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->link(
  94                         $logPage,
  95                         wfMsgHtml( 'viewpagelogs' ),
  96                         array(),
  97                         array( 'page' => $this->mTitle->getPrefixedText() ),
  98                         array( 'known', 'noclasses' )
  99                 );
 100                 $wgOut->setSubtitle( $logLink );
 101
 102                 $feedType = $wgRequest->getVal( 'feed' );
 103                 if( $feedType ) {
 104                         wfProfileOut( __METHOD__ );
 105                         return $this->feed( $feedType );
 106                 }
 107
 108                 /*
 109                  * Fail if article doesn't exist.
 110                  */
 111                 if( !$this->mTitle->exists() ) {
 112                         $wgOut->addWikiMsg( 'nohistory' );
 113                         wfProfileOut( __METHOD__ );
 114                         return;
 115                 }
 116
 117                 /**
 118                  * Add date selector to quickly get to a certain time
 119                  */
 120                 $year = $wgRequest->getInt( 'year' );
 121                 $month = $wgRequest->getInt( 'month' );
 122                 $tagFilter = $wgRequest->getVal( 'tagfilter' );
 123                 $tagSelector = ChangeTags::buildTagFilterSelector( $tagFilter );
 124
 125                 $action = htmlspecialchars( $wgScript );
 126                 $wgOut->addHTML(
 127                         "<form action=\"$action\" method=\"get\" id=\"mw-history-searchform\">" .
 128                         Xml::fieldset( wfMsg( 'history-fieldset-title' ), false, array( 'id' => 'mw-history-search' ) ) .
 129                         Xml::hidden( 'title', $this->mTitle->getPrefixedDBKey() ) . "\n" .
 130                         Xml::hidden( 'action', 'history' ) . "\n" .
 131                         xml::dateMenu( $year, $month ) . '&nbsp;' .
 132                         ( $tagSelector ? ( implode( '&nbsp;', $tagSelector ) . '&nbsp;' ) : '' ) .
 133                         Xml::submitButton( wfMsg( 'allpagessubmit' ) ) . "\n" .
 134                         '</fieldset></form>'
 135                 );
 136
 137                 wfRunHooks( 'PageHistoryBeforeList', array( &$this->mArticle ) );
 138
 139                 /**
 140                  * Do the list
 141                  */
 142                 $pager = new PageHistoryPager( $this, $year, $month, $tagFilter );
 143                 $this->linesonpage = $pager->getNumRows();
 144                 $wgOut->addHTML(
 145                         $pager->getNavigationBar() .
 146                         $this->beginHistoryList() .
 147                         $pager->getBody() .
 148                         $this->endHistoryList() .
 149                         $pager->getNavigationBar()
 150                 );
 151
 152                 wfProfileOut( __METHOD__ );
 153         }
 154
 155         /**
 156          * Creates begin of history list with a submit button
 157          *
 158          * @return string HTML output
 159          */
 160         function beginHistoryList() {
 161                 global $wgUser, $wgScript, $wgEnableHtmlDiff;
 162                 $this->lastdate = '';
 163                 $s = wfMsgExt( 'histlegend', array( 'parse') );
 164                 if( $this->linesonpage > 1 && $wgUser->isAllowed('deleterevision') ) {
 165                         $revdel = SpecialPage::getTitleFor( 'Revisiondelete' );
 166                         $s .= Xml::openElement( 'form',
 167                                 array(
 168                                         'action' => $revdel->getLocalURL( array(
 169                                                 'type' => 'revision',
 170                                                 'target' => $this->mTitle->getPrefixedDbKey()
 171                                         ) ),
 172                                         'method' => 'post',
 173                                         'id' => 'mw-history-revdeleteform',
 174                                         'style'  => 'visibility:hidden;float:right;'
 175                                 )
 176                         );
 177                         $s .= Xml::hidden( 'ids', '', array('id'=>'revdel-oldid') );
 178                         $s .= Xml::submitButton( wfMsg( 'showhideselectedversions' ) );
 179                         $s .= Xml::closeElement( 'form' );
 180                 }
 181                 $s .= Xml::openElement( 'form', array( 'action' => $wgScript,
 182                         'id' => 'mw-history-compare' ) );
 183                 $s .= Xml::hidden( 'title', $this->mTitle->getPrefixedDbKey() );
 184                 if( $wgEnableHtmlDiff ) {
 185                         $s .= $this->submitButton( wfMsg( 'visualcomparison'),
 186                                 array(
 187                                         'name' => 'htmldiff',
 188                                         'class'     => 'historysubmit',
 189                                         'accesskey' => wfMsg( 'accesskey-visualcomparison' ),
 190                                         'title'     => wfMsg( 'tooltip-compareselectedversions' ),
 191                                 )
 192                         );
 193                         $s .= $this->submitButton( wfMsg( 'wikicodecomparison'),
 194                                 array(
 195                                         'class'     => 'historysubmit',
 196                                         'accesskey' => wfMsg( 'accesskey-compareselectedversions' ),
 197                                         'title'     => wfMsg( 'tooltip-compareselectedversions' ),
 198                                 )
 199                         );
 200                 } else {
 201                         $s .= $this->submitButton( wfMsg( 'compareselectedversions'),
 202                                 array(
 203                                         'class'     => 'historysubmit',
 204                                         'accesskey' => wfMsg( 'accesskey-compareselectedversions' ),
 205                                         'title'     => wfMsg( 'tooltip-compareselectedversions' ),
 206                                 )
 207                         );
 208                 }
 209                 $s .= '<ul id="pagehistory">' . "\n";
 210                 return $s;
 211         }
 212
 213         /**
 214          * Creates end of history list with a submit button
 215          *
 216          * @return string HTML output
 217          */
 218         function endHistoryList() {
 219                 global $wgEnableHtmlDiff;
 220                 $s = '</ul>';
 221                 if( $wgEnableHtmlDiff ) {
 222                         $s .= $this->submitButton( wfMsg( 'visualcomparison'),
 223                                 array(
 224                                         'name' => 'htmldiff',
 225                                         'class'     => 'historysubmit',
 226                                         'accesskey' => wfMsg( 'accesskey-visualcomparison' ),
 227                                         'title'     => wfMsg( 'tooltip-compareselectedversions' ),
 228                                 )
 229                         );
 230                         $s .= $this->submitButton( wfMsg( 'wikicodecomparison'),
 231                                 array(
 232                                         'class'     => 'historysubmit',
 233                                         'accesskey' => wfMsg( 'accesskey-compareselectedversions' ),
 234                                         'title'     => wfMsg( 'tooltip-compareselectedversions' ),
 235                                 )
 236                         );
 237                 } else {
 238                         $s .= $this->submitButton( wfMsg( 'compareselectedversions'),
 239                                 array(
 240                                         'class'     => 'historysubmit',
 241                                         'accesskey' => wfMsg( 'accesskey-compareselectedversions' ),
 242                                         'title'     => wfMsg( 'tooltip-compareselectedversions' ),
 243                                 )
 244                         );
 245                 }
 246                 $s .= '</form>';
 247                 return $s;
 248         }
 249
 250         /**
 251          * Creates a submit button
 252          *
 253          * @param array $attributes attributes
 254          * @return string HTML output for the submit button
 255          */
 256         function submitButton($message, $attributes = array() ) {
 257                 # Disable submit button if history has 1 revision only
 258                 if( $this->linesonpage > 1 ) {
 259                         return Xml::submitButton( $message , $attributes );
 260                 } else {
 261                         return '';
 262                 }
 263         }
 264
 265         /**
 266          * Returns a row from the history printout.
 267          *
 268          * @todo document some more, and maybe clean up the code (some params redundant?)
 269          *
 270          * @param Row $row The database row corresponding to the previous line.
 271          * @param mixed $next The database row corresponding to the next line.
 272          * @param int $counter Apparently a counter of what row number we're at, counted from the top row = 1.
 273          * @param $notificationtimestamp
 274          * @param bool $latest Whether this row corresponds to the page's latest revision.
 275          * @param bool $firstInList Whether this row corresponds to the first displayed on this history page.
 276          * @return string HTML output for the row
 277          */
 278         function historyLine( $row, $next, $counter = '', $notificationtimestamp = false,
 279                 $latest = false, $firstInList = false )
 280         {
 281                 global $wgUser, $wgLang;
 282                 $rev = new Revision( $row );
 283                 $rev->setTitle( $this->mTitle );
 284
 285                 $curlink = $this->curLink( $rev, $latest );
 286                 $lastlink = $this->lastLink( $rev, $next, $counter );
 287                 $arbitrary = $this->diffButtons( $rev, $firstInList, $counter );
 288                 $link = $this->revLink( $rev );
 289                 $classes = array();
 290
 291                 $s = "($curlink) ($lastlink) $arbitrary";
 292
 293                 if( $wgUser->isAllowed( 'deleterevision' ) ) {
 294                         // Hide JS by default for non-JS browsing
 295                         $hidden = array( 'style' => 'display:none' );
 296                         // If revision was hidden from sysops
 297                         if( !$rev->userCan( Revision::DELETED_RESTRICTED ) ) {
 298                                 $del = Xml::check( 'deleterevisions', false,
 299                                         $hidden + array('disabled' => 'disabled') );
 300                                 $del .= Xml::tags( 'span', array( 'class'=>'mw-revdelundel-link' ),
 301                                         '(' . $this->message['rev-delundel'] . ')' );
 302                         // Otherwise, show the link...
 303                         } else {
 304                                 $id = $rev->getId();
 305                                 $jsCall = "updateShowHideForm($id,this.checked)";
 306                                 $del = Xml::check( 'showhiderevisions', false,
 307                                         $hidden + array(
 308                                                 'onchange' => $jsCall,
 309                                                 'id' => "mw-revdel-$id" ) );
 310                                 $query = array(
 311                                         'type' => 'revision',
 312                                         'target' => $this->mTitle->getPrefixedDbkey(),
 313                                         'ids' => $rev->getId() );
 314                                 $del .= $this->mSkin->revDeleteLink( $query,
 315                                         $rev->isDeleted( Revision::DELETED_RESTRICTED ) );
 316                         }
 317                         $s .= " $del ";
 318                 }
 319
 320                 $s .= " $link";
 321                 $s .= " <span class='history-user'>" . $this->mSkin->revUserTools( $rev, true ) . "</span>";
 322
 323                 if( $rev->isMinor() ) {
 324                         $s .= ' ' . Xml::element( 'span', array( 'class' => 'minor' ), wfMsg( 'minoreditletter') );
 325                 }
 326
 327                 if( !is_null( $size = $rev->getSize() ) && !$rev->isDeleted( Revision::DELETED_TEXT ) ) {
 328                         $s .= ' ' . $this->mSkin->formatRevisionSize( $size );
 329                 }
 330
 331                 $s .= $this->mSkin->revComment( $rev, false, true );
 332
 333                 if( $notificationtimestamp && ($row->rev_timestamp >= $notificationtimestamp) ) {
 334                         $s .= ' <span class="updatedmarker">' .  wfMsgHtml( 'updatedmarker' ) . '</span>';
 335                 }
 336
 337                 $tools = array();
 338
 339                 if( !is_null( $next ) && is_object( $next ) ) {
 340                         if( $latest && $this->mTitle->userCan( 'rollback' ) && $this->mTitle->userCan( 'edit' ) ) {
 341                                 $tools[] = '<span class="mw-rollback-link">'.
 342                                         $this->mSkin->buildRollbackLink( $rev ).'</span>';
 343                         }
 344
 345                         if( $this->mTitle->quickUserCan( 'edit' )
 346                                 && !$rev->isDeleted( Revision::DELETED_TEXT )
 347                                 && !$next->rev_deleted & Revision::DELETED_TEXT )
 348                         {
 349                                 # Create undo tooltip for the first (=latest) line only
 350                                 $undoTooltip = $latest
 351                                         ? array( 'title' => wfMsg( 'tooltip-undo' ) )
 352                                         : array();
 353                                 $undolink = $this->mSkin->link(
 354                                         $this->mTitle,
 355                                         wfMsgHtml( 'editundo' ),
 356                                         $undoTooltip,
 357                                         array( 'action' => 'edit', 'undoafter' => $next->rev_id, 'undo' => $rev->getId() ),
 358                                         array( 'known', 'noclasses' )
 359                                 );
 360                                 $tools[] = "<span class=\"mw-history-undo\">{$undolink}</span>";
 361                         }
 362                 }
 363
 364                 if( $tools ) {
 365                         $s .= ' (' . $wgLang->pipeList( $tools ) . ')';
 366                 }
 367
 368                 # Tags
 369                 list($tagSummary, $newClasses) = ChangeTags::formatSummaryRow( $row->ts_tags, 'history' );
 370                 $classes = array_merge( $classes, $newClasses );
 371                 $s .= " $tagSummary";
 372
 373                 wfRunHooks( 'PageHistoryLineEnding', array( $this, &$row , &$s ) );
 374
 375                 $classes = implode( ' ', $classes );
 376
 377                 return "<li class=\"$classes\">$s</li>\n";
 378         }
 379
 380         /**
 381          * Create a link to view this revision of the page
 382          * @param Revision $rev
 383          * @returns string
 384          */
 385         function revLink( $rev ) {
 386                 global $wgLang;
 387                 $date = $wgLang->timeanddate( wfTimestamp(TS_MW, $rev->getTimestamp()), true );
 388                 $date = htmlspecialchars( $date );
 389                 if( !$rev->isDeleted( Revision::DELETED_TEXT ) ) {
 390                         $link = $this->mSkin->link(
 391                                 $this->mTitle,
 392                                 $date,
 393                                 array(),
 394                                 array( 'oldid' => $rev->getId() ),
 395                                 array( 'known', 'noclasses' )
 396                         );
 397                 } else {
 398                         $link = "<span class=\"history-deleted\">$date</span>";
 399                 }
 400                 return $link;
 401         }
 402
 403         /**
 404          * Create a diff-to-current link for this revision for this page
 405          * @param Revision $rev
 406          * @param Bool $latest, this is the latest revision of the page?
 407          * @returns string
 408          */
 409         function curLink( $rev, $latest ) {
 410                 $cur = $this->message['cur'];
 411                 if( $latest || !$rev->userCan( Revision::DELETED_TEXT ) ) {
 412                         return $cur;
 413                 } else {
 414                         return $this->mSkin->link(
 415                                 $this->mTitle,
 416                                 $cur,
 417                                 array(),
 418                                 array(
 419                                         'diff' => $this->mTitle->getLatestRevID(),
 420                                         'oldid' => $rev->getId()
 421                                 ),
 422                                 array( 'known', 'noclasses' )
 423                         );
 424                 }
 425         }
 426
 427         /**
 428          * Create a diff-to-previous link for this revision for this page.
 429          * @param Revision $prevRev, the previous revision
 430          * @param mixed $next, the newer revision
 431          * @param int $counter, what row on the history list this is
 432          * @returns string
 433          */
 434         function lastLink( $prevRev, $next, $counter ) {
 435                 $last = $this->message['last'];
 436                 # $next may either be a Row, null, or "unkown"
 437                 $nextRev = is_object($next) ? new Revision( $next ) : $next;
 438                 if( is_null($next) ) {
 439                         # Probably no next row
 440                         return $last;
 441                 } elseif( $next === 'unknown' ) {
 442                         # Next row probably exists but is unknown, use an oldid=prev link
 443                         return $this->mSkin->link(
 444                                 $this->mTitle,
 445                                 $last,
 446                                 array(),
 447                                 array(
 448                                         'diff' => $prevRev->getId(),
 449                                         'oldid' => 'prev'
 450                                 ),
 451                                 array( 'known', 'noclasses' )
 452                         );
 453                 } elseif( !$prevRev->userCan(Revision::DELETED_TEXT) || !$nextRev->userCan(Revision::DELETED_TEXT) ) {
 454                         return $last;
 455                 } else {
 456                         return $this->mSkin->link(
 457                                 $this->mTitle,
 458                                 $last,
 459                                 array(),
 460                                 array(
 461                                         'diff' => $prevRev->getId(),
 462                                         'oldid' => $next->rev_id
 463                                 ),
 464                                 array( 'known', 'noclasses' )
 465                         );
 466                 }
 467         }
 468
 469         /**
 470          * Create radio buttons for page history
 471          *
 472          * @param object $rev Revision
 473          * @param bool $firstInList Is this version the first one?
 474          * @param int $counter A counter of what row number we're at, counted from the top row = 1.
 475          * @return string HTML output for the radio buttons
 476          */
 477         function diffButtons( $rev, $firstInList, $counter ) {
 478                 if( $this->linesonpage > 1 ) {
 479                         $id = $rev->getId();
 480                         $radio = array( 'type'  => 'radio', 'value' => $id );
 481                         /** @todo: move title texts to javascript */
 482                         if( $firstInList ) {
 483                                 $first = Xml::element( 'input',
 484                                         array_merge( $radio, array(
 485                                                 'style' => 'visibility:hidden',
 486                                                 'name'  => 'oldid',
 487                                                 'id' => 'mw-oldid-null' ) )
 488                                 );
 489                                 $checkmark = array( 'checked' => 'checked' );
 490                         } else {
 491                                 # Check visibility of old revisions
 492                                 if( !$rev->userCan( Revision::DELETED_TEXT ) ) {
 493                                         $radio['disabled'] = 'disabled';
 494                                         $checkmark = array(); // We will check the next possible one
 495                                 } else if( $counter == 2 || !$this->mOldIdChecked ) {
 496                                         $checkmark = array( 'checked' => 'checked' );
 497                                         $this->mOldIdChecked = $id;
 498                                 } else {
 499                                         $checkmark = array();
 500                                 }
 501                                 $first = Xml::element( 'input',
 502                                         array_merge( $radio, $checkmark, array(
 503                                                 'name'  => 'oldid',
 504                                                 'id' => "mw-oldid-$id" ) ) );
 505                                 $checkmark = array();
 506                         }
 507                         $second = Xml::element( 'input',
 508                                 array_merge( $radio, $checkmark, array(
 509                                         'name'  => 'diff',
 510                                         'id' => "mw-diff-$id" ) ) );
 511                         return $first . $second;
 512                 } else {
 513                         return '';
 514                 }
 515         }
 516
 517         /**
 518          * Fetch an array of revisions, specified by a given limit, offset and
 519          * direction. This is now only used by the feeds. It was previously
 520          * used by the main UI but that's now handled by the pager.
 521          */
 522         function fetchRevisions($limit, $offset, $direction) {
 523                 $dbr = wfGetDB( DB_SLAVE );
 524
 525                 if( $direction == PageHistory::DIR_PREV )
 526                         list($dirs, $oper) = array("ASC", ">=");
 527                 else /* $direction == PageHistory::DIR_NEXT */
 528                         list($dirs, $oper) = array("DESC", "<=");
 529
 530                 if( $offset )
 531                         $offsets = array("rev_timestamp $oper '$offset'");
 532                 else
 533                         $offsets = array();
 534
 535                 $page_id = $this->mTitle->getArticleID();
 536
 537                 return $dbr->select( 'revision',
 538                         Revision::selectFields(),
 539                         array_merge(array("rev_page=$page_id"), $offsets),
 540                         __METHOD__,
 541                         array( 'ORDER BY' => "rev_timestamp $dirs",
 542                                 'USE INDEX' => 'page_timestamp', 'LIMIT' => $limit)
 543                 );
 544         }
 545
 546         /**
 547          * Output a subscription feed listing recent edits to this page.
 548          * @param string $type
 549          */
 550         function feed( $type ) {
 551                 global $wgFeedClasses, $wgRequest, $wgFeedLimit;
 552                 if( !FeedUtils::checkFeedOutput($type) ) {
 553                         return;
 554                 }
 555
 556                 $feed = new $wgFeedClasses[$type](
 557                         $this->mTitle->getPrefixedText() . ' - ' .
 558                                 wfMsgForContent( 'history-feed-title' ),
 559                         wfMsgForContent( 'history-feed-description' ),
 560                         $this->mTitle->getFullUrl( array( 'action' => 'history' ) )
 561                 );
 562
 563                 // Get a limit on number of feed entries. Provide a sane default
 564                 // of 10 if none is defined (but limit to $wgFeedLimit max)
 565                 $limit = $wgRequest->getInt( 'limit', 10 );
 566                 if( $limit > $wgFeedLimit || $limit < 1 ) {
 567                         $limit = 10;
 568                 }
 569                 $items = $this->fetchRevisions($limit, 0, PageHistory::DIR_NEXT);
 570
 571                 $feed->outHeader();
 572                 if( $items ) {
 573                         foreach( $items as $row ) {
 574                                 $feed->outItem( $this->feedItem( $row ) );
 575                         }
 576                 } else {
 577                         $feed->outItem( $this->feedEmpty() );
 578                 }
 579                 $feed->outFooter();
 580         }
 581
 582         function feedEmpty() {
 583                 global $wgOut;
 584                 return new FeedItem(
 585                         wfMsgForContent( 'nohistory' ),
 586                         $wgOut->parse( wfMsgForContent( 'history-feed-empty' ) ),
 587                         $this->mTitle->getFullUrl(),
 588                         wfTimestamp( TS_MW ),
 589                                 '',
 590                         $this->mTitle->getTalkPage()->getFullUrl() );
 591         }
 592
 593         /**
 594          * Generate a FeedItem object from a given revision table row
 595          * Borrows Recent Changes' feed generation functions for formatting;
 596          * includes a diff to the previous revision (if any).
 597          *
 598          * @param $row
 599          * @return FeedItem
 600          */
 601         function feedItem( $row ) {
 602                 $rev = new Revision( $row );
 603                 $rev->setTitle( $this->mTitle );
 604                 $text = FeedUtils::formatDiffRow( $this->mTitle,
 605                 $this->mTitle->getPreviousRevisionID( $rev->getId() ),
 606                 $rev->getId(),
 607                 $rev->getTimestamp(),
 608                 $rev->getComment() );
 609
 610                 if( $rev->getComment() == '' ) {
 611                         global $wgContLang;
 612                         $ts = $rev->getTimestamp();
 613                         $title = wfMsgForContent( 'history-feed-item-nocomment',
 614                                 $rev->getUserText(),
 615                                 $wgContLang->timeanddate( $ts ),
 616                                 $wgContLang->date( $ts ),
 617                                 $wgContLang->time( $ts ) );
 618                 } else {
 619                         $title = $rev->getUserText() . wfMsgForContent( 'colon-separator' ) . FeedItem::stripComment( $rev->getComment() );
 620                 }
 621
 622                 return new FeedItem(
 623                         $title,
 624                         $text,
 625                         $this->mTitle->getFullUrl( array(
 626                                 'diff' => $rev->getId(),
 627                                 'oldid' => 'prev'
 628                         ) ),
 629                         $rev->getTimestamp(),
 630                         $rev->getUserText(),
 631                         $this->mTitle->getTalkPage()->getFullUrl() );
 632         }
 633 }
 634
 635 /**
 636  * @ingroup Pager
 637  */
 638 class PageHistoryPager extends ReverseChronologicalPager {
 639         public $mLastRow = false, $mPageHistory, $mTitle;
 640
 641         function __construct( $pageHistory, $year='', $month='', $tagFilter = '' ) {
 642                 parent::__construct();
 643                 $this->mPageHistory = $pageHistory;
 644                 $this->mTitle =& $this->mPageHistory->mTitle;
 645                 $this->tagFilter = $tagFilter;
 646                 $this->getDateCond( $year, $month );
 647         }
 648
 649         function getQueryInfo() {
 650                 $queryInfo = array(
 651                         'tables'  => array('revision'),
 652                         'fields'  => array_merge( Revision::selectFields(), array('ts_tags') ),
 653                         'conds'   => array('rev_page' => $this->mPageHistory->mTitle->getArticleID() ),
 654                         'options' => array( 'USE INDEX' => array('revision' => 'page_timestamp') ),
 655                         'join_conds' => array( 'tag_summary' => array( 'LEFT JOIN', 'ts_rev_id=rev_id' ) ),
 656                 );
 657                 ChangeTags::modifyDisplayQuery( $queryInfo['tables'],
 658                                                                                 $queryInfo['fields'],
 659                                                                                 $queryInfo['conds'],
 660                                                                                 $queryInfo['join_conds'],
 661                                                                                 $queryInfo['options'],
 662                                                                                 $this->tagFilter );
 663                 wfRunHooks( 'PageHistoryPager::getQueryInfo', array( &$this, &$queryInfo ) );
 664                 return $queryInfo;
 665         }
 666
 667         function getIndexField() {
 668                 return 'rev_timestamp';
 669         }
 670
 671         function formatRow( $row ) {
 672                 if( $this->mLastRow ) {
 673                         $latest = $this->mCounter == 1 && $this->mIsFirst;
 674                         $firstInList = $this->mCounter == 1;
 675                         $s = $this->mPageHistory->historyLine( $this->mLastRow, $row, $this->mCounter++,
 676                                 $this->mTitle->getNotificationTimestamp(), $latest, $firstInList );
 677                 } else {
 678                         $s = '';
 679                 }
 680                 $this->mLastRow = $row;
 681                 return $s;
 682         }
 683
 684         function getStartBody() {
 685                 $this->mLastRow = false;
 686                 $this->mCounter = 1;
 687                 return '';
 688         }
 689
 690         function getEndBody() {
 691                 if( $this->mLastRow ) {
 692                         $latest = $this->mCounter == 1 && $this->mIsFirst;
 693                         $firstInList = $this->mCounter == 1;
 694                         if( $this->mIsBackwards ) {
 695                                 # Next row is unknown, but for UI reasons, probably exists if an offset has been specified
 696                                 if( $this->mOffset == '' ) {
 697                                         $next = null;
 698                                 } else {
 699                                         $next = 'unknown';
 700                                 }
 701                         } else {
 702                                 # The next row is the past-the-end row
 703                                 $next = $this->mPastTheEndRow;
 704                         }
 705                         $s = $this->mPageHistory->historyLine( $this->mLastRow, $next, $this->mCounter++,
 706                                 $this->mTitle->getNotificationTimestamp(), $latest, $firstInList );
 707                 } else {
 708                         $s = '';
 709                 }
 710                 return $s;
 711         }
 712 }