Add a way for packagers to override some installation details

[mediawiki.git] / includes / installer / WebInstaller.php

<?php
/**
 * Core installer web 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
 * @ingroup Deployment
 */

/**
 * Class for the core installer web interface.
 *
 * @ingroup Deployment
 * @since 1.17
 */
class WebInstaller extends Installer {

        /**
         * @var WebInstallerOutput
         */
        public $output;

        /**
         * WebRequest object.
         *
         * @var WebRequest
         */
        public $request;

        /**
         * Cached session array.
         *
         * @var array
         */
        protected $session;

        /**
         * Captured PHP error text. Temporary.
         * @var array
         */
        protected $phpErrors;

        /**
         * The main sequence of page names. These will be displayed in turn.
         * To add one:
         *    * Add it here
         *    * Add a config-page-<name> message
         *    * Add a WebInstaller_<name> class
         * @var array
         */
        public $pageSequence = array(
                'Language',
                'ExistingWiki',
                'Welcome',
                'DBConnect',
                'Upgrade',
                'DBSettings',
                'Name',
                'Options',
                'Install',
                'Complete',
        );

        /**
         * Out of sequence pages, selectable by the user at any time.
         * @var array
         */
        protected $otherPages = array(
                'Restart',
                'Readme',
                'ReleaseNotes',
                'Copying',
                'UpgradeDoc', // Can't use Upgrade due to Upgrade step
        );

        /**
         * Array of pages which have declared that they have been submitted, have validated
         * their input, and need no further processing.
         * @var array
         */
        protected $happyPages;

        /**
         * List of "skipped" pages. These are pages that will automatically continue
         * to the next page on any GET request. To avoid breaking the "back" button,
         * they need to be skipped during a back operation.
         * @var array
         */
        protected $skippedPages;

        /**
         * Flag indicating that session data may have been lost.
         * @var bool
         */
        public $showSessionWarning = false;

        /**
         * Numeric index of the page we're on
         * @var int
         */
        protected $tabIndex = 1;

        /**
         * Name of the page we're on
         * @var string
         */
        protected $currentPageName;

        /**
         * Constructor.
         *
         * @param $request WebRequest
         */
        public function __construct( WebRequest $request ) {
                parent::__construct();
                $this->output = new WebInstallerOutput( $this );
                $this->request = $request;

                // Add parser hooks
                global $wgParser;
                $wgParser->setHook( 'downloadlink', array( $this, 'downloadLinkHook' ) );
                $wgParser->setHook( 'doclink', array( $this, 'docLink' ) );
        }

        /**
         * Main entry point.
         *
         * @param $session Array: initial session array
         *
         * @return Array: new session array
         */
        public function execute( array $session ) {
                $this->session = $session;

                if ( isset( $session['settings'] ) ) {
                        $this->settings = $session['settings'] + $this->settings;
                }

                $this->exportVars();
                $this->setupLanguage();

                if( ( $this->getVar( '_InstallDone' ) || $this->getVar( '_UpgradeDone' ) )
                        && $this->request->getVal( 'localsettings' ) )
                {
                        $this->request->response()->header( 'Content-type: application/x-httpd-php' );
                        $this->request->response()->header(
                                'Content-Disposition: attachment; filename="LocalSettings.php"'
                        );

                        $ls = InstallerOverrides::getLocalSettingsGenerator( $this );
                        $rightsProfile = $this->rightsProfiles[$this->getVar( '_RightsProfile' )];
                        foreach( $rightsProfile as $group => $rightsArr ) {
                                $ls->setGroupRights( $group, $rightsArr );
                        }
                        echo $ls->getText();
                        return $this->session;
                }

                $cssDir = $this->request->getVal( 'css' );
                if( $cssDir ) {
                        $cssDir = ( $cssDir == 'rtl' ? 'rtl' : 'ltr' );
                        $this->request->response()->header( 'Content-type: text/css' );
                        echo $this->output->getCSS( $cssDir );
                        return $this->session;
                }

                if ( isset( $session['happyPages'] ) ) {
                        $this->happyPages = $session['happyPages'];
                } else {
                        $this->happyPages = array();
                }

                if ( isset( $session['skippedPages'] ) ) {
                        $this->skippedPages = $session['skippedPages'];
                } else {
                        $this->skippedPages = array();
                }

                $lowestUnhappy = $this->getLowestUnhappy();

                # Special case for Creative Commons partner chooser box.
                if ( $this->request->getVal( 'SubmitCC' ) ) {
                        $page = $this->getPageByName( 'Options' );
                        $this->output->useShortHeader();
                        $this->output->allowFrames();
                        $page->submitCC();
                        return $this->finish();
                }

                if ( $this->request->getVal( 'ShowCC' ) ) {
                        $page = $this->getPageByName( 'Options' );
                        $this->output->useShortHeader();
                        $this->output->allowFrames();
                        $this->output->addHTML( $page->getCCDoneBox() );
                        return $this->finish();
                }

                # Get the page name.
                $pageName = $this->request->getVal( 'page' );

                if ( in_array( $pageName, $this->otherPages ) ) {
                        # Out of sequence
                        $pageId = false;
                        $page = $this->getPageByName( $pageName );
                } else {
                        # Main sequence
                        if ( !$pageName || !in_array( $pageName, $this->pageSequence ) ) {
                                $pageId = $lowestUnhappy;
                        } else {
                                $pageId = array_search( $pageName, $this->pageSequence );
                        }

                        # If necessary, move back to the lowest-numbered unhappy page
                        if ( $pageId > $lowestUnhappy ) {
                                $pageId = $lowestUnhappy;
                                if ( $lowestUnhappy == 0 ) {
                                        # Knocked back to start, possible loss of session data.
                                        $this->showSessionWarning = true;
                                }
                        }

                        $pageName = $this->pageSequence[$pageId];
                        $page = $this->getPageByName( $pageName );
                }

                # If a back button was submitted, go back without submitting the form data.
                if ( $this->request->wasPosted() && $this->request->getBool( 'submit-back' ) ) {
                        if ( $this->request->getVal( 'lastPage' ) ) {
                                $nextPage = $this->request->getVal( 'lastPage' );
                        } elseif ( $pageId !== false ) {
                                # Main sequence page
                                # Skip the skipped pages
                                $nextPageId = $pageId;

                                do {
                                        $nextPageId--;
                                        $nextPage = $this->pageSequence[$nextPageId];
                                } while( isset( $this->skippedPages[$nextPage] ) );
                        } else {
                                $nextPage = $this->pageSequence[$lowestUnhappy];
                        }

                        $this->output->redirect( $this->getUrl( array( 'page' => $nextPage ) ) );
                        return $this->finish();
                }

                # Execute the page.
                $this->currentPageName = $page->getName();
                $this->startPageWrapper( $pageName );

                if( $page->isSlow() ) {
                        $this->disableTimeLimit();
                }

                $result = $page->execute();

                $this->endPageWrapper();

                if ( $result == 'skip' ) {
                        # Page skipped without explicit submission.
                        # Skip it when we click "back" so that we don't just go forward again.
                        $this->skippedPages[$pageName] = true;
                        $result = 'continue';
                } else {
                        unset( $this->skippedPages[$pageName] );
                }

                # If it was posted, the page can request a continue to the next page.
                if ( $result === 'continue' && !$this->output->headerDone() ) {
                        if ( $pageId !== false ) {
                                $this->happyPages[$pageId] = true;
                        }

                        $lowestUnhappy = $this->getLowestUnhappy();

                        if ( $this->request->getVal( 'lastPage' ) ) {
                                $nextPage = $this->request->getVal( 'lastPage' );
                        } elseif ( $pageId !== false ) {
                                $nextPage = $this->pageSequence[$pageId + 1];
                        } else {
                                $nextPage = $this->pageSequence[$lowestUnhappy];
                        }

                        if ( array_search( $nextPage, $this->pageSequence ) > $lowestUnhappy ) {
                                $nextPage = $this->pageSequence[$lowestUnhappy];
                        }

                        $this->output->redirect( $this->getUrl( array( 'page' => $nextPage ) ) );
                }

                return $this->finish();
        }

        /**
         * Find the next page in sequence that hasn't been completed
         * @return int
         */
        public function getLowestUnhappy() {
                if ( count( $this->happyPages ) == 0 ) {
                        return 0;
                } else {
                        return max( array_keys( $this->happyPages ) ) + 1;
                }
        }

        /**
         * Start the PHP session. This may be called before execute() to start the PHP session.
         *
         * @return bool
         */
        public function startSession() {
                if( wfIniGetBool( 'session.auto_start' ) || session_id() ) {
                        // Done already
                        return true;
                }

                $this->phpErrors = array();
                set_error_handler( array( $this, 'errorHandler' ) );
                session_start();
                restore_error_handler();

                if ( $this->phpErrors ) {
                        $this->showError( 'config-session-error', $this->phpErrors[0] );
                        return false;
                }

                return true;
        }

        /**
         * Get a hash of data identifying this MW installation.
         *
         * This is used by mw-config/index.php to prevent multiple installations of MW
         * on the same cookie domain from interfering with each other.
         *
         * @return string
         */
        public function getFingerprint() {
                // Get the base URL of the installation
                $url = $this->request->getFullRequestURL();
                if ( preg_match( '!^(.*\?)!', $url, $m) ) {
                        // Trim query string
                        $url = $m[1];
                }
                if ( preg_match( '!^(.*)/[^/]*/[^/]*$!', $url, $m ) ) {
                        // This... seems to try to get the base path from
                        // the /mw-config/index.php. Kinda scary though?
                        $url = $m[1];
                }
                return md5( serialize( array(
                        'local path' => dirname( dirname( __FILE__ ) ),
                        'url' => $url,
                        'version' => $GLOBALS['wgVersion']
                ) ) );
        }

        /**
         * Show an error message in a box. Parameters are like wfMsg().
         * @param $msg
         */
        public function showError( $msg /*...*/ ) {
                $args = func_get_args();
                array_shift( $args );
                $args = array_map( 'htmlspecialchars', $args );
                $msg = wfMsgReal( $msg, $args, false, false, false );
                $this->output->addHTML( $this->getErrorBox( $msg ) );
        }

        /**
         * Temporary error handler for session start debugging.
         * @param $errno
         * @param $errstr string
         */
        public function errorHandler( $errno, $errstr ) {
                $this->phpErrors[] = $errstr;
        }

        /**
         * Clean up from execute()
         *
         * @return array
         */
        public function finish() {
                $this->output->output();

                $this->session['happyPages'] = $this->happyPages;
                $this->session['skippedPages'] = $this->skippedPages;
                $this->session['settings'] = $this->settings;

                return $this->session;
        }

        /**
         * We're restarting the installation, reset the session, happyPages, etc
         */
        public function reset() {
                $this->session = array();
                $this->happyPages = array();
                $this->settings = array();
        }

        /**
         * Get a URL for submission back to the same script.
         *
         * @param $query array
         * @return string
         */
        public function getUrl( $query = array() ) {
                $url = $this->request->getRequestURL();
                # Remove existing query
                $url = preg_replace( '/\?.*$/', '', $url );

                if ( $query ) {
                        $url .= '?' . wfArrayToCGI( $query );
                }

                return $url;
        }

        /**
         * Get a WebInstallerPage by name.
         *
         * @param $pageName String
         * @return WebInstallerPage
         */
        public function getPageByName( $pageName ) {
                $pageClass = 'WebInstaller_' . $pageName;

                return new $pageClass( $this );
        }

        /**
         * Get a session variable.
         *
         * @param $name String
         * @param $default
         * @return null
         */
        public function getSession( $name, $default = null ) {
                if ( !isset( $this->session[$name] ) ) {
                        return $default;
                } else {
                        return $this->session[$name];
                }
        }

        /**
         * Set a session variable.
         * @param $name String key for the variable
         * @param $value Mixed
         */
        public function setSession( $name, $value ) {
                $this->session[$name] = $value;
        }

        /**
         * Get the next tabindex attribute value.
         * @return int
         */
        public function nextTabIndex() {
                return $this->tabIndex++;
        }

        /**
         * Initializes language-related variables.
         */
        public function setupLanguage() {
                global $wgLang, $wgContLang, $wgLanguageCode;

                if ( $this->getSession( 'test' ) === null && !$this->request->wasPosted() ) {
                        $wgLanguageCode = $this->getAcceptLanguage();
                        $wgLang = $wgContLang = Language::factory( $wgLanguageCode );
                        $this->setVar( 'wgLanguageCode', $wgLanguageCode );
                        $this->setVar( '_UserLang', $wgLanguageCode );
                } else {
                        $wgLanguageCode = $this->getVar( 'wgLanguageCode' );
                        $wgContLang = Language::factory( $wgLanguageCode );
                }
        }

        /**
         * Retrieves MediaWiki language from Accept-Language HTTP header.
         *
         * @return string
         */
        public function getAcceptLanguage() {
                global $wgLanguageCode, $wgRequest;

                $mwLanguages = Language::fetchLanguageNames();
                $headerLanguages = array_keys( $wgRequest->getAcceptLang() );

                foreach ( $headerLanguages as $lang ) {
                        if ( isset( $mwLanguages[$lang] ) ) {
                                return $lang;
                        }
                }

                return $wgLanguageCode;
        }

        /**
         * Called by execute() before page output starts, to show a page list.
         *
         * @param $currentPageName String
         */
        private function startPageWrapper( $currentPageName ) {
                $s = "<div class=\"config-page-wrapper\">\n";
                $s .= "<div class=\"config-page\">\n";
                $s .= "<div class=\"config-page-list\"><ul>\n";
                $lastHappy = -1;

                foreach ( $this->pageSequence as $id => $pageName ) {
                        $happy = !empty( $this->happyPages[$id] );
                        $s .= $this->getPageListItem(
                                $pageName,
                                $happy || $lastHappy == $id - 1,
                                $currentPageName
                        );

                        if ( $happy ) {
                                $lastHappy = $id;
                        }
                }

                $s .= "</ul><br/><ul>\n";
                $s .= $this->getPageListItem( 'Restart', true, $currentPageName );
                $s .= "</ul></div>\n"; // end list pane
                $s .= Html::element( 'h2', array(),
                                wfMsg( 'config-page-' . strtolower( $currentPageName ) ) );

                $this->output->addHTMLNoFlush( $s );
        }

        /**
         * Get a list item for the page list.
         *
         * @param $pageName String
         * @param $enabled Boolean
         * @param $currentPageName String
         *
         * @return string
         */
        private function getPageListItem( $pageName, $enabled, $currentPageName ) {
                $s = "<li class=\"config-page-list-item\">";
                $name = wfMsg( 'config-page-' . strtolower( $pageName ) );

                if ( $enabled ) {
                        $query = array( 'page' => $pageName );

                        if ( !in_array( $pageName, $this->pageSequence ) ) {
                                if ( in_array( $currentPageName, $this->pageSequence ) ) {
                                        $query['lastPage'] = $currentPageName;
                                }

                                $link = Html::element( 'a',
                                        array(
                                                'href' => $this->getUrl( $query )
                                        ),
                                        $name
                                );
                        } else {
                                $link = htmlspecialchars( $name );
                        }

                        if ( $pageName == $currentPageName ) {
                                $s .= "<span class=\"config-page-current\">$link</span>";
                        } else {
                                $s .= $link;
                        }
                } else {
                        $s .= Html::element( 'span',
                                array(
                                        'class' => 'config-page-disabled'
                                ),
                                $name
                        );
                }

                $s .= "</li>\n";

                return $s;
        }

        /**
         * Output some stuff after a page is finished.
         */
        private function endPageWrapper() {
                $this->output->addHTMLNoFlush(
                                        "<div class=\"visualClear\"></div>\n" .
                                "</div>\n" .
                                "<div class=\"visualClear\"></div>\n" .
                        "</div>" );
        }

        /**
         * Get HTML for an error box with an icon.
         *
         * @param $text String: wikitext, get this with wfMsgNoTrans()
         *
         * @return string
         */
        public function getErrorBox( $text ) {
                return $this->getInfoBox( $text, 'critical-32.png', 'config-error-box' );
        }

        /**
         * Get HTML for a warning box with an icon.
         *
         * @param $text String: wikitext, get this with wfMsgNoTrans()
         *
         * @return string
         */
        public function getWarningBox( $text ) {
                return $this->getInfoBox( $text, 'warning-32.png', 'config-warning-box' );
        }

        /**
         * Get HTML for an info box with an icon.
         *
         * @param $text String: wikitext, get this with wfMsgNoTrans()
         * @param $icon String: icon name, file in skins/common/images
         * @param $class String: additional class name to add to the wrapper div
         *
         * @return string
         */
        public function getInfoBox( $text, $icon = false, $class = false ) {
                $text = $this->parse( $text, true );
                $icon = ( $icon == false ) ? '../skins/common/images/info-32.png' : '../skins/common/images/'.$icon;
                $alt = wfMsg( 'config-information' );
                return Html::infoBox( $text, $icon, $alt, $class, false );
        }

        /**
         * Get small text indented help for a preceding form field.
         * Parameters like wfMsg().
         *
         * @param $msg
         * @return string
         */
        public function getHelpBox( $msg /*, ... */ ) {
                $args = func_get_args();
                array_shift( $args );
                $args = array_map( 'htmlspecialchars', $args );
                $text = wfMsgReal( $msg, $args, false, false, false );
                $html = $this->parse( $text, true );

                return "<div class=\"mw-help-field-container\">\n" .
                        "<span class=\"mw-help-field-hint\">" . wfMsgHtml( 'config-help' ) . "</span>\n" .
                        "<span class=\"mw-help-field-data\">" . $html . "</span>\n" .
                        "</div>\n";
        }

        /**
         * Output a help box.
         * @param $msg String key for wfMsg()
         */
        public function showHelpBox( $msg /*, ... */ ) {
                $args = func_get_args();
                $html = call_user_func_array( array( $this, 'getHelpBox' ), $args );
                $this->output->addHTML( $html );
        }

        /**
         * Show a short informational message.
         * Output looks like a list.
         *
         * @param $msg string
         */
        public function showMessage( $msg /*, ... */ ) {
                $args = func_get_args();
                array_shift( $args );
                $html = '<div class="config-message">' .
                        $this->parse( wfMsgReal( $msg, $args, false, false, false ) ) .
                        "</div>\n";
                $this->output->addHTML( $html );
        }

        /**
         * @param $status Status
         */
        public function showStatusMessage( Status $status ) {
                $errors = array_merge( $status->getErrorsArray(), $status->getWarningsArray() );
                foreach ( $errors as $error ) {
                        call_user_func_array( array( $this, 'showMessage' ), $error );
                }
        }

        /**
         * Label a control by wrapping a config-input div around it and putting a
         * label before it.
         *
         * @param $msg
         * @param $forId
         * @param $contents
         * @param $helpData string
         * @return string
         */
        public function label( $msg, $forId, $contents, $helpData = "" ) {
                if ( strval( $msg ) == '' ) {
                        $labelText = '&#160;';
                } else {
                        $labelText = wfMsgHtml( $msg );
                }

                $attributes = array( 'class' => 'config-label' );

                if ( $forId ) {
                        $attributes['for'] = $forId;
                }

                return
                        "<div class=\"config-block\">\n" .
                        "  <div class=\"config-block-label\">\n" .
                        Xml::tags( 'label',
                                $attributes,
                                $labelText ) . "\n" .
                                $helpData .
                        "  </div>\n" .
                        "  <div class=\"config-block-elements\">\n" .
                                $contents .
                        "  </div>\n" .
                        "</div>\n";
        }

        /**
         * Get a labelled text box to configure a variable.
         *
         * @param $params Array
         *    Parameters are:
         *      var:        The variable to be configured (required)
         *      label:      The message name for the label (required)
         *      attribs:    Additional attributes for the input element (optional)
         *      controlName: The name for the input element (optional)
         *      value:      The current value of the variable (optional)
         *      help:           The html for the help text (optional)
         *
         * @return string
         */
        public function getTextBox( $params ) {
                if ( !isset( $params['controlName'] ) ) {
                        $params['controlName'] = 'config_' . $params['var'];
                }

                if ( !isset( $params['value'] ) ) {
                        $params['value'] = $this->getVar( $params['var'] );
                }

                if ( !isset( $params['attribs'] ) ) {
                        $params['attribs'] = array();
                }
                if ( !isset( $params['help'] ) ) {
                        $params['help'] = "";
                }
                return
                        $this->label(
                                $params['label'],
                                $params['controlName'],
                                Xml::input(
                                        $params['controlName'],
                                        30, // intended to be overridden by CSS
                                        $params['value'],
                                        $params['attribs'] + array(
                                                'id' => $params['controlName'],
                                                'class' => 'config-input-text',
                                                'tabindex' => $this->nextTabIndex()
                                        )
                                ),
                                $params['help']
                        );
        }

        /**
         * Get a labelled textarea to configure a variable
         *
         * @param $params Array
         *    Parameters are:
         *      var:        The variable to be configured (required)
         *      label:      The message name for the label (required)
         *      attribs:    Additional attributes for the input element (optional)
         *      controlName: The name for the input element (optional)
         *      value:      The current value of the variable (optional)
         *      help:           The html for the help text (optional)
         *
         * @return string
         */
        public function getTextArea( $params ) {
                if ( !isset( $params['controlName'] ) ) {
                        $params['controlName'] = 'config_' . $params['var'];
                }

                if ( !isset( $params['value'] ) ) {
                        $params['value'] = $this->getVar( $params['var'] );
                }

                if ( !isset( $params['attribs'] ) ) {
                        $params['attribs'] = array();
                }
                if ( !isset( $params['help'] ) ) {
                        $params['help'] = "";
                }
                return
                        $this->label(
                                $params['label'],
                                $params['controlName'],
                                Xml::textarea(
                                        $params['controlName'],
                                        $params['value'],
                                        30,
                                        5,
                                        $params['attribs'] + array(
                                                'id' => $params['controlName'],
                                                'class' => 'config-input-text',
                                                'tabindex' => $this->nextTabIndex()
                                        )
                                ),
                                $params['help']
                        );
        }

        /**
         * Get a labelled password box to configure a variable.
         *
         * Implements password hiding
         * @param $params Array
         *    Parameters are:
         *      var:        The variable to be configured (required)
         *      label:      The message name for the label (required)
         *      attribs:    Additional attributes for the input element (optional)
         *      controlName: The name for the input element (optional)
         *      value:      The current value of the variable (optional)
         *      help:           The html for the help text (optional)
         *
         * @return string
         */
        public function getPasswordBox( $params ) {
                if ( !isset( $params['value'] ) ) {
                        $params['value'] = $this->getVar( $params['var'] );
                }

                if ( !isset( $params['attribs'] ) ) {
                        $params['attribs'] = array();
                }

                $params['value'] = $this->getFakePassword( $params['value'] );
                $params['attribs']['type'] = 'password';

                return $this->getTextBox( $params );
        }

        /**
         * Get a labelled checkbox to configure a boolean variable.
         *
         * @param $params Array
         *    Parameters are:
         *      var:        The variable to be configured (required)
         *      label:      The message name for the label (required)
         *      attribs:    Additional attributes for the input element (optional)
         *      controlName: The name for the input element (optional)
         *      value:      The current value of the variable (optional)
         *      help:           The html for the help text (optional)
         *
         * @return string
         */
        public function getCheckBox( $params ) {
                if ( !isset( $params['controlName'] ) ) {
                        $params['controlName'] = 'config_' . $params['var'];
                }

                if ( !isset( $params['value'] ) ) {
                        $params['value'] = $this->getVar( $params['var'] );
                }

                if ( !isset( $params['attribs'] ) ) {
                        $params['attribs'] = array();
                }
                if ( !isset( $params['help'] ) ) {
                        $params['help'] = "";
                }
                if( isset( $params['rawtext'] ) ) {
                        $labelText = $params['rawtext'];
                } else {
                        $labelText = $this->parse( wfMsg( $params['label'] ) );
                }

                return
                        "<div class=\"config-input-check\">\n" .
                        $params['help'] .
                        "<label>\n" .
                        Xml::check(
                                $params['controlName'],
                                $params['value'],
                                $params['attribs'] + array(
                                        'id' => $params['controlName'],
                                        'tabindex' => $this->nextTabIndex(),
                                )
                        ) .
                        $labelText . "\n" .
                        "</label>\n" .
                        "</div>\n";
        }

        /**
         * Get a set of labelled radio buttons.
         *
         * @param $params Array
         *    Parameters are:
         *      var:            The variable to be configured (required)
         *      label:          The message name for the label (required)
         *      itemLabelPrefix: The message name prefix for the item labels (required)
         *      values:         List of allowed values (required)
         *      itemAttribs     Array of attribute arrays, outer key is the value name (optional)
         *      commonAttribs   Attribute array applied to all items
         *      controlName:    The name for the input element (optional)
         *      value:          The current value of the variable (optional)
         *      help:           The html for the help text (optional)
         *
         * @return string
         */
        public function getRadioSet( $params ) {
                if ( !isset( $params['controlName']  ) ) {
                        $params['controlName'] = 'config_' . $params['var'];
                }

                if ( !isset( $params['value'] ) ) {
                        $params['value'] = $this->getVar( $params['var'] );
                }

                if ( !isset( $params['label'] ) ) {
                        $label = '';
                } else {
                        $label = $params['label'];
                }
                if ( !isset( $params['help'] ) ) {
                        $params['help'] = "";
                }
                $s = "<ul>\n";
                foreach ( $params['values'] as $value ) {
                        $itemAttribs = array();

                        if ( isset( $params['commonAttribs'] ) ) {
                                $itemAttribs = $params['commonAttribs'];
                        }

                        if ( isset( $params['itemAttribs'][$value] ) ) {
                                $itemAttribs = $params['itemAttribs'][$value] + $itemAttribs;
                        }

                        $checked = $value == $params['value'];
                        $id = $params['controlName'] . '_' . $value;
                        $itemAttribs['id'] = $id;
                        $itemAttribs['tabindex'] = $this->nextTabIndex();

                        $s .=
                                '<li>' .
                                Xml::radio( $params['controlName'], $value, $checked, $itemAttribs ) .
                                '&#160;' .
                                Xml::tags( 'label', array( 'for' => $id ), $this->parse(
                                        wfMsgNoTrans( $params['itemLabelPrefix'] . strtolower( $value ) )
                                ) ) .
                                "</li>\n";
                }

                $s .= "</ul>\n";

                return $this->label( $label, $params['controlName'], $s, $params['help'] );
        }

        /**
         * Output an error or warning box using a Status object.
         *
         * @param $status Status
         */
        public function showStatusBox( $status ) {
                if( !$status->isGood() ) {
                        $text = $status->getWikiText();

                        if( $status->isOk() ) {
                                $box = $this->getWarningBox( $text );
                        } else {
                                $box = $this->getErrorBox( $text );
                        }

                        $this->output->addHTML( $box );
                }
        }

        /**
         * Convenience function to set variables based on form data.
         * Assumes that variables containing "password" in the name are (potentially
         * fake) passwords.
         *
         * @param $varNames Array
         * @param $prefix String: the prefix added to variables to obtain form names
         *
         * @return array
         */
        public function setVarsFromRequest( $varNames, $prefix = 'config_' ) {
                $newValues = array();

                foreach ( $varNames as $name ) {
                        $value = trim( $this->request->getVal( $prefix . $name ) );
                        $newValues[$name] = $value;

                        if ( $value === null ) {
                                // Checkbox?
                                $this->setVar( $name, false );
                        } else {
                                if ( stripos( $name, 'password' ) !== false ) {
                                        $this->setPassword( $name, $value );
                                } else {
                                        $this->setVar( $name, $value );
                                }
                        }
                }

                return $newValues;
        }

        /**
         * Helper for Installer::docLink()
         *
         * @param $page
         * @return string
         */
        protected function getDocUrl( $page ) {
                $url = "{$_SERVER['PHP_SELF']}?page=" . urlencode( $page );

                if ( in_array( $this->currentPageName, $this->pageSequence ) ) {
                        $url .= '&lastPage=' . urlencode( $this->currentPageName );
                }

                return $url;
        }

        /**
         * Extension tag hook for a documentation link.
         *
         * @param $linkText
         * @param $attribs
         * @param $parser
         * @return string
         */
        public function docLink( $linkText, $attribs, $parser ) {
                $url = $this->getDocUrl( $attribs['href'] );
                return '<a href="' . htmlspecialchars( $url ) . '">' .
                        htmlspecialchars( $linkText ) .
                        '</a>';
        }

        /**
         * Helper for "Download LocalSettings" link on WebInstall_Complete
         *
         * @param $text
         * @param $attribs
         * @param $parser
         * @return String Html for download link
         */
        public function downloadLinkHook( $text, $attribs, $parser  ) {
                $img = Html::element( 'img', array(
                        'src' => '../skins/common/images/download-32.png',
                        'width' => '32',
                        'height' => '32',
                ) );
                $anchor = Html::rawElement( 'a',
                        array( 'href' => $this->getURL( array( 'localsettings' => 1 ) ) ),
                        $img . ' ' . wfMsgHtml( 'config-download-localsettings' ) );
                return Html::rawElement( 'div', array( 'class' => 'config-download-link' ), $anchor );
        }

        /**
         * @return bool
         */
        public function envCheckPath( ) {
                // PHP_SELF isn't available sometimes, such as when PHP is CGI but
                // cgi.fix_pathinfo is disabled. In that case, fall back to SCRIPT_NAME
                // to get the path to the current script... hopefully it's reliable. SIGH
                $path = false;
                if ( !empty( $_SERVER['PHP_SELF'] ) ) {
                        $path = $_SERVER['PHP_SELF'];
                } elseif ( !empty( $_SERVER['SCRIPT_NAME'] ) ) {
                        $path = $_SERVER['SCRIPT_NAME'];
                }
                if ($path !== false) {
                        $uri = preg_replace( '{^(.*)/(mw-)?config.*$}', '$1', $path );
                        $this->setVar( 'wgScriptPath', $uri );
                } else {
                        $this->showError( 'config-no-uri' );
                        return false;
                }
                return parent::envCheckPath();
        }

        protected function envGetDefaultServer() {
                return WebRequest::detectServer();
        }
}