Tweak for r29561: don't grab a database object until we need it
[lhc/web/wiklou.git] / includes / PageHistory.php
index 05f0b9d..9d84665 100644 (file)
 <?php
 /**
  * Page history
- * 
+ *
  * Split off from Article.php and Skin.php, 2003-12-22
- * @package MediaWiki
  */
 
 /**
- * @todo document
- * @package MediaWiki
+ * This class handles printing the history page for an article.  In order to
+ * be efficient, it uses timestamps rather than offsets for paging, to avoid
+ * costly LIMIT,offset queries.
+ *
+ * Construct it by passing in an Article, and call $h->history() to print the
+ * history.
+ *
  */
-
-include_once ( "SpecialValidate.php" ) ;
 class PageHistory {
+       const DIR_PREV = 0;
+       const DIR_NEXT = 1;
+       
        var $mArticle, $mTitle, $mSkin;
        var $lastdate;
        var $linesonpage;
-       function PageHistory( $article ) {
+       var $mNotificationTimestamp;
+       var $mLatestId = null;
+
+       /**
+        * Construct a new PageHistory.
+        *
+        * @param Article $article
+        * @returns nothing
+        */
+       function __construct($article) {
+               global $wgUser;
+
                $this->mArticle =& $article;
                $this->mTitle =& $article->mTitle;
+               $this->mNotificationTimestamp = NULL;
+               $this->mSkin = $wgUser->getSkin();
        }
 
-       # This shares a lot of issues (and code) with Recent Changes
-
+       /**
+        * Print the history page for an article.
+        *
+        * @returns nothing
+        */
        function history() {
-               global $wgUser, $wgOut, $wgLang, $wgShowUpdatedMarker, $wgRequest,
-                       $wgTitle, $wgUseValidation ;
+               global $wgOut, $wgRequest, $wgTitle;
 
-               # If page hasn't changed, client can cache this
+               /*
+                * Allow client caching.
+                */
 
-               if( $wgOut->checkLastModified( $this->mArticle->getTimestamp() ) ){
-                       # Client cache fresh and headers sent, nothing more to do.
+               if( $wgOut->checkLastModified( $this->mArticle->getTimestamp() ) )
+                       /* Client cache fresh and headers sent, nothing more to do. */
                        return;
-               }
+
                $fname = 'PageHistory::history';
                wfProfileIn( $fname );
 
-               $wgOut->setPageTitle( $this->mTitle->getPRefixedText() );
-               $wgOut->setSubtitle( wfMsg( 'revhistory' ) );
+               /*
+                * Setup page variables.
+                */
+               $wgOut->setPageTitle( wfMsg( 'history-title', $this->mTitle->getPrefixedText() ) );
+               $wgOut->setPageTitleActionText( wfMsg( 'history_short' ) );
                $wgOut->setArticleFlag( false );
                $wgOut->setArticleRelated( true );
                $wgOut->setRobotpolicy( 'noindex,nofollow' );
+               $wgOut->setSyndicated( true );
 
-               $id = $this->mTitle->getArticleID();
-               if( $id == 0 ) {
-                       $wgOut->addHTML( wfMsg( 'nohistory' ) );
+               $logPage = SpecialPage::getTitleFor( 'Log' );
+               $logLink = $this->mSkin->makeKnownLinkObj( $logPage, wfMsgHtml( 'viewpagelogs' ), 'page=' . $this->mTitle->getPrefixedUrl() );
+               $wgOut->setSubtitle( $logLink );
+
+               $feedType = $wgRequest->getVal( 'feed' );
+               if( $feedType ) {
                        wfProfileOut( $fname );
-                       return;
+                       return $this->feed( $feedType );
                }
 
-               $limit = $wgRequest->getInt('limit');
-               if (!$limit) $limit = 50;
-               $offset = $wgRequest->getText('offset');
-               if (!isset($offset) || !preg_match("/^[0-9]+$/", $offset)) $offset = 0;
-
-               /* Check one extra row to see whether we need to show 'next' and diff links */
-               $limitplus = $limit + 1;
-
-               $namespace = $this->mTitle->getNamespace();
-               $title = $this->mTitle->getText();
-               $uid = $wgUser->getID();
-               $db =& wfGetDB( DB_SLAVE );
-               if ($uid && $wgShowUpdatedMarker && $wgUser->getOption( 'showupdated' ))
-                       $notificationtimestamp = $db->selectField( 'watchlist',
-                               'wl_notificationtimestamp',
-                               array( 'wl_namespace' => $namespace, 'wl_title' => $this->mTitle->getDBkey(), 'wl_user' => $uid ),
-                               $fname );
-               else $notificationtimestamp = false;
-
-               $use_index = $db->useIndexClause( 'page_timestamp' );
-               $revision = $db->tableName( 'revision' );
-
-               $limits = $offsets = "";
-               $dir = 0;
-               if ($wgRequest->getText("dir") == "prev")
-                       $dir = 1;
-
-               list($dirs, $oper) = array("DESC", "<");
-               if ($dir) {
-                       list($dirs, $oper) = array("ASC", ">");
+               /*
+                * Fail if article doesn't exist.
+                */
+               if( !$this->mTitle->exists() ) {
+                       $wgOut->addWikiText( wfMsg( 'nohistory' ) );
+                       wfProfileOut( $fname );
+                       return;
                }
 
-               if ($offset)
-                       $offsets .= " AND rev_timestamp $oper '$offset' ";
-               if ($limit)
-                       $limits .= " LIMIT $limitplus ";
-
-               $sql = "SELECT rev_id,rev_user," .
-                 "rev_comment,rev_user_text,rev_timestamp,rev_minor_edit,rev_deleted ".
-                 "FROM $revision $use_index " .
-                 "WHERE rev_page=$id " .
-                 $offsets .
-                 "ORDER BY rev_timestamp $dirs " .
-                 $limits;
-               $res = $db->query( $sql, $fname );
-
-               $revs = $db->numRows( $res );
-
-               if( $revs < $limitplus ) // the sql above tries to fetch one extra
-                       $this->linesonpage = $revs;
-               else
-                       $this->linesonpage = $revs - 1;
-
-               $atend = ($revs < $limitplus);
-
-               $this->mSkin = $wgUser->getSkin();
-
-               $pages = array();
-               $lowts = 0;
-               while ($line = $db->fetchObject($res)) {
-                       $pages[] = $line;
+               /*
+                * "go=first" means to jump to the last (earliest) history page.
+                * This is deprecated, it no longer appears in the user interface
+                */
+               if ( $wgRequest->getText("go") == 'first' ) {
+                       $limit = $wgRequest->getInt( 'limit', 50 );
+                       $wgOut->redirect( $wgTitle->getLocalURL( "action=history&limit={$limit}&dir=prev" ) );
+                       return;
                }
-               if ($dir) $pages = array_reverse($pages);
-               if (count($pages) > 1)
-                       $lowts = $pages[count($pages) - 2]->rev_timestamp;
-               else
-                       $lowts = $pages[count($pages) - 1]->rev_timestamp;
-
 
-               $prevurl = $wgTitle->escapeLocalURL("action=history&dir=prev&offset={$offset}&limit={$limit}");
-               $nexturl = $wgTitle->escapeLocalURL("action=history&offset={$lowts}&limit={$limit}");
-               $urls = array();
-               foreach (array(20, 50, 100, 250, 500) as $num) {
-                       $urls[] = "<a href=\"".$wgTitle->escapeLocalURL(
-                               "action=history&offset={$offset}&limit={$num}")."\">".$wgLang->formatNum($num)."</a>";
-               }
-               $bits = implode($urls, ' | ');
-               $numbar = wfMsg("viewprevnext", 
-                               "<a href=\"$prevurl\">".wfMsg("prevn", $limit)."</a>", 
-                               "<a href=\"$nexturl\">".wfMsg("nextn", $limit)."</a>", 
-                               $bits);
-
-               $s = $numbar;
-               $s .= $this->beginHistoryList();
-               $counter = 1;
-               foreach($pages as $i => $line) {
-                       $first = ($counter == 1 && $offset == 0);
-                       $next = isset( $pages[$i + 1] ) ? $pages[$i + 1 ] : null;
-                       $s .= $this->historyLine( $line, $next, $counter, $notificationtimestamp, $first );
-                       $counter++;
-               }
-               $s .= $this->endHistoryList( !$atend );
-               $s .= $numbar;
-               
-               # Validation line
-               if ( isset ( $wgUseValidation ) && $wgUseValidation ) {
-                       $s .= "<p>" . Validation::link2statistics ( $this->mArticle ) . "</p>" ;
-                       }
-               
-               $wgOut->addHTML( $s );
+               wfRunHooks( 'PageHistoryBeforeList', array( &$this->mArticle ) );
+
+               /** 
+                * Do the list
+                */
+               $pager = new PageHistoryPager( $this );
+               $this->linesonpage = $pager->getNumRows();
+               $wgOut->addHTML(
+                       $pager->getNavigationBar() . 
+                       $this->beginHistoryList() . 
+                       $pager->getBody() .
+                       $this->endHistoryList() .
+                       $pager->getNavigationBar()
+               );
                wfProfileOut( $fname );
        }
 
+       /**
+        * Creates begin of history list with a submit button
+        *
+        * @return string HTML output
+        */
        function beginHistoryList() {
                global $wgTitle;
                $this->lastdate = '';
-               $s = '<p>' . wfMsg( 'histlegend' ) . '</p>';
+               $s = wfMsgExt( 'histlegend', array( 'parse') );
                $s .= '<form action="' . $wgTitle->escapeLocalURL( '-' ) . '" method="get">';
                $prefixedkey = htmlspecialchars($wgTitle->getPrefixedDbKey());
+
+               // The following line is SUPPOSED to have double-quotes around the
+               // $prefixedkey variable, because htmlspecialchars() doesn't escape
+               // single-quotes.
+               //
+               // On at least two occasions people have changed it to single-quotes,
+               // which creates invalid HTML and incorrect display of the resulting
+               // link.
+               //
+               // Please do not break this a third time. Thank you for your kind
+               // consideration and cooperation.
+               //
                $s .= "<input type='hidden' name='title' value=\"{$prefixedkey}\" />\n";
+
                $s .= $this->submitButton();
-               $s .= '<ul id="pagehistory">';
+               $s .= '<ul id="pagehistory">' . "\n";
                return $s;
        }
 
+       /**
+        * Creates end of history list with a submit button
+        *
+        * @return string HTML output
+        */
        function endHistoryList() {
-               $last = wfMsg( 'last' );
-
                $s = '</ul>';
                $s .= $this->submitButton( array( 'id' => 'historysubmit' ) );
                $s .= '</form>';
                return $s;
        }
-       
+
+       /**
+        * Creates a submit button
+        *
+        * @param array $bits optional CSS ID
+        * @return string HTML output for the submit button
+        */
        function submitButton( $bits = array() ) {
-               return ( $this->linesonpage > 0 )
-                       ? wfElement( 'input', array_merge( $bits,
-                               array(
+               # Disable submit button if history has 1 revision only
+               if ( $this->linesonpage > 1 ) {
+                       return Xml::submitButton( wfMsg( 'compareselectedversions' ),
+                               $bits + array(
                                        'class'     => 'historysubmit',
-                                       'type'      => 'submit',
                                        'accesskey' => wfMsg( 'accesskey-compareselectedversions' ),
                                        'title'     => wfMsg( 'tooltip-compareselectedversions' ),
-                                       'value'     => wfMsg( 'compareselectedversions' ),
-                               ) ) )
-                       : '';
+                                       )
+                               );
+               } else {
+                       return '';
+               }
        }
 
-       function historyLine( $row, $next, $counter = '', $notificationtimestamp = false, $latest = false ) {
-               global $wgLang, $wgContLang;
+       /**
+        * Returns a row from the history printout.
+        *
+        * @todo document some more, and maybe clean up the code (some params redundant?)
+        *
+        * @param object $row The database row corresponding to the line (or is it the previous line?).
+        * @param object $next The database row corresponding to the next line (or is it this one?).
+        * @param int $counter Apparently a counter of what row number we're at, counted from the top row = 1.
+        * @param $notificationtimestamp
+        * @param bool $latest Whether this row corresponds to the page's latest revision.
+        * @param bool $firstInList Whether this row corresponds to the first displayed on this history page.
+        * @return string HTML output for the row
+        */
+       function historyLine( $row, $next, $counter = '', $notificationtimestamp = false, $latest = false, $firstInList = false ) {
+               global $wgUser, $wgLang;
+               $rev = new Revision( $row );
+               $rev->setTitle( $this->mTitle );
 
-               static $message;
-               if( !isset( $message ) ) {
-                       foreach( explode( ' ', 'cur last selectolderversionfordiff selectnewerversionfordiff minoreditletter' ) as $msg ) {
-                               $message[$msg] = wfMsg( $msg );
+               $s = '<li>';
+               $curlink = $this->curLink( $rev, $latest );
+               $lastlink = $this->lastLink( $rev, $next, $counter );
+               $arbitrary = $this->diffButtons( $rev, $firstInList, $counter );
+               $link = $this->revLink( $rev );
+               
+               $user = $this->mSkin->userLink( $rev->getUser(), $rev->getUserText() )
+                               . $this->mSkin->userToolLinks( $rev->getUser(), $rev->getUserText() );
+               
+               $s .= "($curlink) ($lastlink) $arbitrary";
+               
+               if( $wgUser->isAllowed( 'deleterevision' ) ) {
+                       $revdel = SpecialPage::getTitleFor( 'Revisiondelete' );
+                       if( $firstInList ) {
+                               // We don't currently handle well changing the top revision's settings
+                               $del = wfMsgHtml( 'rev-delundel' );
+                       } else if( !$rev->userCan( Revision::DELETED_RESTRICTED ) ) {
+                       // If revision was hidden from sysops
+                               $del = wfMsgHtml( 'rev-delundel' );                     
+                       } else {
+                               $del = $this->mSkin->makeKnownLinkObj( $revdel,
+                                       wfMsg( 'rev-delundel' ),
+                                       'target=' . urlencode( $this->mTitle->getPrefixedDbkey() ) .
+                                       '&oldid=' . urlencode( $rev->getId() ) );
                        }
+                       $s .= " (<small>$del</small>) ";
                }
                
-               $link = $this->revLink( $row );
-
-               if ( 0 == $row->rev_user ) {
-                       $contribsPage =& Title::makeTitle( NS_SPECIAL, 'Contributions' );
-                       $ul = $this->mSkin->makeKnownLinkObj( $contribsPage,
-                               htmlspecialchars( $row->rev_user_text ),
-                               'target=' . urlencode( $row->rev_user_text ) );
-               } else {
-                       $userPage =& Title::makeTitle( NS_USER, $row->rev_user_text );
-                       $ul = $this->mSkin->makeLinkObj( $userPage , htmlspecialchars( $row->rev_user_text ) );
-               }
-
-               $s = '<li>';
-               if( $row->rev_deleted ) {
-                       $s .= '<span class="deleted">';
+               $s .= " $link";
+               #getUser is safe, but this avoids making the invalid untargeted contribs links
+               if( $row->rev_deleted & Revision::DELETED_USER ) {
+                       $user = '<span class="history-deleted">' . wfMsg('rev-deleted-user') . '</span>';
                }
-               $curlink = $this->curLink( $row, $latest );
-               $lastlink = $this->lastLink( $row, $next, $counter );
-               $arbitrary = $this->diffButtons( $row, $latest, $counter );
-               $s .= "({$curlink}) ({$lastlink}) $arbitrary {$link} <span class='user'>{$ul}</span>";
+               $s .= " <span class='history-user'>$user</span>";
 
                if( $row->rev_minor_edit ) {
-                       $s .= ' ' . wfElement( 'span', array( 'class' => 'minor' ), $message['minoreditletter'] );
+                       $s .= ' ' . wfElement( 'span', array( 'class' => 'minor' ), wfMsg( 'minoreditletter') );
                }
 
+               if ( !is_null( $size = $rev->getSize() ) ) {
+                       if ( $size == 0 )
+                               $stxt = wfMsgHtml( 'historyempty' );
+                       else
+                               $stxt = wfMsgExt( 'historysize', array( 'parsemag' ), $wgLang->formatNum( $size ) );
+                       $s .= " <span class=\"history-size\">$stxt</span>";
+               }
 
-               $s .= $this->mSkin->commentBlock( $row->rev_comment, $this->mTitle );
+               #getComment is safe, but this is better formatted
+               if( $rev->isDeleted( Revision::DELETED_COMMENT ) ) {
+                       $s .= " <span class=\"history-deleted\"><span class=\"comment\">" .
+                       wfMsgHtml( 'rev-deleted-comment' ) . "</span></span>";
+               } else {
+                       $s .= $this->mSkin->revComment( $rev );
+               }
+               
                if ($notificationtimestamp && ($row->rev_timestamp >= $notificationtimestamp)) {
-                       $s .= wfMsg( 'updatedmarker' );
+                       $s .= ' <span class="updatedmarker">' .  wfMsgHtml( 'updatedmarker' ) . '</span>';
                }
-               if( $row->rev_deleted ) {
-                       $s .= "</span> " . htmlspecialchars( wfMsg( 'deletedrev' ) );
+               #add blurb about text having been deleted
+               if( $row->rev_deleted & Revision::DELETED_TEXT ) {
+                       $s .= ' ' . wfMsgHtml( 'deletedrev' );
                }
-               $s .= '</li>';
+               
+               $tools = array();
+               
+               if ( !is_null( $next ) && is_object( $next ) ) {
+                       if( $wgUser->isAllowed( 'rollback' ) && $latest ) {
+                               $tools[] = '<span class="mw-rollback-link">'
+                                       . $this->mSkin->buildRollbackLink( $rev )
+                                       . '</span>';
+                       }
+
+                       if( $this->mTitle->quickUserCan( 'edit' ) ) {
+                               $undolink = $this->mSkin->makeKnownLinkObj(
+                                       $this->mTitle,
+                                       wfMsgHtml( 'editundo' ),
+                                       'action=edit&undoafter=' . $next->rev_id . '&undo=' . $rev->getId()
+                               );
+                               $tools[] = "<span class=\"mw-history-undo\">{$undolink}</span>";
+                       }
+               }
+               
+               if( $tools ) {
+                       $s .= ' (' . implode( ' | ', $tools ) . ')';
+               }
+               
+               wfRunHooks( 'PageHistoryLineEnding', array( &$row , &$s ) );
+               
+               $s .= "</li>\n";
 
                return $s;
        }
-
-       function revLink( $row ) {
-               global $wgUser, $wgLang;
-               $date = $wgLang->timeanddate( $row->rev_timestamp, true );
-               if( $row->rev_deleted && !$wgUser->isAllowed( 'undelete' ) ) {
-                       return $date;
+       
+       /** @todo document */
+       function revLink( $rev ) {
+               global $wgLang;
+               $date = $wgLang->timeanddate( wfTimestamp(TS_MW, $rev->getTimestamp()), true );
+               if( $rev->userCan( Revision::DELETED_TEXT ) ) {
+                       $link = $this->mSkin->makeKnownLinkObj(
+                               $this->mTitle, $date, "oldid=" . $rev->getId() );
                } else {
-                       return $this->mSkin->makeKnownLinkObj(
-                               $this->mTitle,
-                               $date,
-                               'oldid='.$row->rev_id );
+                       $link = $date;
                }
+               if( $rev->isDeleted( Revision::DELETED_TEXT ) ) {
+                       return '<span class="history-deleted">' . $link . '</span>';
+               }
+               return $link;
        }
-       
-       function curLink( $row, $latest ) {
-               global $wgUser;
-               $cur = htmlspecialchars( wfMsg( 'cur' ) );
-               if( $latest
-                       || ( $row->rev_deleted && !$wgUser->isAllowed( 'undelete' ) ) ) {
+
+       /** @todo document */
+       function curLink( $rev, $latest ) {
+               $cur = wfMsgExt( 'cur', array( 'escape') );
+               if( $latest || !$rev->userCan( Revision::DELETED_TEXT ) ) {
                        return $cur;
                } else {
                        return $this->mSkin->makeKnownLinkObj(
-                               $this->mTitle,
-                               $cur,
-                               'diff=0&oldid=' . $row->rev_id );
+                               $this->mTitle, $cur,
+                               'diff=' . $this->getLatestID() .
+                               "&oldid=" . $rev->getId() );
                }
        }
-       
-       function lastLink( $row, $next, $counter ) {
-               global $wgUser;
-               $last = htmlspecialchars( wfMsg( 'last' ) );
-               if( is_null( $next )
-                       || ( $row->rev_deleted && !$wgUser->isAllowed( 'undelete' ) ) ) {
+
+       /** @todo document */
+       function lastLink( $rev, $next, $counter ) {
+               $last = wfMsgExt( 'last', array( 'escape' ) );
+               if ( is_null( $next ) ) {
+                       # Probably no next row
+                       return $last;
+               } elseif ( $next === 'unknown' ) {
+                       # Next row probably exists but is unknown, use an oldid=prev link
+                       return $this->mSkin->makeKnownLinkObj(
+                               $this->mTitle,
+                               $last,
+                               "diff=" . $rev->getId() . "&oldid=prev" );
+               } elseif( !$rev->userCan( Revision::DELETED_TEXT ) ) {
                        return $last;
                } else {
                        return $this->mSkin->makeKnownLinkObj(
-                         $this->mTitle,
-                         $last,
-                         "diff={$row->rev_id}&oldid={$next->rev_id}",
-                         '',
-                         '',
-                         ' tabindex="'.$counter.'"' );
+                               $this->mTitle,
+                               $last,
+                               "diff=" . $rev->getId() . "&oldid={$next->rev_id}"
+                               /*,
+                               '',
+                               '',
+                               "tabindex={$counter}"*/ );
                }
        }
-       
-       function diffButtons( $row, $latest, $counter ) {
-               global $wgUser;
+
+       /**
+        * Create radio buttons for page history
+        *
+        * @param object $rev Revision
+        * @param bool $firstInList Is this version the first one?
+        * @param int $counter A counter of what row number we're at, counted from the top row = 1.
+        * @return string HTML output for the radio buttons
+        */
+       function diffButtons( $rev, $firstInList, $counter ) {
                if( $this->linesonpage > 1) {
                        $radio = array(
                                'type'  => 'radio',
-                               'value' => $row->rev_id,
-                               'title' => wfMsg( 'selectolderversionfordiff' )
+                               'value' => $rev->getId(),
                        );
-                       if( $row->rev_deleted && !$wgUser->isAllowed( 'undelete' ) ) {
+
+                       if( !$rev->userCan( Revision::DELETED_TEXT ) ) {
                                $radio['disabled'] = 'disabled';
                        }
-                       
-                       # XXX: move title texts to javascript
-                       if ( $latest ) {
-                               $first = wfElement( 'input', array_merge(
+
+                       /** @todo: move title texts to javascript */
+                       if ( $firstInList ) {
+                               $first = Xml::element( 'input', array_merge(
                                        $radio,
                                        array(
                                                'style' => 'visibility:hidden',
@@ -305,13 +376,13 @@ class PageHistory {
                                } else {
                                        $checkmark = array();
                                }
-                               $first = wfElement( 'input', array_merge(
+                               $first = Xml::element( 'input', array_merge(
                                        $radio,
                                        $checkmark,
                                        array( 'name'  => 'oldid' ) ) );
                                $checkmark = array();
                        }
-                       $second = wfElement( 'input', array_merge(
+                       $second = Xml::element( 'input', array_merge(
                                $radio,
                                $checkmark,
                                array( 'name'  => 'diff' ) ) );
@@ -320,7 +391,238 @@ class PageHistory {
                        return '';
                }
        }
+
+       /** @todo document */
+       function getLatestId() {
+               if( is_null( $this->mLatestId ) ) {
+                       $id = $this->mTitle->getArticleID();
+                       $db = wfGetDB(DB_SLAVE);
+                       $this->mLatestId = $db->selectField( 'page',
+                               "page_latest",
+                               array( 'page_id' => $id ),
+                               'PageHistory::getLatestID' );
+               }
+               return $this->mLatestId;
+       }
+
+       /**
+        * Fetch an array of revisions, specified by a given limit, offset and
+        * direction. This is now only used by the feeds. It was previously 
+        * used by the main UI but that's now handled by the pager.
+        */
+       function fetchRevisions($limit, $offset, $direction) {
+               $fname = 'PageHistory::fetchRevisions';
+
+               $dbr = wfGetDB( DB_SLAVE );
+
+               if ($direction == PageHistory::DIR_PREV)
+                       list($dirs, $oper) = array("ASC", ">=");
+               else /* $direction == PageHistory::DIR_NEXT */
+                       list($dirs, $oper) = array("DESC", "<=");
+
+               if ($offset)
+                       $offsets = array("rev_timestamp $oper '$offset'");
+               else
+                       $offsets = array();
+
+               $page_id = $this->mTitle->getArticleID();
+
+               $res = $dbr->select(
+                       'revision',
+                       Revision::selectFields(),
+                       array_merge(array("rev_page=$page_id"), $offsets),
+                       $fname,
+                       array('ORDER BY' => "rev_timestamp $dirs",
+                               'USE INDEX' => 'page_timestamp', 'LIMIT' => $limit)
+                       );
+
+               $result = array();
+               while (($obj = $dbr->fetchObject($res)) != NULL)
+                       $result[] = $obj;
+
+               return $result;
+       }
+
+       /** @todo document */
+       function getNotificationTimestamp() {
+               global $wgUser, $wgShowUpdatedMarker;
+               $fname = 'PageHistory::getNotficationTimestamp';
+
+               if ($this->mNotificationTimestamp !== NULL)
+                       return $this->mNotificationTimestamp;
+
+               if ($wgUser->isAnon() || !$wgShowUpdatedMarker)
+                       return $this->mNotificationTimestamp = false;
+
+               $dbr = wfGetDB(DB_SLAVE);
+
+               $this->mNotificationTimestamp = $dbr->selectField(
+                       'watchlist',
+                       'wl_notificationtimestamp',
+                       array(  'wl_namespace' => $this->mTitle->getNamespace(),
+                               'wl_title' => $this->mTitle->getDBkey(),
+                               'wl_user' => $wgUser->getID()
+                       ),
+                       $fname);
+               
+               // Don't use the special value reserved for telling whether the field is filled
+               if ( is_null( $this->mNotificationTimestamp ) ) {
+                       $this->mNotificationTimestamp = false;
+               }
+
+               return $this->mNotificationTimestamp;
+       }
+       
+       /**
+        * Output a subscription feed listing recent edits to this page.
+        * @param string $type
+        */
+       function feed( $type ) {
+               require_once 'SpecialRecentchanges.php';
+               
+               global $wgFeedClasses;
+               if( !isset( $wgFeedClasses[$type] ) ) {
+                       global $wgOut;
+                       $wgOut->addWikiText( wfMsg( 'feed-invalid' ) );
+                       return;
+               }
+               
+               $feed = new $wgFeedClasses[$type](
+                       $this->mTitle->getPrefixedText() . ' - ' .
+                               wfMsgForContent( 'history-feed-title' ),
+                       wfMsgForContent( 'history-feed-description' ),
+                       $this->mTitle->getFullUrl( 'action=history' ) );
+
+               $items = $this->fetchRevisions(10, 0, PageHistory::DIR_NEXT);
+               $feed->outHeader();
+               if( $items ) {
+                       foreach( $items as $row ) {
+                               $feed->outItem( $this->feedItem( $row ) );
+                       }
+               } else {
+                       $feed->outItem( $this->feedEmpty() );
+               }
+               $feed->outFooter();
+       }
+       
+       function feedEmpty() {
+               global $wgOut;
+               return new FeedItem(
+                       wfMsgForContent( 'nohistory' ),
+                       $wgOut->parse( wfMsgForContent( 'history-feed-empty' ) ),
+                       $this->mTitle->getFullUrl(),
+                       wfTimestamp( TS_MW ),
+                       '',
+                       $this->mTitle->getTalkPage()->getFullUrl() );
+       }
+       
+       /**
+        * Generate a FeedItem object from a given revision table row
+        * Borrows Recent Changes' feed generation functions for formatting;
+        * includes a diff to the previous revision (if any).
+        *
+        * @param $row
+        * @return FeedItem
+        */
+       function feedItem( $row ) {
+               $rev = new Revision( $row );
+               $rev->setTitle( $this->mTitle );
+               $text = rcFormatDiffRow( $this->mTitle,
+                       $this->mTitle->getPreviousRevisionID( $rev->getId() ),
+                       $rev->getId(),
+                       $rev->getTimestamp(),
+                       $rev->getComment() );
+               
+               if( $rev->getComment() == '' ) {
+                       global $wgContLang;
+                       $title = wfMsgForContent( 'history-feed-item-nocomment',
+                               $rev->getUserText(),
+                               $wgContLang->timeanddate( $rev->getTimestamp() ) );
+               } else {
+                       $title = $rev->getUserText() . ": " . $this->stripComment( $rev->getComment() );
+               }
+
+               return new FeedItem(
+                       $title,
+                       $text,
+                       $this->mTitle->getFullUrl( 'diff=' . $rev->getId() . '&oldid=prev' ),
+                       $rev->getTimestamp(),
+                       $rev->getUserText(),
+                       $this->mTitle->getTalkPage()->getFullUrl() );
+       }
        
+       /**
+        * Quickie hack... strip out wikilinks to more legible form from the comment.
+        */
+       function stripComment( $text ) {
+               return preg_replace( '/\[\[([^]]*\|)?([^]]+)\]\]/', '\2', $text );
+       }
 }
 
-?>
+
+/**
+ * @addtogroup Pager
+ */
+class PageHistoryPager extends ReverseChronologicalPager {
+       public $mLastRow = false, $mPageHistory;
+       
+       function __construct( $pageHistory ) {
+               parent::__construct();
+               $this->mPageHistory = $pageHistory;
+       }
+
+       function getQueryInfo() {
+               return array(
+                       'tables' => 'revision',
+                       'fields' => Revision::selectFields(),
+                       'conds' => array('rev_page' => $this->mPageHistory->mTitle->getArticleID() ),
+                       'options' => array( 'USE INDEX' => 'page_timestamp' )
+               );
+       }
+
+       function getIndexField() {
+               return 'rev_timestamp';
+       }
+
+       function formatRow( $row ) {
+               if ( $this->mLastRow ) {
+                       $latest = $this->mCounter == 1 && $this->mOffset == '';
+                       $firstInList = $this->mCounter == 1;
+                       $s = $this->mPageHistory->historyLine( $this->mLastRow, $row, $this->mCounter++, 
+                               $this->mPageHistory->getNotificationTimestamp(), $latest, $firstInList );
+               } else {
+                       $s = '';
+               }
+               $this->mLastRow = $row;
+               return $s;
+       }
+       
+       function getStartBody() {
+               $this->mLastRow = false;
+               $this->mCounter = 1;
+               return '';
+       }
+
+       function getEndBody() {
+               if ( $this->mLastRow ) {
+                       $latest = $this->mCounter == 1 && $this->mOffset == 0;
+                       $firstInList = $this->mCounter == 1;
+                       if ( $this->mIsBackwards ) {
+                               # Next row is unknown, but for UI reasons, probably exists if an offset has been specified
+                               if ( $this->mOffset == '' ) {
+                                       $next = null;
+                               } else {
+                                       $next = 'unknown';
+                               }
+                       } else {
+                               # The next row is the past-the-end row
+                               $next = $this->mPastTheEndRow;
+                       }
+                       $s = $this->mPageHistory->historyLine( $this->mLastRow, $next, $this->mCounter++, 
+                               $this->mPageHistory->getNotificationTimestamp(), $latest, $firstInList );
+               } else {
+                       $s = '';
+               }
+               return $s;
+       }
+}