 629                         $latest = $this->mCounter == 1 && $this->mIsFirst;
 630                         $firstInList = $this->mCounter == 1;
 631                         $s = $this->mPageHistory->historyLine( $this->mLastRow, $row, $this->mCounter++,
 632                                 $this->mTitle->getNotificationTimestamp(), $latest, $firstInList );
 633                 } else {
 634                         $s = '';
 635                 }
 636                 $this->mLastRow = $row;
 637                 return $s;
 638         }
 639
 640         function getStartBody() {
 641                 $this->mLastRow = false;
 642                 $this->mCounter = 1;
 643                 return '';
 644         }
 645
 646         function getEndBody() {
 647                 if( $this->mLastRow ) {
 648                         $latest = $this->mCounter == 1 && $this->mIsFirst;
 649                         $firstInList = $this->mCounter == 1;
 650                         if( $this->mIsBackwards ) {
 651                                 # Next row is unknown, but for UI reasons, probably exists if an offset has been specified
 652                                 if( $this->mOffset == '' ) {
 653                                         $next = null;
 654                                 } else {
 655                                         $next = 'unknown';
 656                                 }
 657                         } else {
 658                                 # The next row is the past-the-end row
 659                                 $next = $this->mPastTheEndRow;
 660                         }
 661                         $s = $this->mPageHistory->historyLine( $this->mLastRow, $next, $this->mCounter++,
 662                                 $this->mTitle->getNotificationTimestamp(), $latest, $firstInList );
 663                 } else {
 664                         $s = '';
 665                 }
 666                 return $s;
 667         }
 668 }