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