Implement extension registration from an extension.json file

[mediawiki.git] / includes / CategoryViewer.php

<?php
/**
 * List and paging of category members.
 *
 * 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
 */

class CategoryViewer extends ContextSource {
        /** @var int */
        public $limit;

        /** @var array */
        public $from;

        /** @var array */
        public $until;

        /** @var string[] */
        public $articles;

        /** @var array */
        public $articles_start_char;

        /** @var array */
        public $children;

        /** @var array */
        public $children_start_char;

        /** @var bool */
        public $showGallery;

        /** @var array */
        public $imgsNoGallery_start_char;

        /** @var array */
        public $imgsNoGallery;

        /** @var array */
        public $nextPage;

        /** @var array */
        protected $prevPage;

        /** @var array */
        public $flip;

        /** @var Title */
        public $title;

        /** @var Collation */
        public $collation;

        /** @var ImageGallery */
        public $gallery;

        /** @var Category Category object for this page. */
        private $cat;

        /** @var array The original query array, to be used in generating paging links. */
        private $query;

        /**
         * @since 1.19 $context is a second, required parameter
         * @param Title $title
         * @param IContextSource $context
         * @param array $from An array with keys page, subcat,
         *        and file for offset of results of each section (since 1.17)
         * @param array $until An array with 3 keys for until of each section (since 1.17)
         * @param array $query
         */
        function __construct( $title, IContextSource $context, $from = array(),
                $until = array(), $query = array()
        ) {
                $this->title = $title;
                $this->setContext( $context );
                $this->from = $from;
                $this->until = $until;
                $this->limit = $context->getConfig()->get( 'CategoryPagingLimit' );
                $this->cat = Category::newFromTitle( $title );
                $this->query = $query;
                $this->collation = Collation::singleton();
                unset( $this->query['title'] );
        }

        /**
         * Format the category data list.
         *
         * @return string HTML output
         */
        public function getHTML() {

                $this->showGallery = $this->getConfig()->get( 'CategoryMagicGallery' )
                        && !$this->getOutput()->mNoGallery;

                $this->clearCategoryState();
                $this->doCategoryQuery();
                $this->finaliseCategoryState();

                $r = $this->getSubcategorySection() .
                        $this->getPagesSection() .
                        $this->getImageSection();

                if ( $r == '' ) {
                        // If there is no category content to display, only
                        // show the top part of the navigation links.
                        // @todo FIXME: Cannot be completely suppressed because it
                        //        is unknown if 'until' or 'from' makes this
                        //        give 0 results.
                        $r = $r . $this->getCategoryTop();
                } else {
                        $r = $this->getCategoryTop() .
                                $r .
                                $this->getCategoryBottom();
                }

                // Give a proper message if category is empty
                if ( $r == '' ) {
                        $r = $this->msg( 'category-empty' )->parseAsBlock();
                }

                $lang = $this->getLanguage();
                $langAttribs = array( 'lang' => $lang->getHtmlCode(), 'dir' => $lang->getDir() );
                # put a div around the headings which are in the user language
                $r = Html::openElement( 'div', $langAttribs ) . $r . '</div>';

                return $r;
        }

        function clearCategoryState() {
                $this->articles = array();
                $this->articles_start_char = array();
                $this->children = array();
                $this->children_start_char = array();
                if ( $this->showGallery ) {
                        // Note that null for mode is taken to mean use default.
                        $mode = $this->getRequest()->getVal( 'gallerymode', null );
                        try {
                                $this->gallery = ImageGalleryBase::factory( $mode, $this->getContext() );
                        } catch ( MWException $e ) {
                                // User specified something invalid, fallback to default.
                                $this->gallery = ImageGalleryBase::factory( false, $this->getContext() );
                        }

                        $this->gallery->setHideBadImages();
                } else {
                        $this->imgsNoGallery = array();
                        $this->imgsNoGallery_start_char = array();
                }
        }

        /**
         * Add a subcategory to the internal lists, using a Category object
         * @param Category $cat
         * @param string $sortkey
         * @param int $pageLength
         */
        function addSubcategoryObject( Category $cat, $sortkey, $pageLength ) {
                // Subcategory; strip the 'Category' namespace from the link text.
                $title = $cat->getTitle();

                $link = Linker::link( $title, htmlspecialchars( $title->getText() ) );
                if ( $title->isRedirect() ) {
                        // This didn't used to add redirect-in-category, but might
                        // as well be consistent with the rest of the sections
                        // on a category page.
                        $link = '<span class="redirect-in-category">' . $link . '</span>';
                }
                $this->children[] = $link;

                $this->children_start_char[] =
                        $this->getSubcategorySortChar( $cat->getTitle(), $sortkey );
        }

        /**
         * Get the character to be used for sorting subcategories.
         * If there's a link from Category:A to Category:B, the sortkey of the resulting
         * entry in the categorylinks table is Category:A, not A, which it SHOULD be.
         * Workaround: If sortkey == "Category:".$title, than use $title for sorting,
         * else use sortkey...
         *
         * @param Title $title
         * @param string $sortkey The human-readable sortkey (before transforming to icu or whatever).
         * @return string
         */
        function getSubcategorySortChar( $title, $sortkey ) {
                global $wgContLang;

                if ( $title->getPrefixedText() == $sortkey ) {
                        $word = $title->getDBkey();
                } else {
                        $word = $sortkey;
                }

                $firstChar = $this->collation->getFirstLetter( $word );

                return $wgContLang->convert( $firstChar );
        }

        /**
         * Add a page in the image namespace
         * @param Title $title
         * @param string $sortkey
         * @param int $pageLength
         * @param bool $isRedirect
         */
        function addImage( Title $title, $sortkey, $pageLength, $isRedirect = false ) {
                global $wgContLang;
                if ( $this->showGallery ) {
                        $flip = $this->flip['file'];
                        if ( $flip ) {
                                $this->gallery->insert( $title );
                        } else {
                                $this->gallery->add( $title );
                        }
                } else {
                        $link = Linker::link( $title );
                        if ( $isRedirect ) {
                                // This seems kind of pointless given 'mw-redirect' class,
                                // but keeping for back-compatibility with user css.
                                $link = '<span class="redirect-in-category">' . $link . '</span>';
                        }
                        $this->imgsNoGallery[] = $link;

                        $this->imgsNoGallery_start_char[] = $wgContLang->convert(
                                $this->collation->getFirstLetter( $sortkey ) );
                }
        }

        /**
         * Add a miscellaneous page
         * @param Title $title
         * @param string $sortkey
         * @param int $pageLength
         * @param bool $isRedirect
         */
        function addPage( $title, $sortkey, $pageLength, $isRedirect = false ) {
                global $wgContLang;

                $link = Linker::link( $title );
                if ( $isRedirect ) {
                        // This seems kind of pointless given 'mw-redirect' class,
                        // but keeping for back-compatibility with user css.
                        $link = '<span class="redirect-in-category">' . $link . '</span>';
                }
                $this->articles[] = $link;

                $this->articles_start_char[] = $wgContLang->convert(
                        $this->collation->getFirstLetter( $sortkey ) );
        }

        function finaliseCategoryState() {
                if ( $this->flip['subcat'] ) {
                        $this->children = array_reverse( $this->children );
                        $this->children_start_char = array_reverse( $this->children_start_char );
                }
                if ( $this->flip['page'] ) {
                        $this->articles = array_reverse( $this->articles );
                        $this->articles_start_char = array_reverse( $this->articles_start_char );
                }
                if ( !$this->showGallery && $this->flip['file'] ) {
                        $this->imgsNoGallery = array_reverse( $this->imgsNoGallery );
                        $this->imgsNoGallery_start_char = array_reverse( $this->imgsNoGallery_start_char );
                }
        }

        function doCategoryQuery() {
                $dbr = wfGetDB( DB_SLAVE, 'category' );

                $this->nextPage = array(
                        'page' => null,
                        'subcat' => null,
                        'file' => null,
                );
                $this->prevPage = array(
                        'page' => null,
                        'subcat' => null,
                        'file' => null,
                );

                $this->flip = array( 'page' => false, 'subcat' => false, 'file' => false );

                foreach ( array( 'page', 'subcat', 'file' ) as $type ) {
                        # Get the sortkeys for start/end, if applicable.  Note that if
                        # the collation in the database differs from the one
                        # set in $wgCategoryCollation, pagination might go totally haywire.
                        $extraConds = array( 'cl_type' => $type );
                        if ( isset( $this->from[$type] ) && $this->from[$type] !== null ) {
                                $extraConds[] = 'cl_sortkey >= '
                                        . $dbr->addQuotes( $this->collation->getSortKey( $this->from[$type] ) );
                        } elseif ( isset( $this->until[$type] ) && $this->until[$type] !== null ) {
                                $extraConds[] = 'cl_sortkey < '
                                        . $dbr->addQuotes( $this->collation->getSortKey( $this->until[$type] ) );
                                $this->flip[$type] = true;
                        }

                        $res = $dbr->select(
                                array( 'page', 'categorylinks', 'category' ),
                                array( 'page_id', 'page_title', 'page_namespace', 'page_len',
                                        'page_is_redirect', 'cl_sortkey', 'cat_id', 'cat_title',
                                        'cat_subcats', 'cat_pages', 'cat_files',
                                        'cl_sortkey_prefix', 'cl_collation' ),
                                array_merge( array( 'cl_to' => $this->title->getDBkey() ), $extraConds ),
                                __METHOD__,
                                array(
                                        'USE INDEX' => array( 'categorylinks' => 'cl_sortkey' ),
                                        'LIMIT' => $this->limit + 1,
                                        'ORDER BY' => $this->flip[$type] ? 'cl_sortkey DESC' : 'cl_sortkey',
                                ),
                                array(
                                        'categorylinks' => array( 'INNER JOIN', 'cl_from = page_id' ),
                                        'category' => array( 'LEFT JOIN', array(
                                                'cat_title = page_title',
                                                'page_namespace' => NS_CATEGORY
                                        ))
                                )
                        );

                        $count = 0;
                        foreach ( $res as $row ) {
                                $title = Title::newFromRow( $row );
                                if ( $row->cl_collation === '' ) {
                                        // Hack to make sure that while updating from 1.16 schema
                                        // and db is inconsistent, that the sky doesn't fall.
                                        // See r83544. Could perhaps be removed in a couple decades...
                                        $humanSortkey = $row->cl_sortkey;
                                } else {
                                        $humanSortkey = $title->getCategorySortkey( $row->cl_sortkey_prefix );
                                }

                                if ( ++$count > $this->limit ) {
                                        # We've reached the one extra which shows that there
                                        # are additional pages to be had. Stop here...
                                        $this->nextPage[$type] = $humanSortkey;
                                        break;
                                }
                                if ( $count == $this->limit ) {
                                        $this->prevPage[$type] = $humanSortkey;
                                }

                                if ( $title->getNamespace() == NS_CATEGORY ) {
                                        $cat = Category::newFromRow( $row, $title );
                                        $this->addSubcategoryObject( $cat, $humanSortkey, $row->page_len );
                                } elseif ( $title->getNamespace() == NS_FILE ) {
                                        $this->addImage( $title, $humanSortkey, $row->page_len, $row->page_is_redirect );
                                } else {
                                        $this->addPage( $title, $humanSortkey, $row->page_len, $row->page_is_redirect );
                                }
                        }
                }
        }

        /**
         * @return string
         */
        function getCategoryTop() {
                $r = $this->getCategoryBottom();
                return $r === ''
                        ? $r
                        : "<br style=\"clear:both;\"/>\n" . $r;
        }

        /**
         * @return string
         */
        function getSubcategorySection() {
                # Don't show subcategories section if there are none.
                $r = '';
                $rescnt = count( $this->children );
                $dbcnt = $this->cat->getSubcatCount();
                $countmsg = $this->getCountMessage( $rescnt, $dbcnt, 'subcat' );

                if ( $rescnt > 0 ) {
                        # Showing subcategories
                        $r .= "<div id=\"mw-subcategories\">\n";
                        $r .= '<h2>' . $this->msg( 'subcategories' )->text() . "</h2>\n";
                        $r .= $countmsg;
                        $r .= $this->getSectionPagingLinks( 'subcat' );
                        $r .= $this->formatList( $this->children, $this->children_start_char );
                        $r .= $this->getSectionPagingLinks( 'subcat' );
                        $r .= "\n</div>";
                }
                return $r;
        }

        /**
         * @return string
         */
        function getPagesSection() {
                $ti = wfEscapeWikiText( $this->title->getText() );
                # Don't show articles section if there are none.
                $r = '';

                # @todo FIXME: Here and in the other two sections: we don't need to bother
                # with this rigmarole if the entire category contents fit on one page
                # and have already been retrieved.  We can just use $rescnt in that
                # case and save a query and some logic.
                $dbcnt = $this->cat->getPageCount() - $this->cat->getSubcatCount()
                        - $this->cat->getFileCount();
                $rescnt = count( $this->articles );
                $countmsg = $this->getCountMessage( $rescnt, $dbcnt, 'article' );

                if ( $rescnt > 0 ) {
                        $r = "<div id=\"mw-pages\">\n";
                        $r .= '<h2>' . $this->msg( 'category_header', $ti )->text() . "</h2>\n";
                        $r .= $countmsg;
                        $r .= $this->getSectionPagingLinks( 'page' );
                        $r .= $this->formatList( $this->articles, $this->articles_start_char );
                        $r .= $this->getSectionPagingLinks( 'page' );
                        $r .= "\n</div>";
                }
                return $r;
        }

        /**
         * @return string
         */
        function getImageSection() {
                $r = '';
                $rescnt = $this->showGallery ? $this->gallery->count() : count( $this->imgsNoGallery );
                if ( $rescnt > 0 ) {
                        $dbcnt = $this->cat->getFileCount();
                        $countmsg = $this->getCountMessage( $rescnt, $dbcnt, 'file' );

                        $r .= "<div id=\"mw-category-media\">\n";
                        $r .= '<h2>' .
                                $this->msg(
                                        'category-media-header',
                                        wfEscapeWikiText( $this->title->getText() )
                                )->text() .
                                "</h2>\n";
                        $r .= $countmsg;
                        $r .= $this->getSectionPagingLinks( 'file' );
                        if ( $this->showGallery ) {
                                $r .= $this->gallery->toHTML();
                        } else {
                                $r .= $this->formatList( $this->imgsNoGallery, $this->imgsNoGallery_start_char );
                        }
                        $r .= $this->getSectionPagingLinks( 'file' );
                        $r .= "\n</div>";
                }
                return $r;
        }

        /**
         * Get the paging links for a section (subcats/pages/files), to go at the top and bottom
         * of the output.
         *
         * @param string $type 'page', 'subcat', or 'file'
         * @return string HTML output, possibly empty if there are no other pages
         */
        private function getSectionPagingLinks( $type ) {
                if ( isset( $this->until[$type] ) && $this->until[$type] !== null ) {
                        // The new value for the until parameter should be pointing to the first
                        // result displayed on the page which is the second last result retrieved
                        // from the database.The next link should have a from parameter pointing
                        // to the until parameter of the current page.
                        if ( $this->nextPage[$type] !== null ) {
                                return $this->pagingLinks( $this->prevPage[$type], $this->until[$type], $type );
                        } else {
                                // If the nextPage variable is null, it means that we have reached the first page
                                // and therefore the previous link should be disabled.
                                return $this->pagingLinks( null, $this->until[$type], $type );
                        }
                } elseif ( $this->nextPage[$type] !== null
                        || ( isset( $this->from[$type] ) && $this->from[$type] !== null )
                ) {
                        return $this->pagingLinks( $this->from[$type], $this->nextPage[$type], $type );
                } else {
                        return '';
                }
        }

        /**
         * @return string
         */
        function getCategoryBottom() {
                return '';
        }

        /**
         * Format a list of articles chunked by letter, either as a
         * bullet list or a columnar format, depending on the length.
         *
         * @param array $articles
         * @param array $articles_start_char
         * @param int $cutoff
         * @return string
         * @private
         */
        function formatList( $articles, $articles_start_char, $cutoff = 6 ) {
                $list = '';
                if ( count( $articles ) > $cutoff ) {
                        $list = self::columnList( $articles, $articles_start_char );
                } elseif ( count( $articles ) > 0 ) {
                        // for short lists of articles in categories.
                        $list = self::shortList( $articles, $articles_start_char );
                }

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

                return $list;
        }

        /**
         * Format a list of articles chunked by letter in a three-column
         * list, ordered vertically.
         *
         * TODO: Take the headers into account when creating columns, so they're
         * more visually equal.
         *
         * More distant TODO: Scrap this and use CSS columns, whenever IE finally
         * supports those.
         *
         * @param array $articles
         * @param string[] $articles_start_char
         * @return string
         * @private
         */
        static function columnList( $articles, $articles_start_char ) {
                $columns = array_combine( $articles, $articles_start_char );
                # Split into three columns
                $columns = array_chunk( $columns, ceil( count( $columns ) / 3 ), true /* preserve keys */ );

                $ret = '<table style="width: 100%;"><tr style="vertical-align: top;">';
                $prevchar = null;

                foreach ( $columns as $column ) {
                        $ret .= '<td style="width: 33.3%;">';
                        $colContents = array();

                        # Kind of like array_flip() here, but we keep duplicates in an
                        # array instead of dropping them.
                        foreach ( $column as $article => $char ) {
                                if ( !isset( $colContents[$char] ) ) {
                                        $colContents[$char] = array();
                                }
                                $colContents[$char][] = $article;
                        }

                        $first = true;
                        foreach ( $colContents as $char => $articles ) {
                                # Change space to non-breaking space to keep headers aligned
                                $h3char = $char === ' ' ? '&#160;' : htmlspecialchars( $char );

                                $ret .= '<h3>' . $h3char;
                                if ( $first && $char === $prevchar ) {
                                        # We're continuing a previous chunk at the top of a new
                                        # column, so add " cont." after the letter.
                                        $ret .= ' ' . wfMessage( 'listingcontinuesabbrev' )->escaped();
                                }
                                $ret .= "</h3>\n";

                                $ret .= '<ul><li>';
                                $ret .= implode( "</li>\n<li>", $articles );
                                $ret .= '</li></ul>';

                                $first = false;
                                $prevchar = $char;
                        }

                        $ret .= "</td>\n";
                }

                $ret .= '</tr></table>';
                return $ret;
        }

        /**
         * Format a list of articles chunked by letter in a bullet list.
         * @param array $articles
         * @param string[] $articles_start_char
         * @return string
         * @private
         */
        static function shortList( $articles, $articles_start_char ) {
                $r = '<h3>' . htmlspecialchars( $articles_start_char[0] ) . "</h3>\n";
                $r .= '<ul><li>' . $articles[0] . '</li>';
                $articleCount = count( $articles );
                for ( $index = 1; $index < $articleCount; $index++ ) {
                        if ( $articles_start_char[$index] != $articles_start_char[$index - 1] ) {
                                $r .= "</ul><h3>" . htmlspecialchars( $articles_start_char[$index] ) . "</h3>\n<ul>";
                        }

                        $r .= "<li>{$articles[$index]}</li>";
                }
                $r .= '</ul>';
                return $r;
        }

        /**
         * Create paging links, as a helper method to getSectionPagingLinks().
         *
         * @param string $first The 'until' parameter for the generated URL
         * @param string $last The 'from' parameter for the generated URL
         * @param string $type A prefix for parameters, 'page' or 'subcat' or
         *     'file'
         * @return string HTML
         */
        private function pagingLinks( $first, $last, $type = '' ) {
                $prevLink = $this->msg( 'prevn' )->numParams( $this->limit )->escaped();

                if ( $first != '' ) {
                        $prevQuery = $this->query;
                        $prevQuery["{$type}until"] = $first;
                        unset( $prevQuery["{$type}from"] );
                        $prevLink = Linker::linkKnown(
                                $this->addFragmentToTitle( $this->title, $type ),
                                $prevLink,
                                array(),
                                $prevQuery
                        );
                }

                $nextLink = $this->msg( 'nextn' )->numParams( $this->limit )->escaped();

                if ( $last != '' ) {
                        $lastQuery = $this->query;
                        $lastQuery["{$type}from"] = $last;
                        unset( $lastQuery["{$type}until"] );
                        $nextLink = Linker::linkKnown(
                                $this->addFragmentToTitle( $this->title, $type ),
                                $nextLink,
                                array(),
                                $lastQuery
                        );
                }

                return $this->msg( 'categoryviewer-pagedlinks' )->rawParams( $prevLink, $nextLink )->escaped();
        }

        /**
         * Takes a title, and adds the fragment identifier that
         * corresponds to the correct segment of the category.
         *
         * @param Title $title The title (usually $this->title)
         * @param string $section Which section
         * @throws MWException
         * @return Title
         */
        private function addFragmentToTitle( $title, $section ) {
                switch ( $section ) {
                        case 'page':
                                $fragment = 'mw-pages';
                                break;
                        case 'subcat':
                                $fragment = 'mw-subcategories';
                                break;
                        case 'file':
                                $fragment = 'mw-category-media';
                                break;
                        default:
                                throw new MWException( __METHOD__ .
                                        " Invalid section $section." );
                }

                return Title::makeTitle( $title->getNamespace(),
                        $title->getDBkey(), $fragment );
        }

        /**
         * What to do if the category table conflicts with the number of results
         * returned?  This function says what. Each type is considered independently
         * of the other types.
         *
         * @param int $rescnt The number of items returned by our database query.
         * @param int $dbcnt The number of items according to the category table.
         * @param string $type 'subcat', 'article', or 'file'
         * @return string A message giving the number of items, to output to HTML.
         */
        private function getCountMessage( $rescnt, $dbcnt, $type ) {
                // There are three cases:
                //   1) The category table figure seems sane.  It might be wrong, but
                //      we can't do anything about it if we don't recalculate it on ev-
                //      ery category view.
                //   2) The category table figure isn't sane, like it's smaller than the
                //      number of actual results, *but* the number of results is less
                //      than $this->limit and there's no offset.  In this case we still
                //      know the right figure.
                //   3) We have no idea.

                // Check if there's a "from" or "until" for anything

                // This is a little ugly, but we seem to use different names
                // for the paging types then for the messages.
                if ( $type === 'article' ) {
                        $pagingType = 'page';
                } else {
                        $pagingType = $type;
                }

                $fromOrUntil = false;
                if ( ( isset( $this->from[$pagingType] ) && $this->from[$pagingType] !== null ) ||
                        ( isset( $this->until[$pagingType] ) && $this->until[$pagingType] !== null )
                ) {
                        $fromOrUntil = true;
                }

                if ( $dbcnt == $rescnt ||
                        ( ( $rescnt == $this->limit || $fromOrUntil ) && $dbcnt > $rescnt )
                ) {
                        // Case 1: seems sane.
                        $totalcnt = $dbcnt;
                } elseif ( $rescnt < $this->limit && !$fromOrUntil ) {
                        // Case 2: not sane, but salvageable.  Use the number of results.
                        // Since there are fewer than 200, we can also take this opportunity
                        // to refresh the incorrect category table entry -- which should be
                        // quick due to the small number of entries.
                        $totalcnt = $rescnt;
                        $category = $this->cat;
                        wfGetDB( DB_MASTER )->onTransactionIdle( function () use ( $category ) {
                                $category->refreshCounts();
                        } );
                } else {
                        // Case 3: hopeless.  Don't give a total count at all.
                        // Messages: category-subcat-count-limited, category-article-count-limited,
                        // category-file-count-limited
                        return $this->msg( "category-$type-count-limited" )->numParams( $rescnt )->parseAsBlock();
                }
                // Messages: category-subcat-count, category-article-count, category-file-count
                return $this->msg( "category-$type-count" )->numParams( $rescnt, $totalcnt )->parseAsBlock();
        }
}