Merge "Add ss_active_users in SiteStats::isSane"

[mediawiki.git] / includes / EditPage.php

<?php
/**
 * Page edition user interface.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 * http://www.gnu.org/copyleft/gpl.html
 *
 * @file
 */

/**
 * The edit page/HTML interface (split from Article)
 * The actual database and text munging is still in Article,
 * but it should get easier to call those from alternate
 * interfaces.
 *
 * EditPage cares about two distinct titles:
 * $this->mContextTitle is the page that forms submit to, links point to,
 * redirects go to, etc. $this->mTitle (as well as $mArticle) is the
 * page in the database that is actually being edited. These are
 * usually the same, but they are now allowed to be different.
 *
 * Surgeon General's Warning: prolonged exposure to this class is known to cause
 * headaches, which may be fatal.
 */
class EditPage {

        /**
         * Status: Article successfully updated
         */
        const AS_SUCCESS_UPDATE = 200;

        /**
         * Status: Article successfully created
         */
        const AS_SUCCESS_NEW_ARTICLE = 201;

        /**
         * Status: Article update aborted by a hook function
         */
        const AS_HOOK_ERROR = 210;

        /**
         * Status: A hook function returned an error
         */
        const AS_HOOK_ERROR_EXPECTED = 212;

        /**
         * Status: User is blocked from editing this page
         */
        const AS_BLOCKED_PAGE_FOR_USER = 215;

        /**
         * Status: Content too big (> $wgMaxArticleSize)
         */
        const AS_CONTENT_TOO_BIG = 216;

        /**
         * Status: User cannot edit? (not used)
         */
        const AS_USER_CANNOT_EDIT = 217;

        /**
         * Status: this anonymous user is not allowed to edit this page
         */
        const AS_READ_ONLY_PAGE_ANON = 218;

        /**
         * Status: this logged in user is not allowed to edit this page
         */
        const AS_READ_ONLY_PAGE_LOGGED = 219;

        /**
         * Status: wiki is in readonly mode (wfReadOnly() == true)
         */
        const AS_READ_ONLY_PAGE = 220;

        /**
         * Status: rate limiter for action 'edit' was tripped
         */
        const AS_RATE_LIMITED = 221;

        /**
         * Status: article was deleted while editing and param wpRecreate == false or form
         * was not posted
         */
        const AS_ARTICLE_WAS_DELETED = 222;

        /**
         * Status: user tried to create this page, but is not allowed to do that
         * ( Title->userCan('create') == false )
         */
        const AS_NO_CREATE_PERMISSION = 223;

        /**
         * Status: user tried to create a blank page
         */
        const AS_BLANK_ARTICLE = 224;

        /**
         * Status: (non-resolvable) edit conflict
         */
        const AS_CONFLICT_DETECTED = 225;

        /**
         * Status: no edit summary given and the user has forceeditsummary set and the user is not
         * editing in his own userspace or talkspace and wpIgnoreBlankSummary == false
         */
        const AS_SUMMARY_NEEDED = 226;

        /**
         * Status: user tried to create a new section without content
         */
        const AS_TEXTBOX_EMPTY = 228;

        /**
         * Status: article is too big (> $wgMaxArticleSize), after merging in the new section
         */
        const AS_MAX_ARTICLE_SIZE_EXCEEDED = 229;

        /**
         * not used
         */
        const AS_OK = 230;

        /**
         * Status: WikiPage::doEdit() was unsuccessful
         */
        const AS_END = 231;

        /**
         * Status: summary contained spam according to one of the regexes in $wgSummarySpamRegex
         */
        const AS_SPAM_ERROR = 232;

        /**
         * Status: anonymous user is not allowed to upload (User::isAllowed('upload') == false)
         */
        const AS_IMAGE_REDIRECT_ANON = 233;

        /**
         * Status: logged in user is not allowed to upload (User::isAllowed('upload') == false)
         */
        const AS_IMAGE_REDIRECT_LOGGED = 234;

        /**
         * Status: can't parse content
         */
        const AS_PARSE_ERROR = 240;

        /**
         * HTML id and name for the beginning of the edit form.
         */
        const EDITFORM_ID = 'editform';

        /**
         * Prefix of key for cookie used to pass post-edit state.
         * The revision id edited is added after this
         */
        const POST_EDIT_COOKIE_KEY_PREFIX = 'PostEditRevision';

        /**
         * Duration of PostEdit cookie, in seconds.
         * The cookie will be removed instantly if the JavaScript runs.
         *
         * Otherwise, though, we don't want the cookies to accumulate.
         * RFC 2109 ( https://www.ietf.org/rfc/rfc2109.txt ) specifies a possible limit of only 20 cookies per domain.
         * This still applies at least to some versions of IE without full updates:
         * https://blogs.msdn.com/b/ieinternals/archive/2009/08/20/wininet-ie-cookie-internals-faq.aspx
         *
         * A value of 20 minutes should be enough to take into account slow loads and minor
         * clock skew while still avoiding cookie accumulation when JavaScript is turned off.
         */
        const POST_EDIT_COOKIE_DURATION = 1200;

        /**
         * @var Article
         */
        var $mArticle;

        /**
         * @var Title
         */
        var $mTitle;
        private $mContextTitle = null;
        var $action = 'submit';
        var $isConflict = false;
        var $isCssJsSubpage = false;
        var $isCssSubpage = false;
        var $isJsSubpage = false;
        var $isWrongCaseCssJsPage = false;
        var $isNew = false; // new page or new section
        var $deletedSinceEdit;
        var $formtype;
        var $firsttime;
        var $lastDelete;
        var $mTokenOk = false;
        var $mTokenOkExceptSuffix = false;
        var $mTriedSave = false;
        var $incompleteForm = false;
        var $tooBig = false;
        var $kblength = false;
        var $missingComment = false;
        var $missingSummary = false;
        var $allowBlankSummary = false;
        var $autoSumm = '';
        var $hookError = '';
        #var $mPreviewTemplates;

        /**
         * @var ParserOutput
         */
        var $mParserOutput;

        /**
         * Has a summary been preset using GET parameter &summary= ?
         * @var Bool
         */
        var $hasPresetSummary = false;

        var $mBaseRevision = false;
        var $mShowSummaryField = true;

        # Form values
        var $save = false, $preview = false, $diff = false;
        var $minoredit = false, $watchthis = false, $recreate = false;
        var $textbox1 = '', $textbox2 = '', $summary = '', $nosummary = false;
        var $edittime = '', $section = '', $sectiontitle = '', $starttime = '';
        var $oldid = 0, $editintro = '', $scrolltop = null, $bot = true;
        var $contentModel = null, $contentFormat = null;

        # Placeholders for text injection by hooks (must be HTML)
        # extensions should take care to _append_ to the present value
        public $editFormPageTop = ''; // Before even the preview
        public $editFormTextTop = '';
        public $editFormTextBeforeContent = '';
        public $editFormTextAfterWarn = '';
        public $editFormTextAfterTools = '';
        public $editFormTextBottom = '';
        public $editFormTextAfterContent = '';
        public $previewTextAfterContent = '';
        public $mPreloadContent = null;

        /* $didSave should be set to true whenever an article was successfully altered. */
        public $didSave = false;
        public $undidRev = 0;

        public $suppressIntro = false;

        /**
         * Set to true to allow editing of non-text content types.
         *
         * @var bool
         */
        public $allowNonTextContent = false;

        /**
         * @param $article Article
         */
        public function __construct( Article $article ) {
                $this->mArticle = $article;
                $this->mTitle = $article->getTitle();

                $this->contentModel = $this->mTitle->getContentModel();

                $handler = ContentHandler::getForModelID( $this->contentModel );
                $this->contentFormat = $handler->getDefaultFormat();
        }

        /**
         * @return Article
         */
        public function getArticle() {
                return $this->mArticle;
        }

        /**
         * @since 1.19
         * @return Title
         */
        public function getTitle() {
                return $this->mTitle;
        }

        /**
         * Set the context Title object
         *
         * @param $title Title object or null
         */
        public function setContextTitle( $title ) {
                $this->mContextTitle = $title;
        }

        /**
         * Get the context title object.
         * If not set, $wgTitle will be returned. This behavior might change in
         * the future to return $this->mTitle instead.
         *
         * @return Title object
         */
        public function getContextTitle() {
                if ( is_null( $this->mContextTitle ) ) {
                        global $wgTitle;
                        return $wgTitle;
                } else {
                        return $this->mContextTitle;
                }
        }

        function submit() {
                $this->edit();
        }

        /**
         * This is the function that gets called for "action=edit". It
         * sets up various member variables, then passes execution to
         * another function, usually showEditForm()
         *
         * The edit form is self-submitting, so that when things like
         * preview and edit conflicts occur, we get the same form back
         * with the extra stuff added.  Only when the final submission
         * is made and all is well do we actually save and redirect to
         * the newly-edited page.
         */
        function edit() {
                global $wgOut, $wgRequest, $wgUser;
                // Allow extensions to modify/prevent this form or submission
                if ( !wfRunHooks( 'AlternateEdit', array( $this ) ) ) {
                        return;
                }

                wfProfileIn( __METHOD__ );
                wfDebug( __METHOD__ . ": enter\n" );

                // If they used redlink=1 and the page exists, redirect to the main article
                if ( $wgRequest->getBool( 'redlink' ) && $this->mTitle->exists() ) {
                        $wgOut->redirect( $this->mTitle->getFullURL() );
                        wfProfileOut( __METHOD__ );
                        return;
                }

                $this->importFormData( $wgRequest );
                $this->firsttime = false;

                if ( $this->live ) {
                        $this->livePreview();
                        wfProfileOut( __METHOD__ );
                        return;
                }

                if ( wfReadOnly() && $this->save ) {
                        // Force preview
                        $this->save = false;
                        $this->preview = true;
                }

                if ( $this->save ) {
                        $this->formtype = 'save';
                } elseif ( $this->preview ) {
                        $this->formtype = 'preview';
                } elseif ( $this->diff ) {
                        $this->formtype = 'diff';
                } else { # First time through
                        $this->firsttime = true;
                        if ( $this->previewOnOpen() ) {
                                $this->formtype = 'preview';
                        } else {
                                $this->formtype = 'initial';
                        }
                }

                $permErrors = $this->getEditPermissionErrors();
                if ( $permErrors ) {
                        wfDebug( __METHOD__ . ": User can't edit\n" );
                        // Auto-block user's IP if the account was "hard" blocked
                        $wgUser->spreadAnyEditBlock();

                        $this->displayPermissionsError( $permErrors );

                        wfProfileOut( __METHOD__ );
                        return;
                }

                wfProfileIn( __METHOD__ . "-business-end" );

                $this->isConflict = false;
                // css / js subpages of user pages get a special treatment
                $this->isCssJsSubpage = $this->mTitle->isCssJsSubpage();
                $this->isCssSubpage = $this->mTitle->isCssSubpage();
                $this->isJsSubpage = $this->mTitle->isJsSubpage();
                $this->isWrongCaseCssJsPage = $this->isWrongCaseCssJsPage();

                # Show applicable editing introductions
                if ( $this->formtype == 'initial' || $this->firsttime ) {
                        $this->showIntro();
                }

                # Attempt submission here.  This will check for edit conflicts,
                # and redundantly check for locked database, blocked IPs, etc.
                # that edit() already checked just in case someone tries to sneak
                # in the back door with a hand-edited submission URL.

                if ( 'save' == $this->formtype ) {
                        if ( !$this->attemptSave() ) {
                                wfProfileOut( __METHOD__ . "-business-end" );
                                wfProfileOut( __METHOD__ );
                                return;
                        }
                }

                # First time through: get contents, set time for conflict
                # checking, etc.
                if ( 'initial' == $this->formtype || $this->firsttime ) {
                        if ( $this->initialiseForm() === false ) {
                                $this->noSuchSectionPage();
                                wfProfileOut( __METHOD__ . "-business-end" );
                                wfProfileOut( __METHOD__ );
                                return;
                        }

                        if ( !$this->mTitle->getArticleID() ) {
                                wfRunHooks( 'EditFormPreloadText', array( &$this->textbox1, &$this->mTitle ) );
                        } else {
                                wfRunHooks( 'EditFormInitialText', array( $this ) );
                        }

                }

                $this->showEditForm();
                wfProfileOut( __METHOD__ . "-business-end" );
                wfProfileOut( __METHOD__ );
        }

        /**
         * @return array
         */
        protected function getEditPermissionErrors() {
                global $wgUser;
                $permErrors = $this->mTitle->getUserPermissionsErrors( 'edit', $wgUser );
                # Can this title be created?
                if ( !$this->mTitle->exists() ) {
                        $permErrors = array_merge( $permErrors,
                                wfArrayDiff2( $this->mTitle->getUserPermissionsErrors( 'create', $wgUser ), $permErrors ) );
                }
                # Ignore some permissions errors when a user is just previewing/viewing diffs
                $remove = array();
                foreach ( $permErrors as $error ) {
                        if ( ( $this->preview || $this->diff ) &&
                                ( $error[0] == 'blockedtext' || $error[0] == 'autoblockedtext' ) )
                        {
                                $remove[] = $error;
                        }
                }
                $permErrors = wfArrayDiff2( $permErrors, $remove );
                return $permErrors;
        }

        /**
         * Display a permissions error page, like OutputPage::showPermissionsErrorPage(),
         * but with the following differences:
         * - If redlink=1, the user will be redirected to the page
         * - If there is content to display or the error occurs while either saving,
         *   previewing or showing the difference, it will be a
         *   "View source for ..." page displaying the source code after the error message.
         *
         * @since 1.19
         * @param array $permErrors of permissions errors, as returned by
         *                    Title::getUserPermissionsErrors().
         * @throws PermissionsError
         */
        protected function displayPermissionsError( array $permErrors ) {
                global $wgRequest, $wgOut;

                if ( $wgRequest->getBool( 'redlink' ) ) {
                        // The edit page was reached via a red link.
                        // Redirect to the article page and let them click the edit tab if
                        // they really want a permission error.
                        $wgOut->redirect( $this->mTitle->getFullURL() );
                        return;
                }

                $content = $this->getContentObject();

                # Use the normal message if there's nothing to display
                if ( $this->firsttime && ( !$content || $content->isEmpty() ) ) {
                        $action = $this->mTitle->exists() ? 'edit' :
                                ( $this->mTitle->isTalkPage() ? 'createtalk' : 'createpage' );
                        throw new PermissionsError( $action, $permErrors );
                }

                $wgOut->setRobotPolicy( 'noindex,nofollow' );
                $wgOut->setPageTitle( wfMessage( 'viewsource-title', $this->getContextTitle()->getPrefixedText() ) );
                $wgOut->addBacklinkSubtitle( $this->getContextTitle() );
                $wgOut->addWikiText( $wgOut->formatPermissionsErrorMessage( $permErrors, 'edit' ) );
                $wgOut->addHTML( "<hr />\n" );

                # If the user made changes, preserve them when showing the markup
                # (This happens when a user is blocked during edit, for instance)
                if ( !$this->firsttime ) {
                        $text = $this->textbox1;
                        $wgOut->addWikiMsg( 'viewyourtext' );
                } else {
                        $text = $this->toEditText( $content );
                        $wgOut->addWikiMsg( 'viewsourcetext' );
                }

                $this->showTextbox( $text, 'wpTextbox1', array( 'readonly' ) );

                $wgOut->addHTML( Html::rawElement( 'div', array( 'class' => 'templatesUsed' ),
                        Linker::formatTemplates( $this->getTemplates() ) ) );

                if ( $this->mTitle->exists() ) {
                        $wgOut->returnToMain( null, $this->mTitle );
                }
        }

        /**
         * Show a read-only error
         * Parameters are the same as OutputPage:readOnlyPage()
         * Redirect to the article page if redlink=1
         * @deprecated in 1.19; use displayPermissionsError() instead
         */
        function readOnlyPage( $source = null, $protected = false, $reasons = array(), $action = null ) {
                wfDeprecated( __METHOD__, '1.19' );

                global $wgRequest, $wgOut;
                if ( $wgRequest->getBool( 'redlink' ) ) {
                        // The edit page was reached via a red link.
                        // Redirect to the article page and let them click the edit tab if
                        // they really want a permission error.
                        $wgOut->redirect( $this->mTitle->getFullURL() );
                } else {
                        $wgOut->readOnlyPage( $source, $protected, $reasons, $action );
                }
        }

        /**
         * Should we show a preview when the edit form is first shown?
         *
         * @return bool
         */
        protected function previewOnOpen() {
                global $wgRequest, $wgUser, $wgPreviewOnOpenNamespaces;
                if ( $wgRequest->getVal( 'preview' ) == 'yes' ) {
                        // Explicit override from request
                        return true;
                } elseif ( $wgRequest->getVal( 'preview' ) == 'no' ) {
                        // Explicit override from request
                        return false;
                } elseif ( $this->section == 'new' ) {
                        // Nothing *to* preview for new sections
                        return false;
                } elseif ( ( $wgRequest->getVal( 'preload' ) !== null || $this->mTitle->exists() ) && $wgUser->getOption( 'previewonfirst' ) ) {
                        // Standard preference behavior
                        return true;
                } elseif ( !$this->mTitle->exists() &&
                        isset( $wgPreviewOnOpenNamespaces[$this->mTitle->getNamespace()] ) &&
                        $wgPreviewOnOpenNamespaces[$this->mTitle->getNamespace()] )
                {
                        // Categories are special
                        return true;
                } else {
                        return false;
                }
        }

        /**
         * Checks whether the user entered a skin name in uppercase,
         * e.g. "User:Example/Monobook.css" instead of "monobook.css"
         *
         * @return bool
         */
        protected function isWrongCaseCssJsPage() {
                if ( $this->mTitle->isCssJsSubpage() ) {
                        $name = $this->mTitle->getSkinFromCssJsSubpage();
                        $skins = array_merge(
                                array_keys( Skin::getSkinNames() ),
                                array( 'common' )
                        );
                        return !in_array( $name, $skins )
                                && in_array( strtolower( $name ), $skins );
                } else {
                        return false;
                }
        }

        /**
         * Returns whether section editing is supported for the current page.
         * Subclasses may override this to replace the default behavior, which is
         * to check ContentHandler::supportsSections.
         *
         * @return bool true if this edit page supports sections, false otherwise.
         */
        protected function isSectionEditSupported() {
                $contentHandler = ContentHandler::getForTitle( $this->mTitle );
                return $contentHandler->supportsSections();
        }

        /**
         * This function collects the form data and uses it to populate various member variables.
         * @param $request WebRequest
         */
        function importFormData( &$request ) {
                global $wgContLang, $wgUser;

                wfProfileIn( __METHOD__ );

                # Section edit can come from either the form or a link
                $this->section = $request->getVal( 'wpSection', $request->getVal( 'section' ) );

                if ( $this->section !== null && $this->section !== '' && !$this->isSectionEditSupported() ) {
                        wfProfileOut( __METHOD__ );
                        throw new ErrorPageError( 'sectioneditnotsupported-title', 'sectioneditnotsupported-text' );
                }

                $this->isNew = !$this->mTitle->exists() || $this->section == 'new';

                if ( $request->wasPosted() ) {
                        # These fields need to be checked for encoding.
                        # Also remove trailing whitespace, but don't remove _initial_
                        # whitespace from the text boxes. This may be significant formatting.
                        $this->textbox1 = $this->safeUnicodeInput( $request, 'wpTextbox1' );
                        if ( !$request->getCheck( 'wpTextbox2' ) ) {
                                // Skip this if wpTextbox2 has input, it indicates that we came
                                // from a conflict page with raw page text, not a custom form
                                // modified by subclasses
                                wfProfileIn( get_class( $this ) . "::importContentFormData" );
                                $textbox1 = $this->importContentFormData( $request );
                                if ( $textbox1 !== null ) {
                                        $this->textbox1 = $textbox1;
                                }

                                wfProfileOut( get_class( $this ) . "::importContentFormData" );
                        }

                        # Truncate for whole multibyte characters
                        $this->summary = $wgContLang->truncate( $request->getText( 'wpSummary' ), 255 );

                        # If the summary consists of a heading, e.g. '==Foobar==', extract the title from the
                        # header syntax, e.g. 'Foobar'. This is mainly an issue when we are using wpSummary for
                        # section titles.
                        $this->summary = preg_replace( '/^\s*=+\s*(.*?)\s*=+\s*$/', '$1', $this->summary );

                        # Treat sectiontitle the same way as summary.
                        # Note that wpSectionTitle is not yet a part of the actual edit form, as wpSummary is
                        # currently doing double duty as both edit summary and section title. Right now this
                        # is just to allow API edits to work around this limitation, but this should be
                        # incorporated into the actual edit form when EditPage is rewritten (Bugs 18654, 26312).
                        $this->sectiontitle = $wgContLang->truncate( $request->getText( 'wpSectionTitle' ), 255 );
                        $this->sectiontitle = preg_replace( '/^\s*=+\s*(.*?)\s*=+\s*$/', '$1', $this->sectiontitle );

                        $this->edittime = $request->getVal( 'wpEdittime' );
                        $this->starttime = $request->getVal( 'wpStarttime' );

                        $this->scrolltop = $request->getIntOrNull( 'wpScrolltop' );

                        if ( $this->textbox1 === '' && $request->getVal( 'wpTextbox1' ) === null ) {
                                // wpTextbox1 field is missing, possibly due to being "too big"
                                // according to some filter rules such as Suhosin's setting for
                                // suhosin.request.max_value_length (d'oh)
                                $this->incompleteForm = true;
                        } else {
                                // edittime should be one of our last fields; if it's missing,
                                // the submission probably broke somewhere in the middle.
                                $this->incompleteForm = is_null( $this->edittime );
                        }
                        if ( $this->incompleteForm ) {
                                # If the form is incomplete, force to preview.
                                wfDebug( __METHOD__ . ": Form data appears to be incomplete\n" );
                                wfDebug( "POST DATA: " . var_export( $_POST, true ) . "\n" );
                                $this->preview = true;
                        } else {
                                /* Fallback for live preview */
                                $this->preview = $request->getCheck( 'wpPreview' ) || $request->getCheck( 'wpLivePreview' );
                                $this->diff = $request->getCheck( 'wpDiff' );

                                // Remember whether a save was requested, so we can indicate
                                // if we forced preview due to session failure.
                                $this->mTriedSave = !$this->preview;

                                if ( $this->tokenOk( $request ) ) {
                                        # Some browsers will not report any submit button
                                        # if the user hits enter in the comment box.
                                        # The unmarked state will be assumed to be a save,
                                        # if the form seems otherwise complete.
                                        wfDebug( __METHOD__ . ": Passed token check.\n" );
                                } elseif ( $this->diff ) {
                                        # Failed token check, but only requested "Show Changes".
                                        wfDebug( __METHOD__ . ": Failed token check; Show Changes requested.\n" );
                                } else {
                                        # Page might be a hack attempt posted from
                                        # an external site. Preview instead of saving.
                                        wfDebug( __METHOD__ . ": Failed token check; forcing preview\n" );
                                        $this->preview = true;
                                }
                        }
                        $this->save = !$this->preview && !$this->diff;
                        if ( !preg_match( '/^\d{14}$/', $this->edittime ) ) {
                                $this->edittime = null;
                        }

                        if ( !preg_match( '/^\d{14}$/', $this->starttime ) ) {
                                $this->starttime = null;
                        }

                        $this->recreate = $request->getCheck( 'wpRecreate' );

                        $this->minoredit = $request->getCheck( 'wpMinoredit' );
                        $this->watchthis = $request->getCheck( 'wpWatchthis' );

                        # Don't force edit summaries when a user is editing their own user or talk page
                        if ( ( $this->mTitle->mNamespace == NS_USER || $this->mTitle->mNamespace == NS_USER_TALK ) &&
                                $this->mTitle->getText() == $wgUser->getName() )
                        {
                                $this->allowBlankSummary = true;
                        } else {
                                $this->allowBlankSummary = $request->getBool( 'wpIgnoreBlankSummary' ) || !$wgUser->getOption( 'forceeditsummary' );
                        }

                        $this->autoSumm = $request->getText( 'wpAutoSummary' );
                } else {
                        # Not a posted form? Start with nothing.
                        wfDebug( __METHOD__ . ": Not a posted form.\n" );
                        $this->textbox1 = '';
                        $this->summary = '';
                        $this->sectiontitle = '';
                        $this->edittime = '';
                        $this->starttime = wfTimestampNow();
                        $this->edit = false;
                        $this->preview = false;
                        $this->save = false;
                        $this->diff = false;
                        $this->minoredit = false;
                        $this->watchthis = $request->getBool( 'watchthis', false ); // Watch may be overridden by request parameters
                        $this->recreate = false;

                        // When creating a new section, we can preload a section title by passing it as the
                        // preloadtitle parameter in the URL (Bug 13100)
                        if ( $this->section == 'new' && $request->getVal( 'preloadtitle' ) ) {
                                $this->sectiontitle = $request->getVal( 'preloadtitle' );
                                // Once wpSummary isn't being use for setting section titles, we should delete this.
                                $this->summary = $request->getVal( 'preloadtitle' );
                        }
                        elseif ( $this->section != 'new' && $request->getVal( 'summary' ) ) {
                                $this->summary = $request->getText( 'summary' );
                                if ( $this->summary !== '' ) {
                                        $this->hasPresetSummary = true;
                                }
                        }

                        if ( $request->getVal( 'minor' ) ) {
                                $this->minoredit = true;
                        }
                }

                $this->oldid = $request->getInt( 'oldid' );

                $this->bot = $request->getBool( 'bot', true );
                $this->nosummary = $request->getBool( 'nosummary' );

                $content_handler = ContentHandler::getForTitle( $this->mTitle );
                $this->contentModel = $request->getText( 'model', $content_handler->getModelID() ); #may be overridden by revision
                $this->contentFormat = $request->getText( 'format', $content_handler->getDefaultFormat() ); #may be overridden by revision

                #TODO: check if the desired model is allowed in this namespace, and if a transition from the page's current model to the new model is allowed
                #TODO: check if the desired content model supports the given content format!

                $this->live = $request->getCheck( 'live' );
                $this->editintro = $request->getText( 'editintro',
                        // Custom edit intro for new sections
                        $this->section === 'new' ? 'MediaWiki:addsection-editintro' : '' );

                // Allow extensions to modify form data
                wfRunHooks( 'EditPage::importFormData', array( $this, $request ) );

                wfProfileOut( __METHOD__ );
        }

        /**
         * Subpage overridable method for extracting the page content data from the
         * posted form to be placed in $this->textbox1, if using customized input
         * this method should be overridden and return the page text that will be used
         * for saving, preview parsing and so on...
         *
         * @param $request WebRequest
         */
        protected function importContentFormData( &$request ) {
                return; // Don't do anything, EditPage already extracted wpTextbox1
        }

        /**
         * Initialise form fields in the object
         * Called on the first invocation, e.g. when a user clicks an edit link
         * @return bool -- if the requested section is valid
         */
        function initialiseForm() {
                global $wgUser;
                $this->edittime = $this->mArticle->getTimestamp();

                $content = $this->getContentObject( false ); #TODO: track content object?!
                if ( $content === false ) {
                        return false;
                }
                $this->textbox1 = $this->toEditText( $content );

                // activate checkboxes if user wants them to be always active
                # Sort out the "watch" checkbox
                if ( $wgUser->getOption( 'watchdefault' ) ) {
                        # Watch all edits
                        $this->watchthis = true;
                } elseif ( $wgUser->getOption( 'watchcreations' ) && !$this->mTitle->exists() ) {
                        # Watch creations
                        $this->watchthis = true;
                } elseif ( $wgUser->isWatched( $this->mTitle ) ) {
                        # Already watched
                        $this->watchthis = true;
                }
                if ( $wgUser->getOption( 'minordefault' ) && !$this->isNew ) {
                        $this->minoredit = true;
                }
                if ( $this->textbox1 === false ) {
                        return false;
                }
                wfProxyCheck();
                return true;
        }

        /**
         * Fetch initial editing page content.
         *
         * @param $def_text string|bool
         * @return mixed string on success, $def_text for invalid sections
         * @private
         * @deprecated since 1.21, get WikiPage::getContent() instead.
         */
        function getContent( $def_text = false ) {
                ContentHandler::deprecated( __METHOD__, '1.21' );

                if ( $def_text !== null && $def_text !== false && $def_text !== '' ) {
                        $def_content = $this->toEditContent( $def_text );
                } else {
                        $def_content = false;
                }

                $content = $this->getContentObject( $def_content );

                // Note: EditPage should only be used with text based content anyway.
                return $this->toEditText( $content );
        }

        /**
         * @param Content|null $def_content The default value to return
         *
         * @return mixed Content on success, $def_content for invalid sections
         *
         * @since 1.21
         */
        protected function getContentObject( $def_content = null ) {
                global $wgOut, $wgRequest;

                wfProfileIn( __METHOD__ );

                $content = false;

                // For message page not locally set, use the i18n message.
                // For other non-existent articles, use preload text if any.
                if ( !$this->mTitle->exists() || $this->section == 'new' ) {
                        if ( $this->mTitle->getNamespace() == NS_MEDIAWIKI && $this->section != 'new' ) {
                                # If this is a system message, get the default text.
                                $msg = $this->mTitle->getDefaultMessageText();

                                $content = $this->toEditContent( $msg );
                        }
                        if ( $content === false ) {
                                # If requested, preload some text.
                                $preload = $wgRequest->getVal( 'preload',
                                        // Custom preload text for new sections
                                        $this->section === 'new' ? 'MediaWiki:addsection-preload' : '' );

                                $content = $this->getPreloadedContent( $preload );
                        }
                // For existing pages, get text based on "undo" or section parameters.
                } else {
                        if ( $this->section != '' ) {
                                // Get section edit text (returns $def_text for invalid sections)
                                $orig = $this->getOriginalContent();
                                $content = $orig ? $orig->getSection( $this->section ) : null;

                                if ( !$content ) {
                                        $content = $def_content;
                                }
                        } else {
                                $undoafter = $wgRequest->getInt( 'undoafter' );
                                $undo = $wgRequest->getInt( 'undo' );

                                if ( $undo > 0 && $undoafter > 0 ) {
                                        if ( $undo < $undoafter ) {
                                                # If they got undoafter and undo round the wrong way, switch them
                                                list( $undo, $undoafter ) = array( $undoafter, $undo );
                                        }

                                        $undorev = Revision::newFromId( $undo );
                                        $oldrev = Revision::newFromId( $undoafter );

                                        # Sanity check, make sure it's the right page,
                                        # the revisions exist and they were not deleted.
                                        # Otherwise, $content will be left as-is.
                                        if ( !is_null( $undorev ) && !is_null( $oldrev ) &&
                                                $undorev->getPage() == $oldrev->getPage() &&
                                                $undorev->getPage() == $this->mTitle->getArticleID() &&
                                                !$undorev->isDeleted( Revision::DELETED_TEXT ) &&
                                                !$oldrev->isDeleted( Revision::DELETED_TEXT ) ) {

                                                $content = $this->mArticle->getUndoContent( $undorev, $oldrev );

                                                if ( $content === false ) {
                                                        # Warn the user that something went wrong
                                                        $undoMsg = 'failure';
                                                } else {
                                                        # Inform the user of our success and set an automatic edit summary
                                                        $undoMsg = 'success';

                                                        # If we just undid one rev, use an autosummary
                                                        $firstrev = $oldrev->getNext();
                                                        if ( $firstrev && $firstrev->getId() == $undo ) {
                                                                $undoSummary = wfMessage( 'undo-summary', $undo, $undorev->getUserText() )->inContentLanguage()->text();
                                                                if ( $this->summary === '' ) {
                                                                        $this->summary = $undoSummary;
                                                                } else {
                                                                        $this->summary = $undoSummary . wfMessage( 'colon-separator' )
                                                                                ->inContentLanguage()->text() . $this->summary;
                                                                }
                                                                $this->undidRev = $undo;
                                                        }
                                                        $this->formtype = 'diff';
                                                }
                                        } else {
                                                // Failed basic sanity checks.
                                                // Older revisions may have been removed since the link
                                                // was created, or we may simply have got bogus input.
                                                $undoMsg = 'norev';
                                        }

                                        $class = ( $undoMsg == 'success' ? '' : 'error ' ) . "mw-undo-{$undoMsg}";
                                        $this->editFormPageTop .= $wgOut->parse( "<div class=\"{$class}\">" .
                                                wfMessage( 'undo-' . $undoMsg )->plain() . '</div>', true, /* interface */true );
                                }

                                if ( $content === false ) {
                                        $content = $this->getOriginalContent();
                                }
                        }
                }

                wfProfileOut( __METHOD__ );
                return $content;
        }

        /**
         * Get the content of the wanted revision, without section extraction.
         *
         * The result of this function can be used to compare user's input with
         * section replaced in its context (using WikiPage::replaceSection())
         * to the original text of the edit.
         *
         * This differs from Article::getContent() that when a missing revision is
         * encountered the result will be null and not the
         * 'missing-revision' message.
         *
         * @since 1.19
         * @return Content|null
         */
        private function getOriginalContent() {
                if ( $this->section == 'new' ) {
                        return $this->getCurrentContent();
                }
                $revision = $this->mArticle->getRevisionFetched();
                if ( $revision === null ) {
                        if ( !$this->contentModel ) {
                                $this->contentModel = $this->getTitle()->getContentModel();
                        }
                        $handler = ContentHandler::getForModelID( $this->contentModel );

                        return $handler->makeEmptyContent();
                }
                $content = $revision->getContent();
                return $content;
        }

        /**
         * Get the current content of the page. This is basically similar to
         * WikiPage::getContent( Revision::RAW ) except that when the page doesn't exist an empty
         * content object is returned instead of null.
         *
         * @since 1.21
         * @return Content
         */
        protected function getCurrentContent() {
                $rev = $this->mArticle->getRevision();
                $content = $rev ? $rev->getContent( Revision::RAW ) : null;

                if ( $content === false || $content === null ) {
                        if ( !$this->contentModel ) {
                                $this->contentModel = $this->getTitle()->getContentModel();
                        }
                        $handler = ContentHandler::getForModelID( $this->contentModel );

                        return $handler->makeEmptyContent();
                } else {
                        # nasty side-effect, but needed for consistency
                        $this->contentModel = $rev->getContentModel();
                        $this->contentFormat = $rev->getContentFormat();

                        return $content;
                }
        }

        /**
         * Use this method before edit() to preload some text into the edit box
         *
         * @param $text string
         * @deprecated since 1.21, use setPreloadedContent() instead.
         */
        public function setPreloadedText( $text ) {
                ContentHandler::deprecated( __METHOD__, "1.21" );

                $content = $this->toEditContent( $text );

                $this->setPreloadedContent( $content );
        }

        /**
         * Use this method before edit() to preload some content into the edit box
         *
         * @param $content Content
         *
         * @since 1.21
         */
        public function setPreloadedContent( Content $content ) {
                $this->mPreloadContent = $content;
        }

        /**
         * Get the contents to be preloaded into the box, either set by
         * an earlier setPreloadText() or by loading the given page.
         *
         * @param string $preload representing the title to preload from.
         *
         * @return String
         *
         * @deprecated since 1.21, use getPreloadedContent() instead
         */
        protected function getPreloadedText( $preload ) {
                ContentHandler::deprecated( __METHOD__, "1.21" );

                $content = $this->getPreloadedContent( $preload );
                $text = $this->toEditText( $content );

                return $text;
        }

        /**
         * Get the contents to be preloaded into the box, either set by
         * an earlier setPreloadText() or by loading the given page.
         *
         * @param string $preload representing the title to preload from.
         *
         * @return Content
         *
         * @since 1.21
         */
        protected function getPreloadedContent( $preload ) {
                global $wgUser;

                if ( !empty( $this->mPreloadContent ) ) {
                        return $this->mPreloadContent;
                }

                $handler = ContentHandler::getForTitle( $this->getTitle() );

                if ( $preload === '' ) {
                        return $handler->makeEmptyContent();
                }

                $title = Title::newFromText( $preload );
                # Check for existence to avoid getting MediaWiki:Noarticletext
                if ( $title === null || !$title->exists() || !$title->userCan( 'read', $wgUser ) ) {
                        //TODO: somehow show a warning to the user!
                        return $handler->makeEmptyContent();
                }

                $page = WikiPage::factory( $title );
                if ( $page->isRedirect() ) {
                        $title = $page->getRedirectTarget();
                        # Same as before
                        if ( $title === null || !$title->exists() || !$title->userCan( 'read', $wgUser ) ) {
                                //TODO: somehow show a warning to the user!
                                return $handler->makeEmptyContent();
                        }
                        $page = WikiPage::factory( $title );
                }

                $parserOptions = ParserOptions::newFromUser( $wgUser );
                $content = $page->getContent( Revision::RAW );

                if ( !$content ) {
                        //TODO: somehow show a warning to the user!
                        return $handler->makeEmptyContent();
                }

                if ( $content->getModel() !== $handler->getModelID() ) {
                        $converted = $content->convert( $handler->getModelID() );

                        if ( !$converted ) {
                                //TODO: somehow show a warning to the user!
                                wfDebug( "Attempt to preload incompatible content: "
                                                . "can't convert " . $content->getModel()
                                                . " to " . $handler->getModelID() );

                                return $handler->makeEmptyContent();
                        }

                        $content = $converted;
                }

                return $content->preloadTransform( $title, $parserOptions );
        }

        /**
         * Make sure the form isn't faking a user's credentials.
         *
         * @param $request WebRequest
         * @return bool
         * @private
         */
        function tokenOk( &$request ) {
                global $wgUser;
                $token = $request->getVal( 'wpEditToken' );
                $this->mTokenOk = $wgUser->matchEditToken( $token );
                $this->mTokenOkExceptSuffix = $wgUser->matchEditTokenNoSuffix( $token );
                return $this->mTokenOk;
        }

        /**
         * Sets post-edit cookie indicating the user just saved a particular revision.
         *
         * This uses a temporary cookie for each revision ID so separate saves will never
         * interfere with each other.
         *
         * The cookie is deleted in the mediawiki.action.view.postEdit JS module after
         * the redirect.  It must be clearable by JavaScript code, so it must not be
         * marked HttpOnly. The JavaScript code converts the cookie to a wgPostEdit config
         * variable.
         *
         * Since WebResponse::setcookie does not allow forcing HttpOnly for a single
         * cookie, we have to use PHP's setcookie() directly.
         *
         * We use a path of '/' since wgCookiePath is not exposed to JS
         *
         * If the variable were set on the server, it would be cached, which is unwanted
         * since the post-edit state should only apply to the load right after the save.
         */
        protected function setPostEditCookie() {
                global $wgCookiePrefix, $wgCookieDomain;
                $revisionId = $this->mArticle->getLatest();
                $postEditKey = self::POST_EDIT_COOKIE_KEY_PREFIX . $revisionId;

                setcookie( $wgCookiePrefix . $postEditKey, '1', time() + self::POST_EDIT_COOKIE_DURATION, '/', $wgCookieDomain );
        }

        /**
         * Attempt submission
         * @throws UserBlockedError|ReadOnlyError|ThrottledError|PermissionsError
         * @return bool false if output is done, true if the rest of the form should be displayed
         */
        function attemptSave() {
                global $wgUser, $wgOut;

                $resultDetails = false;
                # Allow bots to exempt some edits from bot flagging
                $bot = $wgUser->isAllowed( 'bot' ) && $this->bot;
                $status = $this->internalAttemptSave( $resultDetails, $bot );
                // FIXME: once the interface for internalAttemptSave() is made nicer, this should use the message in $status
                if ( $status->value == self::AS_SUCCESS_UPDATE || $status->value == self::AS_SUCCESS_NEW_ARTICLE ) {
                        $this->didSave = true;
                        if ( !$resultDetails['nullEdit'] ) {
                                $this->setPostEditCookie();
                        }
                }

                switch ( $status->value ) {
                        case self::AS_HOOK_ERROR_EXPECTED:
                        case self::AS_CONTENT_TOO_BIG:
                        case self::AS_ARTICLE_WAS_DELETED:
                        case self::AS_CONFLICT_DETECTED:
                        case self::AS_SUMMARY_NEEDED:
                        case self::AS_TEXTBOX_EMPTY:
                        case self::AS_MAX_ARTICLE_SIZE_EXCEEDED:
                        case self::AS_END:
                                return true;

                        case self::AS_HOOK_ERROR:
                                return false;

                        case self::AS_PARSE_ERROR:
                                $wgOut->addWikiText( '<div class="error">' . $status->getWikiText() . '</div>' );
                                return true;

                        case self::AS_SUCCESS_NEW_ARTICLE:
                                $query = $resultDetails['redirect'] ? 'redirect=no' : '';
                                $anchor = isset( $resultDetails['sectionanchor'] ) ? $resultDetails['sectionanchor'] : '';
                                $wgOut->redirect( $this->mTitle->getFullURL( $query ) . $anchor );
                                return false;

                        case self::AS_SUCCESS_UPDATE:
                                $extraQuery = '';
                                $sectionanchor = $resultDetails['sectionanchor'];

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

                                if ( $resultDetails['redirect'] ) {
                                        if ( $extraQuery == '' ) {
                                                $extraQuery = 'redirect=no';
                                        } else {
                                                $extraQuery = 'redirect=no&' . $extraQuery;
                                        }
                                }
                                $wgOut->redirect( $this->mTitle->getFullURL( $extraQuery ) . $sectionanchor );
                                return false;

                        case self::AS_BLANK_ARTICLE:
                                $wgOut->redirect( $this->getContextTitle()->getFullURL() );
                                return false;

                        case self::AS_SPAM_ERROR:
                                $this->spamPageWithContent( $resultDetails['spam'] );
                                return false;

                        case self::AS_BLOCKED_PAGE_FOR_USER:
                                throw new UserBlockedError( $wgUser->getBlock() );

                        case self::AS_IMAGE_REDIRECT_ANON:
                        case self::AS_IMAGE_REDIRECT_LOGGED:
                                throw new PermissionsError( 'upload' );

                        case self::AS_READ_ONLY_PAGE_ANON:
                        case self::AS_READ_ONLY_PAGE_LOGGED:
                                throw new PermissionsError( 'edit' );

                        case self::AS_READ_ONLY_PAGE:
                                throw new ReadOnlyError;

                        case self::AS_RATE_LIMITED:
                                throw new ThrottledError();

                        case self::AS_NO_CREATE_PERMISSION:
                                $permission = $this->mTitle->isTalkPage() ? 'createtalk' : 'createpage';
                                throw new PermissionsError( $permission );

                        default:
                                // We don't recognize $status->value. The only way that can happen
                                // is if an extension hook aborted from inside ArticleSave.
                                // Render the status object into $this->hookError
                                // FIXME this sucks, we should just use the Status object throughout
                                $this->hookError = '<div class="error">' . $status->getWikitext() .
                                        '</div>';
                                return true;
                }
        }

        /**
         * Run hooks that can filter edits just before they get saved.
         *
         * @param Content $content the Content to filter.
         * @param Status  $status for reporting the outcome to the caller
         * @param User    $user the user performing the edit
         *
         * @return bool
         */
        protected function runPostMergeFilters( Content $content, Status $status, User $user ) {
                // Run old style post-section-merge edit filter
                if ( !ContentHandler::runLegacyHooks( 'EditFilterMerged',
                        array( $this, $content, &$this->hookError, $this->summary ) ) ) {

                        # Error messages etc. could be handled within the hook...
                        $status->fatal( 'hookaborted' );
                        $status->value = self::AS_HOOK_ERROR;
                        return false;
                } elseif ( $this->hookError != '' ) {
                        # ...or the hook could be expecting us to produce an error
                        $status->fatal( 'hookaborted' );
                        $status->value = self::AS_HOOK_ERROR_EXPECTED;
                        return false;
                }

                // Run new style post-section-merge edit filter
                if ( !wfRunHooks( 'EditFilterMergedContent',
                        array( $this->mArticle->getContext(), $content, $status, $this->summary,
                                $user, $this->minoredit ) ) ) {

                        # Error messages etc. could be handled within the hook...
                        // XXX: $status->value may already be something informative...
                        $this->hookError = $status->getWikiText();
                        $status->fatal( 'hookaborted' );
                        $status->value = self::AS_HOOK_ERROR;
                        return false;
                } elseif ( !$status->isOK() ) {
                        # ...or the hook could be expecting us to produce an error
                        // FIXME this sucks, we should just use the Status object throughout
                        $this->hookError = $status->getWikiText();
                        $status->fatal( 'hookaborted' );
                        $status->value = self::AS_HOOK_ERROR_EXPECTED;
                        return false;
                }

                return true;
        }

        /**
         * Attempt submission (no UI)
         *
         * @param array $result array to add statuses to, currently with the possible keys:
         *  spam - string - Spam string from content if any spam is detected by matchSpamRegex
         *  sectionanchor - string - Section anchor for a section save
         *  nullEdit - boolean - Set if doEditContent is OK.  True if null edit, false otherwise.
         *  redirect - boolean -  Set if doEditContent is OK.  True if resulting revision is a redirect
         * @param bool $bot True if edit is being made under the bot right.
         *
         * @return Status object, possibly with a message, but always with one of the AS_* constants in $status->value,
         *
         * FIXME: This interface is TERRIBLE, but hard to get rid of due to various error display idiosyncrasies. There are
         * also lots of cases where error metadata is set in the object and retrieved later instead of being returned, e.g.
         * AS_CONTENT_TOO_BIG and AS_BLOCKED_PAGE_FOR_USER. All that stuff needs to be cleaned up some time.
         */
        function internalAttemptSave( &$result, $bot = false ) {
                global $wgUser, $wgRequest, $wgParser, $wgMaxArticleSize;

                $status = Status::newGood();

                wfProfileIn( __METHOD__ );
                wfProfileIn( __METHOD__ . '-checks' );

                if ( !wfRunHooks( 'EditPage::attemptSave', array( $this ) ) ) {
                        wfDebug( "Hook 'EditPage::attemptSave' aborted article saving\n" );
                        $status->fatal( 'hookaborted' );
                        $status->value = self::AS_HOOK_ERROR;
                        wfProfileOut( __METHOD__ . '-checks' );
                        wfProfileOut( __METHOD__ );
                        return $status;
                }

                try {
                        # Construct Content object
                        $textbox_content = $this->toEditContent( $this->textbox1 );
                } catch ( MWContentSerializationException $ex ) {
                        $status->fatal( 'content-failed-to-parse', $this->contentModel, $this->contentFormat, $ex->getMessage() );
                        $status->value = self::AS_PARSE_ERROR;
                        wfProfileOut( __METHOD__ . '-checks' );
                        wfProfileOut( __METHOD__ );
                        return $status;
                }

                # Check image redirect
                if ( $this->mTitle->getNamespace() == NS_FILE &&
                        $textbox_content->isRedirect() &&
                        !$wgUser->isAllowed( 'upload' ) ) {
                                $code = $wgUser->isAnon() ? self::AS_IMAGE_REDIRECT_ANON : self::AS_IMAGE_REDIRECT_LOGGED;
                                $status->setResult( false, $code );

                                wfProfileOut( __METHOD__ . '-checks' );
                                wfProfileOut( __METHOD__ );

                                return $status;
                }

                # Check for spam
                $match = self::matchSummarySpamRegex( $this->summary );
                if ( $match === false ) {
                        $match = self::matchSpamRegex( $this->textbox1 );
                }
                if ( $match !== false ) {
                        $result['spam'] = $match;
                        $ip = $wgRequest->getIP();
                        $pdbk = $this->mTitle->getPrefixedDBkey();
                        $match = str_replace( "\n", '', $match );
                        wfDebugLog( 'SpamRegex', "$ip spam regex hit [[$pdbk]]: \"$match\"" );
                        $status->fatal( 'spamprotectionmatch', $match );
                        $status->value = self::AS_SPAM_ERROR;
                        wfProfileOut( __METHOD__ . '-checks' );
                        wfProfileOut( __METHOD__ );
                        return $status;
                }
                if ( !wfRunHooks( 'EditFilter', array( $this, $this->textbox1, $this->section, &$this->hookError, $this->summary ) ) ) {
                        # Error messages etc. could be handled within the hook...
                        $status->fatal( 'hookaborted' );
                        $status->value = self::AS_HOOK_ERROR;
                        wfProfileOut( __METHOD__ . '-checks' );
                        wfProfileOut( __METHOD__ );
                        return $status;
                } elseif ( $this->hookError != '' ) {
                        # ...or the hook could be expecting us to produce an error
                        $status->fatal( 'hookaborted' );
                        $status->value = self::AS_HOOK_ERROR_EXPECTED;
                        wfProfileOut( __METHOD__ . '-checks' );
                        wfProfileOut( __METHOD__ );
                        return $status;
                }

                if ( $wgUser->isBlockedFrom( $this->mTitle, false ) ) {
                        // Auto-block user's IP if the account was "hard" blocked
                        $wgUser->spreadAnyEditBlock();
                        # Check block state against master, thus 'false'.
                        $status->setResult( false, self::AS_BLOCKED_PAGE_FOR_USER );
                        wfProfileOut( __METHOD__ . '-checks' );
                        wfProfileOut( __METHOD__ );
                        return $status;
                }

                $this->kblength = (int)( strlen( $this->textbox1 ) / 1024 );
                if ( $this->kblength > $wgMaxArticleSize ) {
                        // Error will be displayed by showEditForm()
                        $this->tooBig = true;
                        $status->setResult( false, self::AS_CONTENT_TOO_BIG );
                        wfProfileOut( __METHOD__ . '-checks' );
                        wfProfileOut( __METHOD__ );
                        return $status;
                }

                if ( !$wgUser->isAllowed( 'edit' ) ) {
                        if ( $wgUser->isAnon() ) {
                                $status->setResult( false, self::AS_READ_ONLY_PAGE_ANON );
                                wfProfileOut( __METHOD__ . '-checks' );
                                wfProfileOut( __METHOD__ );
                                return $status;
                        } else {
                                $status->fatal( 'readonlytext' );
                                $status->value = self::AS_READ_ONLY_PAGE_LOGGED;
                                wfProfileOut( __METHOD__ . '-checks' );
                                wfProfileOut( __METHOD__ );
                                return $status;
                        }
                }

                if ( wfReadOnly() ) {
                        $status->fatal( 'readonlytext' );
                        $status->value = self::AS_READ_ONLY_PAGE;
                        wfProfileOut( __METHOD__ . '-checks' );
                        wfProfileOut( __METHOD__ );
                        return $status;
                }
                if ( $wgUser->pingLimiter() ) {
                        $status->fatal( 'actionthrottledtext' );
                        $status->value = self::AS_RATE_LIMITED;
                        wfProfileOut( __METHOD__ . '-checks' );
                        wfProfileOut( __METHOD__ );
                        return $status;
                }

                # If the article has been deleted while editing, don't save it without
                # confirmation
                if ( $this->wasDeletedSinceLastEdit() && !$this->recreate ) {
                        $status->setResult( false, self::AS_ARTICLE_WAS_DELETED );
                        wfProfileOut( __METHOD__ . '-checks' );
                        wfProfileOut( __METHOD__ );
                        return $status;
                }

                wfProfileOut( __METHOD__ . '-checks' );

                # Load the page data from the master. If anything changes in the meantime,
                # we detect it by using page_latest like a token in a 1 try compare-and-swap.
                $this->mArticle->loadPageData( 'fromdbmaster' );
                $new = !$this->mArticle->exists();

                if ( $new ) {
                        // Late check for create permission, just in case *PARANOIA*
                        if ( !$this->mTitle->userCan( 'create', $wgUser ) ) {
                                $status->fatal( 'nocreatetext' );
                                $status->value = self::AS_NO_CREATE_PERMISSION;
                                wfDebug( __METHOD__ . ": no create permission\n" );
                                wfProfileOut( __METHOD__ );
                                return $status;
                        }

                        # Don't save a new article if it's blank.
                        if ( $this->textbox1 == '' ) {
                                $status->setResult( false, self::AS_BLANK_ARTICLE );
                                wfProfileOut( __METHOD__ );
                                return $status;
                        }

                        if ( !$this->runPostMergeFilters( $textbox_content, $status, $wgUser ) ) {
                                wfProfileOut( __METHOD__ );
                                return $status;
                        }

                        $content = $textbox_content;

                        $result['sectionanchor'] = '';
                        if ( $this->section == 'new' ) {
                                if ( $this->sectiontitle !== '' ) {
                                        // Insert the section title above the content.
                                        $content = $content->addSectionHeader( $this->sectiontitle );

                                        // Jump to the new section
                                        $result['sectionanchor'] = $wgParser->guessLegacySectionNameFromWikiText( $this->sectiontitle );

                                        // If no edit summary was specified, create one automatically from the section
                                        // title and have it link to the new section. Otherwise, respect the summary as
                                        // passed.
                                        if ( $this->summary === '' ) {
                                                $cleanSectionTitle = $wgParser->stripSectionName( $this->sectiontitle );
                                                $this->summary = wfMessage( 'newsectionsummary' )
                                                        ->rawParams( $cleanSectionTitle )->inContentLanguage()->text();
                                        }
                                } elseif ( $this->summary !== '' ) {
                                        // Insert the section title above the content.
                                        $content = $content->addSectionHeader( $this->summary );

                                        // Jump to the new section
                                        $result['sectionanchor'] = $wgParser->guessLegacySectionNameFromWikiText( $this->summary );

                                        // Create a link to the new section from the edit summary.
                                        $cleanSummary = $wgParser->stripSectionName( $this->summary );
                                        $this->summary = wfMessage( 'newsectionsummary' )
                                                ->rawParams( $cleanSummary )->inContentLanguage()->text();
                                }
                        }

                        $status->value = self::AS_SUCCESS_NEW_ARTICLE;

                } else { # not $new

                        # Article exists. Check for edit conflict.

                        $this->mArticle->clear(); # Force reload of dates, etc.
                        $timestamp = $this->mArticle->getTimestamp();

                        wfDebug( "timestamp: {$timestamp}, edittime: {$this->edittime}\n" );

                        if ( $timestamp != $this->edittime ) {
                                $this->isConflict = true;
                                if ( $this->section == 'new' ) {
                                        if ( $this->mArticle->getUserText() == $wgUser->getName() &&
                                                $this->mArticle->getComment() == $this->summary ) {
                                                // Probably a duplicate submission of a new comment.
                                                // This can happen when squid resends a request after
                                                // a timeout but the first one actually went through.
                                                wfDebug( __METHOD__ . ": duplicate new section submission; trigger edit conflict!\n" );
                                        } else {
                                                // New comment; suppress conflict.
                                                $this->isConflict = false;
                                                wfDebug( __METHOD__ . ": conflict suppressed; new section\n" );
                                        }
                                } elseif ( $this->section == '' && Revision::userWasLastToEdit( DB_MASTER, $this->mTitle->getArticleID(),
                                                        $wgUser->getId(), $this->edittime ) ) {
                                        # Suppress edit conflict with self, except for section edits where merging is required.
                                        wfDebug( __METHOD__ . ": Suppressing edit conflict, same user.\n" );
                                        $this->isConflict = false;
                                }
                        }

                        // If sectiontitle is set, use it, otherwise use the summary as the section title (for
                        // backwards compatibility with old forms/bots).
                        if ( $this->sectiontitle !== '' ) {
                                $sectionTitle = $this->sectiontitle;
                        } else {
                                $sectionTitle = $this->summary;
                        }

                        $content = null;

                        if ( $this->isConflict ) {
                                wfDebug( __METHOD__ . ": conflict! getting section '{$this->section}' for time '{$this->edittime}'"
                                                . " (article time '{$timestamp}')\n" );

                                $content = $this->mArticle->replaceSectionContent( $this->section, $textbox_content, $sectionTitle, $this->edittime );
                        } else {
                                wfDebug( __METHOD__ . ": getting section '{$this->section}'\n" );
                                $content = $this->mArticle->replaceSectionContent( $this->section, $textbox_content, $sectionTitle );
                        }

                        if ( is_null( $content ) ) {
                                wfDebug( __METHOD__ . ": activating conflict; section replace failed.\n" );
                                $this->isConflict = true;
                                $content = $textbox_content; // do not try to merge here!
                        } elseif ( $this->isConflict ) {
                                # Attempt merge
                                if ( $this->mergeChangesIntoContent( $content ) ) {
                                        // Successful merge! Maybe we should tell the user the good news?
                                        $this->isConflict = false;
                                        wfDebug( __METHOD__ . ": Suppressing edit conflict, successful merge.\n" );
                                } else {
                                        $this->section = '';
                                        $this->textbox1 = ContentHandler::getContentText( $content );
                                        wfDebug( __METHOD__ . ": Keeping edit conflict, failed merge.\n" );
                                }
                        }

                        if ( $this->isConflict ) {
                                $status->setResult( false, self::AS_CONFLICT_DETECTED );
                                wfProfileOut( __METHOD__ );
                                return $status;
                        }

                        if ( !$this->runPostMergeFilters( $content, $status, $wgUser ) ) {
                                wfProfileOut( __METHOD__ );
                                return $status;
                        }

                        if ( $this->section == 'new' ) {
                                // Handle the user preference to force summaries here
                                if ( !$this->allowBlankSummary && trim( $this->summary ) == '' ) {
                                        $this->missingSummary = true;
                                        $status->fatal( 'missingsummary' ); // or 'missingcommentheader' if $section == 'new'. Blegh
                                        $status->value = self::AS_SUMMARY_NEEDED;
                                        wfProfileOut( __METHOD__ );
                                        return $status;
                                }

                                // Do not allow the user to post an empty comment
                                if ( $this->textbox1 == '' ) {
                                        $this->missingComment = true;
                                        $status->fatal( 'missingcommenttext' );
                                        $status->value = self::AS_TEXTBOX_EMPTY;
                                        wfProfileOut( __METHOD__ );
                                        return $status;
                                }
                        } elseif ( !$this->allowBlankSummary
                                && !$content->equals( $this->getOriginalContent() )
                                && !$content->isRedirect()
                                && md5( $this->summary ) == $this->autoSumm
                        ) {
                                $this->missingSummary = true;
                                $status->fatal( 'missingsummary' );
                                $status->value = self::AS_SUMMARY_NEEDED;
                                wfProfileOut( __METHOD__ );
                                return $status;
                        }

                        # All's well
                        wfProfileIn( __METHOD__ . '-sectionanchor' );
                        $sectionanchor = '';
                        if ( $this->section == 'new' ) {
                                if ( $this->sectiontitle !== '' ) {
                                        $sectionanchor = $wgParser->guessLegacySectionNameFromWikiText( $this->sectiontitle );
                                        // If no edit summary was specified, create one automatically from the section
                                        // title and have it link to the new section. Otherwise, respect the summary as
                                        // passed.
                                        if ( $this->summary === '' ) {
                                                $cleanSectionTitle = $wgParser->stripSectionName( $this->sectiontitle );
                                                $this->summary = wfMessage( 'newsectionsummary' )
                                                        ->rawParams( $cleanSectionTitle )->inContentLanguage()->text();
                                        }
                                } elseif ( $this->summary !== '' ) {
                                        $sectionanchor = $wgParser->guessLegacySectionNameFromWikiText( $this->summary );
                                        # This is a new section, so create a link to the new section
                                        # in the revision summary.
                                        $cleanSummary = $wgParser->stripSectionName( $this->summary );
                                        $this->summary = wfMessage( 'newsectionsummary' )
                                                ->rawParams( $cleanSummary )->inContentLanguage()->text();
                                }
                        } elseif ( $this->section != '' ) {
                                # Try to get a section anchor from the section source, redirect to edited section if header found
                                # XXX: might be better to integrate this into Article::replaceSection
                                # for duplicate heading checking and maybe parsing
                                $hasmatch = preg_match( "/^ *([=]{1,6})(.*?)(\\1) *\\n/i", $this->textbox1, $matches );
                                # we can't deal with anchors, includes, html etc in the header for now,
                                # headline would need to be parsed to improve this
                                if ( $hasmatch && strlen( $matches[2] ) > 0 ) {
                                        $sectionanchor = $wgParser->guessLegacySectionNameFromWikiText( $matches[2] );
                                }
                        }
                        $result['sectionanchor'] = $sectionanchor;
                        wfProfileOut( __METHOD__ . '-sectionanchor' );

                        // Save errors may fall down to the edit form, but we've now
                        // merged the section into full text. Clear the section field
                        // so that later submission of conflict forms won't try to
                        // replace that into a duplicated mess.
                        $this->textbox1 = $this->toEditText( $content );
                        $this->section = '';

                        $status->value = self::AS_SUCCESS_UPDATE;
                }

                // Check for length errors again now that the section is merged in
                        $this->kblength = (int)( strlen( $this->toEditText( $content ) ) / 1024 );
                if ( $this->kblength > $wgMaxArticleSize ) {
                        $this->tooBig = true;
                        $status->setResult( false, self::AS_MAX_ARTICLE_SIZE_EXCEEDED );
                        wfProfileOut( __METHOD__ );
                        return $status;
                }

                $flags = EDIT_DEFER_UPDATES | EDIT_AUTOSUMMARY |
                        ( $new ? EDIT_NEW : EDIT_UPDATE ) |
                        ( ( $this->minoredit && !$this->isNew ) ? EDIT_MINOR : 0 ) |
                        ( $bot ? EDIT_FORCE_BOT : 0 );

                        $doEditStatus = $this->mArticle->doEditContent( $content, $this->summary, $flags,
                                                                                                                        false, null, $this->contentFormat );

                if ( !$doEditStatus->isOK() ) {
                        // Failure from doEdit()
                        // Show the edit conflict page for certain recognized errors from doEdit(),
                        // but don't show it for errors from extension hooks
                        $errors = $doEditStatus->getErrorsArray();
                        if ( in_array( $errors[0][0], array( 'edit-gone-missing', 'edit-conflict',
                                'edit-already-exists' ) ) )
                        {
                                $this->isConflict = true;
                                // Destroys data doEdit() put in $status->value but who cares
                                $doEditStatus->value = self::AS_END;
                        }
                        wfProfileOut( __METHOD__ );
                        return $doEditStatus;
                }

                $result['nullEdit'] = $doEditStatus->hasMessage( 'edit-no-change' );
                $result['redirect'] = $content->isRedirect();
                $this->updateWatchlist();
                wfProfileOut( __METHOD__ );
                return $status;
        }

        /**
         * Register the change of watch status
         */
        protected function updateWatchlist() {
                global $wgUser;

                if ( $wgUser->isLoggedIn() && $this->watchthis != $wgUser->isWatched( $this->mTitle ) ) {
                        $fname = __METHOD__;
                        $title = $this->mTitle;
                        $watch = $this->watchthis;

                        // Do this in its own transaction to reduce contention...
                        $dbw = wfGetDB( DB_MASTER );
                        $dbw->onTransactionIdle( function() use ( $dbw, $title, $watch, $wgUser, $fname ) {
                                $dbw->begin( $fname );
                                if ( $watch ) {
                                        WatchAction::doWatch( $title, $wgUser );
                                } else {
                                        WatchAction::doUnwatch( $title, $wgUser );
                                }
                                $dbw->commit( $fname );
                        } );
                }
        }

        /**
         * Attempts to merge text content with base and current revisions
         *
         * @param $editText string
         *
         * @return bool
         * @deprecated since 1.21, use mergeChangesIntoContent() instead
         */
        function mergeChangesInto( &$editText ) {
                ContentHandler::deprecated( __METHOD__, "1.21" );

                $editContent = $this->toEditContent( $editText );

                $ok = $this->mergeChangesIntoContent( $editContent );

                if ( $ok ) {
                        $editText = $this->toEditText( $editContent );
                        return true;
                }
                return false;
        }

        /**
         * Attempts to do 3-way merge of edit content with a base revision
         * and current content, in case of edit conflict, in whichever way appropriate
         * for the content type.
         *
         * @since 1.21
         *
         * @param $editContent
         *
         * @return bool
         */
        private function mergeChangesIntoContent( &$editContent ) {
                wfProfileIn( __METHOD__ );

                $db = wfGetDB( DB_MASTER );

                // This is the revision the editor started from
                $baseRevision = $this->getBaseRevision();
                $baseContent = $baseRevision ? $baseRevision->getContent() : null;

                if ( is_null( $baseContent ) ) {
                        wfProfileOut( __METHOD__ );
                        return false;
                }

                // The current state, we want to merge updates into it
                $currentRevision = Revision::loadFromTitle( $db, $this->mTitle );
                $currentContent = $currentRevision ? $currentRevision->getContent() : null;

                if ( is_null( $currentContent ) ) {
                        wfProfileOut( __METHOD__ );
                        return false;
                }

                $handler = ContentHandler::getForModelID( $baseContent->getModel() );

                $result = $handler->merge3( $baseContent, $editContent, $currentContent );

                if ( $result ) {
                        $editContent = $result;
                        wfProfileOut( __METHOD__ );
                        return true;
                }

                wfProfileOut( __METHOD__ );
                return false;
        }

        /**
         * @return Revision
         */
        function getBaseRevision() {
                if ( !$this->mBaseRevision ) {
                        $db = wfGetDB( DB_MASTER );
                        $baseRevision = Revision::loadFromTimestamp(
                                $db, $this->mTitle, $this->edittime );
                        return $this->mBaseRevision = $baseRevision;
                } else {
                        return $this->mBaseRevision;
                }
        }

        /**
         * Check given input text against $wgSpamRegex, and return the text of the first match.
         *
         * @param $text string
         *
         * @return string|bool matching string or false
         */
        public static function matchSpamRegex( $text ) {
                global $wgSpamRegex;
                // For back compatibility, $wgSpamRegex may be a single string or an array of regexes.
                $regexes = (array)$wgSpamRegex;
                return self::matchSpamRegexInternal( $text, $regexes );
        }

        /**
         * Check given input text against $wgSpamRegex, and return the text of the first match.
         *
         * @param $text string
         *
         * @return string|bool  matching string or false
         */
        public static function matchSummarySpamRegex( $text ) {
                global $wgSummarySpamRegex;
                $regexes = (array)$wgSummarySpamRegex;
                return self::matchSpamRegexInternal( $text, $regexes );
        }

        /**
         * @param $text string
         * @param $regexes array
         * @return bool|string
         */
        protected static function matchSpamRegexInternal( $text, $regexes ) {
                foreach ( $regexes as $regex ) {
                        $matches = array();
                        if ( preg_match( $regex, $text, $matches ) ) {
                                return $matches[0];
                        }
                }
                return false;
        }

        function setHeaders() {
                global $wgOut, $wgUser;

                $wgOut->addModules( 'mediawiki.action.edit' );

                if ( $wgUser->getOption( 'uselivepreview', false ) ) {
                        $wgOut->addModules( 'mediawiki.action.edit.preview' );
                }

                if ( $wgUser->getOption( 'useeditwarning', false ) ) {
                        $wgOut->addModules( 'mediawiki.action.edit.editWarning' );
                }

                // Bug #19334: textarea jumps when editing articles in IE8
                $wgOut->addStyle( 'common/IE80Fixes.css', 'screen', 'IE 8' );

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

                # Enabled article-related sidebar, toplinks, etc.
                $wgOut->setArticleRelated( true );

                $contextTitle = $this->getContextTitle();
                if ( $this->isConflict ) {
                        $msg = 'editconflict';
                } elseif ( $contextTitle->exists() && $this->section != '' ) {
                        $msg = $this->section == 'new' ? 'editingcomment' : 'editingsection';
                } else {
                        $msg = $contextTitle->exists() || ( $contextTitle->getNamespace() == NS_MEDIAWIKI && $contextTitle->getDefaultMessageText() !== false ) ?
                                'editing' : 'creating';
                }
                # Use the title defined by DISPLAYTITLE magic word when present
                $displayTitle = isset( $this->mParserOutput ) ? $this->mParserOutput->getDisplayTitle() : false;
                if ( $displayTitle === false ) {
                        $displayTitle = $contextTitle->getPrefixedText();
                }
                $wgOut->setPageTitle( wfMessage( $msg, $displayTitle ) );
        }

        /**
         * Show all applicable editing introductions
         */
        protected function showIntro() {
                global $wgOut, $wgUser;
                if ( $this->suppressIntro ) {
                        return;
                }

                $namespace = $this->mTitle->getNamespace();

                if ( $namespace == NS_MEDIAWIKI ) {
                        # Show a warning if editing an interface message
                        $wgOut->wrapWikiMsg( "<div class='mw-editinginterface'>\n$1\n</div>", 'editinginterface' );
                } elseif ( $namespace == NS_FILE ) {
                        # Show a hint to shared repo
                        $file = wfFindFile( $this->mTitle );
                        if ( $file && !$file->isLocal() ) {
                                $descUrl = $file->getDescriptionUrl();
                                # there must be a description url to show a hint to shared repo
                                if ( $descUrl ) {
                                        if ( !$this->mTitle->exists() ) {
                                                $wgOut->wrapWikiMsg( "<div class=\"mw-sharedupload-desc-create\">\n$1\n</div>", array(
                                                                        'sharedupload-desc-create', $file->getRepo()->getDisplayName(), $descUrl
                                                ) );
                                        } else {
                                                $wgOut->wrapWikiMsg( "<div class=\"mw-sharedupload-desc-edit\">\n$1\n</div>", array(
                                                                        'sharedupload-desc-edit', $file->getRepo()->getDisplayName(), $descUrl
                                                ) );
                                        }
                                }
                        }
                }

                # Show a warning message when someone creates/edits a user (talk) page but the user does not exist
                # Show log extract when the user is currently blocked
                if ( $namespace == NS_USER || $namespace == NS_USER_TALK ) {
                        $parts = explode( '/', $this->mTitle->getText(), 2 );
                        $username = $parts[0];
                        $user = User::newFromName( $username, false /* allow IP users*/ );
                        $ip = User::isIP( $username );
                        if ( !( $user && $user->isLoggedIn() ) && !$ip ) { # User does not exist
                                $wgOut->wrapWikiMsg( "<div class=\"mw-userpage-userdoesnotexist error\">\n$1\n</div>",
                                        array( 'userpage-userdoesnotexist', wfEscapeWikiText( $username ) ) );
                        } elseif ( $user->isBlocked() ) { # Show log extract if the user is currently blocked
                                LogEventsList::showLogExtract(
                                        $wgOut,
                                        'block',
                                        $user->getUserPage(),
                                        '',
                                        array(
                                                'lim' => 1,
                                                'showIfEmpty' => false,
                                                'msgKey' => array(
                                                        'blocked-notice-logextract',
                                                        $user->getName() # Support GENDER in notice
                                                )
                                        )
                                );
                        }
                }
                # Try to add a custom edit intro, or use the standard one if this is not possible.
                if ( !$this->showCustomIntro() && !$this->mTitle->exists() ) {
                        if ( $wgUser->isLoggedIn() ) {
                                $wgOut->wrapWikiMsg( "<div class=\"mw-newarticletext\">\n$1\n</div>", 'newarticletext' );
                        } else {
                                $wgOut->wrapWikiMsg( "<div class=\"mw-newarticletextanon\">\n$1\n</div>", 'newarticletextanon' );
                        }
                }
                # Give a notice if the user is editing a deleted/moved page...
                if ( !$this->mTitle->exists() ) {
                        LogEventsList::showLogExtract( $wgOut, array( 'delete', 'move' ), $this->mTitle,
                                '',
                                array(
                                        'lim' => 10,
                                        'conds' => array( "log_action != 'revision'" ),
                                        'showIfEmpty' => false,
                                        'msgKey' => array( 'recreate-moveddeleted-warn' )
                                )
                        );
                }
        }

        /**
         * Attempt to show a custom editing introduction, if supplied
         *
         * @return bool
         */
        protected function showCustomIntro() {
                if ( $this->editintro ) {
                        $title = Title::newFromText( $this->editintro );
                        if ( $title instanceof Title && $title->exists() && $title->userCan( 'read' ) ) {
                                global $wgOut;
                                // Added using template syntax, to take <noinclude>'s into account.
                                $wgOut->addWikiTextTitleTidy( '{{:' . $title->getFullText() . '}}', $this->mTitle );
                                return true;
                        }
                }
                return false;
        }

        /**
         * Gets an editable textual representation of $content.
         * The textual representation can be turned by into a Content object by the
         * toEditContent() method.
         *
         * If $content is null or false or a string, $content is returned unchanged.
         *
         * If the given Content object is not of a type that can be edited using the text base EditPage,
         * an exception will be raised. Set $this->allowNonTextContent to true to allow editing of non-textual
         * content.
         *
         * @param Content|null|bool|string $content
         * @return String the editable text form of the content.
         *
         * @throws MWException if $content is not an instance of TextContent and $this->allowNonTextContent is not true.
         */
        protected function toEditText( $content ) {
                if ( $content === null || $content === false ) {
                        return $content;
                }

                if ( is_string( $content ) ) {
                        return $content;
                }

                if ( !$this->allowNonTextContent && !( $content instanceof TextContent ) ) {
                        throw new MWException( "This content model can not be edited as text: "
                                                                . ContentHandler::getLocalizedName( $content->getModel() ) );
                }

                return $content->serialize( $this->contentFormat );
        }

        /**
         * Turns the given text into a Content object by unserializing it.
         *
         * If the resulting Content object is not of a type that can be edited using the text base EditPage,
         * an exception will be raised. Set $this->allowNonTextContent to true to allow editing of non-textual
         * content.
         *
         * @param string|null|bool $text Text to unserialize
         * @return Content The content object created from $text. If $text was false or null, false resp. null will be
         *                 returned instead.
         *
         * @throws MWException if unserializing the text results in a Content object that is not an instance of TextContent
         *          and $this->allowNonTextContent is not true.
         */
        protected function toEditContent( $text ) {
                if ( $text === false || $text === null ) {
                        return $text;
                }

                $content = ContentHandler::makeContent( $text, $this->getTitle(),
                        $this->contentModel, $this->contentFormat );

                if ( !$this->allowNonTextContent && !( $content instanceof TextContent ) ) {
                        throw new MWException( "This content model can not be edited as text: "
                                . ContentHandler::getLocalizedName( $content->getModel() ) );
                }

                return $content;
        }

        /**
         * Send the edit form and related headers to $wgOut
         * @param $formCallback Callback|null that takes an OutputPage parameter; will be called
         *     during form output near the top, for captchas and the like.
         */
        function showEditForm( $formCallback = null ) {
                global $wgOut, $wgUser;

                wfProfileIn( __METHOD__ );

                # need to parse the preview early so that we know which templates are used,
                # otherwise users with "show preview after edit box" will get a blank list
                # we parse this near the beginning so that setHeaders can do the title
                # setting work instead of leaving it in getPreviewText
                $previewOutput = '';
                if ( $this->formtype == 'preview' ) {
                        $previewOutput = $this->getPreviewText();
                }

                wfRunHooks( 'EditPage::showEditForm:initial', array( &$this, &$wgOut ) );

                $this->setHeaders();

                if ( $this->showHeader() === false ) {
                        wfProfileOut( __METHOD__ );
                        return;
                }

                $wgOut->addHTML( $this->editFormPageTop );

                if ( $wgUser->getOption( 'previewontop' ) ) {
                        $this->displayPreviewArea( $previewOutput, true );
                }

                $wgOut->addHTML( $this->editFormTextTop );

                $showToolbar = true;
                if ( $this->wasDeletedSinceLastEdit() ) {
                        if ( $this->formtype == 'save' ) {
                                // Hide the toolbar and edit area, user can click preview to get it back
                                // Add an confirmation checkbox and explanation.
                                $showToolbar = false;
                        } else {
                                $wgOut->wrapWikiMsg( "<div class='error mw-deleted-while-editing'>\n$1\n</div>",
                                        'deletedwhileediting' );
                        }
                }

                // @todo add EditForm plugin interface and use it here!
                //       search for textarea1 and textares2, and allow EditForm to override all uses.
                $wgOut->addHTML( Html::openElement( 'form', array( 'id' => self::EDITFORM_ID, 'name' => self::EDITFORM_ID,
                        'method' => 'post', 'action' => $this->getActionURL( $this->getContextTitle() ),
                        'enctype' => 'multipart/form-data' ) ) );

                if ( is_callable( $formCallback ) ) {
                        call_user_func_array( $formCallback, array( &$wgOut ) );
                }

                wfRunHooks( 'EditPage::showEditForm:fields', array( &$this, &$wgOut ) );

                // Put these up at the top to ensure they aren't lost on early form submission
                $this->showFormBeforeText();

                if ( $this->wasDeletedSinceLastEdit() && 'save' == $this->formtype ) {
                        $username = $this->lastDelete->user_name;
                        $comment = $this->lastDelete->log_comment;

                        // It is better to not parse the comment at all than to have templates expanded in the middle
                        // TODO: can the checkLabel be moved outside of the div so that wrapWikiMsg could be used?
                        $key = $comment === ''
                                ? 'confirmrecreate-noreason'
                                : 'confirmrecreate';
                        $wgOut->addHTML(
                                '<div class="mw-confirm-recreate">' .
                                        wfMessage( $key, $username, "<nowiki>$comment</nowiki>" )->parse() .
                                Xml::checkLabel( wfMessage( 'recreate' )->text(), 'wpRecreate', 'wpRecreate', false,
                                        array( 'title' => Linker::titleAttrib( 'recreate' ), 'tabindex' => 1, 'id' => 'wpRecreate' )
                                ) .
                                '</div>'
                        );
                }

                # When the summary is hidden, also hide them on preview/show changes
                if ( $this->nosummary ) {
                        $wgOut->addHTML( Html::hidden( 'nosummary', true ) );
                }

                # If a blank edit summary was previously provided, and the appropriate
                # user preference is active, pass a hidden tag as wpIgnoreBlankSummary. This will stop the
                # user being bounced back more than once in the event that a summary
                # is not required.
                #####
                # For a bit more sophisticated detection of blank summaries, hash the
                # automatic one and pass that in the hidden field wpAutoSummary.
                if ( $this->missingSummary || ( $this->section == 'new' && $this->nosummary ) ) {
                        $wgOut->addHTML( Html::hidden( 'wpIgnoreBlankSummary', true ) );
                }

                if ( $this->undidRev ) {
                        $wgOut->addHTML( Html::hidden( 'wpUndidRevision', $this->undidRev ) );
                }

                if ( $this->hasPresetSummary ) {
                        // If a summary has been preset using &summary= we don't want to prompt for
                        // a different summary. Only prompt for a summary if the summary is blanked.
                        // (Bug 17416)
                        $this->autoSumm = md5( '' );
                }

                $autosumm = $this->autoSumm ? $this->autoSumm : md5( $this->summary );
                $wgOut->addHTML( Html::hidden( 'wpAutoSummary', $autosumm ) );

                $wgOut->addHTML( Html::hidden( 'oldid', $this->oldid ) );

                $wgOut->addHTML( Html::hidden( 'format', $this->contentFormat ) );
                $wgOut->addHTML( Html::hidden( 'model', $this->contentModel ) );

                if ( $this->section == 'new' ) {
                        $this->showSummaryInput( true, $this->summary );
                        $wgOut->addHTML( $this->getSummaryPreview( true, $this->summary ) );
                }

                $wgOut->addHTML( $this->editFormTextBeforeContent );

                if ( !$this->isCssJsSubpage && $showToolbar && $wgUser->getOption( 'showtoolbar' ) ) {
                        $wgOut->addHTML( EditPage::getEditToolbar() );
                }

                if ( $this->isConflict ) {
                        // In an edit conflict bypass the overridable content form method
                        // and fallback to the raw wpTextbox1 since editconflicts can't be
                        // resolved between page source edits and custom ui edits using the
                        // custom edit ui.
                        $this->textbox2 = $this->textbox1;

                        $content = $this->getCurrentContent();
                        $this->textbox1 = $this->toEditText( $content );

                        $this->showTextbox1();
                } else {
                        $this->showContentForm();
                }

                $wgOut->addHTML( $this->editFormTextAfterContent );

                $this->showStandardInputs();

                $this->showFormAfterText();

                $this->showTosSummary();

                $this->showEditTools();

                $wgOut->addHTML( $this->editFormTextAfterTools . "\n" );

                $wgOut->addHTML( Html::rawElement( 'div', array( 'class' => 'templatesUsed' ),
                        Linker::formatTemplates( $this->getTemplates(), $this->preview, $this->section != '' ) ) );

                $wgOut->addHTML( Html::rawElement( 'div', array( 'class' => 'hiddencats' ),
                        Linker::formatHiddenCategories( $this->mArticle->getHiddenCategories() ) ) );

                if ( $this->isConflict ) {
                        try {
                                $this->showConflict();
                        } catch ( MWContentSerializationException $ex ) {
                                // this can't really happen, but be nice if it does.
                                $msg = wfMessage( 'content-failed-to-parse', $this->contentModel, $this->contentFormat, $ex->getMessage() );
                                $wgOut->addWikiText( '<div class="error">' . $msg->text() . '</div>' );
                        }
                }

                $wgOut->addHTML( $this->editFormTextBottom . "\n</form>\n" );

                if ( !$wgUser->getOption( 'previewontop' ) ) {
                        $this->displayPreviewArea( $previewOutput, false );
                }

                wfProfileOut( __METHOD__ );
        }

        /**
         * Extract the section title from current section text, if any.
         *
         * @param string $text
         * @return Mixed|string or false
         */
        public static function extractSectionTitle( $text ) {
                preg_match( "/^(=+)(.+)\\1\\s*(\n|$)/i", $text, $matches );
                if ( !empty( $matches[2] ) ) {
                        global $wgParser;
                        return $wgParser->stripSectionName( trim( $matches[2] ) );
                } else {
                        return false;
                }
        }

        protected function showHeader() {
                global $wgOut, $wgUser, $wgMaxArticleSize, $wgLang;

                if ( $this->mTitle->isTalkPage() ) {
                        $wgOut->addWikiMsg( 'talkpagetext' );
                }

                // Add edit notices
                $wgOut->addHTML( implode( "\n", $this->mTitle->getEditNotices() ) );

                if ( $this->isConflict ) {
                        $wgOut->wrapWikiMsg( "<div class='mw-explainconflict'>\n$1\n</div>", 'explainconflict' );
                        $this->edittime = $this->mArticle->getTimestamp();
                } else {
                        if ( $this->section != '' && !$this->isSectionEditSupported() ) {
                                // We use $this->section to much before this and getVal('wgSection') directly in other places
                                // at this point we can't reset $this->section to '' to fallback to non-section editing.
                                // Someone is welcome to try refactoring though
                                $wgOut->showErrorPage( 'sectioneditnotsupported-title', 'sectioneditnotsupported-text' );
                                return false;
                        }

                        if ( $this->section != '' && $this->section != 'new' ) {
                                if ( !$this->summary && !$this->preview && !$this->diff ) {
                                        $sectionTitle = self::extractSectionTitle( $this->textbox1 ); //FIXME: use Content object
                                        if ( $sectionTitle !== false ) {
                                                $this->summary = "/* $sectionTitle */ ";
                                        }
                                }
                        }

                        if ( $this->missingComment ) {
                                $wgOut->wrapWikiMsg( "<div id='mw-missingcommenttext'>\n$1\n</div>", 'missingcommenttext' );
                        }

                        if ( $this->missingSummary && $this->section != 'new' ) {
                                $wgOut->wrapWikiMsg( "<div id='mw-missingsummary'>\n$1\n</div>", 'missingsummary' );
                        }

                        if ( $this->missingSummary && $this->section == 'new' ) {
                                $wgOut->wrapWikiMsg( "<div id='mw-missingcommentheader'>\n$1\n</div>", 'missingcommentheader' );
                        }

                        if ( $this->hookError !== '' ) {
                                $wgOut->addWikiText( $this->hookError );
                        }

                        if ( !$this->checkUnicodeCompliantBrowser() ) {
                                $wgOut->addWikiMsg( 'nonunicodebrowser' );
                        }

                        if ( $this->section != 'new' ) {
                                $revision = $this->mArticle->getRevisionFetched();
                                if ( $revision ) {
                                        // Let sysop know that this will make private content public if saved

                                        if ( !$revision->userCan( Revision::DELETED_TEXT, $wgUser ) ) {
                                                $wgOut->wrapWikiMsg( "<div class='mw-warning plainlinks'>\n$1\n</div>\n", 'rev-deleted-text-permission' );
                                        } elseif ( $revision->isDeleted( Revision::DELETED_TEXT ) ) {
                                                $wgOut->wrapWikiMsg( "<div class='mw-warning plainlinks'>\n$1\n</div>\n", 'rev-deleted-text-view' );
                                        }

                                        if ( !$revision->isCurrent() ) {
                                                $this->mArticle->setOldSubtitle( $revision->getId() );
                                                $wgOut->addWikiMsg( 'editingold' );
                                        }
                                } elseif ( $this->mTitle->exists() ) {
                                        // Something went wrong

                                        $wgOut->wrapWikiMsg( "<div class='errorbox'>\n$1\n</div>\n",
                                                array( 'missing-revision', $this->oldid ) );
                                }
                        }
                }

                if ( wfReadOnly() ) {
                        $wgOut->wrapWikiMsg( "<div id=\"mw-read-only-warning\">\n$1\n</div>", array( 'readonlywarning', wfReadOnlyReason() ) );
                } elseif ( $wgUser->isAnon() ) {
                        if ( $this->formtype != 'preview' ) {
                                $wgOut->wrapWikiMsg( "<div id=\"mw-anon-edit-warning\">\n$1</div>", 'anoneditwarning' );
                        } else {
                                $wgOut->wrapWikiMsg( "<div id=\"mw-anon-preview-warning\">\n$1</div>", 'anonpreviewwarning' );
                        }
                } else {
                        if ( $this->isCssJsSubpage ) {
                                # Check the skin exists
                                if ( $this->isWrongCaseCssJsPage ) {
                                        $wgOut->wrapWikiMsg( "<div class='error' id='mw-userinvalidcssjstitle'>\n$1\n</div>", array( 'userinvalidcssjstitle', $this->mTitle->getSkinFromCssJsSubpage() ) );
                                }
                                if ( $this->formtype !== 'preview' ) {
                                        if ( $this->isCssSubpage ) {
                                                $wgOut->wrapWikiMsg( "<div id='mw-usercssyoucanpreview'>\n$1\n</div>", array( 'usercssyoucanpreview' ) );
                                        }

                                        if ( $this->isJsSubpage ) {
                                                $wgOut->wrapWikiMsg( "<div id='mw-userjsyoucanpreview'>\n$1\n</div>", array( 'userjsyoucanpreview' ) );
                                        }
                                }
                        }
                }

                if ( $this->mTitle->getNamespace() != NS_MEDIAWIKI && $this->mTitle->isProtected( 'edit' ) ) {
                        # Is the title semi-protected?
                        if ( $this->mTitle->isSemiProtected() ) {
                                $noticeMsg = 'semiprotectedpagewarning';
                        } else {
                                # Then it must be protected based on static groups (regular)
                                $noticeMsg = 'protectedpagewarning';
                        }
                        LogEventsList::showLogExtract( $wgOut, 'protect', $this->mTitle, '',
                                array( 'lim' => 1, 'msgKey' => array( $noticeMsg ) ) );
                }
                if ( $this->mTitle->isCascadeProtected() ) {
                        # Is this page under cascading protection from some source pages?
                        list( $cascadeSources, /* $restrictions */ ) = $this->mTitle->getCascadeProtectionSources();
                        $notice = "<div class='mw-cascadeprotectedwarning'>\n$1\n";
                        $cascadeSourcesCount = count( $cascadeSources );
                        if ( $cascadeSourcesCount > 0 ) {
                                # Explain, and list the titles responsible
                                foreach ( $cascadeSources as $page ) {
                                        $notice .= '* [[:' . $page->getPrefixedText() . "]]\n";
                                }
                        }
                        $notice .= '</div>';
                        $wgOut->wrapWikiMsg( $notice, array( 'cascadeprotectedwarning', $cascadeSourcesCount ) );
                }
                if ( !$this->mTitle->exists() && $this->mTitle->getRestrictions( 'create' ) ) {
                        LogEventsList::showLogExtract( $wgOut, 'protect', $this->mTitle, '',
                                array( 'lim' => 1,
                                        'showIfEmpty' => false,
                                        'msgKey' => array( 'titleprotectedwarning' ),
                                        'wrap' => "<div class=\"mw-titleprotectedwarning\">\n$1</div>" ) );
                }

                if ( $this->kblength === false ) {
                        $this->kblength = (int)( strlen( $this->textbox1 ) / 1024 );
                }

                if ( $this->tooBig || $this->kblength > $wgMaxArticleSize ) {
                        $wgOut->wrapWikiMsg( "<div class='error' id='mw-edit-longpageerror'>\n$1\n</div>",
                                array( 'longpageerror', $wgLang->formatNum( $this->kblength ), $wgLang->formatNum( $wgMaxArticleSize ) ) );
                } else {
                        if ( !wfMessage( 'longpage-hint' )->isDisabled() ) {
                                $wgOut->wrapWikiMsg( "<div id='mw-edit-longpage-hint'>\n$1\n</div>",
                                        array( 'longpage-hint', $wgLang->formatSize( strlen( $this->textbox1 ) ), strlen( $this->textbox1 ) )
                                );
                        }
                }
                # Add header copyright warning
                $this->showHeaderCopyrightWarning();
        }

        /**
         * Standard summary input and label (wgSummary), abstracted so EditPage
         * subclasses may reorganize the form.
         * Note that you do not need to worry about the label's for=, it will be
         * inferred by the id given to the input. You can remove them both by
         * passing array( 'id' => false ) to $userInputAttrs.
         *
         * @param string $summary The value of the summary input
         * @param string $labelText The html to place inside the label
         * @param array $inputAttrs of attrs to use on the input
         * @param array $spanLabelAttrs of attrs to use on the span inside the label
         *
         * @return array An array in the format array( $label, $input )
         */
        function getSummaryInput( $summary = "", $labelText = null, $inputAttrs = null, $spanLabelAttrs = null ) {
                // Note: the maxlength is overridden in JS to 255 and to make it use UTF-8 bytes, not characters.
                $inputAttrs = ( is_array( $inputAttrs ) ? $inputAttrs : array() ) + array(
                        'id' => 'wpSummary',
                        'maxlength' => '200',
                        'tabindex' => '1',
                        'size' => 60,
                        'spellcheck' => 'true',
                ) + Linker::tooltipAndAccesskeyAttribs( 'summary' );

                $spanLabelAttrs = ( is_array( $spanLabelAttrs ) ? $spanLabelAttrs : array() ) + array(
                        'class' => $this->missingSummary ? 'mw-summarymissed' : 'mw-summary',
                        'id' => "wpSummaryLabel"
                );

                $label = null;
                if ( $labelText ) {
                        $label = Xml::tags( 'label', $inputAttrs['id'] ? array( 'for' => $inputAttrs['id'] ) : null, $labelText );
                        $label = Xml::tags( 'span', $spanLabelAttrs, $label );
                }

                $input = Html::input( 'wpSummary', $summary, 'text', $inputAttrs );

                return array( $label, $input );
        }

        /**
         * @param $isSubjectPreview Boolean: true if this is the section subject/title
         *                          up top, or false if this is the comment summary
         *                          down below the textarea
         * @param string $summary The text of the summary to display
         * @return String
         */
        protected function showSummaryInput( $isSubjectPreview, $summary = "" ) {
                global $wgOut, $wgContLang;
                # Add a class if 'missingsummary' is triggered to allow styling of the summary line
                $summaryClass = $this->missingSummary ? 'mw-summarymissed' : 'mw-summary';
                if ( $isSubjectPreview ) {
                        if ( $this->nosummary ) {
                                return;
                        }
                } else {
                        if ( !$this->mShowSummaryField ) {
                                return;
                        }
                }
                $summary = $wgContLang->recodeForEdit( $summary );
                $labelText = wfMessage( $isSubjectPreview ? 'subject' : 'summary' )->parse();
                list( $label, $input ) = $this->getSummaryInput( $summary, $labelText, array( 'class' => $summaryClass ), array() );
                $wgOut->addHTML( "{$label} {$input}" );
        }

        /**
         * @param $isSubjectPreview Boolean: true if this is the section subject/title
         *                          up top, or false if this is the comment summary
         *                          down below the textarea
         * @param string $summary the text of the summary to display
         * @return String
         */
        protected function getSummaryPreview( $isSubjectPreview, $summary = "" ) {
                // avoid spaces in preview, gets always trimmed on save
                $summary = trim( $summary );
                if ( !$summary || ( !$this->preview && !$this->diff ) ) {
                        return "";
                }

                global $wgParser;

                if ( $isSubjectPreview ) {
                        $summary = wfMessage( 'newsectionsummary', $wgParser->stripSectionName( $summary ) )
                                ->inContentLanguage()->text();
                }

                $message = $isSubjectPreview ? 'subject-preview' : 'summary-preview';

                $summary = wfMessage( $message )->parse() . Linker::commentBlock( $summary, $this->mTitle, $isSubjectPreview );
                return Xml::tags( 'div', array( 'class' => 'mw-summary-preview' ), $summary );
        }

        protected function showFormBeforeText() {
                global $wgOut;
                $section = htmlspecialchars( $this->section );
                $wgOut->addHTML( <<<HTML
<input type='hidden' value="{$section}" name="wpSection" />
<input type='hidden' value="{$this->starttime}" name="wpStarttime" />
<input type='hidden' value="{$this->edittime}" name="wpEdittime" />
<input type='hidden' value="{$this->scrolltop}" name="wpScrolltop" id="wpScrolltop" />

HTML
                );
                if ( !$this->checkUnicodeCompliantBrowser() ) {
                        $wgOut->addHTML( Html::hidden( 'safemode', '1' ) );
                }
        }

        protected function showFormAfterText() {
                global $wgOut, $wgUser;
                /**
                 * To make it harder for someone to slip a user a page
                 * which submits an edit form to the wiki without their
                 * knowledge, a random token is associated with the login
                 * session. If it's not passed back with the submission,
                 * we won't save the page, or render user JavaScript and
                 * CSS previews.
                 *
                 * For anon editors, who may not have a session, we just
                 * include the constant suffix to prevent editing from
                 * broken text-mangling proxies.
                 */
                $wgOut->addHTML( "\n" . Html::hidden( "wpEditToken", $wgUser->getEditToken() ) . "\n" );
        }

        /**
         * Subpage overridable method for printing the form for page content editing
         * By default this simply outputs wpTextbox1
         * Subclasses can override this to provide a custom UI for editing;
         * be it a form, or simply wpTextbox1 with a modified content that will be
         * reverse modified when extracted from the post data.
         * Note that this is basically the inverse for importContentFormData
         */
        protected function showContentForm() {
                $this->showTextbox1();
        }

        /**
         * Method to output wpTextbox1
         * The $textoverride method can be used by subclasses overriding showContentForm
         * to pass back to this method.
         *
         * @param array $customAttribs of html attributes to use in the textarea
         * @param string $textoverride optional text to override $this->textarea1 with
         */
        protected function showTextbox1( $customAttribs = null, $textoverride = null ) {
                if ( $this->wasDeletedSinceLastEdit() && $this->formtype == 'save' ) {
                        $attribs = array( 'style' => 'display:none;' );
                } else {
                        $classes = array(); // Textarea CSS
                        if ( $this->mTitle->getNamespace() != NS_MEDIAWIKI && $this->mTitle->isProtected( 'edit' ) ) {
                                # Is the title semi-protected?
                                if ( $this->mTitle->isSemiProtected() ) {
                                        $classes[] = 'mw-textarea-sprotected';
                                } else {
                                        # Then it must be protected based on static groups (regular)
                                        $classes[] = 'mw-textarea-protected';
                                }
                                # Is the title cascade-protected?
                                if ( $this->mTitle->isCascadeProtected() ) {
                                        $classes[] = 'mw-textarea-cprotected';
                                }
                        }

                        $attribs = array( 'tabindex' => 1 );

                        if ( is_array( $customAttribs ) ) {
                                $attribs += $customAttribs;
                        }

                        if ( count( $classes ) ) {
                                if ( isset( $attribs['class'] ) ) {
                                        $classes[] = $attribs['class'];
                                }
                                $attribs['class'] = implode( ' ', $classes );
                        }
                }

                $this->showTextbox( $textoverride !== null ? $textoverride : $this->textbox1, 'wpTextbox1', $attribs );
        }

        protected function showTextbox2() {
                $this->showTextbox( $this->textbox2, 'wpTextbox2', array( 'tabindex' => 6, 'readonly' ) );
        }

        protected function showTextbox( $text, $name, $customAttribs = array() ) {
                global $wgOut, $wgUser;

                $wikitext = $this->safeUnicodeOutput( $text );
                if ( strval( $wikitext ) !== '' ) {
                        // Ensure there's a newline at the end, otherwise adding lines
                        // is awkward.
                        // But don't add a newline if the ext is empty, or Firefox in XHTML
                        // mode will show an extra newline. A bit annoying.
                        $wikitext .= "\n";
                }

                $attribs = $customAttribs + array(
                        'accesskey' => ',',
                        'id' => $name,
                        'cols' => $wgUser->getIntOption( 'cols' ),
                        'rows' => $wgUser->getIntOption( 'rows' ),
                        'style' => '' // avoid php notices when appending preferences (appending allows customAttribs['style'] to still work
                );

                $pageLang = $this->mTitle->getPageLanguage();
                $attribs['lang'] = $pageLang->getCode();
                $attribs['dir'] = $pageLang->getDir();

                $wgOut->addHTML( Html::textarea( $name, $wikitext, $attribs ) );
        }

        protected function displayPreviewArea( $previewOutput, $isOnTop = false ) {
                global $wgOut;
                $classes = array();
                if ( $isOnTop ) {
                        $classes[] = 'ontop';
                }

                $attribs = array( 'id' => 'wikiPreview', 'class' => implode( ' ', $classes ) );

                if ( $this->formtype != 'preview' ) {
                        $attribs['style'] = 'display: none;';
                }

                $wgOut->addHTML( Xml::openElement( 'div', $attribs ) );

                if ( $this->formtype == 'preview' ) {
                        $this->showPreview( $previewOutput );
                }

                $wgOut->addHTML( '</div>' );

                if ( $this->formtype == 'diff' ) {
                        try {
                                $this->showDiff();
                        } catch ( MWContentSerializationException $ex ) {
                                $msg = wfMessage( 'content-failed-to-parse', $this->contentModel, $this->contentFormat, $ex->getMessage() );
                                $wgOut->addWikiText( '<div class="error">' . $msg->text() . '</div>' );
                        }
                }
        }

        /**
         * Append preview output to $wgOut.
         * Includes category rendering if this is a category page.
         *
         * @param string $text the HTML to be output for the preview.
         */
        protected function showPreview( $text ) {
                global $wgOut;
                if ( $this->mTitle->getNamespace() == NS_CATEGORY ) {
                        $this->mArticle->openShowCategory();
                }
                # This hook seems slightly odd here, but makes things more
                # consistent for extensions.
                wfRunHooks( 'OutputPageBeforeHTML', array( &$wgOut, &$text ) );
                $wgOut->addHTML( $text );
                if ( $this->mTitle->getNamespace() == NS_CATEGORY ) {
                        $this->mArticle->closeShowCategory();
                }
        }

        /**
         * Get a diff between the current contents of the edit box and the
         * version of the page we're editing from.
         *
         * If this is a section edit, we'll replace the section as for final
         * save and then make a comparison.
         */
        function showDiff() {
                global $wgUser, $wgContLang, $wgOut;

                $oldtitlemsg = 'currentrev';
                # if message does not exist, show diff against the preloaded default
                if ( $this->mTitle->getNamespace() == NS_MEDIAWIKI && !$this->mTitle->exists() ) {
                        $oldtext = $this->mTitle->getDefaultMessageText();
                        if ( $oldtext !== false ) {
                                $oldtitlemsg = 'defaultmessagetext';
                                $oldContent = $this->toEditContent( $oldtext );
                        } else {
                                $oldContent = null;
                        }
                } else {
                        $oldContent = $this->getCurrentContent();
                }

                $textboxContent = $this->toEditContent( $this->textbox1 );

                $newContent = $this->mArticle->replaceSectionContent(
                                                        $this->section, $textboxContent,
                                                        $this->summary, $this->edittime );

                if ( $newContent ) {
                        ContentHandler::runLegacyHooks( 'EditPageGetDiffText', array( $this, &$newContent ) );
                        wfRunHooks( 'EditPageGetDiffContent', array( $this, &$newContent ) );

                        $popts = ParserOptions::newFromUserAndLang( $wgUser, $wgContLang );
                        $newContent = $newContent->preSaveTransform( $this->mTitle, $wgUser, $popts );
                }

                if ( ( $oldContent && !$oldContent->isEmpty() ) || ( $newContent && !$newContent->isEmpty() ) ) {
                        $oldtitle = wfMessage( $oldtitlemsg )->parse();
                        $newtitle = wfMessage( 'yourtext' )->parse();

                        if ( !$oldContent ) {
                                $oldContent = $newContent->getContentHandler()->makeEmptyContent();
                        }

                        if ( !$newContent ) {
                                $newContent = $oldContent->getContentHandler()->makeEmptyContent();
                        }

                        $de = $oldContent->getContentHandler()->createDifferenceEngine( $this->mArticle->getContext() );
                        $de->setContent( $oldContent, $newContent );

                        $difftext = $de->getDiff( $oldtitle, $newtitle );
                        $de->showDiffStyle();
                } else {
                        $difftext = '';
                }

                $wgOut->addHTML( '<div id="wikiDiff">' . $difftext . '</div>' );
        }

        /**
         * Show the header copyright warning.
         */
        protected function showHeaderCopyrightWarning() {
                $msg = 'editpage-head-copy-warn';
                if ( !wfMessage( $msg )->isDisabled() ) {
                        global $wgOut;
                        $wgOut->wrapWikiMsg( "<div class='editpage-head-copywarn'>\n$1\n</div>",
                                'editpage-head-copy-warn' );
                }
        }

        /**
         * Give a chance for site and per-namespace customizations of
         * terms of service summary link that might exist separately
         * from the copyright notice.
         *
         * This will display between the save button and the edit tools,
         * so should remain short!
         */
        protected function showTosSummary() {
                $msg = 'editpage-tos-summary';
                wfRunHooks( 'EditPageTosSummary', array( $this->mTitle, &$msg ) );
                if ( !wfMessage( $msg )->isDisabled() ) {
                        global $wgOut;
                        $wgOut->addHTML( '<div class="mw-tos-summary">' );
                        $wgOut->addWikiMsg( $msg );
                        $wgOut->addHTML( '</div>' );
                }
        }

        protected function showEditTools() {
                global $wgOut;
                $wgOut->addHTML( '<div class="mw-editTools">' .
                        wfMessage( 'edittools' )->inContentLanguage()->parse() .
                        '</div>' );
        }

        /**
         * Get the copyright warning
         *
         * Renamed to getCopyrightWarning(), old name kept around for backwards compatibility
         */
        protected function getCopywarn() {
                return self::getCopyrightWarning( $this->mTitle );
        }

        public static function getCopyrightWarning( $title ) {
                global $wgRightsText;
                if ( $wgRightsText ) {
                        $copywarnMsg = array( 'copyrightwarning',
                                '[[' . wfMessage( 'copyrightpage' )->inContentLanguage()->text() . ']]',
                                $wgRightsText );
                } else {
                        $copywarnMsg = array( 'copyrightwarning2',
                                '[[' . wfMessage( 'copyrightpage' )->inContentLanguage()->text() . ']]' );
                }
                // Allow for site and per-namespace customization of contribution/copyright notice.
                wfRunHooks( 'EditPageCopyrightWarning', array( $title, &$copywarnMsg ) );

                return "<div id=\"editpage-copywarn\">\n" .
                        call_user_func_array( 'wfMessage', $copywarnMsg )->plain() . "\n</div>";
        }

        protected function showStandardInputs( &$tabindex = 2 ) {
                global $wgOut;
                $wgOut->addHTML( "<div class='editOptions'>\n" );

                if ( $this->section != 'new' ) {
                        $this->showSummaryInput( false, $this->summary );
                        $wgOut->addHTML( $this->getSummaryPreview( false, $this->summary ) );
                }

                $checkboxes = $this->getCheckboxes( $tabindex,
                        array( 'minor' => $this->minoredit, 'watch' => $this->watchthis ) );
                $wgOut->addHTML( "<div class='editCheckboxes'>" . implode( $checkboxes, "\n" ) . "</div>\n" );

                // Show copyright warning.
                $wgOut->addWikiText( $this->getCopywarn() );
                $wgOut->addHTML( $this->editFormTextAfterWarn );

                $wgOut->addHTML( "<div class='editButtons'>\n" );
                $wgOut->addHTML( implode( $this->getEditButtons( $tabindex ), "\n" ) . "\n" );

                $cancel = $this->getCancelLink();
                if ( $cancel !== '' ) {
                        $cancel .= wfMessage( 'pipe-separator' )->text();
                }
                $edithelpurl = Skin::makeInternalOrExternalUrl( wfMessage( 'edithelppage' )->inContentLanguage()->text() );
                $edithelp = '<a target="helpwindow" href="' . $edithelpurl . '">' .
                        wfMessage( 'edithelp' )->escaped() . '</a> ' .
                        wfMessage( 'newwindow' )->parse();
                $wgOut->addHTML( "      <span class='cancelLink'>{$cancel}</span>\n" );
                $wgOut->addHTML( "      <span class='editHelp'>{$edithelp}</span>\n" );
                $wgOut->addHTML( "</div><!-- editButtons -->\n" );
                wfRunHooks( 'EditPage::showStandardInputs:options', array( $this, $wgOut, &$tabindex ) );
                $wgOut->addHTML( "</div><!-- editOptions -->\n" );
        }

        /**
         * Show an edit conflict. textbox1 is already shown in showEditForm().
         * If you want to use another entry point to this function, be careful.
         */
        protected function showConflict() {
                global $wgOut;

                if ( wfRunHooks( 'EditPageBeforeConflictDiff', array( &$this, &$wgOut ) ) ) {
                        $wgOut->wrapWikiMsg( '<h2>$1</h2>', "yourdiff" );

                        $content1 = $this->toEditContent( $this->textbox1 );
                        $content2 = $this->toEditContent( $this->textbox2 );

                        $handler = ContentHandler::getForModelID( $this->contentModel );
                        $de = $handler->createDifferenceEngine( $this->mArticle->getContext() );
                        $de->setContent( $content2, $content1 );
                        $de->showDiff(
                                wfMessage( 'yourtext' )->parse(),
                                wfMessage( 'storedversion' )->text()
                        );

                        $wgOut->wrapWikiMsg( '<h2>$1</h2>', "yourtext" );
                        $this->showTextbox2();
                }
        }

        /**
         * @return string
         */
        public function getCancelLink() {
                $cancelParams = array();
                if ( !$this->isConflict && $this->oldid > 0 ) {
                        $cancelParams['oldid'] = $this->oldid;
                }

                return Linker::linkKnown(
                        $this->getContextTitle(),
                        wfMessage( 'cancel' )->parse(),
                        array( 'id' => 'mw-editform-cancel' ),
                        $cancelParams
                );
        }

        /**
         * Returns the URL to use in the form's action attribute.
         * This is used by EditPage subclasses when simply customizing the action
         * variable in the constructor is not enough. This can be used when the
         * EditPage lives inside of a Special page rather than a custom page action.
         *
         * @param $title Title object for which is being edited (where we go to for &action= links)
         * @return string
         */
        protected function getActionURL( Title $title ) {
                return $title->getLocalURL( array( 'action' => $this->action ) );
        }

        /**
         * Check if a page was deleted while the user was editing it, before submit.
         * Note that we rely on the logging table, which hasn't been always there,
         * but that doesn't matter, because this only applies to brand new
         * deletes.
         */
        protected function wasDeletedSinceLastEdit() {
                if ( $this->deletedSinceEdit !== null ) {
                        return $this->deletedSinceEdit;
                }

                $this->deletedSinceEdit = false;

                if ( $this->mTitle->isDeletedQuick() ) {
                        $this->lastDelete = $this->getLastDelete();
                        if ( $this->lastDelete ) {
                                $deleteTime = wfTimestamp( TS_MW, $this->lastDelete->log_timestamp );
                                if ( $deleteTime > $this->starttime ) {
                                        $this->deletedSinceEdit = true;
                                }
                        }
                }

                return $this->deletedSinceEdit;
        }

        protected function getLastDelete() {
                $dbr = wfGetDB( DB_SLAVE );
                $data = $dbr->selectRow(
                        array( 'logging', 'user' ),
                        array(
                                'log_type',
                                'log_action',
                                'log_timestamp',
                                'log_user',
                                'log_namespace',
                                'log_title',
                                'log_comment',
                                'log_params',
                                'log_deleted',
                                'user_name'
                        ), array(
                                'log_namespace' => $this->mTitle->getNamespace(),
                                'log_title' => $this->mTitle->getDBkey(),
                                'log_type' => 'delete',
                                'log_action' => 'delete',
                                'user_id=log_user'
                        ),
                        __METHOD__,
                        array( 'LIMIT' => 1, 'ORDER BY' => 'log_timestamp DESC' )
                );
                // Quick paranoid permission checks...
                if ( is_object( $data ) ) {
                        if ( $data->log_deleted & LogPage::DELETED_USER ) {
                                $data->user_name = wfMessage( 'rev-deleted-user' )->escaped();
                        }

                        if ( $data->log_deleted & LogPage::DELETED_COMMENT ) {
                                $data->log_comment = wfMessage( 'rev-deleted-comment' )->escaped();
                        }
                }
                return $data;
        }

        /**
         * Get the rendered text for previewing.
         * @throws MWException
         * @return string
         */
        function getPreviewText() {
                global $wgOut, $wgUser, $wgRawHtml, $wgLang;

                wfProfileIn( __METHOD__ );

                if ( $wgRawHtml && !$this->mTokenOk ) {
                        // Could be an offsite preview attempt. This is very unsafe if
                        // HTML is enabled, as it could be an attack.
                        $parsedNote = '';
                        if ( $this->textbox1 !== '' ) {
                                // Do not put big scary notice, if previewing the empty
                                // string, which happens when you initially edit
                                // a category page, due to automatic preview-on-open.
                                $parsedNote = $wgOut->parse( "<div class='previewnote'>" .
                                        wfMessage( 'session_fail_preview_html' )->text() . "</div>", true, /* interface */true );
                        }
                        wfProfileOut( __METHOD__ );
                        return $parsedNote;
                }

                $note = '';

                try {
                        $content = $this->toEditContent( $this->textbox1 );

                        $previewHTML = '';
                        if ( !wfRunHooks( 'AlternateEditPreview', array( $this, &$content, &$previewHTML, &$this->mParserOutput ) ) ) {
                                wfProfileOut( __METHOD__ );
                                return $previewHTML;
                        }

                        if ( $this->mTriedSave && !$this->mTokenOk ) {
                                if ( $this->mTokenOkExceptSuffix ) {
                                        $note = wfMessage( 'token_suffix_mismatch' )->plain();

                                } else {
                                        $note = wfMessage( 'session_fail_preview' )->plain();
                                }
                        } elseif ( $this->incompleteForm ) {
                                $note = wfMessage( 'edit_form_incomplete' )->plain();
                        } else {
                                $note = wfMessage( 'previewnote' )->plain() .
                                        ' [[#' . self::EDITFORM_ID . '|' . $wgLang->getArrow() . ' ' . wfMessage( 'continue-editing' )->text() . ']]';
                        }

                        $parserOptions = $this->mArticle->makeParserOptions( $this->mArticle->getContext() );
                        $parserOptions->setEditSection( false );
                        $parserOptions->setIsPreview( true );
                        $parserOptions->setIsSectionPreview( !is_null( $this->section ) && $this->section !== '' );

                        # don't parse non-wikitext pages, show message about preview
                        if ( $this->mTitle->isCssJsSubpage() || $this->mTitle->isCssOrJsPage() ) {
                                if ( $this->mTitle->isCssJsSubpage() ) {
                                        $level = 'user';
                                } elseif ( $this->mTitle->isCssOrJsPage() ) {
                                        $level = 'site';
                                } else {
                                        $level = false;
                                }

                                if ( $content->getModel() == CONTENT_MODEL_CSS ) {
                                        $format = 'css';
                                } elseif ( $content->getModel() == CONTENT_MODEL_JAVASCRIPT ) {
                                        $format = 'js';
                                } else {
                                        $format = false;
                                }

                                # Used messages to make sure grep find them:
                                # Messages: usercsspreview, userjspreview, sitecsspreview, sitejspreview
                                if ( $level && $format ) {
                                        $note = "<div id='mw-{$level}{$format}preview'>" . wfMessage( "{$level}{$format}preview" )->text() . "</div>";
                                }
                        }

                        $rt = $content->getRedirectChain();
                        if ( $rt ) {
                                $previewHTML = $this->mArticle->viewRedirect( $rt, false );
                        } else {

                                # If we're adding a comment, we need to show the
                                # summary as the headline
                                if ( $this->section === "new" && $this->summary !== "" ) {
                                        $content = $content->addSectionHeader( $this->summary );
                                }

                                $hook_args = array( $this, &$content );
                                ContentHandler::runLegacyHooks( 'EditPageGetPreviewText', $hook_args );
                                wfRunHooks( 'EditPageGetPreviewContent', $hook_args );

                                $parserOptions->enableLimitReport();

                                # For CSS/JS pages, we should have called the ShowRawCssJs hook here.
                                # But it's now deprecated, so never mind

                                $content = $content->preSaveTransform( $this->mTitle, $wgUser, $parserOptions );
                                $parserOutput = $content->getParserOutput( $this->getArticle()->getTitle(), null, $parserOptions );

                                $previewHTML = $parserOutput->getText();
                                $this->mParserOutput = $parserOutput;
                                $wgOut->addParserOutputNoText( $parserOutput );

                                if ( count( $parserOutput->getWarnings() ) ) {
                                        $note .= "\n\n" . implode( "\n\n", $parserOutput->getWarnings() );
                                }
                        }
                } catch ( MWContentSerializationException $ex ) {
                        $m = wfMessage( 'content-failed-to-parse', $this->contentModel, $this->contentFormat, $ex->getMessage() );
                        $note .= "\n\n" . $m->parse();
                        $previewHTML = '';
                }

                if ( $this->isConflict ) {
                        $conflict = '<h2 id="mw-previewconflict">' . wfMessage( 'previewconflict' )->escaped() . "</h2>\n";
                } else {
                        $conflict = '<hr />';
                }

                $previewhead = "<div class='previewnote'>\n" .
                        '<h2 id="mw-previewheader">' . wfMessage( 'preview' )->escaped() . "</h2>" .
                        $wgOut->parse( $note, true, /* interface */true ) . $conflict . "</div>\n";

                $pageLang = $this->mTitle->getPageLanguage();
                $attribs = array( 'lang' => $pageLang->getCode(), 'dir' => $pageLang->getDir(),
                        'class' => 'mw-content-' . $pageLang->getDir() );
                $previewHTML = Html::rawElement( 'div', $attribs, $previewHTML );

                wfProfileOut( __METHOD__ );
                return $previewhead . $previewHTML . $this->previewTextAfterContent;
        }

        /**
         * @return Array
         */
        function getTemplates() {
                if ( $this->preview || $this->section != '' ) {
                        $templates = array();
                        if ( !isset( $this->mParserOutput ) ) {
                                return $templates;
                        }
                        foreach ( $this->mParserOutput->getTemplates() as $ns => $template ) {
                                foreach ( array_keys( $template ) as $dbk ) {
                                        $templates[] = Title::makeTitle( $ns, $dbk );
                                }
                        }
                        return $templates;
                } else {
                        return $this->mTitle->getTemplateLinksFrom();
                }
        }

        /**
         * Shows a bulletin board style toolbar for common editing functions.
         * It can be disabled in the user preferences.
         * The necessary JavaScript code can be found in skins/common/edit.js.
         *
         * @return string
         */
        static function getEditToolbar() {
                global $wgStylePath, $wgContLang, $wgLang, $wgOut;
                global $wgUseTeX, $wgEnableUploads, $wgForeignFileRepos;

                $imagesAvailable = $wgEnableUploads || count( $wgForeignFileRepos );

                /**
                 * $toolarray is an array of arrays each of which includes the
                 * filename of the button image (without path), the opening
                 * tag, the closing tag, optionally a sample text that is
                 * inserted between the two when no selection is highlighted
                 * and.  The tip text is shown when the user moves the mouse
                 * over the button.
                 *
                 * Also here: accesskeys (key), which are not used yet until
                 * someone can figure out a way to make them work in
                 * IE. However, we should make sure these keys are not defined
                 * on the edit page.
                 */
                $toolarray = array(
                        array(
                                'image'  => $wgLang->getImageFile( 'button-bold' ),
                                'id'     => 'mw-editbutton-bold',
                                'open'   => '\'\'\'',
                                'close'  => '\'\'\'',
                                'sample' => wfMessage( 'bold_sample' )->text(),
                                'tip'    => wfMessage( 'bold_tip' )->text(),
                                'key'    => 'B'
                        ),
                        array(
                                'image'  => $wgLang->getImageFile( 'button-italic' ),
                                'id'     => 'mw-editbutton-italic',
                                'open'   => '\'\'',
                                'close'  => '\'\'',
                                'sample' => wfMessage( 'italic_sample' )->text(),
                                'tip'    => wfMessage( 'italic_tip' )->text(),
                                'key'    => 'I'
                        ),
                        array(
                                'image'  => $wgLang->getImageFile( 'button-link' ),
                                'id'     => 'mw-editbutton-link',
                                'open'   => '[[',
                                'close'  => ']]',
                                'sample' => wfMessage( 'link_sample' )->text(),
                                'tip'    => wfMessage( 'link_tip' )->text(),
                                'key'    => 'L'
                        ),
                        array(
                                'image'  => $wgLang->getImageFile( 'button-extlink' ),
                                'id'     => 'mw-editbutton-extlink',
                                'open'   => '[',
                                'close'  => ']',
                                'sample' => wfMessage( 'extlink_sample' )->text(),
                                'tip'    => wfMessage( 'extlink_tip' )->text(),
                                'key'    => 'X'
                        ),
                        array(
                                'image'  => $wgLang->getImageFile( 'button-headline' ),
                                'id'     => 'mw-editbutton-headline',
                                'open'   => "\n== ",
                                'close'  => " ==\n",
                                'sample' => wfMessage( 'headline_sample' )->text(),
                                'tip'    => wfMessage( 'headline_tip' )->text(),
                                'key'    => 'H'
                        ),
                        $imagesAvailable ? array(
                                'image'  => $wgLang->getImageFile( 'button-image' ),
                                'id'     => 'mw-editbutton-image',
                                'open'   => '[[' . $wgContLang->getNsText( NS_FILE ) . ':',
                                'close'  => ']]',
                                'sample' => wfMessage( 'image_sample' )->text(),
                                'tip'    => wfMessage( 'image_tip' )->text(),
                                'key'    => 'D',
                        ) : false,
                        $imagesAvailable ? array(
                                'image'  => $wgLang->getImageFile( 'button-media' ),
                                'id'     => 'mw-editbutton-media',
                                'open'   => '[[' . $wgContLang->getNsText( NS_MEDIA ) . ':',
                                'close'  => ']]',
                                'sample' => wfMessage( 'media_sample' )->text(),
                                'tip'    => wfMessage( 'media_tip' )->text(),
                                'key'    => 'M'
                        ) : false,
                        $wgUseTeX ? array(
                                'image'  => $wgLang->getImageFile( 'button-math' ),
                                'id'     => 'mw-editbutton-math',
                                'open'   => "<math>",
                                'close'  => "</math>",
                                'sample' => wfMessage( 'math_sample' )->text(),
                                'tip'    => wfMessage( 'math_tip' )->text(),
                                'key'    => 'C'
                        ) : false,
                        array(
                                'image'  => $wgLang->getImageFile( 'button-nowiki' ),
                                'id'     => 'mw-editbutton-nowiki',
                                'open'   => "<nowiki>",
                                'close'  => "</nowiki>",
                                'sample' => wfMessage( 'nowiki_sample' )->text(),
                                'tip'    => wfMessage( 'nowiki_tip' )->text(),
                                'key'    => 'N'
                        ),
                        array(
                                'image'  => $wgLang->getImageFile( 'button-sig' ),
                                'id'     => 'mw-editbutton-signature',
                                'open'   => '--~~~~',
                                'close'  => '',
                                'sample' => '',
                                'tip'    => wfMessage( 'sig_tip' )->text(),
                                'key'    => 'Y'
                        ),
                        array(
                                'image'  => $wgLang->getImageFile( 'button-hr' ),
                                'id'     => 'mw-editbutton-hr',
                                'open'   => "\n----\n",
                                'close'  => '',
                                'sample' => '',
                                'tip'    => wfMessage( 'hr_tip' )->text(),
                                'key'    => 'R'
                        )
                );

                $script = 'mw.loader.using("mediawiki.action.edit", function() {';
                foreach ( $toolarray as $tool ) {
                        if ( !$tool ) {
                                continue;
                        }

                        $params = array(
                                $image = $wgStylePath . '/common/images/' . $tool['image'],
                                // Note that we use the tip both for the ALT tag and the TITLE tag of the image.
                                // Older browsers show a "speedtip" type message only for ALT.
                                // Ideally these should be different, realistically they
                                // probably don't need to be.
                                $tip = $tool['tip'],
                                $open = $tool['open'],
                                $close = $tool['close'],
                                $sample = $tool['sample'],
                                $cssId = $tool['id'],
                        );

                        $script .= Xml::encodeJsCall( 'mw.toolbar.addButton', $params );
                }

                // This used to be called on DOMReady from mediawiki.action.edit, which
                // ended up causing race conditions with the setup code above.
                $script .= "\n" .
                        "// Create button bar\n" .
                        "$(function() { mw.toolbar.init(); } );\n";

                $script .= '});';
                $wgOut->addScript( Html::inlineScript( ResourceLoader::makeLoaderConditionalScript( $script ) ) );

                $toolbar = '<div id="toolbar"></div>';

                wfRunHooks( 'EditPageBeforeEditToolbar', array( &$toolbar ) );

                return $toolbar;
        }

        /**
         * Returns an array of html code of the following checkboxes:
         * minor and watch
         *
         * @param int $tabindex Current tabindex
         * @param array $checked of checkbox => bool, where bool indicates the checked
         *                 status of the checkbox
         *
         * @return array
         */
        public function getCheckboxes( &$tabindex, $checked ) {
                global $wgUser;

                $checkboxes = array();

                // don't show the minor edit checkbox if it's a new page or section
                if ( !$this->isNew ) {
                        $checkboxes['minor'] = '';
                        $minorLabel = wfMessage( 'minoredit' )->parse();
                        if ( $wgUser->isAllowed( 'minoredit' ) ) {
                                $attribs = array(
                                        'tabindex' => ++$tabindex,
                                        'accesskey' => wfMessage( 'accesskey-minoredit' )->text(),
                                        'id' => 'wpMinoredit',
                                );
                                $checkboxes['minor'] =
                                        Xml::check( 'wpMinoredit', $checked['minor'], $attribs ) .
                                        "&#160;<label for='wpMinoredit' id='mw-editpage-minoredit'" .
                                        Xml::expandAttributes( array( 'title' => Linker::titleAttrib( 'minoredit', 'withaccess' ) ) ) .
                                        ">{$minorLabel}</label>";
                        }
                }

                $watchLabel = wfMessage( 'watchthis' )->parse();
                $checkboxes['watch'] = '';
                if ( $wgUser->isLoggedIn() ) {
                        $attribs = array(
                                'tabindex' => ++$tabindex,
                                'accesskey' => wfMessage( 'accesskey-watch' )->text(),
                                'id' => 'wpWatchthis',
                        );
                        $checkboxes['watch'] =
                                Xml::check( 'wpWatchthis', $checked['watch'], $attribs ) .
                                "&#160;<label for='wpWatchthis' id='mw-editpage-watch'" .
                                Xml::expandAttributes( array( 'title' => Linker::titleAttrib( 'watch', 'withaccess' ) ) ) .
                                ">{$watchLabel}</label>";
                }
                wfRunHooks( 'EditPageBeforeEditChecks', array( &$this, &$checkboxes, &$tabindex ) );
                return $checkboxes;
        }

        /**
         * Returns an array of html code of the following buttons:
         * save, diff, preview and live
         *
         * @param int $tabindex Current tabindex
         *
         * @return array
         */
        public function getEditButtons( &$tabindex ) {
                $buttons = array();

                $temp = array(
                        'id' => 'wpSave',
                        'name' => 'wpSave',
                        'type' => 'submit',
                        'tabindex' => ++$tabindex,
                        'value' => wfMessage( 'savearticle' )->text(),
                        'accesskey' => wfMessage( 'accesskey-save' )->text(),
                        'title' => wfMessage( 'tooltip-save' )->text() . ' [' . wfMessage( 'accesskey-save' )->text() . ']',
                );
                $buttons['save'] = Xml::element( 'input', $temp, '' );

                ++$tabindex; // use the same for preview and live preview
                $temp = array(
                        'id' => 'wpPreview',
                        'name' => 'wpPreview',
                        'type' => 'submit',
                        'tabindex' => $tabindex,
                        'value' => wfMessage( 'showpreview' )->text(),
                        'accesskey' => wfMessage( 'accesskey-preview' )->text(),
                        'title' => wfMessage( 'tooltip-preview' )->text() . ' [' . wfMessage( 'accesskey-preview' )->text() . ']',
                );
                $buttons['preview'] = Xml::element( 'input', $temp, '' );
                $buttons['live'] = '';

                $temp = array(
                        'id' => 'wpDiff',
                        'name' => 'wpDiff',
                        'type' => 'submit',
                        'tabindex' => ++$tabindex,
                        'value' => wfMessage( 'showdiff' )->text(),
                        'accesskey' => wfMessage( 'accesskey-diff' )->text(),
                        'title' => wfMessage( 'tooltip-diff' )->text() . ' [' . wfMessage( 'accesskey-diff' )->text() . ']',
                );
                $buttons['diff'] = Xml::element( 'input', $temp, '' );

                wfRunHooks( 'EditPageBeforeEditButtons', array( &$this, &$buttons, &$tabindex ) );
                return $buttons;
        }

        /**
         * Output preview text only. This can be sucked into the edit page
         * via JavaScript, and saves the server time rendering the skin as
         * well as theoretically being more robust on the client (doesn't
         * disturb the edit box's undo history, won't eat your text on
         * failure, etc).
         *
         * @todo This doesn't include category or interlanguage links.
         *       Would need to enhance it a bit, "<s>maybe wrap them in XML
         *       or something...</s>" that might also require more skin
         *       initialization, so check whether that's a problem.
         */
        function livePreview() {
                global $wgOut;
                $wgOut->disable();
                header( 'Content-type: text/xml; charset=utf-8' );
                header( 'Cache-control: no-cache' );

                $previewText = $this->getPreviewText();
                #$categories = $skin->getCategoryLinks();

                $s =
                '<?xml version="1.0" encoding="UTF-8" ?>' . "\n" .
                Xml::tags( 'livepreview', null,
                        Xml::element( 'preview', null, $previewText )
                        #.      Xml::element( 'category', null, $categories )
                );
                echo $s;
        }

        /**
         * Call the stock "user is blocked" page
         *
         * @deprecated in 1.19; throw an exception directly instead
         */
        function blockedPage() {
                wfDeprecated( __METHOD__, '1.19' );
                global $wgUser;

                throw new UserBlockedError( $wgUser->getBlock() );
        }

        /**
         * Produce the stock "please login to edit pages" page
         *
         * @deprecated in 1.19; throw an exception directly instead
         */
        function userNotLoggedInPage() {
                wfDeprecated( __METHOD__, '1.19' );
                throw new PermissionsError( 'edit' );
        }

        /**
         * Show an error page saying to the user that he has insufficient permissions
         * to create a new page
         *
         * @deprecated in 1.19; throw an exception directly instead
         */
        function noCreatePermission() {
                wfDeprecated( __METHOD__, '1.19' );
                $permission = $this->mTitle->isTalkPage() ? 'createtalk' : 'createpage';
                throw new PermissionsError( $permission );
        }

        /**
         * Creates a basic error page which informs the user that
         * they have attempted to edit a nonexistent section.
         */
        function noSuchSectionPage() {
                global $wgOut;

                $wgOut->prepareErrorPage( wfMessage( 'nosuchsectiontitle' ) );

                $res = wfMessage( 'nosuchsectiontext', $this->section )->parseAsBlock();
                wfRunHooks( 'EditPageNoSuchSection', array( &$this, &$res ) );
                $wgOut->addHTML( $res );

                $wgOut->returnToMain( false, $this->mTitle );
        }

        /**
         * Produce the stock "your edit contains spam" page
         *
         * @param string|bool $match Text which triggered one or more filters
         * @deprecated since 1.17 Use method spamPageWithContent() instead
         */
        static function spamPage( $match = false ) {
                wfDeprecated( __METHOD__, '1.17' );

                global $wgOut, $wgTitle;

                $wgOut->prepareErrorPage( wfMessage( 'spamprotectiontitle' ) );

                $wgOut->addHTML( '<div id="spamprotected">' );
                $wgOut->addWikiMsg( 'spamprotectiontext' );
                if ( $match ) {
                        $wgOut->addWikiMsg( 'spamprotectionmatch', wfEscapeWikiText( $match ) );
                }
                $wgOut->addHTML( '</div>' );

                $wgOut->returnToMain( false, $wgTitle );
        }

        /**
         * Show "your edit contains spam" page with your diff and text
         *
         * @param $match string|Array|bool Text (or array of texts) which triggered one or more filters
         */
        public function spamPageWithContent( $match = false ) {
                global $wgOut, $wgLang;
                $this->textbox2 = $this->textbox1;

                if ( is_array( $match ) ) {
                        $match = $wgLang->listToText( $match );
                }
                $wgOut->prepareErrorPage( wfMessage( 'spamprotectiontitle' ) );

                $wgOut->addHTML( '<div id="spamprotected">' );
                $wgOut->addWikiMsg( 'spamprotectiontext' );
                if ( $match ) {
                        $wgOut->addWikiMsg( 'spamprotectionmatch', wfEscapeWikiText( $match ) );
                }
                $wgOut->addHTML( '</div>' );

                $wgOut->wrapWikiMsg( '<h2>$1</h2>', "yourdiff" );
                $this->showDiff();

                $wgOut->wrapWikiMsg( '<h2>$1</h2>', "yourtext" );
                $this->showTextbox2();

                $wgOut->addReturnTo( $this->getContextTitle(), array( 'action' => 'edit' ) );
        }

        /**
         * Format an anchor fragment as it would appear for a given section name
         * @param $text String
         * @return String
         * @private
         */
        function sectionAnchor( $text ) {
                global $wgParser;
                return $wgParser->guessSectionNameFromWikiText( $text );
        }

        /**
         * Check if the browser is on a blacklist of user-agents known to
         * mangle UTF-8 data on form submission. Returns true if Unicode
         * should make it through, false if it's known to be a problem.
         * @return bool
         * @private
         */
        function checkUnicodeCompliantBrowser() {
                global $wgBrowserBlackList, $wgRequest;

                $currentbrowser = $wgRequest->getHeader( 'User-Agent' );
                if ( $currentbrowser === false ) {
                        // No User-Agent header sent? Trust it by default...
                        return true;
                }

                foreach ( $wgBrowserBlackList as $browser ) {
                        if ( preg_match( $browser, $currentbrowser ) ) {
                                return false;
                        }
                }
                return true;
        }

        /**
         * Filter an input field through a Unicode de-armoring process if it
         * came from an old browser with known broken Unicode editing issues.
         *
         * @param $request WebRequest
         * @param $field String
         * @return String
         * @private
         */
        function safeUnicodeInput( $request, $field ) {
                $text = rtrim( $request->getText( $field ) );
                return $request->getBool( 'safemode' )
                        ? $this->unmakesafe( $text )
                        : $text;
        }

        /**
         * @param $request WebRequest
         * @param $text string
         * @return string
         */
        function safeUnicodeText( $request, $text ) {
                $text = rtrim( $text );
                return $request->getBool( 'safemode' )
                        ? $this->unmakesafe( $text )
                        : $text;
        }

        /**
         * Filter an output field through a Unicode armoring process if it is
         * going to an old browser with known broken Unicode editing issues.
         *
         * @param $text String
         * @return String
         * @private
         */
        function safeUnicodeOutput( $text ) {
                global $wgContLang;
                $codedText = $wgContLang->recodeForEdit( $text );
                return $this->checkUnicodeCompliantBrowser()
                        ? $codedText
                        : $this->makesafe( $codedText );
        }

        /**
         * A number of web browsers are known to corrupt non-ASCII characters
         * in a UTF-8 text editing environment. To protect against this,
         * detected browsers will be served an armored version of the text,
         * with non-ASCII chars converted to numeric HTML character references.
         *
         * Preexisting such character references will have a 0 added to them
         * to ensure that round-trips do not alter the original data.
         *
         * @param $invalue String
         * @return String
         * @private
         */
        function makesafe( $invalue ) {
                // Armor existing references for reversibility.
                $invalue = strtr( $invalue, array( "&#x" => "&#x0" ) );

                $bytesleft = 0;
                $result = "";
                $working = 0;
                for ( $i = 0; $i < strlen( $invalue ); $i++ ) {
                        $bytevalue = ord( $invalue[$i] );
                        if ( $bytevalue <= 0x7F ) { // 0xxx xxxx
                                $result .= chr( $bytevalue );
                                $bytesleft = 0;
                        } elseif ( $bytevalue <= 0xBF ) { // 10xx xxxx
                                $working = $working << 6;
                                $working += ( $bytevalue & 0x3F );
                                $bytesleft--;
                                if ( $bytesleft <= 0 ) {
                                        $result .= "&#x" . strtoupper( dechex( $working ) ) . ";";
                                }
                        } elseif ( $bytevalue <= 0xDF ) { // 110x xxxx
                                $working = $bytevalue & 0x1F;
                                $bytesleft = 1;
                        } elseif ( $bytevalue <= 0xEF ) { // 1110 xxxx
                                $working = $bytevalue & 0x0F;
                                $bytesleft = 2;
                        } else { // 1111 0xxx
                                $working = $bytevalue & 0x07;
                                $bytesleft = 3;
                        }
                }
                return $result;
        }

        /**
         * Reverse the previously applied transliteration of non-ASCII characters
         * back to UTF-8. Used to protect data from corruption by broken web browsers
         * as listed in $wgBrowserBlackList.
         *
         * @param $invalue String
         * @return String
         * @private
         */
        function unmakesafe( $invalue ) {
                $result = "";
                for ( $i = 0; $i < strlen( $invalue ); $i++ ) {
                        if ( ( substr( $invalue, $i, 3 ) == "&#x" ) && ( $invalue[$i + 3] != '0' ) ) {
                                $i += 3;
                                $hexstring = "";
                                do {
                                        $hexstring .= $invalue[$i];
                                        $i++;
                                } while ( ctype_xdigit( $invalue[$i] ) && ( $i < strlen( $invalue ) ) );

                                // Do some sanity checks. These aren't needed for reversibility,
                                // but should help keep the breakage down if the editor
                                // breaks one of the entities whilst editing.
                                if ( ( substr( $invalue, $i, 1 ) == ";" ) and ( strlen( $hexstring ) <= 6 ) ) {
                                        $codepoint = hexdec( $hexstring );
                                        $result .= codepointToUtf8( $codepoint );
                                } else {
                                        $result .= "&#x" . $hexstring . substr( $invalue, $i, 1 );
                                }
                        } else {
                                $result .= substr( $invalue, $i, 1 );
                        }
                }
                // reverse the transform that we made for reversibility reasons.
                return strtr( $result, array( "&#x0" => "&#x" ) );
        }
}