Implemented the PoolCounter feature and did some general refactoring in the areas...

[lhc/web/wiklou.git] / includes / Article.php

<?php
/**
 * File for articles
 * @file
 */

/**
 * Class representing a MediaWiki article and history.
 *
 * See design.txt for an overview.
 * Note: edit user interface and cache support functions have been
 * moved to separate EditPage and HTMLFileCache classes.
 *
 */
class Article {
        /**@{{
         * @private
         */
        var $mComment = '';               //!<
        var $mContent;                    //!<
        var $mContentLoaded = false;      //!<
        var $mCounter = -1;               //!< Not loaded
        var $mCurID = -1;                 //!< Not loaded
        var $mDataLoaded = false;         //!<
        var $mForUpdate = false;          //!<
        var $mGoodAdjustment = 0;         //!<
        var $mIsRedirect = false;         //!<
        var $mLatest = false;             //!<
        var $mMinorEdit;                  //!<
        var $mOldId;                      //!<
        var $mPreparedEdit = false;       //!< Title object if set
        var $mRedirectedFrom = null;      //!< Title object if set
        var $mRedirectTarget = null;      //!< Title object if set
        var $mRedirectUrl = false;        //!<
        var $mRevIdFetched = 0;           //!<
        var $mRevision;                   //!<
        var $mTimestamp = '';             //!<
        var $mTitle;                      //!<
        var $mTotalAdjustment = 0;        //!<
        var $mTouched = '19700101000000'; //!<
        var $mUser = -1;                  //!< Not loaded
        var $mUserText = '';              //!<
        var $mParserOptions;              //!<
        /**@}}*/

        /**
         * Constructor and clear the article
         * @param $title Reference to a Title object.
         * @param $oldId Integer revision ID, null to fetch from request, zero for current
         */
        public function __construct( Title $title, $oldId = null ) {
                $this->mTitle =& $title;
                $this->mOldId = $oldId;
        }

        /**
         * Constructor from an article article
         * @param $id The article ID to load
         */
        public static function newFromID( $id ) {
                $t = Title::newFromID( $id );
                return $t == null ? null : new Article( $t );
        }

        /**
         * Tell the page view functions that this view was redirected
         * from another page on the wiki.
         * @param $from Title object.
         */
        public function setRedirectedFrom( $from ) {
                $this->mRedirectedFrom = $from;
        }

        /**
         * If this page is a redirect, get its target
         *
         * The target will be fetched from the redirect table if possible.
         * If this page doesn't have an entry there, call insertRedirect()
         * @return mixed Title object, or null if this page is not a redirect
         */
        public function getRedirectTarget() {
                if( !$this->mTitle || !$this->mTitle->isRedirect() )
                        return null;
                if( !is_null($this->mRedirectTarget) )
                        return $this->mRedirectTarget;
                # Query the redirect table
                $dbr = wfGetDB( DB_SLAVE );
                $row = $dbr->selectRow( 'redirect',
                        array('rd_namespace', 'rd_title'),
                        array('rd_from' => $this->getID() ),
                        __METHOD__
                );
                if( $row ) {
                        return $this->mRedirectTarget = Title::makeTitle($row->rd_namespace, $row->rd_title);
                }
                # This page doesn't have an entry in the redirect table
                return $this->mRedirectTarget = $this->insertRedirect();
        }

        /**
         * Insert an entry for this page into the redirect table.
         *
         * Don't call this function directly unless you know what you're doing.
         * @return Title object
         */
        public function insertRedirect() {
                $retval = Title::newFromRedirect( $this->getContent() );
                if( !$retval ) {
                        return null;
                }
                $dbw = wfGetDB( DB_MASTER );
                $dbw->replace( 'redirect', array('rd_from'),
                        array(
                                'rd_from' => $this->getID(),
                                'rd_namespace' => $retval->getNamespace(),
                                'rd_title' => $retval->getDBkey()
                        ),
                        __METHOD__
                );
                return $retval;
        }

        /**
         * Get the Title object this page redirects to
         *
         * @return mixed false, Title of in-wiki target, or string with URL
         */
        public function followRedirect() {
                $text = $this->getContent();
                return $this->followRedirectText( $text );
        }

        /**
         * Get the Title object this text redirects to
         *
         * @return mixed false, Title of in-wiki target, or string with URL
         */
        public function followRedirectText( $text ) {
                $rt = Title::newFromRedirectRecurse( $text ); // recurse through to only get the final target
                # process if title object is valid and not special:userlogout
                if( $rt ) {
                        if( $rt->getInterwiki() != '' ) {
                                if( $rt->isLocal() ) {
                                        // Offsite wikis need an HTTP redirect.
                                        //
                                        // This can be hard to reverse and may produce loops,
                                        // so they may be disabled in the site configuration.
                                        $source = $this->mTitle->getFullURL( 'redirect=no' );
                                        return $rt->getFullURL( 'rdfrom=' . urlencode( $source ) );
                                }
                        } else {
                                if( $rt->getNamespace() == NS_SPECIAL ) {
                                        // Gotta handle redirects to special pages differently:
                                        // Fill the HTTP response "Location" header and ignore
                                        // the rest of the page we're on.
                                        //
                                        // This can be hard to reverse, so they may be disabled.
                                        if( $rt->isSpecial( 'Userlogout' ) ) {
                                                // rolleyes
                                        } else {
                                                return $rt->getFullURL();
                                        }
                                }
                                return $rt;
                        }
                }
                // No or invalid redirect
                return false;
        }

        /**
         * get the title object of the article
         */
        public function getTitle() {
                return $this->mTitle;
        }

        /**
         * Clear the object
         * @private
         */
        public function clear() {
                $this->mDataLoaded    = false;
                $this->mContentLoaded = false;

                $this->mCurID = $this->mUser = $this->mCounter = -1; # Not loaded
                $this->mRedirectedFrom = null; # Title object if set
                $this->mRedirectTarget = null; # Title object if set
                $this->mUserText =
                $this->mTimestamp = $this->mComment = '';
                $this->mGoodAdjustment = $this->mTotalAdjustment = 0;
                $this->mTouched = '19700101000000';
                $this->mForUpdate = false;
                $this->mIsRedirect = false;
                $this->mRevIdFetched = 0;
                $this->mRedirectUrl = false;
                $this->mLatest = false;
                $this->mPreparedEdit = false;
        }

        /**
         * Note that getContent/loadContent do not follow redirects anymore.
         * If you need to fetch redirectable content easily, try
         * the shortcut in Article::followContent()
         *
         * @return Return the text of this revision
        */
        public function getContent() {
                global $wgUser, $wgContLang, $wgOut, $wgMessageCache;
                wfProfileIn( __METHOD__ );
                if( $this->getID() === 0 ) {
                        # If this is a MediaWiki:x message, then load the messages
                        # and return the message value for x.
                        if( $this->mTitle->getNamespace() == NS_MEDIAWIKI ) {
                                # If this is a system message, get the default text.
                                list( $message, $lang ) = $wgMessageCache->figureMessage( $wgContLang->lcfirst( $this->mTitle->getText() ) );
                                $wgMessageCache->loadAllMessages( $lang );
                                $text = wfMsgGetKey( $message, false, $lang, false );
                                if( wfEmptyMsg( $message, $text ) )
                                        $text = '';
                        } else {
                                $text = wfMsgExt( $wgUser->isLoggedIn() ? 'noarticletext' : 'noarticletextanon', 'parsemag' );
                        }
                        wfProfileOut( __METHOD__ );
                        return $text;
                } else {
                        $this->loadContent();
                        wfProfileOut( __METHOD__ );
                        return $this->mContent;
                }
        }

        /**
         * Get the text of the current revision. No side-effects...
         *
         * @return Return the text of the current revision
        */
        public function getRawText() {
                // Check process cache for current revision
                if( $this->mContentLoaded && $this->mOldId == 0 ) {
                        return $this->mContent;
                }
                $rev = Revision::newFromTitle( $this->mTitle );
                $text = $rev ? $rev->getRawText() : false;
                return $text;
        }

        /**
         * This function returns the text of a section, specified by a number ($section).
         * A section is text under a heading like == Heading == or \<h1\>Heading\</h1\>, or
         * the first section before any such heading (section 0).
         *
         * If a section contains subsections, these are also returned.
         *
         * @param $text String: text to look in
         * @param $section Integer: section number
         * @return string text of the requested section
         * @deprecated
         */
        public function getSection( $text, $section ) {
                global $wgParser;
                return $wgParser->getSection( $text, $section );
        }

        /**
         * Get the text that needs to be saved in order to undo all revisions
         * between $undo and $undoafter. Revisions must belong to the same page,
         * must exist and must not be deleted
         * @param $undo Revision
         * @param $undoafter Revision Must be an earlier revision than $undo
         * @return mixed string on success, false on failure
         */
        public function getUndoText( Revision $undo, Revision $undoafter = null ) {
                $undo_text = $undo->getText();
                $undoafter_text = $undoafter->getText();
                $cur_text = $this->getContent();
                if ( $cur_text == $undo_text ) {
                        # No use doing a merge if it's just a straight revert.
                        return $undoafter_text;
                }
                $undone_text = '';
                if ( !wfMerge( $undo_text, $undoafter_text, $cur_text, $undone_text ) )
                        return false;
                return $undone_text;
        }

        /**
         * @return int The oldid of the article that is to be shown, 0 for the
         *             current revision
         */
        public function getOldID() {
                if( is_null( $this->mOldId ) ) {
                        $this->mOldId = $this->getOldIDFromRequest();
                }
                return $this->mOldId;
        }

        /**
         * Sets $this->mRedirectUrl to a correct URL if the query parameters are incorrect
         *
         * @return int The old id for the request
         */
        public function getOldIDFromRequest() {
                global $wgRequest;
                $this->mRedirectUrl = false;
                $oldid = $wgRequest->getVal( 'oldid' );
                if( isset( $oldid ) ) {
                        $oldid = intval( $oldid );
                        if( $wgRequest->getVal( 'direction' ) == 'next' ) {
                                $nextid = $this->mTitle->getNextRevisionID( $oldid );
                                if( $nextid  ) {
                                        $oldid = $nextid;
                                } else {
                                        $this->mRedirectUrl = $this->mTitle->getFullURL( 'redirect=no' );
                                }
                        } elseif( $wgRequest->getVal( 'direction' ) == 'prev' ) {
                                $previd = $this->mTitle->getPreviousRevisionID( $oldid );
                                if( $previd ) {
                                        $oldid = $previd;
                                }
                        }
                }
                if( !$oldid ) {
                        $oldid = 0;
                }
                return $oldid;
        }

        /**
         * Load the revision (including text) into this object
         */
        function loadContent() {
                if( $this->mContentLoaded ) return;
                wfProfileIn( __METHOD__ );
                # Query variables :P
                $oldid = $this->getOldID();
                # Pre-fill content with error message so that if something
                # fails we'll have something telling us what we intended.
                $this->mOldId = $oldid;
                $this->fetchContent( $oldid );
                wfProfileOut( __METHOD__ );
        }


        /**
         * Fetch a page record with the given conditions
         * @param $dbr Database object
         * @param $conditions Array
         */
        protected function pageData( $dbr, $conditions ) {
                $fields = array(
                                'page_id',
                                'page_namespace',
                                'page_title',
                                'page_restrictions',
                                'page_counter',
                                'page_is_redirect',
                                'page_is_new',
                                'page_random',
                                'page_touched',
                                'page_latest',
                                'page_len',
                );
                wfRunHooks( 'ArticlePageDataBefore', array( &$this, &$fields ) );
                $row = $dbr->selectRow(
                        'page',
                        $fields,
                        $conditions,
                        __METHOD__
                );
                wfRunHooks( 'ArticlePageDataAfter', array( &$this, &$row ) );
                return $row ;
        }

        /**
         * @param $dbr Database object
         * @param $title Title object
         */
        public function pageDataFromTitle( $dbr, $title ) {
                return $this->pageData( $dbr, array(
                        'page_namespace' => $title->getNamespace(),
                        'page_title'     => $title->getDBkey() ) );
        }

        /**
         * @param $dbr Database
         * @param $id Integer
         */
        protected function pageDataFromId( $dbr, $id ) {
                return $this->pageData( $dbr, array( 'page_id' => $id ) );
        }

        /**
         * Set the general counter, title etc data loaded from
         * some source.
         *
         * @param $data Database row object or "fromdb"
         */
        public function loadPageData( $data = 'fromdb' ) {
                if( $data === 'fromdb' ) {
                        $dbr = wfGetDB( DB_MASTER );
                        $data = $this->pageDataFromId( $dbr, $this->getId() );
                }

                $lc = LinkCache::singleton();
                if( $data ) {
                        $lc->addGoodLinkObj( $data->page_id, $this->mTitle, $data->page_len, $data->page_is_redirect );

                        $this->mTitle->mArticleID = $data->page_id;

                        # Old-fashioned restrictions
                        $this->mTitle->loadRestrictions( $data->page_restrictions );

                        $this->mCounter     = $data->page_counter;
                        $this->mTouched     = wfTimestamp( TS_MW, $data->page_touched );
                        $this->mIsRedirect  = $data->page_is_redirect;
                        $this->mLatest      = $data->page_latest;
                } else {
                        if( is_object( $this->mTitle ) ) {
                                $lc->addBadLinkObj( $this->mTitle );
                        }
                        $this->mTitle->mArticleID = 0;
                }

                $this->mDataLoaded  = true;
        }

        /**
         * Get text of an article from database
         * Does *NOT* follow redirects.
         * @param $oldid Int: 0 for whatever the latest revision is
         * @return string
         */
        function fetchContent( $oldid = 0 ) {
                if( $this->mContentLoaded ) {
                        return $this->mContent;
                }

                $dbr = wfGetDB( DB_MASTER );

                # Pre-fill content with error message so that if something
                # fails we'll have something telling us what we intended.
                $t = $this->mTitle->getPrefixedText();
                $d = $oldid ? wfMsgExt( 'missingarticle-rev', array( 'escape' ), $oldid ) : '';
                $this->mContent = wfMsg( 'missing-article', $t, $d ) ;

                if( $oldid ) {
                        $revision = Revision::newFromId( $oldid );
                        if( is_null( $revision ) ) {
                                wfDebug( __METHOD__." failed to retrieve specified revision, id $oldid\n" );
                                return false;
                        }
                        $data = $this->pageDataFromId( $dbr, $revision->getPage() );
                        if( !$data ) {
                                wfDebug( __METHOD__." failed to get page data linked to revision id $oldid\n" );
                                return false;
                        }
                        $this->mTitle = Title::makeTitle( $data->page_namespace, $data->page_title );
                        $this->loadPageData( $data );
                } else {
                        if( !$this->mDataLoaded ) {
                                $data = $this->pageDataFromTitle( $dbr, $this->mTitle );
                                if( !$data ) {
                                        wfDebug( __METHOD__." failed to find page data for title " . $this->mTitle->getPrefixedText() . "\n" );
                                        return false;
                                }
                                $this->loadPageData( $data );
                        }
                        $revision = Revision::newFromId( $this->mLatest );
                        if( is_null( $revision ) ) {
                                wfDebug( __METHOD__." failed to retrieve current page, rev_id {$this->mLatest}\n" );
                                return false;
                        }
                }

                // FIXME: Horrible, horrible! This content-loading interface just plain sucks.
                // We should instead work with the Revision object when we need it...
                $this->mContent   = $revision->getText( Revision::FOR_THIS_USER ); // Loads if user is allowed

                $this->mUser      = $revision->getUser();
                $this->mUserText  = $revision->getUserText();
                $this->mComment   = $revision->getComment();
                $this->mTimestamp = wfTimestamp( TS_MW, $revision->getTimestamp() );

                $this->mRevIdFetched = $revision->getId();
                $this->mContentLoaded = true;
                $this->mRevision =& $revision;

                wfRunHooks( 'ArticleAfterFetchContent', array( &$this, &$this->mContent ) ) ;

                return $this->mContent;
        }

        /**
         * Read/write accessor to select FOR UPDATE
         *
         * @param $x Mixed: FIXME
         */
        public function forUpdate( $x = NULL ) {
                return wfSetVar( $this->mForUpdate, $x );
        }

        /**
         * Get the database which should be used for reads
         *
         * @return Database
         * @deprecated - just call wfGetDB( DB_MASTER ) instead
         */
        function getDB() {
                wfDeprecated( __METHOD__ );
                return wfGetDB( DB_MASTER );
        }

        /**
         * Get options for all SELECT statements
         *
         * @param $options Array: an optional options array which'll be appended to
         *                       the default
         * @return Array: options
         */
        protected function getSelectOptions( $options = '' ) {
                if( $this->mForUpdate ) {
                        if( is_array( $options ) ) {
                                $options[] = 'FOR UPDATE';
                        } else {
                                $options = 'FOR UPDATE';
                        }
                }
                return $options;
        }

        /**
         * @return int Page ID
         */
        public function getID() {
                if( $this->mTitle ) {
                        return $this->mTitle->getArticleID();
                } else {
                        return 0;
                }
        }

        /**
         * @return bool Whether or not the page exists in the database
         */
        public function exists() {
                return $this->getId() > 0;
        }

        /**
         * Check if this page is something we're going to be showing
         * some sort of sensible content for. If we return false, page
         * views (plain action=view) will return an HTTP 404 response,
         * so spiders and robots can know they're following a bad link.
         *
         * @return bool
         */
        public function hasViewableContent() {
                return $this->exists() || $this->mTitle->isAlwaysKnown();
        }

        /**
         * @return int The view count for the page
         */
        public function getCount() {
                if( -1 == $this->mCounter ) {
                        $id = $this->getID();
                        if( $id == 0 ) {
                                $this->mCounter = 0;
                        } else {
                                $dbr = wfGetDB( DB_SLAVE );
                                $this->mCounter = $dbr->selectField( 'page',
                                        'page_counter',
                                        array( 'page_id' => $id ),
                                        __METHOD__,
                                        $this->getSelectOptions()
                                );
                        }
                }
                return $this->mCounter;
        }

        /**
         * Determine whether a page  would be suitable for being counted as an
         * article in the site_stats table based on the title & its content
         *
         * @param $text String: text to analyze
         * @return bool
         */
        public function isCountable( $text ) {
                global $wgUseCommaCount;

                $token = $wgUseCommaCount ? ',' : '[[';
                return $this->mTitle->isContentPage() && !$this->isRedirect($text) && in_string($token,$text);
        }

        /**
         * Tests if the article text represents a redirect
         *
         * @param $text String: FIXME
         * @return bool
         */
        public function isRedirect( $text = false ) {
                if( $text === false ) {
                        if( $this->mDataLoaded ) {
                                return $this->mIsRedirect;
                        }
                        // Apparently loadPageData was never called
                        $this->loadContent();
                        $titleObj = Title::newFromRedirectRecurse( $this->fetchContent() );
                } else {
                        $titleObj = Title::newFromRedirect( $text );
                }
                return $titleObj !== NULL;
        }

        /**
         * Returns true if the currently-referenced revision is the current edit
         * to this page (and it exists).
         * @return bool
         */
        public function isCurrent() {
                # If no oldid, this is the current version.
                if( $this->getOldID() == 0 ) {
                        return true;
                }
                return $this->exists() && isset($this->mRevision) && $this->mRevision->isCurrent();
        }

        /**
         * Loads everything except the text
         * This isn't necessary for all uses, so it's only done if needed.
         */
        protected function loadLastEdit() {
                if( -1 != $this->mUser )
                        return;

                # New or non-existent articles have no user information
                $id = $this->getID();
                if( 0 == $id ) return;

                $this->mLastRevision = Revision::loadFromPageId( wfGetDB( DB_MASTER ), $id );
                if( !is_null( $this->mLastRevision ) ) {
                        $this->mUser      = $this->mLastRevision->getUser();
                        $this->mUserText  = $this->mLastRevision->getUserText();
                        $this->mTimestamp = $this->mLastRevision->getTimestamp();
                        $this->mComment   = $this->mLastRevision->getComment();
                        $this->mMinorEdit = $this->mLastRevision->isMinor();
                        $this->mRevIdFetched = $this->mLastRevision->getId();
                }
        }

        public function getTimestamp() {
                // Check if the field has been filled by ParserCache::get()
                if( !$this->mTimestamp ) {
                        $this->loadLastEdit();
                }
                return wfTimestamp(TS_MW, $this->mTimestamp);
        }

        public function getUser() {
                $this->loadLastEdit();
                return $this->mUser;
        }

        public function getUserText() {
                $this->loadLastEdit();
                return $this->mUserText;
        }

        public function getComment() {
                $this->loadLastEdit();
                return $this->mComment;
        }

        public function getMinorEdit() {
                $this->loadLastEdit();
                return $this->mMinorEdit;
        }

        /* Use this to fetch the rev ID used on page views */
        public function getRevIdFetched() {
                $this->loadLastEdit();
                return $this->mRevIdFetched;
        }

        /**
         * @param $limit Integer: default 0.
         * @param $offset Integer: default 0.
         */
        public function getContributors($limit = 0, $offset = 0) {
                # XXX: this is expensive; cache this info somewhere.

                $contribs = array();
                $dbr = wfGetDB( DB_SLAVE );
                $revTable = $dbr->tableName( 'revision' );
                $userTable = $dbr->tableName( 'user' );
                $user = $this->getUser();
                $pageId = $this->getId();

                $deletedBit = $dbr->bitAnd('rev_deleted', Revision::DELETED_USER); // username hidden?

                $sql = "SELECT {$userTable}.*, MAX(rev_timestamp) as timestamp
                        FROM $revTable LEFT JOIN $userTable ON rev_user = user_id
                        WHERE rev_page = $pageId
                        AND rev_user != $user
                        AND $deletedBit = 0
                        GROUP BY rev_user, rev_user_text, user_real_name
                        ORDER BY timestamp DESC";

                if($limit > 0)
                        $sql = $dbr->limitResult($sql, $limit, $offset);

                $sql .= ' '. $this->getSelectOptions();

                $res = $dbr->query($sql, __METHOD__ );

                return new UserArrayFromResult( $res );
        }

        /**
         * This is the default action of the index.php entry point: just view the 
         * page of the given title.
        */
        public function view() {
                global $wgUser, $wgOut, $wgRequest, $wgContLang;
                global $wgEnableParserCache, $wgStylePath, $wgParser;
                global $wgUseTrackbacks;

                wfProfileIn( __METHOD__ );

                # Get variables from query string
                $oldid = $this->getOldID();
                $parserCache = ParserCache::singleton();

                $parserOptions = clone $this->getParserOptions();
                # Render printable version, use printable version cache
                if ( $wgOut->isPrintable() ) {
                        $parserOptions->setIsPrintable( true );
                }

                # Try client and file cache
                if( $oldid === 0 && $this->checkTouched() ) {
                        global $wgUseETag;
                        if( $wgUseETag ) {
                                $wgOut->setETag( $parserCache->getETag( $this, $parserOptions ) );
                        }
                        # Is is client cached?
                        if( $wgOut->checkLastModified( $this->getTouched() ) ) {
                                wfDebug( __METHOD__.": done 304\n" );
                                wfProfileOut( __METHOD__ );
                                return;
                        # Try file cache
                        } else if( $this->tryFileCache() ) {
                                wfDebug( __METHOD__.": done file cache\n" );
                                # tell wgOut that output is taken care of
                                $wgOut->disable();
                                $this->viewUpdates();
                                wfProfileOut( __METHOD__ );
                                return;
                        }
                }

                $sk = $wgUser->getSkin();

                # getOldID may want us to redirect somewhere else
                if( $this->mRedirectUrl ) {
                        $wgOut->redirect( $this->mRedirectUrl );
                        wfDebug( __METHOD__.": redirecting due to oldid\n" );
                        wfProfileOut( __METHOD__ );
                        return;
                }

                $wgOut->setArticleFlag( true );
                $wgOut->setRobotPolicy( $this->getRobotPolicyForView() );
                # Set page title (may be overridden by DISPLAYTITLE)
                $wgOut->setPageTitle( $this->mTitle->getPrefixedText() );

                # If we got diff in the query, we want to see a diff page instead of the article.
                if( !is_null( $wgRequest->getVal( 'diff' ) ) ) {
                        wfDebug( __METHOD__.": showing diff page\n" );
                        $this->showDiffPage();
                        wfProfileOut( __METHOD__ );
                        return;
                }

                # Should the parser cache be used?
                $useParserCache = $this->useParserCache( $oldid );
                wfDebug( 'Article::view using parser cache: ' . ($useParserCache ? 'yes' : 'no' ) . "\n" );
                if( $wgUser->getOption( 'stubthreshold' ) ) {
                        wfIncrStats( 'pcache_miss_stub' );
                }

                # For the main page, overwrite the <title> element with the con-
                # tents of 'pagetitle-view-mainpage' instead of the default (if
                # that's not empty).
                if( $this->mTitle->equals( Title::newMainPage() ) 
                        && wfMsgForContent( 'pagetitle-view-mainpage' ) !== '' ) 
                {
                        $wgOut->setHTMLTitle( wfMsgForContent( 'pagetitle-view-mainpage' ) );
                }

                $wasRedirected = $this->showRedirectedFromHeader();
                $this->showNamespaceHeader();

                $outputDone = false;
                wfRunHooks( 'ArticleViewHeader', array( &$this, &$outputDone, &$useParserCache ) );

                # Try the parser cache
                if( !$outputDone && $useParserCache ) {
                        $parserOutput = $parserCache->get( $this, $parserOptions );
                        if ( $parserOutput !== false ) {
                                wfDebug( __METHOD__.": showing parser cache contents\n" );
                                $wgOut->addParserOutput( $parserOutput );
                                // Ensure that UI elements requiring revision ID have
                                // the correct version information.
                                $wgOut->setRevisionId( $this->mLatest );
                                $outputDone = true;
                        }
                }

                if ( $outputDone ) {
                        $this->showViewFooter();
                        $this->viewUpdates();
                        wfProfileOut( __METHOD__ );
                        return;
                }

                $text = $this->getContent();
                if( $text === false || $this->getID() == 0 ) {
                        wfDebug( __METHOD__.": showing missing article\n" );
                        $this->showMissingArticle();
                        wfProfileOut( __METHOD__ );
                        return;
                }

                # Another whitelist check in case oldid is altering the title
                if( !$this->mTitle->userCanRead() ) {
                        wfDebug( __METHOD__.": denied on secondary read check\n" );
                        $wgOut->loginToUse();
                        $wgOut->output();
                        $wgOut->disable();
                        wfProfileOut( __METHOD__ );
                        return;
                }

                # We're looking at an old revision
                if( $oldid && !is_null( $this->mRevision ) ) {
                        $this->setOldSubtitle( $oldid );
                        if ( !$this->showDeletedRevisionHeader() ) {
                                wfDebug( __METHOD__.": cannot view deleted revision\n" );
                                wfProfileOut( __METHOD__ );
                                return;
                        }

                        if ( $oldid === $this->getLatest() && $this->useParserCache( false ) ) {
                                $parserOutput = $parserCache->get( $this, $parserOptions );
                                if ( $parserOutput ) {
                                        wfDebug( __METHOD__.": showing parser cache for current rev permalink\n" );
                                        $wgOut->addParserOutput( $parserOutput );
                                        $this->showViewFooter();
                                        $this->viewUpdates();
                                        wfProfileOut( __METHOD__ );
                                        return;
                                }
                        }
                }

                // Ensure that UI elements requiring revision ID have
                // the correct version information.
                $wgOut->setRevisionId( $this->getRevIdFetched() );

                // Pages containing custom CSS or JavaScript get special treatment
                if( $this->mTitle->isCssOrJsPage() || $this->mTitle->isCssJsSubpage() ) {
                        wfDebug( __METHOD__.": showing CSS/JS source\n" );
                        $this->showCssOrJsPage();
                        $outputDone = true;
                } else if( $rt = Title::newFromRedirectArray( $text ) ) {
                        wfDebug( __METHOD__.": showing redirect=no page\n" );
                        # Viewing a redirect page (e.g. with parameter redirect=no)
                        # Don't append the subtitle if this was an old revision
                        $wgOut->addHTML( $this->viewRedirect( $rt, !$wasRedirected && $this->isCurrent() ) );
                        # Parse just to get categories, displaytitle, etc.
                        $parserOutput = $wgParser->parse( $text, $this->mTitle, $parserOptions );
                        $wgOut->addParserOutputNoText( $parserOutput );
                        $outputDone = true;
                }
                if ( $outputDone ) {
                        $this->showViewFooter();
                        $this->viewUpdates();
                        wfProfileOut( __METHOD__ );
                        return;
                }

                # Run the parse, protected by a pool counter
                wfDebug( __METHOD__.": doing uncached parse\n" );
                $key = $parserCache->getKey( $this, $parserOptions );
                $poolCounter = PoolCounter::factory( 'Article::view', $key );
                $dirtyCallback = $useParserCache ? array( $this, 'tryDirtyCache' ) : false;
                $status = $poolCounter->executeProtected( array( $this, 'doViewParse' ), $dirtyCallback );

                if ( !$status->isOK() ) {
                        # Connection or timeout error
                        $this->showPoolError( $status );
                        wfProfileOut( __METHOD__ );
                        return;
                }

                $this->showViewFooter();
                $this->viewUpdates();
                wfProfileOut( __METHOD__ );
        }

        /**
         * Show a diff page according to current request variables. For use within
         * Article::view() only, other callers should use the DifferenceEngine class.
         */
        public function showDiffPage() {
                global $wgOut, $wgRequest, $wgUser;
                
                $diff = $wgRequest->getVal( 'diff' );
                $rcid = $wgRequest->getVal( 'rcid' );
                $diffOnly = $wgRequest->getBool( 'diffonly', $wgUser->getOption( 'diffonly' ) );
                $purge = $wgRequest->getVal( 'action' ) == 'purge';
                $htmldiff = $wgRequest->getVal( 'htmldiff' , false);
                $unhide = $wgRequest->getInt('unhide') == 1;
                $oldid = $this->getOldID();

                $de = new DifferenceEngine( $this->mTitle, $oldid, $diff, $rcid, $purge, $htmldiff, $unhide );
                // DifferenceEngine directly fetched the revision:
                $this->mRevIdFetched = $de->mNewid;
                $de->showDiffPage( $diffOnly );

                // Needed to get the page's current revision
                $this->loadPageData();
                if( $diff == 0 || $diff == $this->mLatest ) {
                        # Run view updates for current revision only
                        $this->viewUpdates();
                }
        }

        /**
         * Show a page view for a page formatted as CSS or JavaScript. To be called by 
         * Article::view() only.
         *
         * This is hooked by SyntaxHighlight_GeSHi to do syntax highlighting of these 
         * page views.
         */
        public function showCssOrJsPage() {
                global $wgOut;
                $wgOut->addHTML( wfMsgExt( 'clearyourcache', 'parse' ) );
                // Give hooks a chance to customise the output
                if( wfRunHooks( 'ShowRawCssJs', array( $this->mContent, $this->mTitle, $wgOut ) ) ) {
                        // Wrap the whole lot in a <pre> and don't parse
                        $m = array();
                        preg_match( '!\.(css|js)$!u', $this->mTitle->getText(), $m );
                        $wgOut->addHTML( "<pre class=\"mw-code mw-{$m[1]}\" dir=\"ltr\">\n" );
                        $wgOut->addHTML( htmlspecialchars( $this->mContent ) );
                        $wgOut->addHTML( "\n</pre>\n" );
                }
        }

        /**
         * Get the robot policy to be used for the current action=view request.
         */
        public function getRobotPolicyForView() {
                global $wgOut, $wgArticleRobotPolicies, $wgNamespaceRobotPolicies;
                global $wgDefaultRobotPolicy, $wgRequest;

                $ns = $this->mTitle->getNamespace();
                if( $ns == NS_USER || $ns == NS_USER_TALK ) {
                        # Don't index user and user talk pages for blocked users (bug 11443)
                        if( !$this->mTitle->isSubpage() ) {
                                $block = new Block();
                                if( $block->load( $this->mTitle->getText() ) ) {
                                        return 'noindex,nofollow';
                                }
                        }
                }

                if( $this->getID() === 0 || $this->getOldID() ) {
                        return 'noindex,nofollow';
                } elseif( $wgOut->isPrintable() ) {
                        # Discourage indexing of printable versions, but encourage following
                        return 'noindex,follow';
                } elseif( $wgRequest->getInt('curid') ) {
                        # For ?curid=x urls, disallow indexing
                        return 'noindex,follow';
                } elseif( isset( $wgArticleRobotPolicies[$this->mTitle->getPrefixedText()] ) ) {
                        return $wgArticleRobotPolicies[$this->mTitle->getPrefixedText()];
                } elseif( isset( $wgNamespaceRobotPolicies[$ns] ) ) {
                        # Honour customised robot policies for this namespace
                        return $wgNamespaceRobotPolicies[$ns];
                } else {
                        return $wgDefaultRobotPolicy;
                }
        }

        /**
         * If this request is a redirect view, send "redirected from" subtitle to 
         * $wgOut. Returns true if the header was needed, false if this is not a 
         * redirect view. Handles both local and remote redirects.
         */
        public function showRedirectedFromHeader() {
                global $wgOut, $wgUser, $wgRequest, $wgRedirectSources;

                $rdfrom = $wgRequest->getVal( 'rdfrom' );
                $sk = $wgUser->getSkin();
                if( isset( $this->mRedirectedFrom ) ) {
                        // This is an internally redirected page view.
                        // We'll need a backlink to the source page for navigation.
                        if( wfRunHooks( 'ArticleViewRedirect', array( &$this ) ) ) {
                                $redir = $sk->link(
                                        $this->mRedirectedFrom,
                                        null,
                                        array(),
                                        array( 'redirect' => 'no' ),
                                        array( 'known', 'noclasses' )
                                );
                                $s = wfMsgExt( 'redirectedfrom', array( 'parseinline', 'replaceafter' ), $redir );
                                $wgOut->setSubtitle( $s );

                                // Set the fragment if one was specified in the redirect
                                if( strval( $this->mTitle->getFragment() ) != '' ) {
                                        $fragment = Xml::escapeJsString( $this->mTitle->getFragmentForURL() );
                                        $wgOut->addInlineScript( "redirectToFragment(\"$fragment\");" );
                                }

                                // Add a <link rel="canonical"> tag
                                $wgOut->addLink( array( 'rel' => 'canonical',
                                        'href' => $this->mTitle->getLocalURL() )
                                );
                                return true;
                        }
                } elseif( $rdfrom ) {
                        // This is an externally redirected view, from some other wiki.
                        // If it was reported from a trusted site, supply a backlink.
                        if( $wgRedirectSources && preg_match( $wgRedirectSources, $rdfrom ) ) {
                                $redir = $sk->makeExternalLink( $rdfrom, $rdfrom );
                                $s = wfMsgExt( 'redirectedfrom', array( 'parseinline', 'replaceafter' ), $redir );
                                $wgOut->setSubtitle( $s );
                                return true;
                        }
                }
                return false;
        }

        /**
         * Show a header specific to the namespace currently being viewed, like 
         * [[MediaWiki:Talkpagetext]]. For Article::view().
         */
        public function showNamespaceHeader() {
                global $wgOut;
                if( $this->mTitle->isTalkPage() ) {
                        $msg = wfMsgNoTrans( 'talkpageheader' );
                        if ( $msg !== '-' && !wfEmptyMsg( 'talkpageheader', $msg ) ) {
                                $wgOut->wrapWikiMsg( "<div class=\"mw-talkpageheader\">\n$1</div>", array( 'talkpageheader' ) );
                        }
                }
        }

        /**
         * Show the footer section of an ordinary page view
         */
        public function showViewFooter() {
                global $wgOut, $wgUseTrackbacks, $wgRequest;
                # check if we're displaying a [[User talk:x.x.x.x]] anonymous talk page
                if( $this->mTitle->getNamespace() == NS_USER_TALK && IP::isValid( $this->mTitle->getText() ) ) {
                        $wgOut->addWikiMsg('anontalkpagetext');
                }

                # If we have been passed an &rcid= parameter, we want to give the user a
                # chance to mark this new article as patrolled.
                $this->showPatrolFooter();

                # Trackbacks
                if( $wgUseTrackbacks ) {
                        $this->addTrackbacks();
                }
        }

        /**
         * If patrol is possible, output a patrol UI box. This is called from the 
         * footer section of ordinary page views. If patrol is not possible or not 
         * desired, does nothing.
         */
        public function showPatrolFooter() {
                global $wgOut, $wgRequest;
                $rcid = $wgRequest->getVal( 'rcid' );

                if( !$rcid || !$this->mTitle->exists() || !$this->mTitle->quickUserCan( 'patrol' ) ) {
                        return;
                }

                $wgOut->addHTML(
                        "<div class='patrollink'>" .
                                wfMsgHtml(
                                        'markaspatrolledlink',
                                        $sk->link(
                                                $this->mTitle,
                                                wfMsgHtml( 'markaspatrolledtext' ),
                                                array(),
                                                array(
                                                        'action' => 'markpatrolled',
                                                        'rcid' => $rcid
                                                ),
                                                array( 'known', 'noclasses' )
                                        )
                                ) .
                        '</div>'
                );
        }               

        /**
         * Show the error text for a missing article. For articles in the MediaWiki 
         * namespace, show the default message text. To be called from Article::view().
         */
        public function showMissingArticle() {
                global $wgOut, $wgRequest;
                # Show delete and move logs
                $this->showLogs();

                # Show error message
                $oldid = $this->getOldID();
                if( $oldid ) {
                        $text = wfMsgNoTrans( 'missing-article', 
                                $this->mTitle->getPrefixedText(),
                                wfMsgNoTrans( 'missingarticle-rev', $oldid ) );
                } elseif ( $this->mTitle->getNamespace() === NS_MEDIAWIKI ) {
                        // Use the default message text
                        $text = $this->getContent();
                } else {
                        $text = wfMsgNoTrans( 'noarticletext' );
                }
                $text = "<div class='noarticletext'>\n$text\n</div>";
                if( !$this->hasViewableContent() ) {
                        // If there's no backing content, send a 404 Not Found
                        // for better machine handling of broken links.
                        $wgRequest->response()->header( "HTTP/1.x 404 Not Found" );
                }
                $wgOut->addWikiText( $text );
        }

        /**
         * If the revision requested for view is deleted, check permissions. 
         * Send either an error message or a warning header to $wgOut.
         * Returns true if the view is allowed, false if not.
         */
        public function showDeletedRevisionHeader() {
                global $wgOut, $wgRequest;

                if( !$this->mRevision->isDeleted( Revision::DELETED_TEXT ) ) {
                        // Not deleted
                        return true;
                }

                // If the user is not allowed to see it...
                if( !$this->mRevision->userCan(Revision::DELETED_TEXT) ) {
                        $wgOut->wrapWikiMsg( "<div class='mw-warning plainlinks'>\n$1</div>\n",
                                'rev-deleted-text-permission' );
                        return false;
                // If the user needs to confirm that they want to see it...
                } else if( $wgRequest->getInt('unhide') != 1 ) {
                        # Give explanation and add a link to view the revision...
                        $oldid = intval( $this->getOldID() );
                        $link = $this->mTitle->getFullUrl( "oldid={$oldid}&unhide=1" );
                        $wgOut->wrapWikiMsg( "<div class='mw-warning plainlinks'>\n$1</div>\n",
                                array('rev-deleted-text-unhide',$link) );
                        return false;
                // We are allowed to see...
                } else {
                        $wgOut->wrapWikiMsg( "<div class='mw-warning plainlinks'>\n$1</div>\n",
                                'rev-deleted-text-view' );
                        return true;
                }
        }

        /**
         * Show an excerpt from the deletion and move logs. To be called from the 
         * header section on page views of missing pages.
         */
        public function showLogs() {
                global $wgUser, $wgOut;
                $loglist = new LogEventsList( $wgUser->getSkin(), $wgOut );
                $pager = new LogPager( $loglist, array('move', 'delete'), false,
                        $this->mTitle->getPrefixedText(), '', array( "log_action != 'revision'" ) );
                if( $pager->getNumRows() > 0 ) {
                        $pager->mLimit = 10;
                        $wgOut->addHTML( '<div class="mw-warning-with-logexcerpt">' );
                        $wgOut->addWikiMsg( 'moveddeleted-notice' );
                        $wgOut->addHTML(
                                $loglist->beginLogEventsList() .
                                $pager->getBody() .
                                $loglist->endLogEventsList()
                        );
                        if( $pager->getNumRows() > 10 ) {
                                $wgOut->addHTML( $wgUser->getSkin()->link(
                                        SpecialPage::getTitleFor( 'Log' ),
                                        wfMsgHtml( 'log-fulllog' ),
                                        array(),
                                        array( 'page' => $this->mTitle->getPrefixedText() )
                                ) );
                        }
                        $wgOut->addHTML( '</div>' );
                }
        }

        /*
        * Should the parser cache be used?
        */
        public function useParserCache( $oldid ) {
                global $wgUser, $wgEnableParserCache;

                return $wgEnableParserCache
                        && intval( $wgUser->getOption( 'stubthreshold' ) ) == 0
                        && $this->exists()
                        && empty( $oldid )
                        && !$this->mTitle->isCssOrJsPage()
                        && !$this->mTitle->isCssJsSubpage();
        }

        /**
         * Execute the uncached parse for action=view
         */
        public function doViewParse() {
                global $wgOut;
                $oldid = $this->getOldID();
                $useParserCache = $this->useParserCache( $oldid );
                $parserOptions = clone $this->getParserOptions();
                # Render printable version, use printable version cache
                $parserOptions->setIsPrintable( $wgOut->isPrintable() );
                # Don't show section-edit links on old revisions... this way lies madness.
                $parserOptions->setEditSection( $this->isCurrent() );
                $useParserCache = $this->useParserCache( $oldid );
                $this->outputWikiText( $this->getContent(), $useParserCache, $parserOptions );
        }

        /**
         * Try to fetch an expired entry from the parser cache. If it is present, 
         * output it and return true. If it is not present, output nothing and 
         * return false. This is used as a callback function for 
         * PoolCounter::executeProtected().
         */
        public function tryDirtyCache() {
                global $wgOut;
                $parserCache = ParserCache::singleton();
                $options = $this->getParserOptions();
                $options->setIsPrintable( $wgOut->isPrintable() );
                $output = $parserCache->getDirty( $this, $options );
                if ( $output ) {
                        wfDebug( __METHOD__.": sending dirty output\n" );
                        wfDebugLog( 'dirty', "dirty output " . $parserCache->getKey( $this, $options ) . "\n" );
                        $wgOut->setSquidMaxage( 0 );
                        $wgOut->addParserOutput( $output );
                        $wgOut->addHTML( "<!-- parser cache is expired, sending anyway due to pool overload-->\n" );
                        return true;
                } else {
                        wfDebugLog( 'dirty', "dirty missing\n" );
                        wfDebug( __METHOD__.": no dirty cache\n" );
                        return false;
                }
        }

        /**
         * Show an error page for an error from the pool counter.
         * @param $status Status
         */
        public function showPoolError( $status ) {
                global $wgOut;
                $wgOut->clearHTML(); // for release() errors
                $wgOut->enableClientCache( false );
                $wgOut->setRobotPolicy( 'noindex,nofollow' );
                $wgOut->addWikiText(
                        '<div class="errorbox">' . 
                        $status->getWikiText( false, 'view-pool-error' ) .
                        '</div>'
                );
        }

        /**
         * View redirect
         * @param $target Title object or Array of destination(s) to redirect
         * @param $appendSubtitle Boolean [optional]
         * @param $forceKnown Boolean: should the image be shown as a bluelink regardless of existence?
         */
        public function viewRedirect( $target, $appendSubtitle = true, $forceKnown = false ) {
                global $wgParser, $wgOut, $wgContLang, $wgStylePath, $wgUser;
                # Display redirect
                if( !is_array( $target ) ) {
                        $target = array( $target );
                }
                $imageDir = $wgContLang->isRTL() ? 'rtl' : 'ltr';
                $imageUrl = $wgStylePath . '/common/images/redirect' . $imageDir . '.png';
                $imageUrl2 = $wgStylePath . '/common/images/nextredirect' . $imageDir . '.png';
                $alt2 = $wgContLang->isRTL() ? '&larr;' : '&rarr;'; // should -> and <- be used instead of entities?

                if( $appendSubtitle ) {
                        $wgOut->appendSubtitle( wfMsgHtml( 'redirectpagesub' ) );
                }
                $sk = $wgUser->getSkin();
                // the loop prepends the arrow image before the link, so the first case needs to be outside
                $title = array_shift( $target );
                if( $forceKnown ) {
                        $link = $sk->link(
                                $title,
                                htmlspecialchars( $title->getFullText() ),
                                array(),
                                array(),
                                array( 'known', 'noclasses' )
                        );
                } else {
                        $link = $sk->link( $title, htmlspecialchars( $title->getFullText() ) );
                }
                // automatically append redirect=no to each link, since most of them are redirect pages themselves
                foreach( $target as $rt ) {
                        if( $forceKnown ) {
                                $link .= '<img src="'.$imageUrl2.'" alt="'.$alt2.' " />'
                                        . $sk->link(
                                                $rt,
                                                htmlspecialchars( $rt->getFullText() ),
                                                array(),
                                                array(),
                                                array( 'known', 'noclasses' )
                                        );
                        } else {
                                $link .= '<img src="'.$imageUrl2.'" alt="'.$alt2.' " />'
                                        . $sk->link( $rt, htmlspecialchars( $rt->getFullText() ) );
                        }
                }
                return '<img src="'.$imageUrl.'" alt="#REDIRECT " />' .
                        '<span class="redirectText">'.$link.'</span>';

        }

        public function addTrackbacks() {
                global $wgOut, $wgUser;
                $dbr = wfGetDB( DB_SLAVE );
                $tbs = $dbr->select( 'trackbacks',
                        array('tb_id', 'tb_title', 'tb_url', 'tb_ex', 'tb_name'),
                        array('tb_page' => $this->getID() )
                );
                if( !$dbr->numRows($tbs) ) return;

                $tbtext = "";
                while( $o = $dbr->fetchObject($tbs) ) {
                        $rmvtxt = "";
                        if( $wgUser->isAllowed( 'trackback' ) ) {
                                $delurl = $this->mTitle->getFullURL("action=deletetrackback&tbid=" .
                                        $o->tb_id . "&token=" . urlencode( $wgUser->editToken() ) );
                                $rmvtxt = wfMsg( 'trackbackremove', htmlspecialchars( $delurl ) );
                        }
                        $tbtext .= "\n";
                        $tbtext .= wfMsg(strlen($o->tb_ex) ? 'trackbackexcerpt' : 'trackback',
                                        $o->tb_title,
                                        $o->tb_url,
                                        $o->tb_ex,
                                        $o->tb_name,
                                        $rmvtxt);
                }
                $wgOut->wrapWikiMsg( "<div id='mw_trackbacks'>$1</div>\n", array( 'trackbackbox', $tbtext ) );
                $this->mTitle->invalidateCache();
        }

        public function deletetrackback() {
                global $wgUser, $wgRequest, $wgOut;
                if( !$wgUser->matchEditToken($wgRequest->getVal('token')) ) {
                        $wgOut->addWikiMsg( 'sessionfailure' );
                        return;
                }

                $permission_errors = $this->mTitle->getUserPermissionsErrors( 'delete', $wgUser );
                if( count($permission_errors) ) {
                        $wgOut->showPermissionsErrorPage( $permission_errors );
                        return;
                }

                $db = wfGetDB( DB_MASTER );
                $db->delete( 'trackbacks', array('tb_id' => $wgRequest->getInt('tbid')) );

                $wgOut->addWikiMsg( 'trackbackdeleteok' );
                $this->mTitle->invalidateCache();
        }

        public function render() {
                global $wgOut;
                $wgOut->setArticleBodyOnly(true);
                $this->view();
        }

        /**
         * Handle action=purge
         */
        public function purge() {
                global $wgUser, $wgRequest, $wgOut;
                if( $wgUser->isAllowed( 'purge' ) || $wgRequest->wasPosted() ) {
                        if( wfRunHooks( 'ArticlePurge', array( &$this ) ) ) {
                                $this->doPurge();
                                $this->view();
                        }
                } else {
                        $action = htmlspecialchars( $wgRequest->getRequestURL() );
                        $button = wfMsgExt( 'confirm_purge_button', array('escapenoentities') );
                        $form = "<form method=\"post\" action=\"$action\">\n" .
                                        "<input type=\"submit\" name=\"submit\" value=\"$button\" />\n" .
                                        "</form>\n";
                        $top = wfMsgExt( 'confirm-purge-top', array('parse') );
                        $bottom = wfMsgExt( 'confirm-purge-bottom', array('parse') );
                        $wgOut->setPageTitle( $this->mTitle->getPrefixedText() );
                        $wgOut->setRobotPolicy( 'noindex,nofollow' );
                        $wgOut->addHTML( $top . $form . $bottom );
                }
        }

        /**
         * Perform the actions of a page purging
         */
        public function doPurge() {
                global $wgUseSquid;
                // Invalidate the cache
                $this->mTitle->invalidateCache();

                if( $wgUseSquid ) {
                        // Commit the transaction before the purge is sent
                        $dbw = wfGetDB( DB_MASTER );
                        $dbw->immediateCommit();

                        // Send purge
                        $update = SquidUpdate::newSimplePurge( $this->mTitle );
                        $update->doUpdate();
                }
                if( $this->mTitle->getNamespace() == NS_MEDIAWIKI ) {
                        global $wgMessageCache;
                        if( $this->getID() == 0 ) {
                                $text = false;
                        } else {
                                $text = $this->getRawText();
                        }
                        $wgMessageCache->replace( $this->mTitle->getDBkey(), $text );
                }
        }

        /**
         * Insert a new empty page record for this article.
         * This *must* be followed up by creating a revision
         * and running $this->updateToLatest( $rev_id );
         * or else the record will be left in a funky state.
         * Best if all done inside a transaction.
         *
         * @param $dbw Database
         * @return int The newly created page_id key, or false if the title already existed
         * @private
         */
        public function insertOn( $dbw ) {
                wfProfileIn( __METHOD__ );

                $page_id = $dbw->nextSequenceValue( 'page_page_id_seq' );
                $dbw->insert( 'page', array(
                        'page_id'           => $page_id,
                        'page_namespace'    => $this->mTitle->getNamespace(),
                        'page_title'        => $this->mTitle->getDBkey(),
                        'page_counter'      => 0,
                        'page_restrictions' => '',
                        'page_is_redirect'  => 0, # Will set this shortly...
                        'page_is_new'       => 1,
                        'page_random'       => wfRandom(),
                        'page_touched'      => $dbw->timestamp(),
                        'page_latest'       => 0, # Fill this in shortly...
                        'page_len'          => 0, # Fill this in shortly...
                ), __METHOD__, 'IGNORE' );

                $affected = $dbw->affectedRows();
                if( $affected ) {
                        $newid = $dbw->insertId();
                        $this->mTitle->resetArticleId( $newid );
                }
                wfProfileOut( __METHOD__ );
                return $affected ? $newid : false;
        }

        /**
         * Update the page record to point to a newly saved revision.
         *
         * @param $dbw Database object
         * @param $revision Revision: For ID number, and text used to set
                            length and redirect status fields
         * @param $lastRevision Integer: if given, will not overwrite the page field
         *                      when different from the currently set value.
         *                      Giving 0 indicates the new page flag should be set
         *                      on.
         * @param $lastRevIsRedirect Boolean: if given, will optimize adding and
         *                                                       removing rows in redirect table.
         * @return bool true on success, false on failure
         * @private
         */
        public function updateRevisionOn( &$dbw, $revision, $lastRevision = null, $lastRevIsRedirect = null ) {
                wfProfileIn( __METHOD__ );

                $text = $revision->getText();
                $rt = Title::newFromRedirect( $text );

                $conditions = array( 'page_id' => $this->getId() );
                if( !is_null( $lastRevision ) ) {
                        # An extra check against threads stepping on each other
                        $conditions['page_latest'] = $lastRevision;
                }

                $dbw->update( 'page',
                        array( /* SET */
                                'page_latest'      => $revision->getId(),
                                'page_touched'     => $dbw->timestamp(),
                                'page_is_new'      => ($lastRevision === 0) ? 1 : 0,
                                'page_is_redirect' => $rt !== NULL ? 1 : 0,
                                'page_len'         => strlen( $text ),
                        ),
                        $conditions,
                        __METHOD__ );

                $result = $dbw->affectedRows() != 0;
                if( $result ) {
                        $this->updateRedirectOn( $dbw, $rt, $lastRevIsRedirect );
                }

                wfProfileOut( __METHOD__ );
                return $result;
        }

        /**
         * Add row to the redirect table if this is a redirect, remove otherwise.
         *
         * @param $dbw Database
         * @param $redirectTitle a title object pointing to the redirect target,
         *                                               or NULL if this is not a redirect
         * @param $lastRevIsRedirect If given, will optimize adding and
         *                                                       removing rows in redirect table.
         * @return bool true on success, false on failure
         * @private
         */
        public function updateRedirectOn( &$dbw, $redirectTitle, $lastRevIsRedirect = null ) {
                // Always update redirects (target link might have changed)
                // Update/Insert if we don't know if the last revision was a redirect or not
                // Delete if changing from redirect to non-redirect
                $isRedirect = !is_null($redirectTitle);
                if($isRedirect || is_null($lastRevIsRedirect) || $lastRevIsRedirect !== $isRedirect) {
                        wfProfileIn( __METHOD__ );
                        if( $isRedirect ) {
                                // This title is a redirect, Add/Update row in the redirect table
                                $set = array( /* SET */
                                        'rd_namespace' => $redirectTitle->getNamespace(),
                                        'rd_title'     => $redirectTitle->getDBkey(),
                                        'rd_from'      => $this->getId(),
                                );
                                $dbw->replace( 'redirect', array( 'rd_from' ), $set, __METHOD__ );
                        } else {
                                // This is not a redirect, remove row from redirect table
                                $where = array( 'rd_from' => $this->getId() );
                                $dbw->delete( 'redirect', $where, __METHOD__);
                        }
                        if( $this->getTitle()->getNamespace() == NS_FILE ) {
                                RepoGroup::singleton()->getLocalRepo()->invalidateImageRedirect( $this->getTitle() );
                        }
                        wfProfileOut( __METHOD__ );
                        return ( $dbw->affectedRows() != 0 );
                }
                return true;
        }

        /**
         * If the given revision is newer than the currently set page_latest,
         * update the page record. Otherwise, do nothing.
         *
         * @param $dbw Database object
         * @param $revision Revision object
         */
        public function updateIfNewerOn( &$dbw, $revision ) {
                wfProfileIn( __METHOD__ );
                $row = $dbw->selectRow(
                        array( 'revision', 'page' ),
                        array( 'rev_id', 'rev_timestamp', 'page_is_redirect' ),
                        array(
                                'page_id' => $this->getId(),
                                'page_latest=rev_id' ),
                        __METHOD__ );
                if( $row ) {
                        if( wfTimestamp(TS_MW, $row->rev_timestamp) >= $revision->getTimestamp() ) {
                                wfProfileOut( __METHOD__ );
                                return false;
                        }
                        $prev = $row->rev_id;
                        $lastRevIsRedirect = (bool)$row->page_is_redirect;
                } else {
                        # No or missing previous revision; mark the page as new
                        $prev = 0;
                        $lastRevIsRedirect = null;
                }
                $ret = $this->updateRevisionOn( $dbw, $revision, $prev, $lastRevIsRedirect );
                wfProfileOut( __METHOD__ );
                return $ret;
        }

        /**
         * @param $section empty/null/false or a section number (0, 1, 2, T1, T2...)
         * @return string Complete article text, or null if error
         */
        public function replaceSection( $section, $text, $summary = '', $edittime = NULL ) {
                wfProfileIn( __METHOD__ );
                if( strval( $section ) == '' ) {
                        // Whole-page edit; let the whole text through
                } else {
                        if( is_null($edittime) ) {
                                $rev = Revision::newFromTitle( $this->mTitle );
                        } else {
                                $dbw = wfGetDB( DB_MASTER );
                                $rev = Revision::loadFromTimestamp( $dbw, $this->mTitle, $edittime );
                        }
                        if( !$rev ) {
                                wfDebug( "Article::replaceSection asked for bogus section (page: " .
                                        $this->getId() . "; section: $section; edittime: $edittime)\n" );
                                return null;
                        }
                        $oldtext = $rev->getText();

                        if( $section == 'new' ) {
                                # Inserting a new section
                                $subject = $summary ? wfMsgForContent('newsectionheaderdefaultlevel',$summary) . "\n\n" : '';
                                $text = strlen( trim( $oldtext ) ) > 0
                                                ? "{$oldtext}\n\n{$subject}{$text}"
                                                : "{$subject}{$text}";
                        } else {
                                # Replacing an existing section; roll out the big guns
                                global $wgParser;
                                $text = $wgParser->replaceSection( $oldtext, $section, $text );
                        }
                }
                wfProfileOut( __METHOD__ );
                return $text;
        }

        /**
         * This function is not deprecated until somebody fixes the core not to use
         * it. Nevertheless, use Article::doEdit() instead.
         */
        function insertNewArticle( $text, $summary, $isminor, $watchthis, $suppressRC=false, $comment=false, $bot=false ) {
                $flags = EDIT_NEW | EDIT_DEFER_UPDATES | EDIT_AUTOSUMMARY |
                        ( $isminor ? EDIT_MINOR : 0 ) |
                        ( $suppressRC ? EDIT_SUPPRESS_RC : 0 ) |
                        ( $bot ? EDIT_FORCE_BOT : 0 );

                # If this is a comment, add the summary as headline
                if( $comment && $summary != "" ) {
                        $text = wfMsgForContent('newsectionheaderdefaultlevel',$summary) . "\n\n".$text;
                }

                $this->doEdit( $text, $summary, $flags );

                $dbw = wfGetDB( DB_MASTER );
                if($watchthis) {
                        if(!$this->mTitle->userIsWatching()) {
                                $dbw->begin();
                                $this->doWatch();
                                $dbw->commit();
                        }
                } else {
                        if( $this->mTitle->userIsWatching() ) {
                                $dbw->begin();
                                $this->doUnwatch();
                                $dbw->commit();
                        }
                }
                $this->doRedirect( $this->isRedirect( $text ) );
        }

        /**
         * @deprecated use Article::doEdit()
         */
        function updateArticle( $text, $summary, $minor, $watchthis, $forceBot = false, $sectionanchor = '' ) {
                $flags = EDIT_UPDATE | EDIT_DEFER_UPDATES | EDIT_AUTOSUMMARY |
                        ( $minor ? EDIT_MINOR : 0 ) |
                        ( $forceBot ? EDIT_FORCE_BOT : 0 );

                $status = $this->doEdit( $text, $summary, $flags );
                if( !$status->isOK() ) {
                        return false;
                }

                $dbw = wfGetDB( DB_MASTER );
                if( $watchthis ) {
                        if(!$this->mTitle->userIsWatching()) {
                                $dbw->begin();
                                $this->doWatch();
                                $dbw->commit();
                        }
                } else {
                        if( $this->mTitle->userIsWatching() ) {
                                $dbw->begin();
                                $this->doUnwatch();
                                $dbw->commit();
                        }
                }

                $extraQuery = ''; // Give extensions a chance to modify URL query on update
                wfRunHooks( 'ArticleUpdateBeforeRedirect', array( $this, &$sectionanchor, &$extraQuery ) );

                $this->doRedirect( $this->isRedirect( $text ), $sectionanchor, $extraQuery );
                return true;
        }

        /**
         * Article::doEdit()
         *
         * Change an existing article or create a new article. Updates RC and all necessary caches,
         * optionally via the deferred update array.
         *
         * $wgUser must be set before calling this function.
         *
         * @param $text String: new text
         * @param $summary String: edit summary
         * @param $flags Integer bitfield:
         *      EDIT_NEW
         *          Article is known or assumed to be non-existent, create a new one
         *      EDIT_UPDATE
         *          Article is known or assumed to be pre-existing, update it
         *      EDIT_MINOR
         *          Mark this edit minor, if the user is allowed to do so
         *      EDIT_SUPPRESS_RC
         *          Do not log the change in recentchanges
         *      EDIT_FORCE_BOT
         *          Mark the edit a "bot" edit regardless of user rights
         *      EDIT_DEFER_UPDATES
         *          Defer some of the updates until the end of index.php
         *      EDIT_AUTOSUMMARY
         *          Fill in blank summaries with generated text where possible
         *
         * If neither EDIT_NEW nor EDIT_UPDATE is specified, the status of the article will be detected.
         * If EDIT_UPDATE is specified and the article doesn't exist, the function will an
         * edit-gone-missing error. If EDIT_NEW is specified and the article does exist, an
         * edit-already-exists error will be returned. These two conditions are also possible with
         * auto-detection due to MediaWiki's performance-optimised locking strategy.
         *
         * @param $baseRevId the revision ID this edit was based off, if any
         * @param $user Optional user object, $wgUser will be used if not passed
         *
         * @return Status object. Possible errors:
         *     edit-hook-aborted:       The ArticleSave hook aborted the edit but didn't set the fatal flag of $status
         *     edit-gone-missing:       In update mode, but the article didn't exist
         *     edit-conflict:           In update mode, the article changed unexpectedly
         *     edit-no-change:          Warning that the text was the same as before
         *     edit-already-exists:     In creation mode, but the article already exists
         *
         *  Extensions may define additional errors.
         *
         *  $return->value will contain an associative array with members as follows:
         *     new:                     Boolean indicating if the function attempted to create a new article
         *     revision:                The revision object for the inserted revision, or null
         *
         *  Compatibility note: this function previously returned a boolean value indicating success/failure
         */
        public function doEdit( $text, $summary, $flags = 0, $baseRevId = false, $user = null ) {
                global $wgUser, $wgDBtransactions, $wgUseAutomaticEditSummaries;

                # Low-level sanity check
                if( $this->mTitle->getText() == '' ) {
                        throw new MWException( 'Something is trying to edit an article with an empty title' );
                }

                wfProfileIn( __METHOD__ );

                $user = is_null($user) ? $wgUser : $user;
                $status = Status::newGood( array() );

                # Load $this->mTitle->getArticleID() and $this->mLatest if it's not already
                $this->loadPageData();

                if( !($flags & EDIT_NEW) && !($flags & EDIT_UPDATE) ) {
                        $aid = $this->mTitle->getArticleID();
                        if( $aid ) {
                                $flags |= EDIT_UPDATE;
                        } else {
                                $flags |= EDIT_NEW;
                        }
                }

                if( !wfRunHooks( 'ArticleSave', array( &$this, &$user, &$text, &$summary,
                        $flags & EDIT_MINOR, null, null, &$flags, &$status ) ) )
                {
                        wfDebug( __METHOD__ . ": ArticleSave hook aborted save!\n" );
                        wfProfileOut( __METHOD__ );
                        if( $status->isOK() ) {
                                $status->fatal( 'edit-hook-aborted');
                        }
                        return $status;
                }

                # Silently ignore EDIT_MINOR if not allowed
                $isminor = ( $flags & EDIT_MINOR ) && $user->isAllowed('minoredit');
                $bot = $flags & EDIT_FORCE_BOT;

                $oldtext = $this->getRawText(); // current revision
                $oldsize = strlen( $oldtext );

                # Provide autosummaries if one is not provided and autosummaries are enabled.
                if( $wgUseAutomaticEditSummaries && $flags & EDIT_AUTOSUMMARY && $summary == '' ) {
                        $summary = $this->getAutosummary( $oldtext, $text, $flags );
                }

                $editInfo = $this->prepareTextForEdit( $text );
                $text = $editInfo->pst;
                $newsize = strlen( $text );

                $dbw = wfGetDB( DB_MASTER );
                $now = wfTimestampNow();

                if( $flags & EDIT_UPDATE ) {
                        # Update article, but only if changed.
                        $status->value['new'] = false;
                        # Make sure the revision is either completely inserted or not inserted at all
                        if( !$wgDBtransactions ) {
                                $userAbort = ignore_user_abort( true );
                        }

                        $revisionId = 0;

                        $changed = ( strcmp( $text, $oldtext ) != 0 );

                        if( $changed ) {
                                $this->mGoodAdjustment = (int)$this->isCountable( $text )
                                  - (int)$this->isCountable( $oldtext );
                                $this->mTotalAdjustment = 0;

                                if( !$this->mLatest ) {
                                        # Article gone missing
                                        wfDebug( __METHOD__.": EDIT_UPDATE specified but article doesn't exist\n" );
                                        $status->fatal( 'edit-gone-missing' );
                                        wfProfileOut( __METHOD__ );
                                        return $status;
                                }

                                $revision = new Revision( array(
                                        'page'       => $this->getId(),
                                        'comment'    => $summary,
                                        'minor_edit' => $isminor,
                                        'text'       => $text,
                                        'parent_id'  => $this->mLatest,
                                        'user'       => $user->getId(),
                                        'user_text'  => $user->getName(),
                                        ) );

                                $dbw->begin();
                                $revisionId = $revision->insertOn( $dbw );

                                # Update page
                                #
                                # Note that we use $this->mLatest instead of fetching a value from the master DB
                                # during the course of this function. This makes sure that EditPage can detect
                                # edit conflicts reliably, either by $ok here, or by $article->getTimestamp()
                                # before this function is called. A previous function used a separate query, this
                                # creates a window where concurrent edits can cause an ignored edit conflict.
                                $ok = $this->updateRevisionOn( $dbw, $revision, $this->mLatest );

                                if( !$ok ) {
                                        /* Belated edit conflict! Run away!! */
                                        $status->fatal( 'edit-conflict' );
                                        # Delete the invalid revision if the DB is not transactional
                                        if( !$wgDBtransactions ) {
                                                $dbw->delete( 'revision', array( 'rev_id' => $revisionId ), __METHOD__ );
                                        }
                                        $revisionId = 0;
                                        $dbw->rollback();
                                } else {
                                        global $wgUseRCPatrol;
                                        wfRunHooks( 'NewRevisionFromEditComplete', array($this, $revision, $baseRevId, $user) );
                                        # Update recentchanges
                                        if( !( $flags & EDIT_SUPPRESS_RC ) ) {
                                                # Mark as patrolled if the user can do so
                                                $patrolled = $wgUseRCPatrol && $this->mTitle->userCan('autopatrol');
                                                # Add RC row to the DB
                                                $rc = RecentChange::notifyEdit( $now, $this->mTitle, $isminor, $user, $summary,
                                                        $this->mLatest, $this->getTimestamp(), $bot, '', $oldsize, $newsize,
                                                        $revisionId, $patrolled
                                                );
                                                # Log auto-patrolled edits
                                                if( $patrolled ) {
                                                        PatrolLog::record( $rc, true );
                                                }
                                        }
                                        $user->incEditCount();
                                        $dbw->commit();
                                }
                        } else {
                                $status->warning( 'edit-no-change' );
                                $revision = null;
                                // Keep the same revision ID, but do some updates on it
                                $revisionId = $this->getRevIdFetched();
                                // Update page_touched, this is usually implicit in the page update
                                // Other cache updates are done in onArticleEdit()
                                $this->mTitle->invalidateCache();
                        }

                        if( !$wgDBtransactions ) {
                                ignore_user_abort( $userAbort );
                        }
                        // Now that ignore_user_abort is restored, we can respond to fatal errors
                        if( !$status->isOK() ) {
                                wfProfileOut( __METHOD__ );
                                return $status;
                        }

                        # Invalidate cache of this article and all pages using this article
                        # as a template. Partly deferred.
                        Article::onArticleEdit( $this->mTitle );
                        # Update links tables, site stats, etc.
                        $this->editUpdates( $text, $summary, $isminor, $now, $revisionId, $changed );
                } else {
                        # Create new article
                        $status->value['new'] = true;

                        # Set statistics members
                        # We work out if it's countable after PST to avoid counter drift
                        # when articles are created with {{subst:}}
                        $this->mGoodAdjustment = (int)$this->isCountable( $text );
                        $this->mTotalAdjustment = 1;

                        $dbw->begin();

                        # Add the page record; stake our claim on this title!
                        # This will return false if the article already exists
                        $newid = $this->insertOn( $dbw );

                        if( $newid === false ) {
                                $dbw->rollback();
                                $status->fatal( 'edit-already-exists' );
                                wfProfileOut( __METHOD__ );
                                return $status;
                        }

                        # Save the revision text...
                        $revision = new Revision( array(
                                'page'       => $newid,
                                'comment'    => $summary,
                                'minor_edit' => $isminor,
                                'text'       => $text,
                                'user'       => $user->getId(),
                                'user_text'  => $user->getName(),
                                ) );
                        $revisionId = $revision->insertOn( $dbw );

                        $this->mTitle->resetArticleID( $newid );

                        # Update the page record with revision data
                        $this->updateRevisionOn( $dbw, $revision, 0 );

                        wfRunHooks( 'NewRevisionFromEditComplete', array($this, $revision, false, $user) );
                        # Update recentchanges
                        if( !( $flags & EDIT_SUPPRESS_RC ) ) {
                                global $wgUseRCPatrol, $wgUseNPPatrol;
                                # Mark as patrolled if the user can do so
                                $patrolled = ($wgUseRCPatrol || $wgUseNPPatrol) && $this->mTitle->userCan('autopatrol');
                                # Add RC row to the DB
                                $rc = RecentChange::notifyNew( $now, $this->mTitle, $isminor, $user, $summary, $bot,
                                        '', strlen($text), $revisionId, $patrolled );
                                # Log auto-patrolled edits
                                if( $patrolled ) {
                                        PatrolLog::record( $rc, true );
                                }
                        }
                        $user->incEditCount();
                        $dbw->commit();

                        # Update links, etc.
                        $this->editUpdates( $text, $summary, $isminor, $now, $revisionId, true );

                        # Clear caches
                        Article::onArticleCreate( $this->mTitle );

                        wfRunHooks( 'ArticleInsertComplete', array( &$this, &$user, $text, $summary,
                                $flags & EDIT_MINOR, null, null, &$flags, $revision ) );
                }

                # Do updates right now unless deferral was requested
                if( !( $flags & EDIT_DEFER_UPDATES ) ) {
                        wfDoUpdates();
                }

                // Return the new revision (or null) to the caller
                $status->value['revision'] = $revision;

                wfRunHooks( 'ArticleSaveComplete', array( &$this, &$user, $text, $summary,
                        $flags & EDIT_MINOR, null, null, &$flags, $revision, &$status, $baseRevId ) );

                wfProfileOut( __METHOD__ );
                return $status;
        }

        /**
         * @deprecated wrapper for doRedirect
         */
        public function showArticle( $text, $subtitle , $sectionanchor = '', $me2, $now, $summary, $oldid ) {
                wfDeprecated( __METHOD__ );
                $this->doRedirect( $this->isRedirect( $text ), $sectionanchor );
        }

        /**
         * Output a redirect back to the article.
         * This is typically used after an edit.
         *
         * @param $noRedir Boolean: add redirect=no
         * @param $sectionAnchor String: section to redirect to, including "#"
         * @param $extraQuery String: extra query params
         */
        public function doRedirect( $noRedir = false, $sectionAnchor = '', $extraQuery = '' ) {
                global $wgOut;
                if( $noRedir ) {
                        $query = 'redirect=no';
                        if( $extraQuery )
                                $query .= "&$query";
                } else {
                        $query = $extraQuery;
                }
                $wgOut->redirect( $this->mTitle->getFullURL( $query ) . $sectionAnchor );
        }

        /**
         * Mark this particular edit/page as patrolled
         */
        public function markpatrolled() {
                global $wgOut, $wgRequest, $wgUseRCPatrol, $wgUseNPPatrol, $wgUser;
                $wgOut->setRobotPolicy( 'noindex,nofollow' );

                # If we haven't been given an rc_id value, we can't do anything
                $rcid = (int) $wgRequest->getVal('rcid');
                $rc = RecentChange::newFromId($rcid);
                if( is_null($rc) ) {
                        $wgOut->showErrorPage( 'markedaspatrollederror', 'markedaspatrollederrortext' );
                        return;
                }

                #It would be nice to see where the user had actually come from, but for now just guess
                $returnto = $rc->getAttribute( 'rc_type' ) == RC_NEW ? 'Newpages' : 'Recentchanges';
                $return = SpecialPage::getTitleFor( $returnto );

                $dbw = wfGetDB( DB_MASTER );
                $errors = $rc->doMarkPatrolled();

                if( in_array(array('rcpatroldisabled'), $errors) ) {
                        $wgOut->showErrorPage( 'rcpatroldisabled', 'rcpatroldisabledtext' );
                        return;
                }

                if( in_array(array('hookaborted'), $errors) ) {
                        // The hook itself has handled any output
                        return;
                }

                if( in_array(array('markedaspatrollederror-noautopatrol'), $errors) ) {
                        $wgOut->setPageTitle( wfMsg( 'markedaspatrollederror' ) );
                        $wgOut->addWikiMsg( 'markedaspatrollederror-noautopatrol' );
                        $wgOut->returnToMain( false, $return );
                        return;
                }

                if( !empty($errors) ) {
                        $wgOut->showPermissionsErrorPage( $errors );
                        return;
                }

                # Inform the user
                $wgOut->setPageTitle( wfMsg( 'markedaspatrolled' ) );
                $wgOut->addWikiMsg( 'markedaspatrolledtext' );
                $wgOut->returnToMain( false, $return );
        }

        /**
         * User-interface handler for the "watch" action
         */

        public function watch() {
                global $wgUser, $wgOut;
                if( $wgUser->isAnon() ) {
                        $wgOut->showErrorPage( 'watchnologin', 'watchnologintext' );
                        return;
                }
                if( wfReadOnly() ) {
                        $wgOut->readOnlyPage();
                        return;
                }
                if( $this->doWatch() ) {
                        $wgOut->setPagetitle( wfMsg( 'addedwatch' ) );
                        $wgOut->setRobotPolicy( 'noindex,nofollow' );
                        $wgOut->addWikiMsg( 'addedwatchtext', $this->mTitle->getPrefixedText() );
                }
                $wgOut->returnToMain( true, $this->mTitle->getPrefixedText() );
        }

        /**
         * Add this page to $wgUser's watchlist
         * @return bool true on successful watch operation
         */
        public function doWatch() {
                global $wgUser;
                if( $wgUser->isAnon() ) {
                        return false;
                }
                if( wfRunHooks('WatchArticle', array(&$wgUser, &$this)) ) {
                        $wgUser->addWatch( $this->mTitle );
                        return wfRunHooks('WatchArticleComplete', array(&$wgUser, &$this));
                }
                return false;
        }

        /**
         * User interface handler for the "unwatch" action.
         */
        public function unwatch() {
                global $wgUser, $wgOut;
                if( $wgUser->isAnon() ) {
                        $wgOut->showErrorPage( 'watchnologin', 'watchnologintext' );
                        return;
                }
                if( wfReadOnly() ) {
                        $wgOut->readOnlyPage();
                        return;
                }
                if( $this->doUnwatch() ) {
                        $wgOut->setPagetitle( wfMsg( 'removedwatch' ) );
                        $wgOut->setRobotPolicy( 'noindex,nofollow' );
                        $wgOut->addWikiMsg( 'removedwatchtext', $this->mTitle->getPrefixedText() );
                }
                $wgOut->returnToMain( true, $this->mTitle->getPrefixedText() );
        }

        /**
         * Stop watching a page
         * @return bool true on successful unwatch
         */
        public function doUnwatch() {
                global $wgUser;
                if( $wgUser->isAnon() ) {
                        return false;
                }
                if( wfRunHooks('UnwatchArticle', array(&$wgUser, &$this)) ) {
                        $wgUser->removeWatch( $this->mTitle );
                        return wfRunHooks('UnwatchArticleComplete', array(&$wgUser, &$this));
                }
                return false;
        }

        /**
         * action=protect handler
         */
        public function protect() {
                $form = new ProtectionForm( $this );
                $form->execute();
        }

        /**
         * action=unprotect handler (alias)
         */
        public function unprotect() {
                $this->protect();
        }

        /**
         * Update the article's restriction field, and leave a log entry.
         *
         * @param $limit Array: set of restriction keys
         * @param $reason String
         * @param &$cascade Integer. Set to false if cascading protection isn't allowed.
         * @param $expiry Array: per restriction type expiration
         * @return bool true on success
         */
        public function updateRestrictions( $limit = array(), $reason = '', &$cascade = 0, $expiry = array() ) {
                global $wgUser, $wgRestrictionTypes, $wgContLang;

                $id = $this->mTitle->getArticleID();
                if ( $id <= 0 ) {
                        wfDebug( "updateRestrictions failed: $id <= 0\n" );
                        return false;
                }

                if ( wfReadOnly() ) {
                        wfDebug( "updateRestrictions failed: read-only\n" );
                        return false;
                }

                if ( !$this->mTitle->userCan( 'protect' ) ) {
                        wfDebug( "updateRestrictions failed: insufficient permissions\n" );
                        return false;
                }

                if( !$cascade ) {
                        $cascade = false;
                }

                // Take this opportunity to purge out expired restrictions
                Title::purgeExpiredRestrictions();

                # FIXME: Same limitations as described in ProtectionForm.php (line 37);
                # we expect a single selection, but the schema allows otherwise.
                $current = array();
                $updated = Article::flattenRestrictions( $limit );
                $changed = false;
                foreach( $wgRestrictionTypes as $action ) {
                        if( isset( $expiry[$action] ) ) {
                                # Get current restrictions on $action
                                $aLimits = $this->mTitle->getRestrictions( $action );
                                $current[$action] = implode( '', $aLimits );
                                # Are any actual restrictions being dealt with here?
                                $aRChanged = count($aLimits) || !empty($limit[$action]);
                                # If something changed, we need to log it. Checking $aRChanged
                                # assures that "unprotecting" a page that is not protected does
                                # not log just because the expiry was "changed".
                                if( $aRChanged && $this->mTitle->mRestrictionsExpiry[$action] != $expiry[$action] ) {
                                        $changed = true;
                                }
                        }
                }

                $current = Article::flattenRestrictions( $current );

                $changed = ($changed || $current != $updated );
                $changed = $changed || ($updated && $this->mTitle->areRestrictionsCascading() != $cascade);
                $protect = ( $updated != '' );

                # If nothing's changed, do nothing
                if( $changed ) {
                        if( wfRunHooks( 'ArticleProtect', array( &$this, &$wgUser, $limit, $reason ) ) ) {

                                $dbw = wfGetDB( DB_MASTER );

                                # Prepare a null revision to be added to the history
                                $modified = $current != '' && $protect;
                                if( $protect ) {
                                        $comment_type = $modified ? 'modifiedarticleprotection' : 'protectedarticle';
                                } else {
                                        $comment_type = 'unprotectedarticle';
                                }
                                $comment = $wgContLang->ucfirst( wfMsgForContent( $comment_type, $this->mTitle->getPrefixedText() ) );

                                # Only restrictions with the 'protect' right can cascade...
                                # Otherwise, people who cannot normally protect can "protect" pages via transclusion
                                $editrestriction = isset( $limit['edit'] ) ? array( $limit['edit'] ) : $this->mTitle->getRestrictions( 'edit' );
                                # The schema allows multiple restrictions
                                if(!in_array('protect', $editrestriction) && !in_array('sysop', $editrestriction))
                                        $cascade = false;
                                $cascade_description = '';
                                if( $cascade ) {
                                        $cascade_description = ' ['.wfMsgForContent('protect-summary-cascade').']';
                                }

                                if( $reason )
                                        $comment .= ": $reason";

                                $editComment = $comment;
                                $encodedExpiry = array();
                                $protect_description = '';
                                foreach( $limit as $action => $restrictions  ) {
                                        if ( !isset($expiry[$action]) )
                                                $expiry[$action] = 'infinite';

                                        $encodedExpiry[$action] = Block::encodeExpiry($expiry[$action], $dbw );
                                        if( $restrictions != '' ) {
                                                $protect_description .= "[$action=$restrictions] (";
                                                if( $encodedExpiry[$action] != 'infinity' ) {
                                                        $protect_description .= wfMsgForContent( 'protect-expiring',
                                                                $wgContLang->timeanddate( $expiry[$action], false, false ) ,
                                                                $wgContLang->date( $expiry[$action], false, false ) ,
                                                                $wgContLang->time( $expiry[$action], false, false ) );
                                                } else {
                                                        $protect_description .= wfMsgForContent( 'protect-expiry-indefinite' );
                                                }
                                                $protect_description .= ') ';
                                        }
                                }
                                $protect_description = trim($protect_description);

                                if( $protect_description && $protect )
                                        $editComment .= " ($protect_description)";
                                if( $cascade )
                                        $editComment .= "$cascade_description";
                                # Update restrictions table
                                foreach( $limit as $action => $restrictions ) {
                                        if($restrictions != '' ) {
                                                $dbw->replace( 'page_restrictions', array(array('pr_page', 'pr_type')),
                                                        array( 'pr_page' => $id,
                                                                'pr_type' => $action,
                                                                'pr_level' => $restrictions,
                                                                'pr_cascade' => ($cascade && $action == 'edit') ? 1 : 0,
                                                                'pr_expiry' => $encodedExpiry[$action] ), __METHOD__  );
                                        } else {
                                                $dbw->delete( 'page_restrictions', array( 'pr_page' => $id,
                                                        'pr_type' => $action ), __METHOD__ );
                                        }
                                }

                                # Insert a null revision
                                $nullRevision = Revision::newNullRevision( $dbw, $id, $editComment, true );
                                $nullRevId = $nullRevision->insertOn( $dbw );

                                $latest = $this->getLatest();
                                # Update page record
                                $dbw->update( 'page',
                                        array( /* SET */
                                                'page_touched' => $dbw->timestamp(),
                                                'page_restrictions' => '',
                                                'page_latest' => $nullRevId
                                        ), array( /* WHERE */
                                                'page_id' => $id
                                        ), 'Article::protect'
                                );

                                wfRunHooks( 'NewRevisionFromEditComplete', array($this, $nullRevision, $latest, $wgUser) );
                                wfRunHooks( 'ArticleProtectComplete', array( &$this, &$wgUser, $limit, $reason ) );

                                # Update the protection log
                                $log = new LogPage( 'protect' );
                                if( $protect ) {
                                        $params = array($protect_description,$cascade ? 'cascade' : '');
                                        $log->addEntry( $modified ? 'modify' : 'protect', $this->mTitle, trim( $reason), $params );
                                } else {
                                        $log->addEntry( 'unprotect', $this->mTitle, $reason );
                                }

                        } # End hook
                } # End "changed" check

                return true;
        }

        /**
         * Take an array of page restrictions and flatten it to a string
         * suitable for insertion into the page_restrictions field.
         * @param $limit Array
         * @return String
         */
        protected static function flattenRestrictions( $limit ) {
                if( !is_array( $limit ) ) {
                        throw new MWException( 'Article::flattenRestrictions given non-array restriction set' );
                }
                $bits = array();
                ksort( $limit );
                foreach( $limit as $action => $restrictions ) {
                        if( $restrictions != '' ) {
                                $bits[] = "$action=$restrictions";
                        }
                }
                return implode( ':', $bits );
        }

        /**
         * Auto-generates a deletion reason
         * @param &$hasHistory Boolean: whether the page has a history
         */
        public function generateReason( &$hasHistory ) {
                global $wgContLang;
                $dbw = wfGetDB( DB_MASTER );
                // Get the last revision
                $rev = Revision::newFromTitle( $this->mTitle );
                if( is_null( $rev ) )
                        return false;

                // Get the article's contents
                $contents = $rev->getText();
                $blank = false;
                // If the page is blank, use the text from the previous revision,
                // which can only be blank if there's a move/import/protect dummy revision involved
                if( $contents == '' ) {
                        $prev = $rev->getPrevious();
                        if( $prev )     {
                                $contents = $prev->getText();
                                $blank = true;
                        }
                }

                // Find out if there was only one contributor
                // Only scan the last 20 revisions
                $res = $dbw->select( 'revision', 'rev_user_text',
                        array( 'rev_page' => $this->getID(), $dbw->bitAnd('rev_deleted', Revision::DELETED_USER) . ' = 0' ),
                        __METHOD__,
                        array( 'LIMIT' => 20 )
                );
                if( $res === false )
                        // This page has no revisions, which is very weird
                        return false;

                $hasHistory = ( $res->numRows() > 1 );
                $row = $dbw->fetchObject( $res );
                $onlyAuthor = $row->rev_user_text;
                // Try to find a second contributor
                foreach( $res as $row ) {
                        if( $row->rev_user_text != $onlyAuthor ) {
                                $onlyAuthor = false;
                                break;
                        }
                }
                $dbw->freeResult( $res );

                // Generate the summary with a '$1' placeholder
                if( $blank ) {
                        // The current revision is blank and the one before is also
                        // blank. It's just not our lucky day
                        $reason = wfMsgForContent( 'exbeforeblank', '$1' );
                } else {
                        if( $onlyAuthor )
                                $reason = wfMsgForContent( 'excontentauthor', '$1', $onlyAuthor );
                        else
                                $reason = wfMsgForContent( 'excontent', '$1' );
                }

                if( $reason == '-' ) {
                        // Allow these UI messages to be blanked out cleanly
                        return '';
                }

                // Replace newlines with spaces to prevent uglyness
                $contents = preg_replace( "/[\n\r]/", ' ', $contents );
                // Calculate the maximum amount of chars to get
                // Max content length = max comment length - length of the comment (excl. $1) - '...'
                $maxLength = 255 - (strlen( $reason ) - 2) - 3;
                $contents = $wgContLang->truncate( $contents, $maxLength );
                // Remove possible unfinished links
                $contents = preg_replace( '/\[\[([^\]]*)\]?$/', '$1', $contents );
                // Now replace the '$1' placeholder
                $reason = str_replace( '$1', $contents, $reason );
                return $reason;
        }


        /*
         * UI entry point for page deletion
         */
        public function delete() {
                global $wgUser, $wgOut, $wgRequest;

                $confirm = $wgRequest->wasPosted() &&
                                $wgUser->matchEditToken( $wgRequest->getVal( 'wpEditToken' ) );

                $this->DeleteReasonList = $wgRequest->getText( 'wpDeleteReasonList', 'other' );
                $this->DeleteReason = $wgRequest->getText( 'wpReason' );

                $reason = $this->DeleteReasonList;

                if( $reason != 'other' && $this->DeleteReason != '' ) {
                        // Entry from drop down menu + additional comment
                        $reason .= wfMsgForContent( 'colon-separator' ) . $this->DeleteReason;
                } elseif( $reason == 'other' ) {
                        $reason = $this->DeleteReason;
                }
                # Flag to hide all contents of the archived revisions
                $suppress = $wgRequest->getVal( 'wpSuppress' ) && $wgUser->isAllowed( 'suppressrevision' );

                # This code desperately needs to be totally rewritten

                # Read-only check...
                if( wfReadOnly() ) {
                        $wgOut->readOnlyPage();
                        return;
                }

                # Check permissions
                $permission_errors = $this->mTitle->getUserPermissionsErrors( 'delete', $wgUser );

                if( count( $permission_errors ) > 0 ) {
                        $wgOut->showPermissionsErrorPage( $permission_errors );
                        return;
                }

                $wgOut->setPagetitle( wfMsg( 'delete-confirm', $this->mTitle->getPrefixedText() ) );

                # Better double-check that it hasn't been deleted yet!
                $dbw = wfGetDB( DB_MASTER );
                $conds = $this->mTitle->pageCond();
                $latest = $dbw->selectField( 'page', 'page_latest', $conds, __METHOD__ );
                if( $latest === false ) {
                        $wgOut->showFatalError( wfMsgExt( 'cannotdelete', array( 'parse' ) ) );
                        $wgOut->addHTML( Xml::element( 'h2', null, LogPage::logName( 'delete' ) ) );
                        LogEventsList::showLogExtract( $wgOut, 'delete', $this->mTitle->getPrefixedText() );
                        return;
                }

                # Hack for big sites
                $bigHistory = $this->isBigDeletion();
                if( $bigHistory && !$this->mTitle->userCan( 'bigdelete' ) ) {
                        global $wgLang, $wgDeleteRevisionsLimit;
                        $wgOut->wrapWikiMsg( "<div class='error'>\n$1</div>\n",
                                array( 'delete-toobig', $wgLang->formatNum( $wgDeleteRevisionsLimit ) ) );
                        return;
                }

                if( $confirm ) {
                        $this->doDelete( $reason, $suppress );
                        if( $wgRequest->getCheck( 'wpWatch' ) ) {
                                $this->doWatch();
                        } elseif( $this->mTitle->userIsWatching() ) {
                                $this->doUnwatch();
                        }
                        return;
                }

                // Generate deletion reason
                $hasHistory = false;
                if( !$reason ) $reason = $this->generateReason($hasHistory);

                // If the page has a history, insert a warning
                if( $hasHistory && !$confirm ) {
                        $skin = $wgUser->getSkin();
                        $wgOut->addHTML( '<strong>' . wfMsgExt( 'historywarning', array( 'parseinline' ) ) . ' ' . $skin->historyLink() . '</strong>' );
                        if( $bigHistory ) {
                                global $wgLang, $wgDeleteRevisionsLimit;
                                $wgOut->wrapWikiMsg( "<div class='error'>\n$1</div>\n",
                                        array( 'delete-warning-toobig', $wgLang->formatNum( $wgDeleteRevisionsLimit ) ) );
                        }
                }

                return $this->confirmDelete( $reason );
        }

        /**
         * @return bool whether or not the page surpasses $wgDeleteRevisionsLimit revisions
         */
        public function isBigDeletion() {
                global $wgDeleteRevisionsLimit;
                if( $wgDeleteRevisionsLimit ) {
                        $revCount = $this->estimateRevisionCount();
                        return $revCount > $wgDeleteRevisionsLimit;
                }
                return false;
        }

        /**
         * @return int approximate revision count
         */
        public function estimateRevisionCount() {
                $dbr = wfGetDB( DB_SLAVE );
                // For an exact count...
                //return $dbr->selectField( 'revision', 'COUNT(*)',
                //      array( 'rev_page' => $this->getId() ), __METHOD__ );
                return $dbr->estimateRowCount( 'revision', '*',
                        array( 'rev_page' => $this->getId() ), __METHOD__ );
        }

        /**
         * Get the last N authors
         * @param $num Integer: number of revisions to get
         * @param $revLatest String: the latest rev_id, selected from the master (optional)
         * @return array Array of authors, duplicates not removed
         */
        public function getLastNAuthors( $num, $revLatest = 0 ) {
                wfProfileIn( __METHOD__ );
                // First try the slave
                // If that doesn't have the latest revision, try the master
                $continue = 2;
                $db = wfGetDB( DB_SLAVE );
                do {
                        $res = $db->select( array( 'page', 'revision' ),
                                array( 'rev_id', 'rev_user_text' ),
                                array(
                                        'page_namespace' => $this->mTitle->getNamespace(),
                                        'page_title' => $this->mTitle->getDBkey(),
                                        'rev_page = page_id'
                                ), __METHOD__, $this->getSelectOptions( array(
                                        'ORDER BY' => 'rev_timestamp DESC',
                                        'LIMIT' => $num
                                ) )
                        );
                        if( !$res ) {
                                wfProfileOut( __METHOD__ );
                                return array();
                        }
                        $row = $db->fetchObject( $res );
                        if( $continue == 2 && $revLatest && $row->rev_id != $revLatest ) {
                                $db = wfGetDB( DB_MASTER );
                                $continue--;
                        } else {
                                $continue = 0;
                        }
                } while ( $continue );

                $authors = array( $row->rev_user_text );
                while ( $row = $db->fetchObject( $res ) ) {
                        $authors[] = $row->rev_user_text;
                }
                wfProfileOut( __METHOD__ );
                return $authors;
        }

        /**
         * Output deletion confirmation dialog
         * @param $reason String: prefilled reason
         */
        public function confirmDelete( $reason ) {
                global $wgOut, $wgUser;

                wfDebug( "Article::confirmDelete\n" );

                $deleteBackLink = $wgUser->getSkin()->link(
                        $this->mTitle,
                        null,
                        array(),
                        array(),
                        array( 'known', 'noclasses' )
                );
                $wgOut->setSubtitle( wfMsgHtml( 'delete-backlink', $deleteBackLink ) );
                $wgOut->setRobotPolicy( 'noindex,nofollow' );
                $wgOut->addWikiMsg( 'confirmdeletetext' );

                if( $wgUser->isAllowed( 'suppressrevision' ) ) {
                        $suppress = "<tr id=\"wpDeleteSuppressRow\" name=\"wpDeleteSuppressRow\">
                                        <td></td>
                                        <td class='mw-input'><strong>" .
                                                Xml::checkLabel( wfMsg( 'revdelete-suppress' ),
                                                        'wpSuppress', 'wpSuppress', false, array( 'tabindex' => '4' ) ) .
                                        "</strong></td>
                                </tr>";
                } else {
                        $suppress = '';
                }
                $checkWatch = $wgUser->getBoolOption( 'watchdeletion' ) || $this->mTitle->userIsWatching();

                $form = Xml::openElement( 'form', array( 'method' => 'post',
                        'action' => $this->mTitle->getLocalURL( 'action=delete' ), 'id' => 'deleteconfirm' ) ) .
                        Xml::openElement( 'fieldset', array( 'id' => 'mw-delete-table' ) ) .
                        Xml::tags( 'legend', null, wfMsgExt( 'delete-legend', array( 'parsemag', 'escapenoentities' ) ) ) .
                        Xml::openElement( 'table', array( 'id' => 'mw-deleteconfirm-table' ) ) .
                        "<tr id=\"wpDeleteReasonListRow\">
                                <td class='mw-label'>" .
                                        Xml::label( wfMsg( 'deletecomment' ), 'wpDeleteReasonList' ) .
                                "</td>
                                <td class='mw-input'>" .
                                        Xml::listDropDown( 'wpDeleteReasonList',
                                                wfMsgForContent( 'deletereason-dropdown' ),
                                                wfMsgForContent( 'deletereasonotherlist' ), '', 'wpReasonDropDown', 1 ) .
                                "</td>
                        </tr>
                        <tr id=\"wpDeleteReasonRow\">
                                <td class='mw-label'>" .
                                        Xml::label( wfMsg( 'deleteotherreason' ), 'wpReason' ) .
                                "</td>
                                <td class='mw-input'>" .
                                        Xml::input( 'wpReason', 60, $reason, array( 'type' => 'text', 'maxlength' => '255',
                                                'tabindex' => '2', 'id' => 'wpReason' ) ) .
                                "</td>
                        </tr>
                        <tr>
                                <td></td>
                                <td class='mw-input'>" .
                                        Xml::checkLabel( wfMsg( 'watchthis' ),
                                                'wpWatch', 'wpWatch', $checkWatch, array( 'tabindex' => '3' ) ) .
                                "</td>
                        </tr>
                        $suppress
                        <tr>
                                <td></td>
                                <td class='mw-submit'>" .
                                        Xml::submitButton( wfMsg( 'deletepage' ),
                                                array( 'name' => 'wpConfirmB', 'id' => 'wpConfirmB', 'tabindex' => '5' ) ) .
                                "</td>
                        </tr>" .
                        Xml::closeElement( 'table' ) .
                        Xml::closeElement( 'fieldset' ) .
                        Xml::hidden( 'wpEditToken', $wgUser->editToken() ) .
                        Xml::closeElement( 'form' );

                        if( $wgUser->isAllowed( 'editinterface' ) ) {
                                $skin = $wgUser->getSkin();
                                $title = Title::makeTitle( NS_MEDIAWIKI, 'Deletereason-dropdown' );
                                $link = $skin->link(
                                        $title,
                                        wfMsgHtml( 'delete-edit-reasonlist' ),
                                        array(),
                                        array( 'action' => 'edit' )
                                );
                                $form .= '<p class="mw-delete-editreasons">' . $link . '</p>';
                        }

                $wgOut->addHTML( $form );
                $wgOut->addHTML( Xml::element( 'h2', null, LogPage::logName( 'delete' ) ) );
                LogEventsList::showLogExtract( $wgOut, 'delete', $this->mTitle->getPrefixedText() );
        }

        /**
         * Perform a deletion and output success or failure messages
         */
        public function doDelete( $reason, $suppress = false ) {
                global $wgOut, $wgUser;
                $id = $this->mTitle->getArticleID( GAID_FOR_UPDATE );

                $error = '';
                if( wfRunHooks('ArticleDelete', array(&$this, &$wgUser, &$reason, &$error)) ) {
                        if( $this->doDeleteArticle( $reason, $suppress, $id ) ) {
                                $deleted = $this->mTitle->getPrefixedText();

                                $wgOut->setPagetitle( wfMsg( 'actioncomplete' ) );
                                $wgOut->setRobotPolicy( 'noindex,nofollow' );

                                $loglink = '[[Special:Log/delete|' . wfMsgNoTrans( 'deletionlog' ) . ']]';

                                $wgOut->addWikiMsg( 'deletedtext', $deleted, $loglink );
                                $wgOut->returnToMain( false );
                                wfRunHooks('ArticleDeleteComplete', array(&$this, &$wgUser, $reason, $id));
                        } else {
                                if( $error == '' ) {
                                        $wgOut->showFatalError( wfMsgExt( 'cannotdelete', array( 'parse' ) ) );
                                        $wgOut->addHTML( Xml::element( 'h2', null, LogPage::logName( 'delete' ) ) );
                                        LogEventsList::showLogExtract( $wgOut, 'delete', $this->mTitle->getPrefixedText() );
                                } else {
                                        $wgOut->showFatalError( $error );
                                }
                        }
                }
        }

        /**
         * Back-end article deletion
         * Deletes the article with database consistency, writes logs, purges caches
         * Returns success
         */
        public function doDeleteArticle( $reason, $suppress = false, $id = 0 ) {
                global $wgUseSquid, $wgDeferredUpdateList;
                global $wgUseTrackbacks;

                wfDebug( __METHOD__."\n" );

                $dbw = wfGetDB( DB_MASTER );
                $ns = $this->mTitle->getNamespace();
                $t = $this->mTitle->getDBkey();
                $id = $id ? $id : $this->mTitle->getArticleID( GAID_FOR_UPDATE );

                if( $t == '' || $id == 0 ) {
                        return false;
                }

                $u = new SiteStatsUpdate( 0, 1, -(int)$this->isCountable( $this->getRawText() ), -1 );
                array_push( $wgDeferredUpdateList, $u );

                // Bitfields to further suppress the content
                if( $suppress ) {
                        $bitfield = 0;
                        // This should be 15...
                        $bitfield |= Revision::DELETED_TEXT;
                        $bitfield |= Revision::DELETED_COMMENT;
                        $bitfield |= Revision::DELETED_USER;
                        $bitfield |= Revision::DELETED_RESTRICTED;
                } else {
                        $bitfield = 'rev_deleted';
                }

                $dbw->begin();
                // For now, shunt the revision data into the archive table.
                // Text is *not* removed from the text table; bulk storage
                // is left intact to avoid breaking block-compression or
                // immutable storage schemes.
                //
                // For backwards compatibility, note that some older archive
                // table entries will have ar_text and ar_flags fields still.
                //
                // In the future, we may keep revisions and mark them with
                // the rev_deleted field, which is reserved for this purpose.
                $dbw->insertSelect( 'archive', array( 'page', 'revision' ),
                        array(
                                'ar_namespace'  => 'page_namespace',
                                'ar_title'      => 'page_title',
                                'ar_comment'    => 'rev_comment',
                                'ar_user'       => 'rev_user',
                                'ar_user_text'  => 'rev_user_text',
                                'ar_timestamp'  => 'rev_timestamp',
                                'ar_minor_edit' => 'rev_minor_edit',
                                'ar_rev_id'     => 'rev_id',
                                'ar_text_id'    => 'rev_text_id',
                                'ar_text'       => '\'\'', // Be explicit to appease
                                'ar_flags'      => '\'\'', // MySQL's "strict mode"...
                                'ar_len'        => 'rev_len',
                                'ar_page_id'    => 'page_id',
                                'ar_deleted'    => $bitfield
                        ), array(
                                'page_id' => $id,
                                'page_id = rev_page'
                        ), __METHOD__
                );

                # Delete restrictions for it
                $dbw->delete( 'page_restrictions', array ( 'pr_page' => $id ), __METHOD__ );

                # Now that it's safely backed up, delete it
                $dbw->delete( 'page', array( 'page_id' => $id ), __METHOD__);
                $ok = ( $dbw->affectedRows() > 0 ); // getArticleId() uses slave, could be laggy
                if( !$ok ) {
                        $dbw->rollback();
                        return false;
                }

                # Fix category table counts
                $cats = array();
                $res = $dbw->select( 'categorylinks', 'cl_to', array( 'cl_from' => $id ), __METHOD__ );
                foreach( $res as $row ) {
                        $cats []= $row->cl_to;
                }
                $this->updateCategoryCounts( array(), $cats );

                # If using cascading deletes, we can skip some explicit deletes
                if( !$dbw->cascadingDeletes() ) {
                        $dbw->delete( 'revision', array( 'rev_page' => $id ), __METHOD__ );

                        if($wgUseTrackbacks)
                                $dbw->delete( 'trackbacks', array( 'tb_page' => $id ), __METHOD__ );

                        # Delete outgoing links
                        $dbw->delete( 'pagelinks', array( 'pl_from' => $id ) );
                        $dbw->delete( 'imagelinks', array( 'il_from' => $id ) );
                        $dbw->delete( 'categorylinks', array( 'cl_from' => $id ) );
                        $dbw->delete( 'templatelinks', array( 'tl_from' => $id ) );
                        $dbw->delete( 'externallinks', array( 'el_from' => $id ) );
                        $dbw->delete( 'langlinks', array( 'll_from' => $id ) );
                        $dbw->delete( 'redirect', array( 'rd_from' => $id ) );
                }

                # If using cleanup triggers, we can skip some manual deletes
                if( !$dbw->cleanupTriggers() ) {
                        # Clean up recentchanges entries...
                        $dbw->delete( 'recentchanges',
                                array( 'rc_type != '.RC_LOG,
                                        'rc_namespace' => $this->mTitle->getNamespace(),
                                        'rc_title' => $this->mTitle->getDBkey() ),
                                __METHOD__ );
                        $dbw->delete( 'recentchanges',
                                array( 'rc_type != '.RC_LOG, 'rc_cur_id' => $id ),
                                __METHOD__ );
                }

                # Clear caches
                Article::onArticleDelete( $this->mTitle );

                # Clear the cached article id so the interface doesn't act like we exist
                $this->mTitle->resetArticleID( 0 );

                # Log the deletion, if the page was suppressed, log it at Oversight instead
                $logtype = $suppress ? 'suppress' : 'delete';
                $log = new LogPage( $logtype );

                # Make sure logging got through
                $log->addEntry( 'delete', $this->mTitle, $reason, array() );

                $dbw->commit();

                return true;
        }

        /**
         * Roll back the most recent consecutive set of edits to a page
         * from the same user; fails if there are no eligible edits to
         * roll back to, e.g. user is the sole contributor. This function
         * performs permissions checks on $wgUser, then calls commitRollback()
         * to do the dirty work
         *
         * @param $fromP String: Name of the user whose edits to rollback.
         * @param $summary String: Custom summary. Set to default summary if empty.
         * @param $token String: Rollback token.
         * @param $bot Boolean: If true, mark all reverted edits as bot.
         *
         * @param $resultDetails Array: contains result-specific array of additional values
         *    'alreadyrolled' : 'current' (rev)
         *    success        : 'summary' (str), 'current' (rev), 'target' (rev)
         *
         * @return array of errors, each error formatted as
         *   array(messagekey, param1, param2, ...).
         * On success, the array is empty.  This array can also be passed to
         * OutputPage::showPermissionsErrorPage().
         */
        public function doRollback( $fromP, $summary, $token, $bot, &$resultDetails ) {
                global $wgUser;
                $resultDetails = null;

                # Check permissions
                $editErrors = $this->mTitle->getUserPermissionsErrors( 'edit', $wgUser );
                $rollbackErrors = $this->mTitle->getUserPermissionsErrors( 'rollback', $wgUser );
                $errors = array_merge( $editErrors, wfArrayDiff2( $rollbackErrors, $editErrors ) );

                if( !$wgUser->matchEditToken( $token, array( $this->mTitle->getPrefixedText(), $fromP ) ) )
                        $errors[] = array( 'sessionfailure' );

                if( $wgUser->pingLimiter( 'rollback' ) || $wgUser->pingLimiter() ) {
                        $errors[] = array( 'actionthrottledtext' );
                }
                # If there were errors, bail out now
                if( !empty( $errors ) )
                        return $errors;

                return $this->commitRollback($fromP, $summary, $bot, $resultDetails);
        }

        /**
         * Backend implementation of doRollback(), please refer there for parameter
         * and return value documentation
         *
         * NOTE: This function does NOT check ANY permissions, it just commits the
         * rollback to the DB Therefore, you should only call this function direct-
         * ly if you want to use custom permissions checks. If you don't, use
         * doRollback() instead.
         */
        public function commitRollback($fromP, $summary, $bot, &$resultDetails) {
                global $wgUseRCPatrol, $wgUser, $wgLang;
                $dbw = wfGetDB( DB_MASTER );

                if( wfReadOnly() ) {
                        return array( array( 'readonlytext' ) );
                }

                # Get the last editor
                $current = Revision::newFromTitle( $this->mTitle );
                if( is_null( $current ) ) {
                        # Something wrong... no page?
                        return array(array('notanarticle'));
                }

                $from = str_replace( '_', ' ', $fromP );
                if( $from != $current->getUserText() ) {
                        $resultDetails = array( 'current' => $current );
                        return array(array('alreadyrolled',
                                htmlspecialchars($this->mTitle->getPrefixedText()),
                                htmlspecialchars($fromP),
                                htmlspecialchars($current->getUserText())
                        ));
                }

                # Get the last edit not by this guy
                $user = intval( $current->getUser() );
                $user_text = $dbw->addQuotes( $current->getUserText() );
                $s = $dbw->selectRow( 'revision',
                        array( 'rev_id', 'rev_timestamp', 'rev_deleted' ),
                        array(  'rev_page' => $current->getPage(),
                                "rev_user != {$user} OR rev_user_text != {$user_text}"
                        ), __METHOD__,
                        array(  'USE INDEX' => 'page_timestamp',
                                'ORDER BY'  => 'rev_timestamp DESC' )
                        );
                if( $s === false ) {
                        # No one else ever edited this page
                        return array(array('cantrollback'));
                } else if( $s->rev_deleted & REVISION::DELETED_TEXT || $s->rev_deleted & REVISION::DELETED_USER ) {
                        # Only admins can see this text
                        return array(array('notvisiblerev'));
                }

                $set = array();
                if( $bot && $wgUser->isAllowed('markbotedits') ) {
                        # Mark all reverted edits as bot
                        $set['rc_bot'] = 1;
                }
                if( $wgUseRCPatrol ) {
                        # Mark all reverted edits as patrolled
                        $set['rc_patrolled'] = 1;
                }

                if( $set ) {
                        $dbw->update( 'recentchanges', $set,
                                        array( /* WHERE */
                                                'rc_cur_id' => $current->getPage(),
                                                'rc_user_text' => $current->getUserText(),
                                                "rc_timestamp > '{$s->rev_timestamp}'",
                                        ), __METHOD__
                                );
                }

                # Generate the edit summary if necessary
                $target = Revision::newFromId( $s->rev_id );
                if( empty( $summary ) ){
                        $summary = wfMsgForContent( 'revertpage' );
                }

                # Allow the custom summary to use the same args as the default message
                $args = array(
                        $target->getUserText(), $from, $s->rev_id,
                        $wgLang->timeanddate(wfTimestamp(TS_MW, $s->rev_timestamp), true),
                        $current->getId(), $wgLang->timeanddate($current->getTimestamp())
                );
                $summary = wfMsgReplaceArgs( $summary, $args );

                # Save
                $flags = EDIT_UPDATE;

                if( $wgUser->isAllowed('minoredit') )
                        $flags |= EDIT_MINOR;

                if( $bot && ($wgUser->isAllowed('markbotedits') || $wgUser->isAllowed('bot')) )
                        $flags |= EDIT_FORCE_BOT;
                # Actually store the edit
                $status = $this->doEdit( $target->getText(), $summary, $flags, $target->getId() );
                if( !empty( $status->value['revision'] ) ) {
                        $revId = $status->value['revision']->getId();
                } else {
                        $revId = false;
                }

                wfRunHooks( 'ArticleRollbackComplete', array( $this, $wgUser, $target, $current ) );

                $resultDetails = array(
                        'summary' => $summary,
                        'current' => $current,
                        'target' => $target,
                        'newid' => $revId
                );
                return array();
        }

        /**
         * User interface for rollback operations
         */
        public function rollback() {
                global $wgUser, $wgOut, $wgRequest, $wgUseRCPatrol;
                $details = null;

                $result = $this->doRollback(
                        $wgRequest->getVal( 'from' ),
                        $wgRequest->getText( 'summary' ),
                        $wgRequest->getVal( 'token' ),
                        $wgRequest->getBool( 'bot' ),
                        $details
                );

                if( in_array( array( 'actionthrottledtext' ), $result ) ) {
                        $wgOut->rateLimited();
                        return;
                }
                if( isset( $result[0][0] ) && ( $result[0][0] == 'alreadyrolled' || $result[0][0] == 'cantrollback' ) ) {
                        $wgOut->setPageTitle( wfMsg( 'rollbackfailed' ) );
                        $errArray = $result[0];
                        $errMsg = array_shift( $errArray );
                        $wgOut->addWikiMsgArray( $errMsg, $errArray );
                        if( isset( $details['current'] ) ){
                                $current = $details['current'];
                                if( $current->getComment() != '' ) {
                                        $wgOut->addWikiMsgArray( 'editcomment', array(
                                                $wgUser->getSkin()->formatComment( $current->getComment() ) ), array( 'replaceafter' ) );
                                }
                        }
                        return;
                }
                # Display permissions errors before read-only message -- there's no
                # point in misleading the user into thinking the inability to rollback
                # is only temporary.
                if( !empty( $result ) && $result !== array( array( 'readonlytext' ) ) ) {
                        # array_diff is completely broken for arrays of arrays, sigh.  Re-
                        # move any 'readonlytext' error manually.
                        $out = array();
                        foreach( $result as $error ) {
                                if( $error != array( 'readonlytext' ) ) {
                                        $out []= $error;
                                }
                        }
                        $wgOut->showPermissionsErrorPage( $out );
                        return;
                }
                if( $result == array( array( 'readonlytext' ) ) ) {
                        $wgOut->readOnlyPage();
                        return;
                }

                $current = $details['current'];
                $target = $details['target'];
                $newId = $details['newid'];
                $wgOut->setPageTitle( wfMsg( 'actioncomplete' ) );
                $wgOut->setRobotPolicy( 'noindex,nofollow' );
                $old = $wgUser->getSkin()->userLink( $current->getUser(), $current->getUserText() )
                        . $wgUser->getSkin()->userToolLinks( $current->getUser(), $current->getUserText() );
                $new = $wgUser->getSkin()->userLink( $target->getUser(), $target->getUserText() )
                        . $wgUser->getSkin()->userToolLinks( $target->getUser(), $target->getUserText() );
                $wgOut->addHTML( wfMsgExt( 'rollback-success', array( 'parse', 'replaceafter' ), $old, $new ) );
                $wgOut->returnToMain( false, $this->mTitle );

                if( !$wgRequest->getBool( 'hidediff', false ) && !$wgUser->getBoolOption( 'norollbackdiff', false ) ) {
                        $de = new DifferenceEngine( $this->mTitle, $current->getId(), $newId, false, true );
                        $de->showDiff( '', '' );
                }
        }


        /**
         * Do standard deferred updates after page view
         */
        public function viewUpdates() {
                global $wgDeferredUpdateList, $wgDisableCounters, $wgUser;
                # Don't update page view counters on views from bot users (bug 14044)
                if( !$wgDisableCounters && !$wgUser->isAllowed('bot') && $this->getID() ) {
                        Article::incViewCount( $this->getID() );
                        $u = new SiteStatsUpdate( 1, 0, 0 );
                        array_push( $wgDeferredUpdateList, $u );
                }
                # Update newtalk / watchlist notification status
                $wgUser->clearNotification( $this->mTitle );
        }

        /**
         * Prepare text which is about to be saved.
         * Returns a stdclass with source, pst and output members
         */
        public function prepareTextForEdit( $text, $revid=null ) {
                if( $this->mPreparedEdit && $this->mPreparedEdit->newText == $text && $this->mPreparedEdit->revid == $revid) {
                        // Already prepared
                        return $this->mPreparedEdit;
                }
                global $wgParser;
                $edit = (object)array();
                $edit->revid = $revid;
                $edit->newText = $text;
                $edit->pst = $this->preSaveTransform( $text );
                $options = $this->getParserOptions();
                $edit->output = $wgParser->parse( $edit->pst, $this->mTitle, $options, true, true, $revid );
                $edit->oldText = $this->getContent();
                $this->mPreparedEdit = $edit;
                return $edit;
        }

        /**
         * Do standard deferred updates after page edit.
         * Update links tables, site stats, search index and message cache.
         * Purges pages that include this page if the text was changed here.
         * Every 100th edit, prune the recent changes table.
         *
         * @private
         * @param $text New text of the article
         * @param $summary Edit summary
         * @param $minoredit Minor edit
         * @param $timestamp_of_pagechange Timestamp associated with the page change
         * @param $newid rev_id value of the new revision
         * @param $changed Whether or not the content actually changed
         */
        public function editUpdates( $text, $summary, $minoredit, $timestamp_of_pagechange, $newid, $changed = true ) {
                global $wgDeferredUpdateList, $wgMessageCache, $wgUser, $wgParser, $wgEnableParserCache;

                wfProfileIn( __METHOD__ );

                # Parse the text
                # Be careful not to double-PST: $text is usually already PST-ed once
                if( !$this->mPreparedEdit || $this->mPreparedEdit->output->getFlag( 'vary-revision' ) ) {
                        wfDebug( __METHOD__ . ": No prepared edit or vary-revision is set...\n" );
                        $editInfo = $this->prepareTextForEdit( $text, $newid );
                } else {
                        wfDebug( __METHOD__ . ": No vary-revision, using prepared edit...\n" );
                        $editInfo = $this->mPreparedEdit;
                }

                # Save it to the parser cache
                if( $wgEnableParserCache ) {
                        $popts = $this->getParserOptions();
                        $parserCache = ParserCache::singleton();
                        $parserCache->save( $editInfo->output, $this, $popts );
                }

                # Update the links tables
                $u = new LinksUpdate( $this->mTitle, $editInfo->output );
                $u->doUpdate();

                wfRunHooks( 'ArticleEditUpdates', array( &$this, &$editInfo, $changed ) );

                if( wfRunHooks( 'ArticleEditUpdatesDeleteFromRecentchanges', array( &$this ) ) ) {
                        if( 0 == mt_rand( 0, 99 ) ) {
                                // Flush old entries from the `recentchanges` table; we do this on
                                // random requests so as to avoid an increase in writes for no good reason
                                global $wgRCMaxAge;
                                $dbw = wfGetDB( DB_MASTER );
                                $cutoff = $dbw->timestamp( time() - $wgRCMaxAge );
                                $recentchanges = $dbw->tableName( 'recentchanges' );
                                $sql = "DELETE FROM $recentchanges WHERE rc_timestamp < '{$cutoff}'";
                                $dbw->query( $sql );
                        }
                }

                $id = $this->getID();
                $title = $this->mTitle->getPrefixedDBkey();
                $shortTitle = $this->mTitle->getDBkey();

                if( 0 == $id ) {
                        wfProfileOut( __METHOD__ );
                        return;
                }

                $u = new SiteStatsUpdate( 0, 1, $this->mGoodAdjustment, $this->mTotalAdjustment );
                array_push( $wgDeferredUpdateList, $u );
                $u = new SearchUpdate( $id, $title, $text );
                array_push( $wgDeferredUpdateList, $u );

                # If this is another user's talk page, update newtalk
                # Don't do this if $changed = false otherwise some idiot can null-edit a
                # load of user talk pages and piss people off, nor if it's a minor edit
                # by a properly-flagged bot.
                if( $this->mTitle->getNamespace() == NS_USER_TALK && $shortTitle != $wgUser->getTitleKey() && $changed
                        && !( $minoredit && $wgUser->isAllowed( 'nominornewtalk' ) ) ) {
                        if( wfRunHooks('ArticleEditUpdateNewTalk', array( &$this ) ) ) {
                                $other = User::newFromName( $shortTitle, false );
                                if( !$other ) {
                                        wfDebug( __METHOD__.": invalid username\n" );
                                } elseif( User::isIP( $shortTitle ) ) {
                                        // An anonymous user
                                        $other->setNewtalk( true );
                                } elseif( $other->isLoggedIn() ) {
                                        $other->setNewtalk( true );
                                } else {
                                        wfDebug( __METHOD__. ": don't need to notify a nonexistent user\n" );
                                }
                        }
                }

                if( $this->mTitle->getNamespace() == NS_MEDIAWIKI ) {
                        $wgMessageCache->replace( $shortTitle, $text );
                }

                wfProfileOut( __METHOD__ );
        }

        /**
         * Perform article updates on a special page creation.
         *
         * @param $rev Revision object
         *
         * @todo This is a shitty interface function. Kill it and replace the
         * other shitty functions like editUpdates and such so it's not needed
         * anymore.
         */
        public function createUpdates( $rev ) {
                $this->mGoodAdjustment = $this->isCountable( $rev->getText() );
                $this->mTotalAdjustment = 1;
                $this->editUpdates( $rev->getText(), $rev->getComment(),
                        $rev->isMinor(), wfTimestamp(), $rev->getId(), true );
        }

        /**
         * Generate the navigation links when browsing through an article revisions
         * It shows the information as:
         *   Revision as of \<date\>; view current revision
         *   \<- Previous version | Next Version -\>
         *
         * @param $oldid String: revision ID of this article revision
         */
        public function setOldSubtitle( $oldid = 0 ) {
                global $wgLang, $wgOut, $wgUser, $wgRequest;

                if( !wfRunHooks( 'DisplayOldSubtitle', array( &$this, &$oldid ) ) ) {
                        return;
                }

                $revision = Revision::newFromId( $oldid );

                $current = ( $oldid == $this->mLatest );
                $td = $wgLang->timeanddate( $this->mTimestamp, true );
                $tddate = $wgLang->date( $this->mTimestamp, true );
                $tdtime = $wgLang->time( $this->mTimestamp, true );
                $sk = $wgUser->getSkin();
                $lnk = $current
                        ? wfMsgHtml( 'currentrevisionlink' )
                        : $sk->link(
                                $this->mTitle,
                                wfMsgHtml( 'currentrevisionlink' ),
                                array(),
                                array(),
                                array( 'known', 'noclasses' )
                        );
                $curdiff = $current
                        ? wfMsgHtml( 'diff' )
                        : $sk->link(
                                $this->mTitle,
                                wfMsgHtml( 'diff' ),
                                array(),
                                array(
                                        'diff' => 'cur',
                                        'oldid' => $oldid
                                ),
                                array( 'known', 'noclasses' )
                        );
                $prev = $this->mTitle->getPreviousRevisionID( $oldid ) ;
                $prevlink = $prev
                        ? $sk->link(
                                $this->mTitle,
                                wfMsgHtml( 'previousrevision' ),
                                array(),
                                array(
                                        'direction' => 'prev',
                                        'oldid' => $oldid
                                ),
                                array( 'known', 'noclasses' )
                        )
                        : wfMsgHtml( 'previousrevision' );
                $prevdiff = $prev
                        ? $sk->link(
                                $this->mTitle,
                                wfMsgHtml( 'diff' ),
                                array(),
                                array(
                                        'diff' => 'prev',
                                        'oldid' => $oldid
                                ),
                                array( 'known', 'noclasses' )
                        )
                        : wfMsgHtml( 'diff' );
                $nextlink = $current
                        ? wfMsgHtml( 'nextrevision' )
                        : $sk->link(
                                $this->mTitle,
                                wfMsgHtml( 'nextrevision' ),
                                array(),
                                array(
                                        'direction' => 'next',
                                        'oldid' => $oldid
                                ),
                                array( 'known', 'noclasses' )
                        );
                $nextdiff = $current
                        ? wfMsgHtml( 'diff' )
                        : $sk->link(
                                $this->mTitle,
                                wfMsgHtml( 'diff' ),
                                array(),
                                array(
                                        'diff' => 'next',
                                        'oldid' => $oldid
                                ),
                                array( 'known', 'noclasses' )
                        );

                $cdel='';
                if( $wgUser->isAllowed( 'deleterevision' ) ) {
                        $revdel = SpecialPage::getTitleFor( 'Revisiondelete' );
                        if( $revision->isCurrent() ) {
                        // We don't handle top deleted edits too well
                                $cdel = wfMsgHtml( 'rev-delundel' );
                        } else if( !$revision->userCan( Revision::DELETED_RESTRICTED ) ) {
                        // If revision was hidden from sysops
                                $cdel = wfMsgHtml( 'rev-delundel' );
                        } else {
                                $cdel = $sk->link(
                                        $revdel,
                                        wfMsgHtml('rev-delundel'),
                                        array(),
                                        array(
                                                'type' => 'revision',
                                                'target' => urlencode( $this->mTitle->getPrefixedDbkey() ),
                                                'ids' => urlencode( $oldid )
                                        ),
                                        array( 'known', 'noclasses' )
                                );
                                // Bolden oversighted content
                                if( $revision->isDeleted( Revision::DELETED_RESTRICTED ) )
                                        $cdel = "<strong>$cdel</strong>";
                        }
                        $cdel = "(<small>$cdel</small>) ";
                }
                $unhide = $wgRequest->getInt('unhide') == 1 && $wgUser->matchEditToken( $wgRequest->getVal('token'), $oldid );
                # Show user links if allowed to see them. If hidden, then show them only if requested...
                $userlinks = $sk->revUserTools( $revision, !$unhide );

                $m = wfMsg( 'revision-info-current' );
                $infomsg = $current && !wfEmptyMsg( 'revision-info-current', $m ) && $m != '-'
                        ? 'revision-info-current'
                        : 'revision-info';

                $r = "\n\t\t\t\t<div id=\"mw-{$infomsg}\">" .
                        wfMsgExt(
                                $infomsg,
                                array( 'parseinline', 'replaceafter' ), 
                                $td,
                                $userlinks,
                                $revision->getID(),
                                $tddate,
                                $tdtime
                        ) .
                        "</div>\n" .
                        "\n\t\t\t\t<div id=\"mw-revision-nav\">" . $cdel . wfMsgExt( 'revision-nav', array( 'escapenoentities', 'parsemag', 'replaceafter' ),
                        $prevdiff, $prevlink, $lnk, $curdiff, $nextlink, $nextdiff ) . "</div>\n\t\t\t";
                $wgOut->setSubtitle( $r );
        }

        /**
         * This function is called right before saving the wikitext,
         * so we can do things like signatures and links-in-context.
         *
         * @param $text String
         */
        public function preSaveTransform( $text ) {
                global $wgParser, $wgUser;
                return $wgParser->preSaveTransform( $text, $this->mTitle, $wgUser, ParserOptions::newFromUser( $wgUser ) );
        }

        /* Caching functions */

        /**
         * checkLastModified returns true if it has taken care of all
         * output to the client that is necessary for this request.
         * (that is, it has sent a cached version of the page)
         */
        protected function tryFileCache() {
                static $called = false;
                if( $called ) {
                        wfDebug( "Article::tryFileCache(): called twice!?\n" );
                        return false;
                }
                $called = true;
                if( $this->isFileCacheable() ) {
                        $cache = new HTMLFileCache( $this->mTitle );
                        if( $cache->isFileCacheGood( $this->mTouched ) ) {
                                wfDebug( "Article::tryFileCache(): about to load file\n" );
                                $cache->loadFromFileCache();
                                return true;
                        } else {
                                wfDebug( "Article::tryFileCache(): starting buffer\n" );
                                ob_start( array(&$cache, 'saveToFileCache' ) );
                        }
                } else {
                        wfDebug( "Article::tryFileCache(): not cacheable\n" );
                }
                return false;
        }

        /**
         * Check if the page can be cached
         * @return bool
         */
        public function isFileCacheable() {
                $cacheable = false;
                if( HTMLFileCache::useFileCache() ) {
                        $cacheable = $this->getID() && !$this->mRedirectedFrom;
                        // Extension may have reason to disable file caching on some pages.
                        if( $cacheable ) {
                                $cacheable = wfRunHooks( 'IsFileCacheable', array( &$this ) );
                        }
                }
                return $cacheable;
        }

        /**
         * Loads page_touched and returns a value indicating if it should be used
         *
         */
        public function checkTouched() {
                if( !$this->mDataLoaded ) {
                        $this->loadPageData();
                }
                return !$this->mIsRedirect;
        }

        /**
         * Get the page_touched field
         */
        public function getTouched() {
                # Ensure that page data has been loaded
                if( !$this->mDataLoaded ) {
                        $this->loadPageData();
                }
                return $this->mTouched;
        }

        /**
         * Get the page_latest field
         */
        public function getLatest() {
                if( !$this->mDataLoaded ) {
                        $this->loadPageData();
                }
                return (int)$this->mLatest;
        }

        /**
         * Edit an article without doing all that other stuff
         * The article must already exist; link tables etc
         * are not updated, caches are not flushed.
         *
         * @param $text String: text submitted
         * @param $comment String: comment submitted
         * @param $minor Boolean: whereas it's a minor modification
         */
        public function quickEdit( $text, $comment = '', $minor = 0 ) {
                wfProfileIn( __METHOD__ );

                $dbw = wfGetDB( DB_MASTER );
                $revision = new Revision( array(
                        'page'       => $this->getId(),
                        'text'       => $text,
                        'comment'    => $comment,
                        'minor_edit' => $minor ? 1 : 0,
                        ) );
                $revision->insertOn( $dbw );
                $this->updateRevisionOn( $dbw, $revision );

                wfRunHooks( 'NewRevisionFromEditComplete', array($this, $revision, false, $wgUser) );

                wfProfileOut( __METHOD__ );
        }

        /**
         * Used to increment the view counter
         *
         * @param $id Integer: article id
         */
        public static function incViewCount( $id ) {
                $id = intval( $id );
                global $wgHitcounterUpdateFreq, $wgDBtype;

                $dbw = wfGetDB( DB_MASTER );
                $pageTable = $dbw->tableName( 'page' );
                $hitcounterTable = $dbw->tableName( 'hitcounter' );
                $acchitsTable = $dbw->tableName( 'acchits' );

                if( $wgHitcounterUpdateFreq <= 1 ) {
                        $dbw->query( "UPDATE $pageTable SET page_counter = page_counter + 1 WHERE page_id = $id" );
                        return;
                }

                # Not important enough to warrant an error page in case of failure
                $oldignore = $dbw->ignoreErrors( true );

                $dbw->query( "INSERT INTO $hitcounterTable (hc_id) VALUES ({$id})" );

                $checkfreq = intval( $wgHitcounterUpdateFreq/25 + 1 );
                if( (rand() % $checkfreq != 0) or ($dbw->lastErrno() != 0) ){
                        # Most of the time (or on SQL errors), skip row count check
                        $dbw->ignoreErrors( $oldignore );
                        return;
                }

                $res = $dbw->query("SELECT COUNT(*) as n FROM $hitcounterTable");
                $row = $dbw->fetchObject( $res );
                $rown = intval( $row->n );
                if( $rown >= $wgHitcounterUpdateFreq ){
                        wfProfileIn( 'Article::incViewCount-collect' );
                        $old_user_abort = ignore_user_abort( true );

                        if($wgDBtype == 'mysql')
                                $dbw->query("LOCK TABLES $hitcounterTable WRITE");
                        $tabletype = $wgDBtype == 'mysql' ? "ENGINE=HEAP " : '';
                        $dbw->query("CREATE TEMPORARY TABLE $acchitsTable $tabletype AS ".
                                "SELECT hc_id,COUNT(*) AS hc_n FROM $hitcounterTable ".
                                'GROUP BY hc_id');
                        $dbw->query("DELETE FROM $hitcounterTable");
                        if($wgDBtype == 'mysql') {
                                $dbw->query('UNLOCK TABLES');
                                $dbw->query("UPDATE $pageTable,$acchitsTable SET page_counter=page_counter + hc_n ".
                                        'WHERE page_id = hc_id');
                        }
                        else {
                                $dbw->query("UPDATE $pageTable SET page_counter=page_counter + hc_n ".
                                        "FROM $acchitsTable WHERE page_id = hc_id");
                        }
                        $dbw->query("DROP TABLE $acchitsTable");

                        ignore_user_abort( $old_user_abort );
                        wfProfileOut( 'Article::incViewCount-collect' );
                }
                $dbw->ignoreErrors( $oldignore );
        }

        /**#@+
         * The onArticle*() functions are supposed to be a kind of hooks
         * which should be called whenever any of the specified actions
         * are done.
         *
         * This is a good place to put code to clear caches, for instance.
         *
         * This is called on page move and undelete, as well as edit
         *
         * @param $title a title object
         */

        public static function onArticleCreate( $title ) {
                # Update existence markers on article/talk tabs...
                if( $title->isTalkPage() ) {
                        $other = $title->getSubjectPage();
                } else {
                        $other = $title->getTalkPage();
                }
                $other->invalidateCache();
                $other->purgeSquid();

                $title->touchLinks();
                $title->purgeSquid();
                $title->deleteTitleProtection();
        }

        public static function onArticleDelete( $title ) {
                global $wgMessageCache;
                # Update existence markers on article/talk tabs...
                if( $title->isTalkPage() ) {
                        $other = $title->getSubjectPage();
                } else {
                        $other = $title->getTalkPage();
                }
                $other->invalidateCache();
                $other->purgeSquid();

                $title->touchLinks();
                $title->purgeSquid();

                # File cache
                HTMLFileCache::clearFileCache( $title );

                # Messages
                if( $title->getNamespace() == NS_MEDIAWIKI ) {
                        $wgMessageCache->replace( $title->getDBkey(), false );
                }
                # Images
                if( $title->getNamespace() == NS_FILE ) {
                        $update = new HTMLCacheUpdate( $title, 'imagelinks' );
                        $update->doUpdate();
                }
                # User talk pages
                if( $title->getNamespace() == NS_USER_TALK ) {
                        $user = User::newFromName( $title->getText(), false );
                        $user->setNewtalk( false );
                }
                # Image redirects
                RepoGroup::singleton()->getLocalRepo()->invalidateImageRedirect( $title );
        }

        /**
         * Purge caches on page update etc
         */
        public static function onArticleEdit( $title, $flags = '' ) {
                global $wgDeferredUpdateList;

                // Invalidate caches of articles which include this page
                $wgDeferredUpdateList[] = new HTMLCacheUpdate( $title, 'templatelinks' );

                // Invalidate the caches of all pages which redirect here
                $wgDeferredUpdateList[] = new HTMLCacheUpdate( $title, 'redirect' );

                # Purge squid for this page only
                $title->purgeSquid();

                # Clear file cache for this page only
                HTMLFileCache::clearFileCache( $title );
        }

        /**#@-*/

        /**
         * Overriden by ImagePage class, only present here to avoid a fatal error
         * Called for ?action=revert
         */
        public function revert() {
                global $wgOut;
                $wgOut->showErrorPage( 'nosuchaction', 'nosuchactiontext' );
        }

        /**
         * Info about this page
         * Called for ?action=info when $wgAllowPageInfo is on.
         */
        public function info() {
                global $wgLang, $wgOut, $wgAllowPageInfo, $wgUser;

                if( !$wgAllowPageInfo ) {
                        $wgOut->showErrorPage( 'nosuchaction', 'nosuchactiontext' );
                        return;
                }

                $page = $this->mTitle->getSubjectPage();

                $wgOut->setPagetitle( $page->getPrefixedText() );
                $wgOut->setPageTitleActionText( wfMsg( 'info_short' ) );
                $wgOut->setSubtitle( wfMsgHtml( 'infosubtitle' ) );

                if( !$this->mTitle->exists() ) {
                        $wgOut->addHTML( '<div class="noarticletext">' );
                        if( $this->mTitle->getNamespace() == NS_MEDIAWIKI ) {
                                // This doesn't quite make sense; the user is asking for
                                // information about the _page_, not the message... -- RC
                                $wgOut->addHTML( htmlspecialchars( wfMsgWeirdKey( $this->mTitle->getText() ) ) );
                        } else {
                                $msg = $wgUser->isLoggedIn()
                                        ? 'noarticletext'
                                        : 'noarticletextanon';
                                $wgOut->addHTML( wfMsgExt( $msg, 'parse' ) );
                        }
                        $wgOut->addHTML( '</div>' );
                } else {
                        $dbr = wfGetDB( DB_SLAVE );
                        $wl_clause = array(
                                'wl_title'     => $page->getDBkey(),
                                'wl_namespace' => $page->getNamespace() );
                        $numwatchers = $dbr->selectField(
                                'watchlist',
                                'COUNT(*)',
                                $wl_clause,
                                __METHOD__,
                                $this->getSelectOptions() );

                        $pageInfo = $this->pageCountInfo( $page );
                        $talkInfo = $this->pageCountInfo( $page->getTalkPage() );

                        $wgOut->addHTML( "<ul><li>" . wfMsg("numwatchers", $wgLang->formatNum( $numwatchers ) ) . '</li>' );
                        $wgOut->addHTML( "<li>" . wfMsg('numedits', $wgLang->formatNum( $pageInfo['edits'] ) ) . '</li>');
                        if( $talkInfo ) {
                                $wgOut->addHTML( '<li>' . wfMsg("numtalkedits", $wgLang->formatNum( $talkInfo['edits'] ) ) . '</li>');
                        }
                        $wgOut->addHTML( '<li>' . wfMsg("numauthors", $wgLang->formatNum( $pageInfo['authors'] ) ) . '</li>' );
                        if( $talkInfo ) {
                                $wgOut->addHTML( '<li>' . wfMsg('numtalkauthors', $wgLang->formatNum( $talkInfo['authors'] ) ) . '</li>' );
                        }
                        $wgOut->addHTML( '</ul>' );
                }
        }

        /**
         * Return the total number of edits and number of unique editors
         * on a given page. If page does not exist, returns false.
         *
         * @param $title Title object
         * @return array
         */
        public function pageCountInfo( $title ) {
                $id = $title->getArticleId();
                if( $id == 0 ) {
                        return false;
                }
                $dbr = wfGetDB( DB_SLAVE );
                $rev_clause = array( 'rev_page' => $id );
                $edits = $dbr->selectField(
                        'revision',
                        'COUNT(rev_page)',
                        $rev_clause,
                        __METHOD__,
                        $this->getSelectOptions()
                );
                $authors = $dbr->selectField(
                        'revision',
                        'COUNT(DISTINCT rev_user_text)',
                        $rev_clause,
                        __METHOD__,
                        $this->getSelectOptions()
                );
                return array( 'edits' => $edits, 'authors' => $authors );
        }

        /**
         * Return a list of templates used by this article.
         * Uses the templatelinks table
         *
         * @return Array of Title objects
         */
        public function getUsedTemplates() {
                $result = array();
                $id = $this->mTitle->getArticleID();
                if( $id == 0 ) {
                        return array();
                }
                $dbr = wfGetDB( DB_SLAVE );
                $res = $dbr->select( array( 'templatelinks' ),
                        array( 'tl_namespace', 'tl_title' ),
                        array( 'tl_from' => $id ),
                        __METHOD__ );
                if( $res !== false ) {
                        foreach( $res as $row ) {
                                $result[] = Title::makeTitle( $row->tl_namespace, $row->tl_title );
                        }
                }
                $dbr->freeResult( $res );
                return $result;
        }

        /**
         * Returns a list of hidden categories this page is a member of.
         * Uses the page_props and categorylinks tables.
         *
         * @return Array of Title objects
         */
        public function getHiddenCategories() {
                $result = array();
                $id = $this->mTitle->getArticleID();
                if( $id == 0 ) {
                        return array();
                }
                $dbr = wfGetDB( DB_SLAVE );
                $res = $dbr->select( array( 'categorylinks', 'page_props', 'page' ),
                        array( 'cl_to' ),
                        array( 'cl_from' => $id, 'pp_page=page_id', 'pp_propname' => 'hiddencat',
                                'page_namespace' => NS_CATEGORY, 'page_title=cl_to'),
                        __METHOD__ );
                if( $res !== false ) {
                        foreach( $res as $row ) {
                                $result[] = Title::makeTitle( NS_CATEGORY, $row->cl_to );
                        }
                }
                $dbr->freeResult( $res );
                return $result;
        }

        /**
        * Return an applicable autosummary if one exists for the given edit.
        * @param $oldtext String: the previous text of the page.
        * @param $newtext String: The submitted text of the page.
        * @param $flags Bitmask: a bitmask of flags submitted for the edit.
        * @return string An appropriate autosummary, or an empty string.
        */
        public static function getAutosummary( $oldtext, $newtext, $flags ) {
                # Decide what kind of autosummary is needed.

                # Redirect autosummaries
                $ot = Title::newFromRedirect( $oldtext );
                $rt = Title::newFromRedirect( $newtext );
                if( is_object( $rt ) && ( !is_object( $ot ) || !$rt->equals( $ot ) || $ot->getFragment() != $rt->getFragment() ) ) {
                        return wfMsgForContent( 'autoredircomment', $rt->getFullText() );
                }

                # New page autosummaries
                if( $flags & EDIT_NEW && strlen( $newtext ) ) {
                        # If they're making a new article, give its text, truncated, in the summary.
                        global $wgContLang;
                        $truncatedtext = $wgContLang->truncate(
                                str_replace("\n", ' ', $newtext),
                                max( 0, 200 - strlen( wfMsgForContent( 'autosumm-new' ) ) ) );
                        return wfMsgForContent( 'autosumm-new', $truncatedtext );
                }

                # Blanking autosummaries
                if( $oldtext != '' && $newtext == '' ) {
                        return wfMsgForContent( 'autosumm-blank' );
                } elseif( strlen( $oldtext ) > 10 * strlen( $newtext ) && strlen( $newtext ) < 500) {
                        # Removing more than 90% of the article
                        global $wgContLang;
                        $truncatedtext = $wgContLang->truncate(
                                $newtext,
                                max( 0, 200 - strlen( wfMsgForContent( 'autosumm-replace' ) ) ) );
                        return wfMsgForContent( 'autosumm-replace', $truncatedtext );
                }

                # If we reach this point, there's no applicable autosummary for our case, so our
                # autosummary is empty.
                return '';
        }

        /**
         * Add the primary page-view wikitext to the output buffer
         * Saves the text into the parser cache if possible.
         * Updates templatelinks if it is out of date.
         *
         * @param $text String
         * @param $cache Boolean
         */
        public function outputWikiText( $text, $cache = true, $parserOptions = false ) {
                global $wgOut;
                
                $parserOutput = $this->getOutputFromWikitext( $text, $cache, $parserOptions );
                $wgOut->addParserOutput( $parserOutput );
        }
        
        /**
         * This does all the heavy lifting for outputWikitext, except it returns the parser
         * output instead of sending it straight to $wgOut. Makes things nice and simple for,
         * say, embedding thread pages within a discussion system (LiquidThreads)
         */
        public function getOutputFromWikitext( $text, $cache = true, $parserOptions = false ) {
                global $wgParser, $wgOut, $wgEnableParserCache, $wgUseFileCache;

                if ( !$parserOptions ) {
                        $parserOptions = $this->getParserOptions();
                }

                $time = -wfTime();
                $parserOutput = $wgParser->parse( $text, $this->mTitle,
                        $parserOptions, true, true, $this->getRevIdFetched() );
                $time += wfTime();

                # Timing hack
                if( $time > 3 ) {
                        wfDebugLog( 'slow-parse', sprintf( "%-5.2f %s", $time,
                                $this->mTitle->getPrefixedDBkey()));
                }

                if( $wgEnableParserCache && $cache && $this && $parserOutput->getCacheTime() != -1 ) {
                        $parserCache = ParserCache::singleton();
                        $parserCache->save( $parserOutput, $this, $parserOptions );
                }
                // Make sure file cache is not used on uncacheable content.
                // Output that has magic words in it can still use the parser cache
                // (if enabled), though it will generally expire sooner.
                if( $parserOutput->getCacheTime() == -1 || $parserOutput->containsOldMagic() ) {
                        $wgUseFileCache = false;
                }
                $this->doCascadeProtectionUpdates( $parserOutput );
                return $parserOutput;
        }

        /**
         * Get parser options suitable for rendering the primary article wikitext
         */
        public function getParserOptions() {
                global $wgUser;
                if ( !$this->mParserOptions ) {
                        $this->mParserOptions = new ParserOptions( $wgUser );
                        $this->mParserOptions->setTidy( true );
                        $this->mParserOptions->enableLimitReport();
                }
                return $this->mParserOptions;
        }

        protected function doCascadeProtectionUpdates( $parserOutput ) {
                if( !$this->isCurrent() || wfReadOnly() || !$this->mTitle->areRestrictionsCascading() ) {
                        return;
                }

                // templatelinks table may have become out of sync,
                // especially if using variable-based transclusions.
                // For paranoia, check if things have changed and if
                // so apply updates to the database. This will ensure
                // that cascaded protections apply as soon as the changes
                // are visible.

                # Get templates from templatelinks
                $id = $this->mTitle->getArticleID();

                $tlTemplates = array();

                $dbr = wfGetDB( DB_SLAVE );
                $res = $dbr->select( array( 'templatelinks' ),
                        array( 'tl_namespace', 'tl_title' ),
                        array( 'tl_from' => $id ),
                        __METHOD__ );

                global $wgContLang;
                foreach( $res as $row ) {
                        $tlTemplates["{$row->tl_namespace}:{$row->tl_title}"] = true;
                }

                # Get templates from parser output.
                $poTemplates = array();
                foreach ( $parserOutput->getTemplates() as $ns => $templates ) {
                        foreach ( $templates as $dbk => $id ) {
                                $poTemplates["$ns:$dbk"] = true;
                        }
                }

                # Get the diff
                # Note that we simulate array_diff_key in PHP <5.0.x
                $templates_diff = array_diff_key( $poTemplates, $tlTemplates );

                if( count( $templates_diff ) > 0 ) {
                        # Whee, link updates time.
                        $u = new LinksUpdate( $this->mTitle, $parserOutput, false );
                        $u->doUpdate();
                }
        }

        /**
         * Update all the appropriate counts in the category table, given that
         * we've added the categories $added and deleted the categories $deleted.
         *
         * @param $added array   The names of categories that were added
         * @param $deleted array The names of categories that were deleted
         * @return null
         */
        public function updateCategoryCounts( $added, $deleted ) {
                $ns = $this->mTitle->getNamespace();
                $dbw = wfGetDB( DB_MASTER );

                # First make sure the rows exist.  If one of the "deleted" ones didn't
                # exist, we might legitimately not create it, but it's simpler to just
                # create it and then give it a negative value, since the value is bogus
                # anyway.
                #
                # Sometimes I wish we had INSERT ... ON DUPLICATE KEY UPDATE.
                $insertCats = array_merge( $added, $deleted );
                if( !$insertCats ) {
                        # Okay, nothing to do
                        return;
                }
                $insertRows = array();
                foreach( $insertCats as $cat ) {
                        $insertRows[] = array( 'cat_title' => $cat );
                }
                $dbw->insert( 'category', $insertRows, __METHOD__, 'IGNORE' );

                $addFields    = array( 'cat_pages = cat_pages + 1' );
                $removeFields = array( 'cat_pages = cat_pages - 1' );
                if( $ns == NS_CATEGORY ) {
                        $addFields[]    = 'cat_subcats = cat_subcats + 1';
                        $removeFields[] = 'cat_subcats = cat_subcats - 1';
                } elseif( $ns == NS_FILE ) {
                        $addFields[]    = 'cat_files = cat_files + 1';
                        $removeFields[] = 'cat_files = cat_files - 1';
                }

                if( $added ) {
                        $dbw->update(
                                'category',
                                $addFields,
                                array( 'cat_title' => $added ),
                                __METHOD__
                        );
                }
                if( $deleted ) {
                        $dbw->update(
                                'category',
                                $removeFields,
                                array( 'cat_title' => $deleted ),
                                __METHOD__
                        );
                }
        }
        
        /** Lightweight method to get the parser output for a page, checking the parser cache
          * and so on. Doesn't consider most of the stuff that Article::view is forced to
          * consider, so it's not appropriate to use there. */
        function getParserOutput( $oldid = null ) {
                global $wgEnableParserCache, $wgUser, $wgOut;

                // Should the parser cache be used?
                $useParserCache = $wgEnableParserCache &&
                          intval( $wgUser->getOption( 'stubthreshold' ) ) == 0 &&
                          $this->exists() &&
                                  $oldid === null;
                                  
                wfDebug( __METHOD__.': using parser cache: ' . ( $useParserCache ? 'yes' : 'no' ) . "\n" );
                if ( $wgUser->getOption( 'stubthreshold' ) ) {
                        wfIncrStats( 'pcache_miss_stub' );
                }

                $parserOutput = false;
                if ( $useParserCache ) {
                        $parserOutput = ParserCache::singleton()->get( $this, $this->getParserOptions() );
                }

                if ( $parserOutput === false ) {
                        // Cache miss; parse and output it.
                        $rev = Revision::newFromTitle( $this->getTitle(), $oldid );
                        
                        return $this->getOutputFromWikitext( $rev->getText(), $useParserCache );
                } else {
                        return $parserOutput;
                }
        }
}