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