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 = [],
  88                 $until = [], $query = []
  89         ) {
  90                 $this->title = $title;
  91                 $this->setContext( $context );
  92                 $this->getOutput()->addModuleStyles( [
  93                         'mediawiki.action.view.categoryPage.styles'
  94                 ] );
  95                 $this->from = $from;
  96                 $this->until = $until;
  97                 $this->limit = $context->getConfig()->get( 'CategoryPagingLimit' );
  98                 $this->cat = Category::newFromTitle( $title );
  99                 $this->query = $query;
 100                 $this->collation = Collation::singleton();
 101                 unset( $this->query['title'] );
 102         }
 103
 104         /**
 105          * Format the category data list.
 106          *
 107          * @return string HTML output
 108          */
 109         public function getHTML() {
 110
 111                 $this->showGallery = $this->getConfig()->get( 'CategoryMagicGallery' )
 112                         && !$this->getOutput()->mNoGallery;
 113
 114                 $this->clearCategoryState();
 115                 $this->doCategoryQuery();
 116                 $this->finaliseCategoryState();
 117
 118                 $r = $this->getSubcategorySection() .
 119                         $this->getPagesSection() .
 120                         $this->getImageSection();
 121
 122                 if ( $r == '' ) {
 123                         // If there is no category content to display, only
 124                         // show the top part of the navigation links.
 125                         // @todo FIXME: Cannot be completely suppressed because it
 126                         //        is unknown if 'until' or 'from' makes this
 127                         //        give 0 results.
 128                         $r = $r . $this->getCategoryTop();
 129                 } else {
 130                         $r = $this->getCategoryTop() .
 131                                 $r .
 132                                 $this->getCategoryBottom();
 133                 }
 134
 135                 // Give a proper message if category is empty
 136                 if ( $r == '' ) {
 137                         $r = $this->msg( 'category-empty' )->parseAsBlock();
 138                 }
 139
 140                 $lang = $this->getLanguage();
 141                 $attribs = [
 142                         'class' => 'mw-category-generated',
 143                         'lang' => $lang->getHtmlCode(),
 144                         'dir' => $lang->getDir()
 145                 ];
 146                 # put a div around the headings which are in the user language
 147                 $r = Html::openElement( 'div', $attribs ) . $r . '</div>';
 148
 149                 return $r;
 150         }
 151
 152         function clearCategoryState() {
 153                 $this->articles = [];
 154                 $this->articles_start_char = [];
 155                 $this->children = [];
 156                 $this->children_start_char = [];
 157                 if ( $this->showGallery ) {
 158                         // Note that null for mode is taken to mean use default.
 159                         $mode = $this->getRequest()->getVal( 'gallerymode', null );
 160                         try {
 161                                 $this->gallery = ImageGalleryBase::factory( $mode, $this->getContext() );
 162                         } catch ( Exception $e ) {
 163                                 // User specified something invalid, fallback to default.
 164                                 $this->gallery = ImageGalleryBase::factory( false, $this->getContext() );
 165                         }
 166
 167                         $this->gallery->setHideBadImages();
 168                 } else {
 169                         $this->imgsNoGallery = [];
 170                         $this->imgsNoGallery_start_char = [];
 171                 }
 172         }
 173
 174         /**
 175          * Add a subcategory to the internal lists, using a Category object
 176          * @param Category $cat
 177          * @param string $sortkey
 178          * @param int $pageLength
 179          */
 180         function addSubcategoryObject( Category $cat, $sortkey, $pageLength ) {
 181                 // Subcategory; strip the 'Category' namespace from the link text.
 182                 $title = $cat->getTitle();
 183
 184                 $this->children[] = $this->generateLink(
 185                         'subcat',
 186                         $title,
 187                         $title->isRedirect(),
 188                         htmlspecialchars( $title->getText() )
 189                 );
 190
 191                 $this->children_start_char[] =
 192                         $this->getSubcategorySortChar( $cat->getTitle(), $sortkey );
 193         }
 194
 195         function generateLink( $type, Title $title, $isRedirect, $html = null ) {
 196                 $link = null;
 197                 Hooks::run( 'CategoryViewer::generateLink', [ $type, $title, $html, &$link ] );
 198                 if ( $link === null ) {
 199                         $link = Linker::link( $title, $html );
 200                 }
 201                 if ( $isRedirect ) {
 202                         $link = '<span class="redirect-in-category">' . $link . '</span>';
 203                 }
 204
 205                 return $link;
 206         }
 207
 208         /**
 209          * Get the character to be used for sorting subcategories.
 210          * If there's a link from Category:A to Category:B, the sortkey of the resulting
 211          * entry in the categorylinks table is Category:A, not A, which it SHOULD be.
 212          * Workaround: If sortkey == "Category:".$title, than use $title for sorting,
 213          * else use sortkey...
 214          *
 215          * @param Title $title
 216          * @param string $sortkey The human-readable sortkey (before transforming to icu or whatever).
 217          * @return string
 218          */
 219         function getSubcategorySortChar( $title, $sortkey ) {
 220                 global $wgContLang;
 221
 222                 if ( $title->getPrefixedText() == $sortkey ) {
 223                         $word = $title->getDBkey();
 224                 } else {
 225                         $word = $sortkey;
 226                 }
 227
 228                 $firstChar = $this->collation->getFirstLetter( $word );
 229
 230                 return $wgContLang->convert( $firstChar );
 231         }
 232
 233         /**
 234          * Add a page in the image namespace
 235          * @param Title $title
 236          * @param string $sortkey
 237          * @param int $pageLength
 238          * @param bool $isRedirect
 239          */
 240         function addImage( Title $title, $sortkey, $pageLength, $isRedirect = false ) {
 241                 global $wgContLang;
 242                 if ( $this->showGallery ) {
 243                         $flip = $this->flip['file'];
 244                         if ( $flip ) {
 245                                 $this->gallery->insert( $title );
 246                         } else {
 247                                 $this->gallery->add( $title );
 248                         }
 249                 } else {
 250                         $this->imgsNoGallery[] = $this->generateLink( 'image', $title, $isRedirect );
 251
 252                         $this->imgsNoGallery_start_char[] = $wgContLang->convert(
 253                                 $this->collation->getFirstLetter( $sortkey ) );
 254                 }
 255         }
 256
 257         /**
 258          * Add a miscellaneous page
 259          * @param Title $title
 260          * @param string $sortkey
 261          * @param int $pageLength
 262          * @param bool $isRedirect
 263          */
 264         function addPage( $title, $sortkey, $pageLength, $isRedirect = false ) {
 265                 global $wgContLang;
 266
 267                 $this->articles[] = $this->generateLink( 'page', $title, $isRedirect );
 268
 269                 $this->articles_start_char[] = $wgContLang->convert(
 270                         $this->collation->getFirstLetter( $sortkey ) );
 271         }
 272
 273         function finaliseCategoryState() {
 274                 if ( $this->flip['subcat'] ) {
 275                         $this->children = array_reverse( $this->children );
 276                         $this->children_start_char = array_reverse( $this->children_start_char );
 277                 }
 278                 if ( $this->flip['page'] ) {
 279                         $this->articles = array_reverse( $this->articles );
 280                         $this->articles_start_char = array_reverse( $this->articles_start_char );
 281                 }
 282                 if ( !$this->showGallery && $this->flip['file'] ) {
 283                         $this->imgsNoGallery = array_reverse( $this->imgsNoGallery );
 284                         $this->imgsNoGallery_start_char = array_reverse( $this->imgsNoGallery_start_char );
 285                 }
 286         }
 287
 288         function doCategoryQuery() {
 289                 $dbr = wfGetDB( DB_SLAVE, 'category' );
 290
 291                 $this->nextPage = [
 292                         'page' => null,
 293                         'subcat' => null,
 294                         'file' => null,
 295                 ];
 296                 $this->prevPage = [
 297                         'page' => null,
 298                         'subcat' => null,
 299                         'file' => null,
 300                 ];
 301
 302                 $this->flip = [ 'page' => false, 'subcat' => false, 'file' => false ];
 303
 304                 foreach ( [ 'page', 'subcat', 'file' ] as $type ) {
 305                         # Get the sortkeys for start/end, if applicable.  Note that if
 306                         # the collation in the database differs from the one
 307                         # set in $wgCategoryCollation, pagination might go totally haywire.
 308                         $extraConds = [ 'cl_type' => $type ];
 309                         if ( isset( $this->from[$type] ) && $this->from[$type] !== null ) {
 310                                 $extraConds[] = 'cl_sortkey >= '
 311                                         . $dbr->addQuotes( $this->collation->getSortKey( $this->from[$type] ) );
 312                         } elseif ( isset( $this->until[$type] ) && $this->until[$type] !== null ) {
 313                                 $extraConds[] = 'cl_sortkey < '
 314                                         . $dbr->addQuotes( $this->collation->getSortKey( $this->until[$type] ) );
 315                                 $this->flip[$type] = true;
 316                         }
 317
 318                         $res = $dbr->select(
 319                                 [ 'page', 'categorylinks', 'category' ],
 320                                 [ 'page_id', 'page_title', 'page_namespace', 'page_len',
 321                                         'page_is_redirect', 'cl_sortkey', 'cat_id', 'cat_title',
 322                                         'cat_subcats', 'cat_pages', 'cat_files',
 323                                         'cl_sortkey_prefix', 'cl_collation' ],
 324                                 array_merge( [ 'cl_to' => $this->title->getDBkey() ], $extraConds ),
 325                                 __METHOD__,
 326                                 [
 327                                         'USE INDEX' => [ 'categorylinks' => 'cl_sortkey' ],
 328                                         'LIMIT' => $this->limit + 1,
 329                                         'ORDER BY' => $this->flip[$type] ? 'cl_sortkey DESC' : 'cl_sortkey',
 330                                 ],
 331                                 [
 332                                         'categorylinks' => [ 'INNER JOIN', 'cl_from = page_id' ],
 333                                         'category' => [ 'LEFT JOIN', [
 334                                                 'cat_title = page_title',
 335                                                 'page_namespace' => NS_CATEGORY
 336                                         ] ]
 337                                 ]
 338                         );
 339
 340                         Hooks::run( 'CategoryViewer::doCategoryQuery', [ $type, $res ] );
 341
 342                         $count = 0;
 343                         foreach ( $res as $row ) {
 344                                 $title = Title::newFromRow( $row );
 345                                 if ( $row->cl_collation === '' ) {
 346                                         // Hack to make sure that while updating from 1.16 schema
 347                                         // and db is inconsistent, that the sky doesn't fall.
 348                                         // See r83544. Could perhaps be removed in a couple decades...
 349                                         $humanSortkey = $row->cl_sortkey;
 350                                 } else {
 351                                         $humanSortkey = $title->getCategorySortkey( $row->cl_sortkey_prefix );
 352                                 }
 353
 354                                 if ( ++$count > $this->limit ) {
 355                                         # We've reached the one extra which shows that there
 356                                         # are additional pages to be had. Stop here...
 357                                         $this->nextPage[$type] = $humanSortkey;
 358                                         break;
 359                                 }
 360                                 if ( $count == $this->limit ) {
 361                                         $this->prevPage[$type] = $humanSortkey;
 362                                 }
 363
 364                                 if ( $title->getNamespace() == NS_CATEGORY ) {
 365                                         $cat = Category::newFromRow( $row, $title );
 366                                         $this->addSubcategoryObject( $cat, $humanSortkey, $row->page_len );
 367                                 } elseif ( $title->getNamespace() == NS_FILE ) {
 368                                         $this->addImage( $title, $humanSortkey, $row->page_len, $row->page_is_redirect );
 369                                 } else {
 370                                         $this->addPage( $title, $humanSortkey, $row->page_len, $row->page_is_redirect );
 371                                 }
 372                         }
 373                 }
 374         }
 375
 376         /**
 377          * @return string
 378          */
 379         function getCategoryTop() {
 380                 $r = $this->getCategoryBottom();
 381                 return $r === ''
 382                         ? $r
 383                         : "<br style=\"clear:both;\"/>\n" . $r;
 384         }
 385
 386         /**
 387          * @return string
 388          */
 389         function getSubcategorySection() {
 390                 # Don't show subcategories section if there are none.
 391                 $r = '';
 392                 $rescnt = count( $this->children );
 393                 $dbcnt = $this->cat->getSubcatCount();
 394                 // This function should be called even if the result isn't used, it has side-effects
 395                 $countmsg = $this->getCountMessage( $rescnt, $dbcnt, 'subcat' );
 396
 397                 if ( $rescnt > 0 ) {
 398                         # Showing subcategories
 399                         $r .= "<div id=\"mw-subcategories\">\n";
 400                         $r .= '<h2>' . $this->msg( 'subcategories' )->parse() . "</h2>\n";
 401                         $r .= $countmsg;
 402                         $r .= $this->getSectionPagingLinks( 'subcat' );
 403                         $r .= $this->formatList( $this->children, $this->children_start_char );
 404                         $r .= $this->getSectionPagingLinks( 'subcat' );
 405                         $r .= "\n</div>";
 406                 }
 407                 return $r;
 408         }
 409
 410         /**
 411          * @return string
 412          */
 413         function getPagesSection() {
 414                 $ti = wfEscapeWikiText( $this->title->getText() );
 415                 # Don't show articles section if there are none.
 416                 $r = '';
 417
 418                 # @todo FIXME: Here and in the other two sections: we don't need to bother
 419                 # with this rigmarole if the entire category contents fit on one page
 420                 # and have already been retrieved.  We can just use $rescnt in that
 421                 # case and save a query and some logic.
 422                 $dbcnt = $this->cat->getPageCount() - $this->cat->getSubcatCount()
 423                         - $this->cat->getFileCount();
 424                 $rescnt = count( $this->articles );
 425                 // This function should be called even if the result isn't used, it has side-effects
 426                 $countmsg = $this->getCountMessage( $rescnt, $dbcnt, 'article' );
 427
 428                 if ( $rescnt > 0 ) {
 429                         $r = "<div id=\"mw-pages\">\n";
 430                         $r .= '<h2>' . $this->msg( 'category_header', $ti )->parse() . "</h2>\n";
 431                         $r .= $countmsg;
 432                         $r .= $this->getSectionPagingLinks( 'page' );
 433                         $r .= $this->formatList( $this->articles, $this->articles_start_char );
 434                         $r .= $this->getSectionPagingLinks( 'page' );
 435                         $r .= "\n</div>";
 436                 }
 437                 return $r;
 438         }
 439
 440         /**
 441          * @return string
 442          */
 443         function getImageSection() {
 444                 $r = '';
 445                 $rescnt = $this->showGallery ? $this->gallery->count() : count( $this->imgsNoGallery );
 446                 $dbcnt = $this->cat->getFileCount();
 447                 // This function should be called even if the result isn't used, it has side-effects
 448                 $countmsg = $this->getCountMessage( $rescnt, $dbcnt, 'file' );
 449
 450                 if ( $rescnt > 0 ) {
 451                         $r .= "<div id=\"mw-category-media\">\n";
 452                         $r .= '<h2>' .
 453                                 $this->msg(
 454                                         'category-media-header',
 455                                         wfEscapeWikiText( $this->title->getText() )
 456                                 )->text() .
 457                                 "</h2>\n";
 458                         $r .= $countmsg;
 459                         $r .= $this->getSectionPagingLinks( 'file' );
 460                         if ( $this->showGallery ) {
 461                                 $r .= $this->gallery->toHTML();
 462                         } else {
 463                                 $r .= $this->formatList( $this->imgsNoGallery, $this->imgsNoGallery_start_char );
 464                         }
 465                         $r .= $this->getSectionPagingLinks( 'file' );
 466                         $r .= "\n</div>";
 467                 }
 468                 return $r;
 469         }
 470
 471         /**
 472          * Get the paging links for a section (subcats/pages/files), to go at the top and bottom
 473          * of the output.
 474          *
 475          * @param string $type 'page', 'subcat', or 'file'
 476          * @return string HTML output, possibly empty if there are no other pages
 477          */
 478         private function getSectionPagingLinks( $type ) {
 479                 if ( isset( $this->until[$type] ) && $this->until[$type] !== null ) {
 480                         // The new value for the until parameter should be pointing to the first
 481                         // result displayed on the page which is the second last result retrieved
 482                         // from the database.The next link should have a from parameter pointing
 483                         // to the until parameter of the current page.
 484                         if ( $this->nextPage[$type] !== null ) {
 485                                 return $this->pagingLinks( $this->prevPage[$type], $this->until[$type], $type );
 486                         } else {
 487                                 // If the nextPage variable is null, it means that we have reached the first page
 488                                 // and therefore the previous link should be disabled.
 489                                 return $this->pagingLinks( null, $this->until[$type], $type );
 490                         }
 491                 } elseif ( $this->nextPage[$type] !== null
 492                         || ( isset( $this->from[$type] ) && $this->from[$type] !== null )
 493                 ) {
 494                         return $this->pagingLinks( $this->from[$type], $this->nextPage[$type], $type );
 495                 } else {
 496                         return '';
 497                 }
 498         }
 499
 500         /**
 501          * @return string
 502          */
 503         function getCategoryBottom() {
 504                 return '';
 505         }
 506
 507         /**
 508          * Format a list of articles chunked by letter, either as a
 509          * bullet list or a columnar format, depending on the length.
 510          *
 511          * @param array $articles
 512          * @param array $articles_start_char
 513          * @param int $cutoff
 514          * @return string
 515          * @private
 516          */
 517         function formatList( $articles, $articles_start_char, $cutoff = 6 ) {
 518                 $list = '';
 519                 if ( count( $articles ) > $cutoff ) {
 520                         $list = self::columnList( $articles, $articles_start_char );
 521                 } elseif ( count( $articles ) > 0 ) {
 522                         // for short lists of articles in categories.
 523                         $list = self::shortList( $articles, $articles_start_char );
 524                 }
 525
 526                 $pageLang = $this->title->getPageLanguage();
 527                 $attribs = [ 'lang' => $pageLang->getHtmlCode(), 'dir' => $pageLang->getDir(),
 528                         'class' => 'mw-content-' . $pageLang->getDir() ];
 529                 $list = Html::rawElement( 'div', $attribs, $list );
 530
 531                 return $list;
 532         }
 533
 534         /**
 535          * Format a list of articles chunked by letter in a three-column
 536          * list, ordered vertically.
 537          *
 538          * TODO: Take the headers into account when creating columns, so they're
 539          * more visually equal.
 540          *
 541          * TODO: shortList and columnList are similar, need merging
 542          *
 543          * @param array $articles
 544          * @param string[] $articles_start_char
 545          * @return string
 546          * @private
 547          */
 548         static function columnList( $articles, $articles_start_char ) {
 549                 $columns = array_combine( $articles, $articles_start_char );
 550
 551                 $ret = Html::openElement( 'div', [ 'class' => 'mw-category' ] );
 552
 553                 $colContents = [];
 554
 555                 # Kind of like array_flip() here, but we keep duplicates in an
 556                 # array instead of dropping them.
 557                 foreach ( $columns as $article => $char ) {
 558                         if ( !isset( $colContents[$char] ) ) {
 559                                 $colContents[$char] = [];
 560                         }
 561                         $colContents[$char][] = $article;
 562                 }
 563
 564                 foreach ( $colContents as $char => $articles ) {
 565                         # Change space to non-breaking space to keep headers aligned
 566                         $h3char = $char === ' ' ? '&#160;' : htmlspecialchars( $char );
 567
 568                         $ret .= '<div class="mw-category-group"><h3>' . $h3char;
 569                         $ret .= "</h3>\n";
 570
 571                         $ret .= '<ul><li>';
 572                         $ret .= implode( "</li>\n<li>", $articles );
 573                         $ret .= '</li></ul></div>';
 574
 575                 }
 576
 577                 $ret .= Html::closeElement( 'div' );
 578                 return $ret;
 579         }
 580
 581         /**
 582          * Format a list of articles chunked by letter in a bullet list.
 583          * @param array $articles
 584          * @param string[] $articles_start_char
 585          * @return string
 586          * @private
 587          */
 588         static function shortList( $articles, $articles_start_char ) {
 589                 $r = '<h3>' . htmlspecialchars( $articles_start_char[0] ) . "</h3>\n";
 590                 $r .= '<ul><li>' . $articles[0] . '</li>';
 591                 $articleCount = count( $articles );
 592                 for ( $index = 1; $index < $articleCount; $index++ ) {
 593                         if ( $articles_start_char[$index] != $articles_start_char[$index - 1] ) {
 594                                 $r .= "</ul><h3>" . htmlspecialchars( $articles_start_char[$index] ) . "</h3>\n<ul>";
 595                         }
 596
 597                         $r .= "<li>{$articles[$index]}</li>";
 598                 }
 599                 $r .= '</ul>';
 600                 return $r;
 601         }
 602
 603         /**
 604          * Create paging links, as a helper method to getSectionPagingLinks().
 605          *
 606          * @param string $first The 'until' parameter for the generated URL
 607          * @param string $last The 'from' parameter for the generated URL
 608          * @param string $type A prefix for parameters, 'page' or 'subcat' or
 609          *     'file'
 610          * @return string HTML
 611          */
 612         private function pagingLinks( $first, $last, $type = '' ) {
 613                 $prevLink = $this->msg( 'prev-page' )->text();
 614
 615                 if ( $first != '' ) {
 616                         $prevQuery = $this->query;
 617                         $prevQuery["{$type}until"] = $first;
 618                         unset( $prevQuery["{$type}from"] );
 619                         $prevLink = Linker::linkKnown(
 620                                 $this->addFragmentToTitle( $this->title, $type ),
 621                                 $prevLink,
 622                                 [],
 623                                 $prevQuery
 624                         );
 625                 }
 626
 627                 $nextLink = $this->msg( 'next-page' )->text();
 628
 629                 if ( $last != '' ) {
 630                         $lastQuery = $this->query;
 631                         $lastQuery["{$type}from"] = $last;
 632                         unset( $lastQuery["{$type}until"] );
 633                         $nextLink = Linker::linkKnown(
 634                                 $this->addFragmentToTitle( $this->title, $type ),
 635                                 $nextLink,
 636                                 [],
 637                                 $lastQuery
 638                         );
 639                 }
 640
 641                 return $this->msg( 'categoryviewer-pagedlinks' )->rawParams( $prevLink, $nextLink )->escaped();
 642         }
 643
 644         /**
 645          * Takes a title, and adds the fragment identifier that
 646          * corresponds to the correct segment of the category.
 647          *
 648          * @param Title $title The title (usually $this->title)
 649          * @param string $section Which section
 650          * @throws MWException
 651          * @return Title
 652          */
 653         private function addFragmentToTitle( $title, $section ) {
 654                 switch ( $section ) {
 655                         case 'page':
 656                                 $fragment = 'mw-pages';
 657                                 break;
 658                         case 'subcat':
 659                                 $fragment = 'mw-subcategories';
 660                                 break;
 661                         case 'file':
 662                                 $fragment = 'mw-category-media';
 663                                 break;
 664                         default:
 665                                 throw new MWException( __METHOD__ .
 666                                         " Invalid section $section." );
 667                 }
 668
 669                 return Title::makeTitle( $title->getNamespace(),
 670                         $title->getDBkey(), $fragment );
 671         }
 672
 673         /**
 674          * What to do if the category table conflicts with the number of results
 675          * returned?  This function says what. Each type is considered independently
 676          * of the other types.
 677          *
 678          * @param int $rescnt The number of items returned by our database query.
 679          * @param int $dbcnt The number of items according to the category table.
 680          * @param string $type 'subcat', 'article', or 'file'
 681          * @return string A message giving the number of items, to output to HTML.
 682          */
 683         private function getCountMessage( $rescnt, $dbcnt, $type ) {
 684                 // There are three cases:
 685                 //   1) The category table figure seems sane.  It might be wrong, but
 686                 //      we can't do anything about it if we don't recalculate it on ev-
 687                 //      ery category view.
 688                 //   2) The category table figure isn't sane, like it's smaller than the
 689                 //      number of actual results, *but* the number of results is less
 690                 //      than $this->limit and there's no offset.  In this case we still
 691                 //      know the right figure.
 692                 //   3) We have no idea.
 693
 694                 // Check if there's a "from" or "until" for anything
 695
 696                 // This is a little ugly, but we seem to use different names
 697                 // for the paging types then for the messages.
 698                 if ( $type === 'article' ) {
 699                         $pagingType = 'page';
 700                 } else {
 701                         $pagingType = $type;
 702                 }
 703
 704                 $fromOrUntil = false;
 705                 if ( ( isset( $this->from[$pagingType] ) && $this->from[$pagingType] !== null ) ||
 706                         ( isset( $this->until[$pagingType] ) && $this->until[$pagingType] !== null )
 707                 ) {
 708                         $fromOrUntil = true;
 709                 }
 710
 711                 if ( $dbcnt == $rescnt ||
 712                         ( ( $rescnt == $this->limit || $fromOrUntil ) && $dbcnt > $rescnt )
 713                 ) {
 714                         // Case 1: seems sane.
 715                         $totalcnt = $dbcnt;
 716                 } elseif ( $rescnt < $this->limit && !$fromOrUntil ) {
 717                         // Case 2: not sane, but salvageable.  Use the number of results.
 718                         // Since there are fewer than 200, we can also take this opportunity
 719                         // to refresh the incorrect category table entry -- which should be
 720                         // quick due to the small number of entries.
 721                         $totalcnt = $rescnt;
 722                         $category = $this->cat;
 723                         DeferredUpdates::addCallableUpdate( function () use ( $category ) {
 724                                 $category->refreshCounts();
 725                         } );
 726                 } else {
 727                         // Case 3: hopeless.  Don't give a total count at all.
 728                         // Messages: category-subcat-count-limited, category-article-count-limited,
 729                         // category-file-count-limited
 730                         return $this->msg( "category-$type-count-limited" )->numParams( $rescnt )->parseAsBlock();
 731                 }
 732                 // Messages: category-subcat-count, category-article-count, category-file-count
 733                 return $this->msg( "category-$type-count" )->numParams( $rescnt, $totalcnt )->parseAsBlock();
 734         }
 735 }