includes/CategoryPage.php

   1 <?php
   2 /**
   3  * Class for viewing MediaWiki category description pages.
   4  * Modelled after ImagePage.php.
   5  *
   6  * @file
   7  */
   8
   9 if ( !defined( 'MEDIAWIKI' ) )
  10         die( 1 );
  11
  12 /**
  13  * Special handling for category description pages, showing pages,
  14  * subcategories and file that belong to the category
  15  */
  16 class CategoryPage extends Article {
  17         # Subclasses can change this to override the viewer class.
  18         protected $mCategoryViewerClass = 'CategoryViewer';
  19
  20         protected function newPage( Title $title ) {
  21                 // Overload mPage with a category-specific page
  22                 return new WikiCategoryPage( $title );
  23         }
  24
  25         /**
  26          * Constructor from a page id
  27          * @param $id Int article ID to load
  28          */
  29         public static function newFromID( $id ) {
  30                 $t = Title::newFromID( $id );
  31                 # @todo FIXME: Doesn't inherit right
  32                 return $t == null ? null : new self( $t );
  33                 # return $t == null ? null : new static( $t ); // PHP 5.3
  34         }
  35
  36         function view() {
  37                 $request = $this->getContext()->getRequest();
  38                 $diff = $request->getVal( 'diff' );
  39                 $diffOnly = $request->getBool( 'diffonly',
  40                         $this->getContext()->getUser()->getOption( 'diffonly' ) );
  41
  42                 if ( isset( $diff ) && $diffOnly ) {
  43                         return parent::view();
  44                 }
  45
  46                 if ( !wfRunHooks( 'CategoryPageView', array( &$this ) ) ) {
  47                         return;
  48                 }
  49
  50                 if ( NS_CATEGORY == $this->mTitle->getNamespace() ) {
  51                         $this->openShowCategory();
  52                 }
  53
  54                 parent::view();
  55
  56                 if ( NS_CATEGORY == $this->mTitle->getNamespace() ) {
  57                         $this->closeShowCategory();
  58                 }
  59         }
  60
  61         function openShowCategory() {
  62                 # For overloading
  63         }
  64
  65         function closeShowCategory() {
  66                 // Use these as defaults for back compat --catrope
  67                 $request = $this->getContext()->getRequest();
  68                 $oldFrom = $request->getVal( 'from' );
  69                 $oldUntil = $request->getVal( 'until' );
  70
  71                 $reqArray = $request->getValues();
  72
  73                 $from = $until = array();
  74                 foreach ( array( 'page', 'subcat', 'file' ) as $type ) {
  75                         $from[$type] = $request->getVal( "{$type}from", $oldFrom );
  76                         $until[$type] = $request->getVal( "{$type}until", $oldUntil );
  77
  78                         // Do not want old-style from/until propagating in nav links.
  79                         if ( !isset( $reqArray["{$type}from"] ) && isset( $reqArray["from"] ) ) {
  80                                 $reqArray["{$type}from"] = $reqArray["from"];
  81                         }
  82                         if ( !isset( $reqArray["{$type}to"] ) && isset( $reqArray["to"] ) ) {
  83                                 $reqArray["{$type}to"] = $reqArray["to"];
  84                         }
  85                 }
  86
  87                 unset( $reqArray["from"] );
  88                 unset( $reqArray["to"] );
  89
  90                 $viewer = new $this->mCategoryViewerClass( $this->mTitle, $this->getContext(), $from, $until, $reqArray );
  91                 $this->getContext()->getOutput()->addHTML( $viewer->getHTML() );
  92         }
  93 }
  94
  95 class CategoryViewer extends ContextSource {
  96         var $limit, $from, $until,
  97                 $articles, $articles_start_char,
  98                 $children, $children_start_char,
  99                 $showGallery, $imgsNoGalley,
 100                 $imgsNoGallery_start_char,
 101                 $imgsNoGallery;
 102
 103         /**
 104          * @var
 105          */
 106         var $nextPage;
 107
 108         /**
 109          * @var Array
 110          */
 111         var $flip;
 112
 113         /**
 114          * @var Title
 115          */
 116         var $title;
 117
 118         /**
 119          * @var Collation
 120          */
 121         var $collation;
 122
 123         /**
 124          * @var ImageGallery
 125          */
 126         var $gallery;
 127
 128         /**
 129          * Category object for this page
 130          * @var Category
 131          */
 132         private $cat;
 133
 134         /**
 135          * The original query array, to be used in generating paging links.
 136          * @var array
 137          */
 138         private $query;
 139
 140         /**
 141          * Constructor
 142          *
 143          * @since 1.19 $context is a second, required parameter
 144          * @param $title Title
 145          * @param $context IContextSource
 146          * @param $from String
 147          * @param $until String
 148          * @param $query Array
 149          */
 150         function __construct( $title, IContextSource $context, $from = '', $until = '', $query = array() ) {
 151                 global $wgCategoryPagingLimit;
 152                 $this->title = $title;
 153                 $this->setContext( $context );
 154                 $this->from = $from;
 155                 $this->until = $until;
 156                 $this->limit = $wgCategoryPagingLimit;
 157                 $this->cat = Category::newFromTitle( $title );
 158                 $this->query = $query;
 159                 $this->collation = Collation::singleton();
 160                 unset( $this->query['title'] );
 161         }
 162
 163         /**
 164          * Format the category data list.
 165          *
 166          * @return string HTML output
 167          */
 168         public function getHTML() {
 169                 global $wgCategoryMagicGallery;
 170                 wfProfileIn( __METHOD__ );
 171
 172                 $this->showGallery = $wgCategoryMagicGallery && !$this->getOutput()->mNoGallery;
 173
 174                 $this->clearCategoryState();
 175                 $this->doCategoryQuery();
 176                 $this->finaliseCategoryState();
 177
 178                 $r = $this->getSubcategorySection() .
 179                         $this->getPagesSection() .
 180                         $this->getImageSection();
 181
 182                 if ( $r == '' ) {
 183                         // If there is no category content to display, only
 184                         // show the top part of the navigation links.
 185                         // @todo FIXME: Cannot be completely suppressed because it
 186                         //        is unknown if 'until' or 'from' makes this
 187                         //        give 0 results.
 188                         $r = $r . $this->getCategoryTop();
 189                 } else {
 190                         $r = $this->getCategoryTop() .
 191                                 $r .
 192                                 $this->getCategoryBottom();
 193                 }
 194
 195                 // Give a proper message if category is empty
 196                 if ( $r == '' ) {
 197                         $r = wfMsgExt( 'category-empty', array( 'parse' ) );
 198                 }
 199
 200                 $lang = $this->getLang();
 201                 $langAttribs = array( 'lang' => $lang->getCode(), 'dir' => $lang->getDir() );
 202                 # put a div around the headings which are in the user language
 203                 $r = Html::openElement( 'div', $langAttribs ) . $r . '</div>';
 204
 205                 wfProfileOut( __METHOD__ );
 206                 return $r;
 207         }
 208
 209         function clearCategoryState() {
 210                 $this->articles = array();
 211                 $this->articles_start_char = array();
 212                 $this->children = array();
 213                 $this->children_start_char = array();
 214                 if ( $this->showGallery ) {
 215                         $this->gallery = new ImageGallery();
 216                         $this->gallery->setHideBadImages();
 217                 } else {
 218                         $this->imgsNoGallery = array();
 219                         $this->imgsNoGallery_start_char = array();
 220                 }
 221         }
 222
 223         /**
 224          * Add a subcategory to the internal lists, using a Category object
 225          */
 226         function addSubcategoryObject( Category $cat, $sortkey, $pageLength ) {
 227                 // Subcategory; strip the 'Category' namespace from the link text.
 228                 $title = $cat->getTitle();
 229
 230                 $link = Linker::link( $title, htmlspecialchars( $title->getText() ) );
 231                 if ( $title->isRedirect() ) {
 232                         // This didn't used to add redirect-in-category, but might
 233                         // as well be consistent with the rest of the sections
 234                         // on a category page.
 235                         $link = '<span class="redirect-in-category">' . $link . '</span>';
 236                 }
 237                 $this->children[] = $link;
 238
 239                 $this->children_start_char[] =
 240                         $this->getSubcategorySortChar( $cat->getTitle(), $sortkey );
 241         }
 242
 243         /**
 244          * Add a subcategory to the internal lists, using a title object
 245          * @deprecated since 1.17 kept for compatibility, please use addSubcategoryObject instead
 246          */
 247         function addSubcategory( Title $title, $sortkey, $pageLength ) {
 248                 $this->addSubcategoryObject( Category::newFromTitle( $title ), $sortkey, $pageLength );
 249         }
 250
 251         /**
 252         * Get the character to be used for sorting subcategories.
 253         * If there's a link from Category:A to Category:B, the sortkey of the resulting
 254         * entry in the categorylinks table is Category:A, not A, which it SHOULD be.
 255         * Workaround: If sortkey == "Category:".$title, than use $title for sorting,
 256         * else use sortkey...
 257         *
 258         * @param Title $title
 259         * @param string $sortkey The human-readable sortkey (before transforming to icu or whatever).
 260         */
 261         function getSubcategorySortChar( $title, $sortkey ) {
 262                 global $wgContLang;
 263
 264                 if ( $title->getPrefixedText() == $sortkey ) {
 265                         $word = $title->getDBkey();
 266                 } else {
 267                         $word = $sortkey;
 268                 }
 269
 270                 $firstChar = $this->collation->getFirstLetter( $word );
 271
 272                 return $wgContLang->convert( $firstChar );
 273         }
 274
 275         /**
 276          * Add a page in the image namespace
 277          */
 278         function addImage( Title $title, $sortkey, $pageLength, $isRedirect = false ) {
 279                 global $wgContLang;
 280                 if ( $this->showGallery ) {
 281                         $flip = $this->flip['file'];
 282                         if ( $flip ) {
 283                                 $this->gallery->insert( $title );
 284                         } else {
 285                                 $this->gallery->add( $title );
 286                         }
 287                 } else {
 288                         $link = Linker::link( $title );
 289                         if ( $isRedirect ) {
 290                                 // This seems kind of pointless given 'mw-redirect' class,
 291                                 // but keeping for back-compatibility with user css.
 292                                 $link = '<span class="redirect-in-category">' . $link . '</span>';
 293                         }
 294                         $this->imgsNoGallery[] = $link;
 295
 296                         $this->imgsNoGallery_start_char[] = $wgContLang->convert(
 297                                 $this->collation->getFirstLetter( $sortkey ) );
 298                 }
 299         }
 300
 301         /**
 302          * Add a miscellaneous page
 303          */
 304         function addPage( $title, $sortkey, $pageLength, $isRedirect = false ) {
 305                 global $wgContLang;
 306
 307                 $link = Linker::link( $title );
 308                 if ( $isRedirect ) {
 309                         // This seems kind of pointless given 'mw-redirect' class,
 310                         // but keeping for back-compatiability with user css.
 311                         $link = '<span class="redirect-in-category">' . $link . '</span>';
 312                 }
 313                 $this->articles[] = $link;
 314
 315                 $this->articles_start_char[] = $wgContLang->convert(
 316                         $this->collation->getFirstLetter( $sortkey ) );
 317         }
 318
 319         function finaliseCategoryState() {
 320                 if ( $this->flip['subcat'] ) {
 321                         $this->children            = array_reverse( $this->children );
 322                         $this->children_start_char = array_reverse( $this->children_start_char );
 323                 }
 324                 if ( $this->flip['page'] ) {
 325                         $this->articles            = array_reverse( $this->articles );
 326                         $this->articles_start_char = array_reverse( $this->articles_start_char );
 327                 }
 328                 if ( !$this->showGallery && $this->flip['file'] ) {
 329                         $this->imgsNoGallery            = array_reverse( $this->imgsNoGallery );
 330                         $this->imgsNoGallery_start_char = array_reverse( $this->imgsNoGallery_start_char );
 331                 }
 332         }
 333
 334         function doCategoryQuery() {
 335                 $dbr = wfGetDB( DB_SLAVE, 'category' );
 336
 337                 $this->nextPage = array(
 338                         'page' => null,
 339                         'subcat' => null,
 340                         'file' => null,
 341                 );
 342                 $this->flip = array( 'page' => false, 'subcat' => false, 'file' => false );
 343
 344                 foreach ( array( 'page', 'subcat', 'file' ) as $type ) {
 345                         # Get the sortkeys for start/end, if applicable.  Note that if
 346                         # the collation in the database differs from the one
 347                         # set in $wgCategoryCollation, pagination might go totally haywire.
 348                         $extraConds = array( 'cl_type' => $type );
 349                         if ( $this->from[$type] !== null ) {
 350                                 $extraConds[] = 'cl_sortkey >= '
 351                                         . $dbr->addQuotes( $this->collation->getSortKey( $this->from[$type] ) );
 352                         } elseif ( $this->until[$type] !== null ) {
 353                                 $extraConds[] = 'cl_sortkey < '
 354                                         . $dbr->addQuotes( $this->collation->getSortKey( $this->until[$type] ) );
 355                                 $this->flip[$type] = true;
 356                         }
 357
 358                         $res = $dbr->select(
 359                                 array( 'page', 'categorylinks', 'category' ),
 360                                 array( 'page_id', 'page_title', 'page_namespace', 'page_len',
 361                                         'page_is_redirect', 'cl_sortkey', 'cat_id', 'cat_title',
 362                                         'cat_subcats', 'cat_pages', 'cat_files',
 363                                         'cl_sortkey_prefix', 'cl_collation' ),
 364                                 array_merge( array( 'cl_to' => $this->title->getDBkey() ),  $extraConds ),
 365                                 __METHOD__,
 366                                 array(
 367                                         'USE INDEX' => array( 'categorylinks' => 'cl_sortkey' ),
 368                                         'LIMIT' => $this->limit + 1,
 369                                         'ORDER BY' => $this->flip[$type] ? 'cl_sortkey DESC' : 'cl_sortkey',
 370                                 ),
 371                                 array(
 372                                         'categorylinks'  => array( 'INNER JOIN', 'cl_from = page_id' ),
 373                                         'category' => array( 'LEFT JOIN', 'cat_title = page_title AND page_namespace = ' . NS_CATEGORY )
 374                                 )
 375                         );
 376
 377                         $count = 0;
 378                         foreach ( $res as $row ) {
 379                                 $title = Title::newFromRow( $row );
 380                                 if ( $row->cl_collation === '' ) {
 381                                         // Hack to make sure that while updating from 1.16 schema
 382                                         // and db is inconsistent, that the sky doesn't fall.
 383                                         // See r83544. Could perhaps be removed in a couple decades...
 384                                         $humanSortkey = $row->cl_sortkey;
 385                                 } else {
 386                                         $humanSortkey = $title->getCategorySortkey( $row->cl_sortkey_prefix );
 387                                 }
 388
 389                                 if ( ++$count > $this->limit ) {
 390                                         # We've reached the one extra which shows that there
 391                                         # are additional pages to be had. Stop here...
 392                                         $this->nextPage[$type] = $humanSortkey;
 393                                         break;
 394                                 }
 395
 396                                 if ( $title->getNamespace() == NS_CATEGORY ) {
 397                                         $cat = Category::newFromRow( $row, $title );
 398                                         $this->addSubcategoryObject( $cat, $humanSortkey, $row->page_len );
 399                                 } elseif ( $title->getNamespace() == NS_FILE ) {
 400                                         $this->addImage( $title, $humanSortkey, $row->page_len, $row->page_is_redirect );
 401                                 } else {
 402                                         $this->addPage( $title, $humanSortkey, $row->page_len, $row->page_is_redirect );
 403                                 }
 404                         }
 405                 }
 406         }
 407
 408         function getCategoryTop() {
 409                 $r = $this->getCategoryBottom();
 410                 return $r === ''
 411                         ? $r
 412                         : "<br style=\"clear:both;\"/>\n" . $r;
 413         }
 414
 415         function getSubcategorySection() {
 416                 # Don't show subcategories section if there are none.
 417                 $r = '';
 418                 $rescnt = count( $this->children );
 419                 $dbcnt = $this->cat->getSubcatCount();
 420                 $countmsg = $this->getCountMessage( $rescnt, $dbcnt, 'subcat' );
 421
 422                 if ( $rescnt > 0 ) {
 423                         # Showing subcategories
 424                         $r .= "<div id=\"mw-subcategories\">\n";
 425                         $r .= '<h2>' . wfMsg( 'subcategories' ) . "</h2>\n";
 426                         $r .= $countmsg;
 427                         $r .= $this->getSectionPagingLinks( 'subcat' );
 428                         $r .= $this->formatList( $this->children, $this->children_start_char );
 429                         $r .= $this->getSectionPagingLinks( 'subcat' );
 430                         $r .= "\n</div>";
 431                 }
 432                 return $r;
 433         }
 434
 435         function getPagesSection() {
 436                 $ti = htmlspecialchars( $this->title->getText() );
 437                 # Don't show articles section if there are none.
 438                 $r = '';
 439
 440                 # @todo FIXME: Here and in the other two sections: we don't need to bother
 441                 # with this rigamarole if the entire category contents fit on one page
 442                 # and have already been retrieved.  We can just use $rescnt in that
 443                 # case and save a query and some logic.
 444                 $dbcnt = $this->cat->getPageCount() - $this->cat->getSubcatCount()
 445                         - $this->cat->getFileCount();
 446                 $rescnt = count( $this->articles );
 447                 $countmsg = $this->getCountMessage( $rescnt, $dbcnt, 'article' );
 448
 449                 if ( $rescnt > 0 ) {
 450                         $r = "<div id=\"mw-pages\">\n";
 451                         $r .= '<h2>' . wfMsg( 'category_header', $ti ) . "</h2>\n";
 452                         $r .= $countmsg;
 453                         $r .= $this->getSectionPagingLinks( 'page' );
 454                         $r .= $this->formatList( $this->articles, $this->articles_start_char );
 455                         $r .= $this->getSectionPagingLinks( 'page' );
 456                         $r .= "\n</div>";
 457                 }
 458                 return $r;
 459         }
 460
 461         function getImageSection() {
 462                 $r = '';
 463                 $rescnt = $this->showGallery ? $this->gallery->count() : count( $this->imgsNoGallery );
 464                 if ( $rescnt > 0 ) {
 465                         $dbcnt = $this->cat->getFileCount();
 466                         $countmsg = $this->getCountMessage( $rescnt, $dbcnt, 'file' );
 467
 468                         $r .= "<div id=\"mw-category-media\">\n";
 469                         $r .= '<h2>' . wfMsg( 'category-media-header', htmlspecialchars( $this->title->getText() ) ) . "</h2>\n";
 470                         $r .= $countmsg;
 471                         $r .= $this->getSectionPagingLinks( 'file' );
 472                         if ( $this->showGallery ) {
 473                                 $r .= $this->gallery->toHTML();
 474                         } else {
 475                                 $r .= $this->formatList( $this->imgsNoGallery, $this->imgsNoGallery_start_char );
 476                         }
 477                         $r .= $this->getSectionPagingLinks( 'file' );
 478                         $r .= "\n</div>";
 479                 }
 480                 return $r;
 481         }
 482
 483         /**
 484          * Get the paging links for a section (subcats/pages/files), to go at the top and bottom
 485          * of the output.
 486          *
 487          * @param $type String: 'page', 'subcat', or 'file'
 488          * @return String: HTML output, possibly empty if there are no other pages
 489          */
 490         private function getSectionPagingLinks( $type ) {
 491                 if ( $this->until[$type] !== null ) {
 492                         return $this->pagingLinks( $this->nextPage[$type], $this->until[$type], $type );
 493                 } elseif ( $this->nextPage[$type] !== null || $this->from[$type] !== null ) {
 494                         return $this->pagingLinks( $this->from[$type], $this->nextPage[$type], $type );
 495                 } else {
 496                         return '';
 497                 }
 498         }
 499
 500         function getCategoryBottom() {
 501                 return '';
 502         }
 503
 504         /**
 505          * Format a list of articles chunked by letter, either as a
 506          * bullet list or a columnar format, depending on the length.
 507          *
 508          * @param $articles Array
 509          * @param $articles_start_char Array
 510          * @param $cutoff Int
 511          * @return String
 512          * @private
 513          */
 514         function formatList( $articles, $articles_start_char, $cutoff = 6 ) {
 515                 $list = '';
 516                 if ( count ( $articles ) > $cutoff ) {
 517                         $list = self::columnList( $articles, $articles_start_char );
 518                 } elseif ( count( $articles ) > 0 ) {
 519                         // for short lists of articles in categories.
 520                         $list = self::shortList( $articles, $articles_start_char );
 521                 }
 522
 523                 $pageLang = $this->title->getPageLanguage();
 524                 $attribs = array( 'lang' => $pageLang->getCode(), 'dir' => $pageLang->getDir(),
 525                         'class' => 'mw-content-'.$pageLang->getDir() );
 526                 $list = Html::rawElement( 'div', $attribs, $list );
 527
 528                 return $list;
 529         }
 530
 531         /**
 532          * Format a list of articles chunked by letter in a three-column
 533          * list, ordered vertically.
 534          *
 535          * TODO: Take the headers into account when creating columns, so they're
 536          * more visually equal.
 537          *
 538          * More distant TODO: Scrap this and use CSS columns, whenever IE finally
 539          * supports those.
 540          *
 541          * @param $articles Array
 542          * @param $articles_start_char Array
 543          * @return String
 544          * @private
 545          */
 546         static function columnList( $articles, $articles_start_char ) {
 547                 $columns = array_combine( $articles, $articles_start_char );
 548                 # Split into three columns
 549                 $columns = array_chunk( $columns, ceil( count( $columns ) / 3 ), true /* preserve keys */ );
 550
 551                 $ret = '<table width="100%"><tr valign="top"><td>';
 552                 $prevchar = null;
 553
 554                 foreach ( $columns as $column ) {
 555                         $colContents = array();
 556
 557                         # Kind of like array_flip() here, but we keep duplicates in an
 558                         # array instead of dropping them.
 559                         foreach ( $column as $article => $char ) {
 560                                 if ( !isset( $colContents[$char] ) ) {
 561                                         $colContents[$char] = array();
 562                                 }
 563                                 $colContents[$char][] = $article;
 564                         }
 565
 566                         $first = true;
 567                         foreach ( $colContents as $char => $articles ) {
 568                                 $ret .= '<h3>' . htmlspecialchars( $char );
 569                                 if ( $first && $char === $prevchar ) {
 570                                         # We're continuing a previous chunk at the top of a new
 571                                         # column, so add " cont." after the letter.
 572                                         $ret .= ' ' . wfMsgHtml( 'listingcontinuesabbrev' );
 573                                 }
 574                                 $ret .= "</h3>\n";
 575
 576                                 $ret .= '<ul><li>';
 577                                 $ret .= implode( "</li>\n<li>", $articles );
 578                                 $ret .= '</li></ul>';
 579
 580                                 $first = false;
 581                                 $prevchar = $char;
 582                         }
 583
 584                         $ret .= "</td>\n<td>";
 585                 }
 586
 587                 $ret .= '</td></tr></table>';
 588                 return $ret;
 589         }
 590
 591         /**
 592          * Format a list of articles chunked by letter in a bullet list.
 593          * @param $articles Array
 594          * @param $articles_start_char Array
 595          * @return String
 596          * @private
 597          */
 598         static function shortList( $articles, $articles_start_char ) {
 599                 $r = '<h3>' . htmlspecialchars( $articles_start_char[0] ) . "</h3>\n";
 600                 $r .= '<ul><li>' . $articles[0] . '</li>';
 601                 for ( $index = 1; $index < count( $articles ); $index++ ) {
 602                         if ( $articles_start_char[$index] != $articles_start_char[$index - 1] ) {
 603                                 $r .= "</ul><h3>" . htmlspecialchars( $articles_start_char[$index] ) . "</h3>\n<ul>";
 604                         }
 605
 606                         $r .= "<li>{$articles[$index]}</li>";
 607                 }
 608                 $r .= '</ul>';
 609                 return $r;
 610         }
 611
 612         /**
 613          * Create paging links, as a helper method to getSectionPagingLinks().
 614          *
 615          * @param $first String The 'until' parameter for the generated URL
 616          * @param $last String The 'from' parameter for the genererated URL
 617          * @param $type String A prefix for parameters, 'page' or 'subcat' or
 618          *     'file'
 619          * @return String HTML
 620          */
 621         private function pagingLinks( $first, $last, $type = '' ) {
 622                 $prevLink = wfMessage( 'prevn' )->numParams( $this->limit )->escaped();
 623
 624                 if ( $first != '' ) {
 625                         $prevQuery = $this->query;
 626                         $prevQuery["{$type}until"] = $first;
 627                         unset( $prevQuery["{$type}from"] );
 628                         $prevLink = Linker::linkKnown(
 629                                 $this->addFragmentToTitle( $this->title, $type ),
 630                                 $prevLink,
 631                                 array(),
 632                                 $prevQuery
 633                         );
 634                 }
 635
 636                 $nextLink = wfMessage( 'nextn' )->numParams( $this->limit )->escaped();
 637
 638                 if ( $last != '' ) {
 639                         $lastQuery = $this->query;
 640                         $lastQuery["{$type}from"] = $last;
 641                         unset( $lastQuery["{$type}until"] );
 642                         $nextLink = Linker::linkKnown(
 643                                 $this->addFragmentToTitle( $this->title, $type ),
 644                                 $nextLink,
 645                                 array(),
 646                                 $lastQuery
 647                         );
 648                 }
 649
 650                 return "($prevLink) ($nextLink)";
 651         }
 652
 653         /**
 654          * Takes a title, and adds the fragment identifier that
 655          * corresponds to the correct segment of the category.
 656          *
 657          * @param Title $title: The title (usually $this->title)
 658          * @param String $section: Which section
 659          */
 660         private function addFragmentToTitle( $title, $section ) {
 661                 switch ( $section ) {
 662                         case 'page':
 663                                 $fragment = 'mw-pages';
 664                                 break;
 665                         case 'subcat':
 666                                 $fragment = 'mw-subcategories';
 667                                 break;
 668                         case 'file':
 669                                 $fragment = 'mw-category-media';
 670                                 break;
 671                         default:
 672                                 throw new MWException( __METHOD__ .
 673                                         " Invalid section $section." );
 674                 }
 675
 676                 return Title::makeTitle( $title->getNamespace(),
 677                         $title->getDBkey(), $fragment );
 678         }
 679         /**
 680          * What to do if the category table conflicts with the number of results
 681          * returned?  This function says what. Each type is considered independently
 682          * of the other types.
 683          *
 684          * Note for grepping: uses the messages category-article-count,
 685          * category-article-count-limited, category-subcat-count,
 686          * category-subcat-count-limited, category-file-count,
 687          * category-file-count-limited.
 688          *
 689          * @param $rescnt Int: The number of items returned by our database query.
 690          * @param $dbcnt Int: The number of items according to the category table.
 691          * @param $type String: 'subcat', 'article', or 'file'
 692          * @return String: A message giving the number of items, to output to HTML.
 693          */
 694         private function getCountMessage( $rescnt, $dbcnt, $type ) {
 695                 # There are three cases:
 696                 #   1) The category table figure seems sane.  It might be wrong, but
 697                 #      we can't do anything about it if we don't recalculate it on ev-
 698                 #      ery category view.
 699                 #   2) The category table figure isn't sane, like it's smaller than the
 700                 #      number of actual results, *but* the number of results is less
 701                 #      than $this->limit and there's no offset.  In this case we still
 702                 #      know the right figure.
 703                 #   3) We have no idea.
 704
 705                 # Check if there's a "from" or "until" for anything
 706
 707                 // This is a little ugly, but we seem to use different names
 708                 // for the paging types then for the messages.
 709                 if ( $type === 'article' ) {
 710                         $pagingType = 'page';
 711                 } else {
 712                         $pagingType = $type;
 713                 }
 714
 715                 $fromOrUntil = false;
 716                 if ( $this->from[$pagingType] !== null || $this->until[$pagingType] !== null ) {
 717                         $fromOrUntil = true;
 718                 }
 719
 720                 if ( $dbcnt == $rescnt || ( ( $rescnt == $this->limit || $fromOrUntil )
 721                         && $dbcnt > $rescnt ) ) {
 722                         # Case 1: seems sane.
 723                         $totalcnt = $dbcnt;
 724                 } elseif ( $rescnt < $this->limit && !$fromOrUntil ) {
 725                         # Case 2: not sane, but salvageable.  Use the number of results.
 726                         # Since there are fewer than 200, we can also take this opportunity
 727                         # to refresh the incorrect category table entry -- which should be
 728                         # quick due to the small number of entries.
 729                         $totalcnt = $rescnt;
 730                         $this->cat->refreshCounts();
 731                 } else {
 732                         # Case 3: hopeless.  Don't give a total count at all.
 733                         return wfMessage( "category-$type-count-limited" )->numParams( $rescnt )->parseAsBlock();
 734                 }
 735                 return wfMessage( "category-$type-count" )->numParams( $rescnt, $totalcnt )->parseAsBlock();
 736         }
 737 }