includes/CategoryViewer.php

   1 <?php
   2 /**
   3  * List and paging of category members.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  */
  22
  23 class CategoryViewer extends ContextSource {
  24         /** @var int */
  25         public $limit;
  26
  27         /** @var array */
  28         public $from;
  29
  30         /** @var array */
  31         public $until;
  32
  33         /** @var string[] */
  34         public $articles;
  35
  36         /** @var array */
  37         public $articles_start_char;
  38
  39         /** @var array */
  40         public $children;
  41
  42         /** @var array */
  43         public $children_start_char;
  44
  45         /** @var bool */
  46         public $showGallery;
  47
  48         /** @var array */
  49         public $imgsNoGallery_start_char;
  50
  51         /** @var array */
  52         public $imgsNoGallery;
  53
  54         /** @var array */
  55         public $nextPage;
  56
  57         /** @var array */
  58         protected $prevPage;
  59
  60         /** @var array */
  61         public $flip;
  62
  63         /** @var Title */
  64         public $title;
  65
  66         /** @var Collation */
  67         public $collation;
  68
  69         /** @var ImageGallery */
  70         public $gallery;
  71
  72         /** @var Category Category object for this page. */
  73         private $cat;
  74
  75         /** @var array The original query array, to be used in generating paging links. */
  76         private $query;
  77
  78         /**
  79          * @since 1.19 $context is a second, required parameter
  80          * @param Title $title
  81          * @param IContextSource $context
  82          * @param array $from An array with keys page, subcat,
  83          *        and file for offset of results of each section (since 1.17)
  84          * @param array $until An array with 3 keys for until of each section (since 1.17)
  85          * @param array $query
  86          */
  87         function __construct( $title, IContextSource $context, $from = array(),
  88                 $until = array(), $query = array()
  89         ) {
  90                 $this->title = $title;
  91                 $this->setContext( $context );
  92                 $this->from = $from;
  93                 $this->until = $until;
  94                 $this->limit = $context->getConfig()->get( 'CategoryPagingLimit' );
  95                 $this->cat = Category::newFromTitle( $title );
  96                 $this->query = $query;
  97                 $this->collation = Collation::singleton();
  98                 unset( $this->query['title'] );
  99         }
 100
 101         /**
 102          * Format the category data list.
 103          *
 104          * @return string HTML output
 105          */
 106         public function getHTML() {
 107
 108                 $this->showGallery = $this->getConfig()->get( 'CategoryMagicGallery' )
 109                         && !$this->getOutput()->mNoGallery;
 110
 111                 $this->clearCategoryState();
 112                 $this->doCategoryQuery();
 113                 $this->finaliseCategoryState();
 114
 115                 $r = $this->getSubcategorySection() .
 116                         $this->getPagesSection() .
 117                         $this->getImageSection();
 118
 119                 if ( $r == '' ) {
 120                         // If there is no category content to display, only
 121                         // show the top part of the navigation links.
 122                         // @todo FIXME: Cannot be completely suppressed because it
 123                         //        is unknown if 'until' or 'from' makes this
 124                         //        give 0 results.
 125                         $r = $r . $this->getCategoryTop();
 126                 } else {
 127                         $r = $this->getCategoryTop() .
 128                                 $r .
 129                                 $this->getCategoryBottom();
 130                 }
 131
 132                 // Give a proper message if category is empty
 133                 if ( $r == '' ) {
 134                         $r = $this->msg( 'category-empty' )->parseAsBlock();
 135                 }
 136
 137                 $lang = $this->getLanguage();
 138                 $langAttribs = array( 'lang' => $lang->getHtmlCode(), 'dir' => $lang->getDir() );
 139                 # put a div around the headings which are in the user language
 140                 $r = Html::openElement( 'div', $langAttribs ) . $r . '</div>';
 141
 142                 return $r;
 143         }
 144
 145         function clearCategoryState() {
 146                 $this->articles = array();
 147                 $this->articles_start_char = array();
 148                 $this->children = array();
 149                 $this->children_start_char = array();
 150                 if ( $this->showGallery ) {
 151                         // Note that null for mode is taken to mean use default.
 152                         $mode = $this->getRequest()->getVal( 'gallerymode', null );
 153                         try {
 154                                 $this->gallery = ImageGalleryBase::factory( $mode, $this->getContext() );
 155                         } catch ( Exception $e ) {
 156                                 // User specified something invalid, fallback to default.
 157                                 $this->gallery = ImageGalleryBase::factory( false, $this->getContext() );
 158                         }
 159
 160                         $this->gallery->setHideBadImages();
 161                 } else {
 162                         $this->imgsNoGallery = array();
 163                         $this->imgsNoGallery_start_char = array();
 164                 }
 165         }
 166
 167         /**
 168          * Add a subcategory to the internal lists, using a Category object
 169          * @param Category $cat
 170          * @param string $sortkey
 171          * @param int $pageLength
 172          */
 173         function addSubcategoryObject( Category $cat, $sortkey, $pageLength ) {
 174                 // Subcategory; strip the 'Category' namespace from the link text.
 175                 $title = $cat->getTitle();
 176
 177                 $this->children[] = $this->generateLink(
 178                         'subcat',
 179                         $title,
 180                         $title->isRedirect(),
 181                         htmlspecialchars( $title->getText() )
 182                 );
 183
 184                 $this->children_start_char[] =
 185                         $this->getSubcategorySortChar( $cat->getTitle(), $sortkey );
 186         }
 187
 188         function generateLink( $type, Title $title, $isRedirect, $html = null ) {
 189                 $link = null;
 190                 Hooks::run( 'CategoryViewer::generateLink', array( $type, $title, $html, &$link ) );
 191                 if ( $link === null ) {
 192                         $link = Linker::link( $title, $html );
 193                 }
 194                 if ( $isRedirect ) {
 195                         $link = '<span class="redirect-in-category">' . $link . '</span>';
 196                 }
 197
 198                 return $link;
 199         }
 200
 201         /**
 202          * Get the character to be used for sorting subcategories.
 203          * If there's a link from Category:A to Category:B, the sortkey of the resulting
 204          * entry in the categorylinks table is Category:A, not A, which it SHOULD be.
 205          * Workaround: If sortkey == "Category:".$title, than use $title for sorting,
 206          * else use sortkey...
 207          *
 208          * @param Title $title
 209          * @param string $sortkey The human-readable sortkey (before transforming to icu or whatever).
 210          * @return string
 211          */
 212         function getSubcategorySortChar( $title, $sortkey ) {
 213                 global $wgContLang;
 214
 215                 if ( $title->getPrefixedText() == $sortkey ) {
 216                         $word = $title->getDBkey();
 217                 } else {
 218                         $word = $sortkey;
 219                 }
 220
 221                 $firstChar = $this->collation->getFirstLetter( $word );
 222
 223                 return $wgContLang->convert( $firstChar );
 224         }
 225
 226         /**
 227          * Add a page in the image namespace
 228          * @param Title $title
 229          * @param string $sortkey
 230          * @param int $pageLength
 231          * @param bool $isRedirect
 232          */
 233         function addImage( Title $title, $sortkey, $pageLength, $isRedirect = false ) {
 234                 global $wgContLang;
 235                 if ( $this->showGallery ) {
 236                         $flip = $this->flip['file'];
 237                         if ( $flip ) {
 238                                 $this->gallery->insert( $title );
 239                         } else {
 240                                 $this->gallery->add( $title );
 241                         }
 242                 } else {
 243                         $this->imgsNoGallery[] = $this->generateLink( 'image', $title, $isRedirect );
 244
 245                         $this->imgsNoGallery_start_char[] = $wgContLang->convert(
 246                                 $this->collation->getFirstLetter( $sortkey ) );
 247                 }
 248         }
 249
 250         /**
 251          * Add a miscellaneous page
 252          * @param Title $title
 253          * @param string $sortkey
 254          * @param int $pageLength
 255          * @param bool $isRedirect
 256          */
 257         function addPage( $title, $sortkey, $pageLength, $isRedirect = false ) {
 258                 global $wgContLang;
 259
 260                 $this->articles[] = $this->generateLink( 'page', $title, $isRedirect );
 261
 262                 $this->articles_start_char[] = $wgContLang->convert(
 263                         $this->collation->getFirstLetter( $sortkey ) );
 264         }
 265
 266         function finaliseCategoryState() {
 267                 if ( $this->flip['subcat'] ) {
 268                         $this->children = array_reverse( $this->children );
 269                         $this->children_start_char = array_reverse( $this->children_start_char );
 270                 }
 271                 if ( $this->flip['page'] ) {
 272                         $this->articles = array_reverse( $this->articles );
 273                         $this->articles_start_char = array_reverse( $this->articles_start_char );
 274                 }
 275                 if ( !$this->showGallery && $this->flip['file'] ) {
 276                         $this->imgsNoGallery = array_reverse( $this->imgsNoGallery );
 277                         $this->imgsNoGallery_start_char = array_reverse( $this->imgsNoGallery_start_char );
 278                 }
 279         }
 280
 281         function doCategoryQuery() {
 282                 $dbr = wfGetDB( DB_SLAVE, 'category' );
 283
 284                 $this->nextPage = array(
 285                         'page' => null,
 286                         'subcat' => null,
 287                         'file' => null,
 288                 );
 289                 $this->prevPage = array(
 290                         'page' => null,
 291                         'subcat' => null,
 292                         'file' => null,
 293                 );
 294
 295                 $this->flip = array( 'page' => false, 'subcat' => false, 'file' => false );
 296
 297                 foreach ( array( 'page', 'subcat', 'file' ) as $type ) {
 298                         # Get the sortkeys for start/end, if applicable.  Note that if
 299                         # the collation in the database differs from the one
 300                         # set in $wgCategoryCollation, pagination might go totally haywire.
 301                         $extraConds = array( 'cl_type' => $type );
 302                         if ( isset( $this->from[$type] ) && $this->from[$type] !== null ) {
 303                                 $extraConds[] = 'cl_sortkey >= '
 304                                         . $dbr->addQuotes( $this->collation->getSortKey( $this->from[$type] ) );
 305                         } elseif ( isset( $this->until[$type] ) && $this->until[$type] !== null ) {
 306                                 $extraConds[] = 'cl_sortkey < '
 307                                         . $dbr->addQuotes( $this->collation->getSortKey( $this->until[$type] ) );
 308                                 $this->flip[$type] = true;
 309                         }
 310
 311                         $res = $dbr->select(
 312                                 array( 'page', 'categorylinks', 'category' ),
 313                                 array( 'page_id', 'page_title', 'page_namespace', 'page_len',
 314                                         'page_is_redirect', 'cl_sortkey', 'cat_id', 'cat_title',
 315                                         'cat_subcats', 'cat_pages', 'cat_files',
 316                                         'cl_sortkey_prefix', 'cl_collation' ),
 317                                 array_merge( array( 'cl_to' => $this->title->getDBkey() ), $extraConds ),
 318                                 __METHOD__,
 319                                 array(
 320                                         'USE INDEX' => array( 'categorylinks' => 'cl_sortkey' ),
 321                                         'LIMIT' => $this->limit + 1,
 322                                         'ORDER BY' => $this->flip[$type] ? 'cl_sortkey DESC' : 'cl_sortkey',
 323                                 ),
 324                                 array(
 325                                         'categorylinks' => array( 'INNER JOIN', 'cl_from = page_id' ),
 326                                         'category' => array( 'LEFT JOIN', array(
 327                                                 'cat_title = page_title',
 328                                                 'page_namespace' => NS_CATEGORY
 329                                         ))
 330                                 )
 331                         );
 332
 333                         Hooks::run( 'CategoryViewer::doCategoryQuery', array( $type, $res ) );
 334
 335                         $count = 0;
 336                         foreach ( $res as $row ) {
 337                                 $title = Title::newFromRow( $row );
 338                                 if ( $row->cl_collation === '' ) {
 339                                         // Hack to make sure that while updating from 1.16 schema
 340                                         // and db is inconsistent, that the sky doesn't fall.
 341                                         // See r83544. Could perhaps be removed in a couple decades...
 342                                         $humanSortkey = $row->cl_sortkey;
 343                                 } else {
 344                                         $humanSortkey = $title->getCategorySortkey( $row->cl_sortkey_prefix );
 345                                 }
 346
 347                                 if ( ++$count > $this->limit ) {
 348                                         # We've reached the one extra which shows that there
 349                                         # are additional pages to be had. Stop here...
 350                                         $this->nextPage[$type] = $humanSortkey;
 351                                         break;
 352                                 }
 353                                 if ( $count == $this->limit ) {
 354                                         $this->prevPage[$type] = $humanSortkey;
 355                                 }
 356
 357                                 if ( $title->getNamespace() == NS_CATEGORY ) {
 358                                         $cat = Category::newFromRow( $row, $title );
 359                                         $this->addSubcategoryObject( $cat, $humanSortkey, $row->page_len );
 360                                 } elseif ( $title->getNamespace() == NS_FILE ) {
 361                                         $this->addImage( $title, $humanSortkey, $row->page_len, $row->page_is_redirect );
 362                                 } else {
 363                                         $this->addPage( $title, $humanSortkey, $row->page_len, $row->page_is_redirect );
 364                                 }
 365                         }
 366                 }
 367         }
 368
 369         /**
 370          * @return string
 371          */
 372         function getCategoryTop() {
 373                 $r = $this->getCategoryBottom();
 374                 return $r === ''
 375                         ? $r
 376                         : "<br style=\"clear:both;\"/>\n" . $r;
 377         }
 378
 379         /**
 380          * @return string
 381          */
 382         function getSubcategorySection() {
 383                 # Don't show subcategories section if there are none.
 384                 $r = '';
 385                 $rescnt = count( $this->children );
 386                 $dbcnt = $this->cat->getSubcatCount();
 387                 $countmsg = $this->getCountMessage( $rescnt, $dbcnt, 'subcat' );
 388
 389                 if ( $rescnt > 0 ) {
 390                         # Showing subcategories
 391                         $r .= "<div id=\"mw-subcategories\">\n";
 392                         $r .= '<h2>' . $this->msg( 'subcategories' )->parse() . "</h2>\n";
 393                         $r .= $countmsg;
 394                         $r .= $this->getSectionPagingLinks( 'subcat' );
 395                         $r .= $this->formatList( $this->children, $this->children_start_char );
 396                         $r .= $this->getSectionPagingLinks( 'subcat' );
 397                         $r .= "\n</div>";
 398                 }
 399                 return $r;
 400         }
 401
 402         /**
 403          * @return string
 404          */
 405         function getPagesSection() {
 406                 $ti = wfEscapeWikiText( $this->title->getText() );
 407                 # Don't show articles section if there are none.
 408                 $r = '';
 409
 410                 # @todo FIXME: Here and in the other two sections: we don't need to bother
 411                 # with this rigmarole if the entire category contents fit on one page
 412                 # and have already been retrieved.  We can just use $rescnt in that
 413                 # case and save a query and some logic.
 414                 $dbcnt = $this->cat->getPageCount() - $this->cat->getSubcatCount()
 415                         - $this->cat->getFileCount();
 416                 $rescnt = count( $this->articles );
 417                 $countmsg = $this->getCountMessage( $rescnt, $dbcnt, 'article' );
 418
 419                 if ( $rescnt > 0 ) {
 420                         $r = "<div id=\"mw-pages\">\n";
 421                         $r .= '<h2>' . $this->msg( 'category_header', $ti )->parse() . "</h2>\n";
 422                         $r .= $countmsg;
 423                         $r .= $this->getSectionPagingLinks( 'page' );
 424                         $r .= $this->formatList( $this->articles, $this->articles_start_char );
 425                         $r .= $this->getSectionPagingLinks( 'page' );
 426                         $r .= "\n</div>";
 427                 }
 428                 return $r;
 429         }
 430
 431         /**
 432          * @return string
 433          */
 434         function getImageSection() {
 435                 $r = '';
 436                 $rescnt = $this->showGallery ? $this->gallery->count() : count( $this->imgsNoGallery );
 437                 if ( $rescnt > 0 ) {
 438                         $dbcnt = $this->cat->getFileCount();
 439                         $countmsg = $this->getCountMessage( $rescnt, $dbcnt, 'file' );
 440
 441                         $r .= "<div id=\"mw-category-media\">\n";
 442                         $r .= '<h2>' .
 443                                 $this->msg(
 444                                         'category-media-header',
 445                                         wfEscapeWikiText( $this->title->getText() )
 446                                 )->text() .
 447                                 "</h2>\n";
 448                         $r .= $countmsg;
 449                         $r .= $this->getSectionPagingLinks( 'file' );
 450                         if ( $this->showGallery ) {
 451                                 $r .= $this->gallery->toHTML();
 452                         } else {
 453                                 $r .= $this->formatList( $this->imgsNoGallery, $this->imgsNoGallery_start_char );
 454                         }
 455                         $r .= $this->getSectionPagingLinks( 'file' );
 456                         $r .= "\n</div>";
 457                 }
 458                 return $r;
 459         }
 460
 461         /**
 462          * Get the paging links for a section (subcats/pages/files), to go at the top and bottom
 463          * of the output.
 464          *
 465          * @param string $type 'page', 'subcat', or 'file'
 466          * @return string HTML output, possibly empty if there are no other pages
 467          */
 468         private function getSectionPagingLinks( $type ) {
 469                 if ( isset( $this->until[$type] ) && $this->until[$type] !== null ) {
 470                         // The new value for the until parameter should be pointing to the first
 471                         // result displayed on the page which is the second last result retrieved
 472                         // from the database.The next link should have a from parameter pointing
 473                         // to the until parameter of the current page.
 474                         if ( $this->nextPage[$type] !== null ) {
 475                                 return $this->pagingLinks( $this->prevPage[$type], $this->until[$type], $type );
 476                         } else {
 477                                 // If the nextPage variable is null, it means that we have reached the first page
 478                                 // and therefore the previous link should be disabled.
 479                                 return $this->pagingLinks( null, $this->until[$type], $type );
 480                         }
 481                 } elseif ( $this->nextPage[$type] !== null
 482                         || ( isset( $this->from[$type] ) && $this->from[$type] !== null )
 483                 ) {
 484                         return $this->pagingLinks( $this->from[$type], $this->nextPage[$type], $type );
 485                 } else {
 486                         return '';
 487                 }
 488         }
 489
 490         /**
 491          * @return string
 492          */
 493         function getCategoryBottom() {
 494                 return '';
 495         }
 496
 497         /**
 498          * Format a list of articles chunked by letter, either as a
 499          * bullet list or a columnar format, depending on the length.
 500          *
 501          * @param array $articles
 502          * @param array $articles_start_char
 503          * @param int $cutoff
 504          * @return string
 505          * @private
 506          */
 507         function formatList( $articles, $articles_start_char, $cutoff = 6 ) {
 508                 $list = '';
 509                 if ( count( $articles ) > $cutoff ) {
 510                         $list = self::columnList( $articles, $articles_start_char );
 511                 } elseif ( count( $articles ) > 0 ) {
 512                         // for short lists of articles in categories.
 513                         $list = self::shortList( $articles, $articles_start_char );
 514                 }
 515
 516                 $pageLang = $this->title->getPageLanguage();
 517                 $attribs = array( 'lang' => $pageLang->getHtmlCode(), 'dir' => $pageLang->getDir(),
 518                         'class' => 'mw-content-' . $pageLang->getDir() );
 519                 $list = Html::rawElement( 'div', $attribs, $list );
 520
 521                 return $list;
 522         }
 523
 524         /**
 525          * Format a list of articles chunked by letter in a three-column
 526          * list, ordered vertically.
 527          *
 528          * TODO: Take the headers into account when creating columns, so they're
 529          * more visually equal.
 530          *
 531          * More distant TODO: Scrap this and use CSS columns, whenever IE finally
 532          * supports those.
 533          *
 534          * @param array $articles
 535          * @param string[] $articles_start_char
 536          * @return string
 537          * @private
 538          */
 539         static function columnList( $articles, $articles_start_char ) {
 540                 $columns = array_combine( $articles, $articles_start_char );
 541                 # Split into three columns
 542                 $columns = array_chunk( $columns, ceil( count( $columns ) / 3 ), true /* preserve keys */ );
 543
 544                 $ret = '<table style="width: 100%;"><tr style="vertical-align: top;">';
 545                 $prevchar = null;
 546
 547                 foreach ( $columns as $column ) {
 548                         $ret .= '<td style="width: 33.3%;">';
 549                         $colContents = array();
 550
 551                         # Kind of like array_flip() here, but we keep duplicates in an
 552                         # array instead of dropping them.
 553                         foreach ( $column as $article => $char ) {
 554                                 if ( !isset( $colContents[$char] ) ) {
 555                                         $colContents[$char] = array();
 556                                 }
 557                                 $colContents[$char][] = $article;
 558                         }
 559
 560                         $first = true;
 561                         foreach ( $colContents as $char => $articles ) {
 562                                 # Change space to non-breaking space to keep headers aligned
 563                                 $h3char = $char === ' ' ? '&#160;' : htmlspecialchars( $char );
 564
 565                                 $ret .= '<h3>' . $h3char;
 566                                 if ( $first && $char === $prevchar ) {
 567                                         # We're continuing a previous chunk at the top of a new
 568                                         # column, so add " cont." after the letter.
 569                                         $ret .= ' ' . wfMessage( 'listingcontinuesabbrev' )->escaped();
 570                                 }
 571                                 $ret .= "</h3>\n";
 572
 573                                 $ret .= '<ul><li>';
 574                                 $ret .= implode( "</li>\n<li>", $articles );
 575                                 $ret .= '</li></ul>';
 576
 577                                 $first = false;
 578                                 $prevchar = $char;
 579                         }
 580
 581                         $ret .= "</td>\n";
 582                 }
 583
 584                 $ret .= '</tr></table>';
 585                 return $ret;
 586         }
 587
 588         /**
 589          * Format a list of articles chunked by letter in a bullet list.
 590          * @param array $articles
 591          * @param string[] $articles_start_char
 592          * @return string
 593          * @private
 594          */
 595         static function shortList( $articles, $articles_start_char ) {
 596                 $r = '<h3>' . htmlspecialchars( $articles_start_char[0] ) . "</h3>\n";
 597                 $r .= '<ul><li>' . $articles[0] . '</li>';
 598                 $articleCount = count( $articles );
 599                 for ( $index = 1; $index < $articleCount; $index++ ) {
 600                         if ( $articles_start_char[$index] != $articles_start_char[$index - 1] ) {
 601                                 $r .= "</ul><h3>" . htmlspecialchars( $articles_start_char[$index] ) . "</h3>\n<ul>";
 602                         }
 603
 604                         $r .= "<li>{$articles[$index]}</li>";
 605                 }
 606                 $r .= '</ul>';
 607                 return $r;
 608         }
 609
 610         /**
 611          * Create paging links, as a helper method to getSectionPagingLinks().
 612          *
 613          * @param string $first The 'until' parameter for the generated URL
 614          * @param string $last The 'from' parameter for the generated URL
 615          * @param string $type A prefix for parameters, 'page' or 'subcat' or
 616          *     'file'
 617          * @return string HTML
 618          */
 619         private function pagingLinks( $first, $last, $type = '' ) {
 620                 $prevLink = $this->msg( 'prevn' )->numParams( $this->limit )->escaped();
 621
 622                 if ( $first != '' ) {
 623                         $prevQuery = $this->query;
 624                         $prevQuery["{$type}until"] = $first;
 625                         unset( $prevQuery["{$type}from"] );
 626                         $prevLink = Linker::linkKnown(
 627                                 $this->addFragmentToTitle( $this->title, $type ),
 628                                 $prevLink,
 629                                 array(),
 630                                 $prevQuery
 631                         );
 632                 }
 633
 634                 $nextLink = $this->msg( 'nextn' )->numParams( $this->limit )->escaped();
 635
 636                 if ( $last != '' ) {
 637                         $lastQuery = $this->query;
 638                         $lastQuery["{$type}from"] = $last;
 639                         unset( $lastQuery["{$type}until"] );
 640                         $nextLink = Linker::linkKnown(
 641                                 $this->addFragmentToTitle( $this->title, $type ),
 642                                 $nextLink,
 643                                 array(),
 644                                 $lastQuery
 645                         );
 646                 }
 647
 648                 return $this->msg( 'categoryviewer-pagedlinks' )->rawParams( $prevLink, $nextLink )->escaped();
 649         }
 650
 651         /**
 652          * Takes a title, and adds the fragment identifier that
 653          * corresponds to the correct segment of the category.
 654          *
 655          * @param Title $title The title (usually $this->title)
 656          * @param string $section Which section
 657          * @throws MWException
 658          * @return Title
 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         /**
 681          * What to do if the category table conflicts with the number of results
 682          * returned?  This function says what. Each type is considered independently
 683          * of the other types.
 684          *
 685          * @param int $rescnt The number of items returned by our database query.
 686          * @param int $dbcnt The number of items according to the category table.
 687          * @param string $type 'subcat', 'article', or 'file'
 688          * @return string A message giving the number of items, to output to HTML.
 689          */
 690         private function getCountMessage( $rescnt, $dbcnt, $type ) {
 691                 // There are three cases:
 692                 //   1) The category table figure seems sane.  It might be wrong, but
 693                 //      we can't do anything about it if we don't recalculate it on ev-
 694                 //      ery category view.
 695                 //   2) The category table figure isn't sane, like it's smaller than the
 696                 //      number of actual results, *but* the number of results is less
 697                 //      than $this->limit and there's no offset.  In this case we still
 698                 //      know the right figure.
 699                 //   3) We have no idea.
 700
 701                 // Check if there's a "from" or "until" for anything
 702
 703                 // This is a little ugly, but we seem to use different names
 704                 // for the paging types then for the messages.
 705                 if ( $type === 'article' ) {
 706                         $pagingType = 'page';
 707                 } else {
 708                         $pagingType = $type;
 709                 }
 710
 711                 $fromOrUntil = false;
 712                 if ( ( isset( $this->from[$pagingType] ) && $this->from[$pagingType] !== null ) ||
 713                         ( isset( $this->until[$pagingType] ) && $this->until[$pagingType] !== null )
 714                 ) {
 715                         $fromOrUntil = true;
 716                 }
 717
 718                 if ( $dbcnt == $rescnt ||
 719                         ( ( $rescnt == $this->limit || $fromOrUntil ) && $dbcnt > $rescnt )
 720                 ) {
 721                         // Case 1: seems sane.
 722                         $totalcnt = $dbcnt;
 723                 } elseif ( $rescnt < $this->limit && !$fromOrUntil ) {
 724                         // Case 2: not sane, but salvageable.  Use the number of results.
 725                         // Since there are fewer than 200, we can also take this opportunity
 726                         // to refresh the incorrect category table entry -- which should be
 727                         // quick due to the small number of entries.
 728                         $totalcnt = $rescnt;
 729                         $category = $this->cat;
 730                         wfGetDB( DB_MASTER )->onTransactionIdle( function () use ( $category ) {
 731                                 $category->refreshCounts();
 732                         } );
 733                 } else {
 734                         // Case 3: hopeless.  Don't give a total count at all.
 735                         // Messages: category-subcat-count-limited, category-article-count-limited,
 736                         // category-file-count-limited
 737                         return $this->msg( "category-$type-count-limited" )->numParams( $rescnt )->parseAsBlock();
 738                 }
 739                 // Messages: category-subcat-count, category-article-count, category-file-count
 740                 return $this->msg( "category-$type-count" )->numParams( $rescnt, $totalcnt )->parseAsBlock();
 741         }
 742 }