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         /**
  21          * @var Title
  22          */
  23         protected $mTitle;
  24
  25         /**
  26          * @param $title Title
  27          * @return WikiCategoryPage
  28          */
  29         protected function newPage( Title $title ) {
  30                 // Overload mPage with a category-specific page
  31                 return new WikiCategoryPage( $title );
  32         }
  33
  34         /**
  35          * Constructor from a page id
  36          * @param $id Int article ID to load
  37          */
  38         public static function newFromID( $id ) {
  39                 $t = Title::newFromID( $id );
  40                 # @todo FIXME: Doesn't inherit right
  41                 return $t == null ? null : new self( $t );
  42                 # return $t == null ? null : new static( $t ); // PHP 5.3
  43         }
  44
  45         function view() {
  46                 $request = $this->getContext()->getRequest();
  47                 $diff = $request->getVal( 'diff' );
  48                 $diffOnly = $request->getBool( 'diffonly',
  49                         $this->getContext()->getUser()->getOption( 'diffonly' ) );
  50
  51                 if ( isset( $diff ) && $diffOnly ) {
  52                         return parent::view();
  53                 }
  54
  55                 if ( !wfRunHooks( 'CategoryPageView', array( &$this ) ) ) {
  56                         return;
  57                 }
  58
  59                 if ( NS_CATEGORY == $this->mTitle->getNamespace() ) {
  60                         $this->openShowCategory();
  61                 }
  62
  63                 parent::view();
  64
  65                 if ( NS_CATEGORY == $this->mTitle->getNamespace() ) {
  66                         $this->closeShowCategory();
  67                 }
  68         }
  69
  70         function openShowCategory() {
  71                 # For overloading
  72         }
  73
  74         function closeShowCategory() {
  75                 // Use these as defaults for back compat --catrope
  76                 $request = $this->getContext()->getRequest();
  77                 $oldFrom = $request->getVal( 'from' );
  78                 $oldUntil = $request->getVal( 'until' );
  79
  80                 $reqArray = $request->getValues();
  81
  82                 $from = $until = array();
  83                 foreach ( array( 'page', 'subcat', 'file' ) as $type ) {
  84                         $from[$type] = $request->getVal( "{$type}from", $oldFrom );
  85                         $until[$type] = $request->getVal( "{$type}until", $oldUntil );
  86
  87                         // Do not want old-style from/until propagating in nav links.
  88                         if ( !isset( $reqArray["{$type}from"] ) && isset( $reqArray["from"] ) ) {
  89                                 $reqArray["{$type}from"] = $reqArray["from"];
  90                         }
  91                         if ( !isset( $reqArray["{$type}to"] ) && isset( $reqArray["to"] ) ) {
  92                                 $reqArray["{$type}to"] = $reqArray["to"];
  93                         }
  94                 }
  95
  96                 unset( $reqArray["from"] );
  97                 unset( $reqArray["to"] );
  98
  99                 $viewer = new $this->mCategoryViewerClass( $this->mTitle, $this->getContext(), $from, $until, $reqArray );
 100                 $this->getContext()->getOutput()->addHTML( $viewer->getHTML() );
 101         }
 102 }
 103
 104 class CategoryViewer extends ContextSource {
 105         var $limit, $from, $until,
 106                 $articles, $articles_start_char,
 107                 $children, $children_start_char,
 108                 $showGallery, $imgsNoGalley,
 109                 $imgsNoGallery_start_char,
 110                 $imgsNoGallery;
 111
 112         /**
 113          * @var
 114          */
 115         var $nextPage;
 116
 117         /**
 118          * @var Array
 119          */
 120         var $flip;
 121
 122         /**
 123          * @var Title
 124          */
 125         var $title;
 126
 127         /**
 128          * @var Collation
 129          */
 130         var $collation;
 131
 132         /**
 133          * @var ImageGallery
 134          */
 135         var $gallery;
 136
 137         /**
 138          * Category object for this page
 139          * @var Category
 140          */
 141         private $cat;
 142
 143         /**
 144          * The original query array, to be used in generating paging links.
 145          * @var array
 146          */
 147         private $query;
 148
 149         /**
 150          * Constructor
 151          *
 152          * @since 1.19 $context is a second, required parameter
 153          * @param $title Title
 154          * @param $context IContextSource
 155          * @param $from String
 156          * @param $until String
 157          * @param $query Array
 158          */
 159         function __construct( $title, IContextSource $context, $from = '', $until = '', $query = array() ) {
 160                 global $wgCategoryPagingLimit;
 161                 $this->title = $title;
 162                 $this->setContext( $context );
 163                 $this->from = $from;
 164                 $this->until = $until;
 165                 $this->limit = $wgCategoryPagingLimit;
 166                 $this->cat = Category::newFromTitle( $title );
 167                 $this->query = $query;
 168                 $this->collation = Collation::singleton();
 169                 unset( $this->query['title'] );
 170         }
 171
 172         /**
 173          * Format the category data list.
 174          *
 175          * @return string HTML output
 176          */
 177         public function getHTML() {
 178                 global $wgCategoryMagicGallery;
 179                 wfProfileIn( __METHOD__ );
 180
 181                 $this->showGallery = $wgCategoryMagicGallery && !$this->getOutput()->mNoGallery;
 182
 183                 $this->clearCategoryState();
 184                 $this->doCategoryQuery();
 185                 $this->finaliseCategoryState();
 186
 187                 $r = $this->getSubcategorySection() .
 188                         $this->getPagesSection() .
 189                         $this->getImageSection();
 190
 191                 if ( $r == '' ) {
 192                         // If there is no category content to display, only
 193                         // show the top part of the navigation links.
 194                         // @todo FIXME: Cannot be completely suppressed because it
 195                         //        is unknown if 'until' or 'from' makes this
 196                         //        give 0 results.
 197                         $r = $r . $this->getCategoryTop();
 198                 } else {
 199                         $r = $this->getCategoryTop() .
 200                                 $r .
 201                                 $this->getCategoryBottom();
 202                 }
 203
 204                 // Give a proper message if category is empty
 205                 if ( $r == '' ) {
 206                         $r = wfMsgExt( 'category-empty', array( 'parse' ) );
 207                 }
 208
 209                 $lang = $this->getLang();
 210                 $langAttribs = array( 'lang' => $lang->getCode(), 'dir' => $lang->getDir() );
 211                 # put a div around the headings which are in the user language
 212                 $r = Html::openElement( 'div', $langAttribs ) . $r . '</div>';
 213
 214                 wfProfileOut( __METHOD__ );
 215                 return $r;
 216         }
 217
 218         function clearCategoryState() {
 219                 $this->articles = array();
 220                 $this->articles_start_char = array();
 221                 $this->children = array();
 222                 $this->children_start_char = array();
 223                 if ( $this->showGallery ) {
 224                         $this->gallery = new ImageGallery();
 225                         $this->gallery->setHideBadImages();
 226                 } else {
 227                         $this->imgsNoGallery = array();
 228                         $this->imgsNoGallery_start_char = array();
 229                 }
 230         }
 231
 232         /**
 233          * Add a subcategory to the internal lists, using a Category object
 234          */
 235         function addSubcategoryObject( Category $cat, $sortkey, $pageLength ) {
 236                 // Subcategory; strip the 'Category' namespace from the link text.
 237                 $title = $cat->getTitle();
 238
 239                 $link = Linker::link( $title, htmlspecialchars( $title->getText() ) );
 240                 if ( $title->isRedirect() ) {
 241                         // This didn't used to add redirect-in-category, but might
 242                         // as well be consistent with the rest of the sections
 243                         // on a category page.
 244                         $link = '<span class="redirect-in-category">' . $link . '</span>';
 245                 }
 246                 $this->children[] = $link;
 247
 248                 $this->children_start_char[] =
 249                         $this->getSubcategorySortChar( $cat->getTitle(), $sortkey );
 250         }
 251
 252         /**
 253          * Add a subcategory to the internal lists, using a title object
 254          * @deprecated since 1.17 kept for compatibility, please use addSubcategoryObject instead
 255          */
 256         function addSubcategory( Title $title, $sortkey, $pageLength ) {
 257                 $this->addSubcategoryObject( Category::newFromTitle( $title ), $sortkey, $pageLength );
 258         }
 259
 260         /**
 261         * Get the character to be used for sorting subcategories.
 262         * If there's a link from Category:A to Category:B, the sortkey of the resulting
 263         * entry in the categorylinks table is Category:A, not A, which it SHOULD be.
 264         * Workaround: If sortkey == "Category:".$title, than use $title for sorting,
 265         * else use sortkey...
 266         *
 267         * @param Title $title
 268         * @param string $sortkey The human-readable sortkey (before transforming to icu or whatever).
 269         */
 270         function getSubcategorySortChar( $title, $sortkey ) {
 271                 global $wgContLang;
 272
 273                 if ( $title->getPrefixedText() == $sortkey ) {
 274                         $word = $title->getDBkey();
 275                 } else {
 276                         $word = $sortkey;
 277                 }
 278
 279                 $firstChar = $this->collation->getFirstLetter( $word );
 280
 281                 return $wgContLang->convert( $firstChar );
 282         }
 283
 284         /**
 285          * Add a page in the image namespace
 286          */
 287         function addImage( Title $title, $sortkey, $pageLength, $isRedirect = false ) {
 288                 global $wgContLang;
 289                 if ( $this->showGallery ) {
 290                         $flip = $this->flip['file'];
 291                         if ( $flip ) {
 292                                 $this->gallery->insert( $title );
 293                         } else {
 294                                 $this->gallery->add( $title );
 295                         }
 296                 } else {
 297                         $link = Linker::link( $title );
 298                         if ( $isRedirect ) {
 299                                 // This seems kind of pointless given 'mw-redirect' class,
 300                                 // but keeping for back-compatibility with user css.
 301                                 $link = '<span class="redirect-in-category">' . $link . '</span>';
 302                         }
 303                         $this->imgsNoGallery[] = $link;
 304
 305                         $this->imgsNoGallery_start_char[] = $wgContLang->convert(
 306                                 $this->collation->getFirstLetter( $sortkey ) );
 307                 }
 308         }
 309
 310         /**
 311          * Add a miscellaneous page
 312          */
 313         function addPage( $title, $sortkey, $pageLength, $isRedirect = false ) {
 314                 global $wgContLang;
 315
 316                 $link = Linker::link( $title );
 317                 if ( $isRedirect ) {
 318                         // This seems kind of pointless given 'mw-redirect' class,
 319                         // but keeping for back-compatiability with user css.
 320                         $link = '<span class="redirect-in-category">' . $link . '</span>';
 321                 }
 322                 $this->articles[] = $link;
 323
 324                 $this->articles_start_char[] = $wgContLang->convert(
 325                         $this->collation->getFirstLetter( $sortkey ) );
 326         }
 327
 328         function finaliseCategoryState() {
 329                 if ( $this->flip['subcat'] ) {
 330                         $this->children            = array_reverse( $this->children );
 331                         $this->children_start_char = array_reverse( $this->children_start_char );
 332                 }
 333                 if ( $this->flip['page'] ) {
 334                         $this->articles            = array_reverse( $this->articles );
 335                         $this->articles_start_char = array_reverse( $this->articles_start_char );
 336                 }
 337                 if ( !$this->showGallery && $this->flip['file'] ) {
 338                         $this->imgsNoGallery            = array_reverse( $this->imgsNoGallery );
 339                         $this->imgsNoGallery_start_char = array_reverse( $this->imgsNoGallery_start_char );
 340                 }
 341         }
 342
 343         function doCategoryQuery() {
 344                 $dbr = wfGetDB( DB_SLAVE, 'category' );
 345
 346                 $this->nextPage = array(
 347                         'page' => null,
 348                         'subcat' => null,
 349                         'file' => null,
 350                 );
 351                 $this->flip = array( 'page' => false, 'subcat' => false, 'file' => false );
 352
 353                 foreach ( array( 'page', 'subcat', 'file' ) as $type ) {
 354                         # Get the sortkeys for start/end, if applicable.  Note that if
 355                         # the collation in the database differs from the one
 356                         # set in $wgCategoryCollation, pagination might go totally haywire.
 357                         $extraConds = array( 'cl_type' => $type );
 358                         if ( $this->from[$type] !== null ) {
 359                                 $extraConds[] = 'cl_sortkey >= '
 360                                         . $dbr->addQuotes( $this->collation->getSortKey( $this->from[$type] ) );
 361                         } elseif ( $this->until[$type] !== null ) {
 362                                 $extraConds[] = 'cl_sortkey < '
 363                                         . $dbr->addQuotes( $this->collation->getSortKey( $this->until[$type] ) );
 364                                 $this->flip[$type] = true;
 365                         }
 366
 367                         $res = $dbr->select(
 368                                 array( 'page', 'categorylinks', 'category' ),
 369                                 array( 'page_id', 'page_title', 'page_namespace', 'page_len',
 370                                         'page_is_redirect', 'cl_sortkey', 'cat_id', 'cat_title',
 371                                         'cat_subcats', 'cat_pages', 'cat_files',
 372                                         'cl_sortkey_prefix', 'cl_collation' ),
 373                                 array_merge( array( 'cl_to' => $this->title->getDBkey() ),  $extraConds ),
 374                                 __METHOD__,
 375                                 array(
 376                                         'USE INDEX' => array( 'categorylinks' => 'cl_sortkey' ),
 377                                         'LIMIT' => $this->limit + 1,
 378                                         'ORDER BY' => $this->flip[$type] ? 'cl_sortkey DESC' : 'cl_sortkey',
 379                                 ),
 380                                 array(
 381                                         'categorylinks'  => array( 'INNER JOIN', 'cl_from = page_id' ),
 382                                         'category' => array( 'LEFT JOIN', 'cat_title = page_title AND page_namespace = ' . NS_CATEGORY )
 383                                 )
 384                         );
 385
 386                         $count = 0;
 387                         foreach ( $res as $row ) {
 388                                 $title = Title::newFromRow( $row );
 389                                 if ( $row->cl_collation === '' ) {
 390                                         // Hack to make sure that while updating from 1.16 schema
 391                                         // and db is inconsistent, that the sky doesn't fall.
 392                                         // See r83544. Could perhaps be removed in a couple decades...
 393                                         $humanSortkey = $row->cl_sortkey;
 394                                 } else {
 395                                         $humanSortkey = $title->getCategorySortkey( $row->cl_sortkey_prefix );
 396                                 }
 397
 398                                 if ( ++$count > $this->limit ) {
 399                                         # We've reached the one extra which shows that there
 400                                         # are additional pages to be had. Stop here...
 401                                         $this->nextPage[$type] = $humanSortkey;
 402                                         break;
 403                                 }
 404
 405                                 if ( $title->getNamespace() == NS_CATEGORY ) {
 406                                         $cat = Category::newFromRow( $row, $title );
 407                                         $this->addSubcategoryObject( $cat, $humanSortkey, $row->page_len );
 408                                 } elseif ( $title->getNamespace() == NS_FILE ) {
 409                                         $this->addImage( $title, $humanSortkey, $row->page_len, $row->page_is_redirect );
 410                                 } else {
 411                                         $this->addPage( $title, $humanSortkey, $row->page_len, $row->page_is_redirect );
 412                                 }
 413                         }
 414                 }
 415         }
 416
 417         function getCategoryTop() {
 418                 $r = $this->getCategoryBottom();
 419                 return $r === ''
 420                         ? $r
 421                         : "<br style=\"clear:both;\"/>\n" . $r;
 422         }
 423
 424         function getSubcategorySection() {
 425                 # Don't show subcategories section if there are none.
 426                 $r = '';
 427                 $rescnt = count( $this->children );
 428                 $dbcnt = $this->cat->getSubcatCount();
 429                 $countmsg = $this->getCountMessage( $rescnt, $dbcnt, 'subcat' );
 430
 431                 if ( $rescnt > 0 ) {
 432                         # Showing subcategories
 433                         $r .= "<div id=\"mw-subcategories\">\n";
 434                         $r .= '<h2>' . wfMsg( 'subcategories' ) . "</h2>\n";
 435                         $r .= $countmsg;
 436                         $r .= $this->getSectionPagingLinks( 'subcat' );
 437                         $r .= $this->formatList( $this->children, $this->children_start_char );
 438                         $r .= $this->getSectionPagingLinks( 'subcat' );
 439                         $r .= "\n</div>";
 440                 }
 441                 return $r;
 442         }
 443
 444         function getPagesSection() {
 445                 $ti = htmlspecialchars( $this->title->getText() );
 446                 # Don't show articles section if there are none.
 447                 $r = '';
 448
 449                 # @todo FIXME: Here and in the other two sections: we don't need to bother
 450                 # with this rigamarole if the entire category contents fit on one page
 451                 # and have already been retrieved.  We can just use $rescnt in that
 452                 # case and save a query and some logic.
 453                 $dbcnt = $this->cat->getPageCount() - $this->cat->getSubcatCount()
 454                         - $this->cat->getFileCount();
 455                 $rescnt = count( $this->articles );
 456                 $countmsg = $this->getCountMessage( $rescnt, $dbcnt, 'article' );
 457
 458                 if ( $rescnt > 0 ) {
 459                         $r = "<div id=\"mw-pages\">\n";
 460                         $r .= '<h2>' . wfMsg( 'category_header', $ti ) . "</h2>\n";
 461                         $r .= $countmsg;
 462                         $r .= $this->getSectionPagingLinks( 'page' );
 463                         $r .= $this->formatList( $this->articles, $this->articles_start_char );
 464                         $r .= $this->getSectionPagingLinks( 'page' );
 465                         $r .= "\n</div>";
 466                 }
 467                 return $r;
 468         }
 469
 470         function getImageSection() {
 471                 $r = '';
 472                 $rescnt = $this->showGallery ? $this->gallery->count() : count( $this->imgsNoGallery );
 473                 if ( $rescnt > 0 ) {
 474                         $dbcnt = $this->cat->getFileCount();
 475                         $countmsg = $this->getCountMessage( $rescnt, $dbcnt, 'file' );
 476
 477                         $r .= "<div id=\"mw-category-media\">\n";
 478                         $r .= '<h2>' . wfMsg( 'category-media-header', htmlspecialchars( $this->title->getText() ) ) . "</h2>\n";
 479                         $r .= $countmsg;
 480                         $r .= $this->getSectionPagingLinks( 'file' );
 481                         if ( $this->showGallery ) {
 482                                 $r .= $this->gallery->toHTML();
 483                         } else {
 484                                 $r .= $this->formatList( $this->imgsNoGallery, $this->imgsNoGallery_start_char );
 485                         }
 486                         $r .= $this->getSectionPagingLinks( 'file' );
 487                         $r .= "\n</div>";
 488                 }
 489                 return $r;
 490         }
 491
 492         /**
 493          * Get the paging links for a section (subcats/pages/files), to go at the top and bottom
 494          * of the output.
 495          *
 496          * @param $type String: 'page', 'subcat', or 'file'
 497          * @return String: HTML output, possibly empty if there are no other pages
 498          */
 499         private function getSectionPagingLinks( $type ) {
 500                 if ( $this->until[$type] !== null ) {
 501                         return $this->pagingLinks( $this->nextPage[$type], $this->until[$type], $type );
 502                 } elseif ( $this->nextPage[$type] !== null || $this->from[$type] !== null ) {
 503                         return $this->pagingLinks( $this->from[$type], $this->nextPage[$type], $type );
 504                 } else {
 505                         return '';
 506                 }
 507         }
 508
 509         function getCategoryBottom() {
 510                 return '';
 511         }
 512
 513         /**
 514          * Format a list of articles chunked by letter, either as a
 515          * bullet list or a columnar format, depending on the length.
 516          *
 517          * @param $articles Array
 518          * @param $articles_start_char Array
 519          * @param $cutoff Int
 520          * @return String
 521          * @private
 522          */
 523         function formatList( $articles, $articles_start_char, $cutoff = 6 ) {
 524                 $list = '';
 525                 if ( count ( $articles ) > $cutoff ) {
 526                         $list = self::columnList( $articles, $articles_start_char );
 527                 } elseif ( count( $articles ) > 0 ) {
 528                         // for short lists of articles in categories.
 529                         $list = self::shortList( $articles, $articles_start_char );
 530                 }
 531
 532                 $pageLang = $this->title->getPageLanguage();
 533                 $attribs = array( 'lang' => $pageLang->getCode(), 'dir' => $pageLang->getDir(),
 534                         'class' => 'mw-content-'.$pageLang->getDir() );
 535                 $list = Html::rawElement( 'div', $attribs, $list );
 536
 537                 return $list;
 538         }
 539
 540         /**
 541          * Format a list of articles chunked by letter in a three-column
 542          * list, ordered vertically.
 543          *
 544          * TODO: Take the headers into account when creating columns, so they're
 545          * more visually equal.
 546          *
 547          * More distant TODO: Scrap this and use CSS columns, whenever IE finally
 548          * supports those.
 549          *
 550          * @param $articles Array
 551          * @param $articles_start_char Array
 552          * @return String
 553          * @private
 554          */
 555         static function columnList( $articles, $articles_start_char ) {
 556                 $columns = array_combine( $articles, $articles_start_char );
 557                 # Split into three columns
 558                 $columns = array_chunk( $columns, ceil( count( $columns ) / 3 ), true /* preserve keys */ );
 559
 560                 $ret = '<table width="100%"><tr valign="top"><td>';
 561                 $prevchar = null;
 562
 563                 foreach ( $columns as $column ) {
 564                         $colContents = array();
 565
 566                         # Kind of like array_flip() here, but we keep duplicates in an
 567                         # array instead of dropping them.
 568                         foreach ( $column as $article => $char ) {
 569                                 if ( !isset( $colContents[$char] ) ) {
 570                                         $colContents[$char] = array();
 571                                 }
 572                                 $colContents[$char][] = $article;
 573                         }
 574
 575                         $first = true;
 576                         foreach ( $colContents as $char => $articles ) {
 577                                 $ret .= '<h3>' . htmlspecialchars( $char );
 578                                 if ( $first && $char === $prevchar ) {
 579                                         # We're continuing a previous chunk at the top of a new
 580                                         # column, so add " cont." after the letter.
 581                                         $ret .= ' ' . wfMsgHtml( 'listingcontinuesabbrev' );
 582                                 }
 583                                 $ret .= "</h3>\n";
 584
 585                                 $ret .= '<ul><li>';
 586                                 $ret .= implode( "</li>\n<li>", $articles );
 587                                 $ret .= '</li></ul>';
 588
 589                                 $first = false;
 590                                 $prevchar = $char;
 591                         }
 592
 593                         $ret .= "</td>\n<td>";
 594                 }
 595
 596                 $ret .= '</td></tr></table>';
 597                 return $ret;
 598         }
 599
 600         /**
 601          * Format a list of articles chunked by letter in a bullet list.
 602          * @param $articles Array
 603          * @param $articles_start_char Array
 604          * @return String
 605          * @private
 606          */
 607         static function shortList( $articles, $articles_start_char ) {
 608                 $r = '<h3>' . htmlspecialchars( $articles_start_char[0] ) . "</h3>\n";
 609                 $r .= '<ul><li>' . $articles[0] . '</li>';
 610                 for ( $index = 1; $index < count( $articles ); $index++ ) {
 611                         if ( $articles_start_char[$index] != $articles_start_char[$index - 1] ) {
 612                                 $r .= "</ul><h3>" . htmlspecialchars( $articles_start_char[$index] ) . "</h3>\n<ul>";
 613                         }
 614
 615                         $r .= "<li>{$articles[$index]}</li>";
 616                 }
 617                 $r .= '</ul>';
 618                 return $r;
 619         }
 620
 621         /**
 622          * Create paging links, as a helper method to getSectionPagingLinks().
 623          *
 624          * @param $first String The 'until' parameter for the generated URL
 625          * @param $last String The 'from' parameter for the genererated URL
 626          * @param $type String A prefix for parameters, 'page' or 'subcat' or
 627          *     'file'
 628          * @return String HTML
 629          */
 630         private function pagingLinks( $first, $last, $type = '' ) {
 631                 $prevLink = wfMessage( 'prevn' )->numParams( $this->limit )->escaped();
 632
 633                 if ( $first != '' ) {
 634                         $prevQuery = $this->query;
 635                         $prevQuery["{$type}until"] = $first;
 636                         unset( $prevQuery["{$type}from"] );
 637                         $prevLink = Linker::linkKnown(
 638                                 $this->addFragmentToTitle( $this->title, $type ),
 639                                 $prevLink,
 640                                 array(),
 641                                 $prevQuery
 642                         );
 643                 }
 644
 645                 $nextLink = wfMessage( 'nextn' )->numParams( $this->limit )->escaped();
 646
 647                 if ( $last != '' ) {
 648                         $lastQuery = $this->query;
 649                         $lastQuery["{$type}from"] = $last;
 650                         unset( $lastQuery["{$type}until"] );
 651                         $nextLink = Linker::linkKnown(
 652                                 $this->addFragmentToTitle( $this->title, $type ),
 653                                 $nextLink,
 654                                 array(),
 655                                 $lastQuery
 656                         );
 657                 }
 658
 659                 return "($prevLink) ($nextLink)";
 660         }
 661
 662         /**
 663          * Takes a title, and adds the fragment identifier that
 664          * corresponds to the correct segment of the category.
 665          *
 666          * @param Title $title: The title (usually $this->title)
 667          * @param String $section: Which section
 668          */
 669         private function addFragmentToTitle( $title, $section ) {
 670                 switch ( $section ) {
 671                         case 'page':
 672                                 $fragment = 'mw-pages';
 673                                 break;
 674                         case 'subcat':
 675                                 $fragment = 'mw-subcategories';
 676                                 break;
 677                         case 'file':
 678                                 $fragment = 'mw-category-media';
 679                                 break;
 680                         default:
 681                                 throw new MWException( __METHOD__ .
 682                                         " Invalid section $section." );
 683                 }
 684
 685                 return Title::makeTitle( $title->getNamespace(),
 686                         $title->getDBkey(), $fragment );
 687         }
 688         /**
 689          * What to do if the category table conflicts with the number of results
 690          * returned?  This function says what. Each type is considered independently
 691          * of the other types.
 692          *
 693          * Note for grepping: uses the messages category-article-count,
 694          * category-article-count-limited, category-subcat-count,
 695          * category-subcat-count-limited, category-file-count,
 696          * category-file-count-limited.
 697          *
 698          * @param $rescnt Int: The number of items returned by our database query.
 699          * @param $dbcnt Int: The number of items according to the category table.
 700          * @param $type String: 'subcat', 'article', or 'file'
 701          * @return String: A message giving the number of items, to output to HTML.
 702          */
 703         private function getCountMessage( $rescnt, $dbcnt, $type ) {
 704                 # There are three cases:
 705                 #   1) The category table figure seems sane.  It might be wrong, but
 706                 #      we can't do anything about it if we don't recalculate it on ev-
 707                 #      ery category view.
 708                 #   2) The category table figure isn't sane, like it's smaller than the
 709                 #      number of actual results, *but* the number of results is less
 710                 #      than $this->limit and there's no offset.  In this case we still
 711                 #      know the right figure.
 712                 #   3) We have no idea.
 713
 714                 # Check if there's a "from" or "until" for anything
 715
 716                 // This is a little ugly, but we seem to use different names
 717                 // for the paging types then for the messages.
 718                 if ( $type === 'article' ) {
 719                         $pagingType = 'page';
 720                 } else {
 721                         $pagingType = $type;
 722                 }
 723
 724                 $fromOrUntil = false;
 725                 if ( $this->from[$pagingType] !== null || $this->until[$pagingType] !== null ) {
 726                         $fromOrUntil = true;
 727                 }
 728
 729                 if ( $dbcnt == $rescnt || ( ( $rescnt == $this->limit || $fromOrUntil )
 730                         && $dbcnt > $rescnt ) ) {
 731                         # Case 1: seems sane.
 732                         $totalcnt = $dbcnt;
 733                 } elseif ( $rescnt < $this->limit && !$fromOrUntil ) {
 734                         # Case 2: not sane, but salvageable.  Use the number of results.
 735                         # Since there are fewer than 200, we can also take this opportunity
 736                         # to refresh the incorrect category table entry -- which should be
 737                         # quick due to the small number of entries.
 738                         $totalcnt = $rescnt;
 739                         $this->cat->refreshCounts();
 740                 } else {
 741                         # Case 3: hopeless.  Don't give a total count at all.
 742                         return wfMessage( "category-$type-count-limited" )->numParams( $rescnt )->parseAsBlock();
 743                 }
 744                 return wfMessage( "category-$type-count" )->numParams( $rescnt, $totalcnt )->parseAsBlock();
 745         }
 746 }