CategoryViewer.php

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<?php
class CategoryViewer extends ContextSource {
    var $limit, $from, $until,
        $articles, $articles_start_char,
        $children, $children_start_char,
        $showGallery, $imgsNoGalley,
        $imgsNoGallery_start_char,
        $imgsNoGallery;
 
    var $nextPage;
 
    var $flip;
 
    var $title;
 
    var $collation;
 
    var $gallery;
 
    private $cat;
 
    private $query;
 
    function __construct( $title, IContextSource $context, $from = array(),
        $until = array(), $query = array()
    ) {
        global $wgCategoryPagingLimit;
        $this->title = $title;
        $this->setContext( $context );
        $this->from = $from;
        $this->until = $until;
        $this->limit = $wgCategoryPagingLimit;
        $this->cat = Category::newFromTitle( $title );
        $this->query = $query;
        $this->collation = Collation::singleton();
        unset( $this->query['title'] );
    }
 
    public function getHTML() {
        global $wgCategoryMagicGallery;
        wfProfileIn( __METHOD__ );
 
        $this->showGallery = $wgCategoryMagicGallery && !$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->getCode(), 'dir' => $lang->getDir() );
        # put a div around the headings which are in the user language
        $r = Html::openElement( 'div', $langAttribs ) . $r . '</div>';
 
        wfProfileOut( __METHOD__ );
        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 );
            } catch ( MWException $e ) {
                // User specified something invalid, fallback to default.
                $this->gallery = ImageGalleryBase::factory();
            }
 
            $this->gallery->setHideBadImages();
            $this->gallery->setContext( $this->getContext() );
        } else {
            $this->imgsNoGallery = array();
            $this->imgsNoGallery_start_char = array();
        }
    }
 
    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 );
    }
 
    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 );
    }
 
    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 ) );
        }
    }
 
    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->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 ( $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 );
                }
            }
        }
    }
 
    function getCategoryTop() {
        $r = $this->getCategoryBottom();
        return $r === ''
            ? $r
            : "<br style=\"clear:both;\"/>\n" . $r;
    }
 
    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;
    }
 
    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;
    }
 
    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;
    }
 
    private function getSectionPagingLinks( $type ) {
        if ( isset( $this->until[$type] ) && $this->until[$type] !== null ) {
            return $this->pagingLinks( $this->nextPage[$type], $this->until[$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 '';
        }
    }
 
    function getCategoryBottom() {
        return '';
    }
 
    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->getCode(), 'dir' => $pageLang->getDir(),
            'class' => 'mw-content-' . $pageLang->getDir() );
        $list = Html::rawElement( 'div', $attribs, $list );
 
        return $list;
    }
 
    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;
    }
 
    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;
    }
 
    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();
    }
 
    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 );
    }
 
    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;
            $this->cat->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();
    }
}