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 use MediaWiki\MediaWikiServices;
  23
  24 class CategoryViewer extends ContextSource {
  25         /** @var int */
  26         public $limit;
  27
  28         /** @var array */
  29         public $from;
  30
  31         /** @var array */
  32         public $until;
  33
  34         /** @var string[] */
  35         public $articles;
  36
  37         /** @var array */
  38         public $articles_start_char;
  39
  40         /** @var array */
  41         public $children;
  42
  43         /** @var array */
  44         public $children_start_char;
  45
  46         /** @var bool */
  47         public $showGallery;
  48
  49         /** @var array */
  50         public $imgsNoGallery_start_char;
  51
  52         /** @var array */
  53         public $imgsNoGallery;
  54
  55         /** @var array */
  56         public $nextPage;
  57
  58         /** @var array */
  59         protected $prevPage;
  60
  61         /** @var array */
  62         public $flip;
  63
  64         /** @var Title */
  65         public $title;
  66
  67         /** @var Collation */
  68         public $collation;
  69
  70         /** @var ImageGalleryBase */
  71         public $gallery;
  72
  73         /** @var Category Category object for this page. */
  74         private $cat;
  75
  76         /** @var array The original query array, to be used in generating paging links. */
  77         private $query;
  78
  79         /**
  80          * @since 1.19 $context is a second, required parameter
  81          * @param Title $title
  82          * @param IContextSource $context
  83          * @param array $from An array with keys page, subcat,
  84          *        and file for offset of results of each section (since 1.17)
  85          * @param array $until An array with 3 keys for until of each section (since 1.17)
  86          * @param array $query
  87          */
  88         function __construct( $title, IContextSource $context, $from = [],
  89                 $until = [], $query = []
  90         ) {
  91                 $this->title = $title;
  92                 $this->setContext( $context );
  93                 $this->getOutput()->addModuleStyles( [
  94                         'mediawiki.action.view.categoryPage.styles'
  95                 ] );
  96                 $this->from = $from;
  97                 $this->until = $until;
  98                 $this->limit = $context->getConfig()->get( 'CategoryPagingLimit' );
  99                 $this->cat = Category::newFromTitle( $title );
 100                 $this->query = $query;
 101                 $this->collation = Collation::singleton();
 102                 unset( $this->query['title'] );
 103         }
 104
 105         /**
 106          * Format the category data list.
 107          *
 108          * @return string HTML output
 109          */
 110         public function getHTML() {
 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                         $linkRenderer = MediaWikiServices::getInstance()->getLinkRenderer();
 200                         if ( $html !== null ) {
 201                                 $html = new HtmlArmor( $html );
 202                         }
 203                         $link = $linkRenderer->makeLink( $title, $html );
 204                 }
 205                 if ( $isRedirect ) {
 206                         $link = '<span class="redirect-in-category">' . $link . '</span>';
 207                 }
 208
 209                 return $link;
 210         }
 211
 212         /**
 213          * Get the character to be used for sorting subcategories.
 214          * If there's a link from Category:A to Category:B, the sortkey of the resulting
 215          * entry in the categorylinks table is Category:A, not A, which it SHOULD be.
 216          * Workaround: If sortkey == "Category:".$title, than use $title for sorting,
 217          * else use sortkey...
 218          *
 219          * @param Title $title
 220          * @param string $sortkey The human-readable sortkey (before transforming to icu or whatever).
 221          * @return string
 222          */
 223         function getSubcategorySortChar( $title, $sortkey ) {
 224                 if ( $title->getPrefixedText() == $sortkey ) {
 225                         $word = $title->getDBkey();
 226                 } else {
 227                         $word = $sortkey;
 228                 }
 229
 230                 $firstChar = $this->collation->getFirstLetter( $word );
 231
 232                 return MediaWikiServices::getInstance()->getContentLanguage()->convert( $firstChar );
 233         }
 234
 235         /**
 236          * Add a page in the image namespace
 237          * @param Title $title
 238          * @param string $sortkey
 239          * @param int $pageLength
 240          * @param bool $isRedirect
 241          */
 242         function addImage( Title $title, $sortkey, $pageLength, $isRedirect = false ) {
 243                 if ( $this->showGallery ) {
 244                         $flip = $this->flip['file'];
 245                         if ( $flip ) {
 246                                 $this->gallery->insert( $title );
 247                         } else {
 248                                 $this->gallery->add( $title );
 249                         }
 250                 } else {
 251                         $this->imgsNoGallery[] = $this->generateLink( 'image', $title, $isRedirect );
 252
 253                         $this->imgsNoGallery_start_char[] = MediaWikiServices::getInstance()->
 254                                 getContentLanguage()->convert( $this->collation->getFirstLetter( $sortkey ) );
 255                 }
 256         }
 257
 258         /**
 259          * Add a miscellaneous page
 260          * @param Title $title
 261          * @param string $sortkey
 262          * @param int $pageLength
 263          * @param bool $isRedirect
 264          */
 265         function addPage( $title, $sortkey, $pageLength, $isRedirect = false ) {
 266                 $this->articles[] = $this->generateLink( 'page', $title, $isRedirect );
 267
 268                 $this->articles_start_char[] = MediaWikiServices::getInstance()->
 269                         getContentLanguage()->convert( $this->collation->getFirstLetter( $sortkey ) );
 270         }
 271
 272         function finaliseCategoryState() {
 273                 if ( $this->flip['subcat'] ) {
 274                         $this->children = array_reverse( $this->children );
 275                         $this->children_start_char = array_reverse( $this->children_start_char );
 276                 }
 277                 if ( $this->flip['page'] ) {
 278                         $this->articles = array_reverse( $this->articles );
 279                         $this->articles_start_char = array_reverse( $this->articles_start_char );
 280                 }
 281                 if ( !$this->showGallery && $this->flip['file'] ) {
 282                         $this->imgsNoGallery = array_reverse( $this->imgsNoGallery );
 283                         $this->imgsNoGallery_start_char = array_reverse( $this->imgsNoGallery_start_char );
 284                 }
 285         }
 286
 287         function doCategoryQuery() {
 288                 $dbr = wfGetDB( DB_REPLICA, 'category' );
 289
 290                 $this->nextPage = [
 291                         'page' => null,
 292                         'subcat' => null,
 293                         'file' => null,
 294                 ];
 295                 $this->prevPage = [
 296                         'page' => null,
 297                         'subcat' => null,
 298                         'file' => null,
 299                 ];
 300
 301                 $this->flip = [ 'page' => false, 'subcat' => false, 'file' => false ];
 302
 303                 foreach ( [ 'page', 'subcat', 'file' ] as $type ) {
 304                         # Get the sortkeys for start/end, if applicable.  Note that if
 305                         # the collation in the database differs from the one
 306                         # set in $wgCategoryCollation, pagination might go totally haywire.
 307                         $extraConds = [ 'cl_type' => $type ];
 308                         if ( isset( $this->from[$type] ) && $this->from[$type] !== null ) {
 309                                 $extraConds[] = 'cl_sortkey >= '
 310                                         . $dbr->addQuotes( $this->collation->getSortKey( $this->from[$type] ) );
 311                         } elseif ( isset( $this->until[$type] ) && $this->until[$type] !== null ) {
 312                                 $extraConds[] = 'cl_sortkey < '
 313                                         . $dbr->addQuotes( $this->collation->getSortKey( $this->until[$type] ) );
 314                                 $this->flip[$type] = true;
 315                         }
 316
 317                         $res = $dbr->select(
 318                                 [ 'page', 'categorylinks', 'category' ],
 319                                 array_merge(
 320                                         LinkCache::getSelectFields(),
 321                                         [
 322                                                 'page_namespace',
 323                                                 'page_title',
 324                                                 'cl_sortkey',
 325                                                 'cat_id',
 326                                                 'cat_title',
 327                                                 'cat_subcats',
 328                                                 'cat_pages',
 329                                                 'cat_files',
 330                                                 'cl_sortkey_prefix',
 331                                                 'cl_collation'
 332                                         ]
 333                                 ),
 334                                 array_merge( [ 'cl_to' => $this->title->getDBkey() ], $extraConds ),
 335                                 __METHOD__,
 336                                 [
 337                                         'USE INDEX' => [ 'categorylinks' => 'cl_sortkey' ],
 338                                         'LIMIT' => $this->limit + 1,
 339                                         'ORDER BY' => $this->flip[$type] ? 'cl_sortkey DESC' : 'cl_sortkey',
 340                                 ],
 341                                 [
 342                                         'categorylinks' => [ 'INNER JOIN', 'cl_from = page_id' ],
 343                                         'category' => [ 'LEFT JOIN', [
 344                                                 'cat_title = page_title',
 345                                                 'page_namespace' => NS_CATEGORY
 346                                         ] ]
 347                                 ]
 348                         );
 349
 350                         Hooks::run( 'CategoryViewer::doCategoryQuery', [ $type, $res ] );
 351                         $linkCache = MediaWikiServices::getInstance()->getLinkCache();
 352
 353                         $count = 0;
 354                         foreach ( $res as $row ) {
 355                                 $title = Title::newFromRow( $row );
 356                                 $linkCache->addGoodLinkObjFromRow( $title, $row );
 357
 358                                 if ( $row->cl_collation === '' ) {
 359                                         // Hack to make sure that while updating from 1.16 schema
 360                                         // and db is inconsistent, that the sky doesn't fall.
 361                                         // See r83544. Could perhaps be removed in a couple decades...
 362                                         $humanSortkey = $row->cl_sortkey;
 363                                 } else {
 364                                         $humanSortkey = $title->getCategorySortkey( $row->cl_sortkey_prefix );
 365                                 }
 366
 367                                 if ( ++$count > $this->limit ) {
 368                                         # We've reached the one extra which shows that there
 369                                         # are additional pages to be had. Stop here...
 370                                         $this->nextPage[$type] = $humanSortkey;
 371                                         break;
 372                                 }
 373                                 if ( $count == $this->limit ) {
 374                                         $this->prevPage[$type] = $humanSortkey;
 375                                 }
 376
 377                                 if ( $title->getNamespace() == NS_CATEGORY ) {
 378                                         $cat = Category::newFromRow( $row, $title );
 379                                         $this->addSubcategoryObject( $cat, $humanSortkey, $row->page_len );
 380                                 } elseif ( $title->getNamespace() == NS_FILE ) {
 381                                         $this->addImage( $title, $humanSortkey, $row->page_len, $row->page_is_redirect );
 382                                 } else {
 383                                         $this->addPage( $title, $humanSortkey, $row->page_len, $row->page_is_redirect );
 384                                 }
 385                         }
 386                 }
 387         }
 388
 389         /**
 390          * @return string
 391          */
 392         function getCategoryTop() {
 393                 $r = $this->getCategoryBottom();
 394                 return $r === ''
 395                         ? $r
 396                         : "<br style=\"clear:both;\"/>\n" . $r;
 397         }
 398
 399         /**
 400          * @return string
 401          */
 402         function getSubcategorySection() {
 403                 # Don't show subcategories section if there are none.
 404                 $r = '';
 405                 $rescnt = count( $this->children );
 406                 $dbcnt = $this->cat->getSubcatCount();
 407                 // This function should be called even if the result isn't used, it has side-effects
 408                 $countmsg = $this->getCountMessage( $rescnt, $dbcnt, 'subcat' );
 409
 410                 if ( $rescnt > 0 ) {
 411                         # Showing subcategories
 412                         $r .= "<div id=\"mw-subcategories\">\n";
 413                         $r .= '<h2>' . $this->msg( 'subcategories' )->parse() . "</h2>\n";
 414                         $r .= $countmsg;
 415                         $r .= $this->getSectionPagingLinks( 'subcat' );
 416                         $r .= $this->formatList( $this->children, $this->children_start_char );
 417                         $r .= $this->getSectionPagingLinks( 'subcat' );
 418                         $r .= "\n</div>";
 419                 }
 420                 return $r;
 421         }
 422
 423         /**
 424          * @return string
 425          */
 426         function getPagesSection() {
 427                 $name = $this->getOutput()->getUnprefixedDisplayTitle();
 428                 # Don't show articles section if there are none.
 429                 $r = '';
 430
 431                 # @todo FIXME: Here and in the other two sections: we don't need to bother
 432                 # with this rigmarole if the entire category contents fit on one page
 433                 # and have already been retrieved.  We can just use $rescnt in that
 434                 # case and save a query and some logic.
 435                 $dbcnt = $this->cat->getPageCount() - $this->cat->getSubcatCount()
 436                         - $this->cat->getFileCount();
 437                 $rescnt = count( $this->articles );
 438                 // This function should be called even if the result isn't used, it has side-effects
 439                 $countmsg = $this->getCountMessage( $rescnt, $dbcnt, 'article' );
 440
 441                 if ( $rescnt > 0 ) {
 442                         $r = "<div id=\"mw-pages\">\n";
 443                         $r .= '<h2>' . $this->msg( 'category_header' )->rawParams( $name )->parse() . "</h2>\n";
 444                         $r .= $countmsg;
 445                         $r .= $this->getSectionPagingLinks( 'page' );
 446                         $r .= $this->formatList( $this->articles, $this->articles_start_char );
 447                         $r .= $this->getSectionPagingLinks( 'page' );
 448                         $r .= "\n</div>";
 449                 }
 450                 return $r;
 451         }
 452
 453         /**
 454          * @return string
 455          */
 456         function getImageSection() {
 457                 $name = $this->getOutput()->getUnprefixedDisplayTitle();
 458                 $r = '';
 459                 $rescnt = $this->showGallery ? $this->gallery->count() : count( $this->imgsNoGallery );
 460                 $dbcnt = $this->cat->getFileCount();
 461                 // This function should be called even if the result isn't used, it has side-effects
 462                 $countmsg = $this->getCountMessage( $rescnt, $dbcnt, 'file' );
 463
 464                 if ( $rescnt > 0 ) {
 465                         $r .= "<div id=\"mw-category-media\">\n";
 466                         $r .= '<h2>' .
 467                                 $this->msg( 'category-media-header' )->rawParams( $name )->parse() .
 468                                 "</h2>\n";
 469                         $r .= $countmsg;
 470                         $r .= $this->getSectionPagingLinks( 'file' );
 471                         if ( $this->showGallery ) {
 472                                 $r .= $this->gallery->toHTML();
 473                         } else {
 474                                 $r .= $this->formatList( $this->imgsNoGallery, $this->imgsNoGallery_start_char );
 475                         }
 476                         $r .= $this->getSectionPagingLinks( 'file' );
 477                         $r .= "\n</div>";
 478                 }
 479                 return $r;
 480         }
 481
 482         /**
 483          * Get the paging links for a section (subcats/pages/files), to go at the top and bottom
 484          * of the output.
 485          *
 486          * @param string $type 'page', 'subcat', or 'file'
 487          * @return string HTML output, possibly empty if there are no other pages
 488          */
 489         private function getSectionPagingLinks( $type ) {
 490                 if ( isset( $this->until[$type] ) && $this->until[$type] !== null ) {
 491                         // The new value for the until parameter should be pointing to the first
 492                         // result displayed on the page which is the second last result retrieved
 493                         // from the database.The next link should have a from parameter pointing
 494                         // to the until parameter of the current page.
 495                         if ( $this->nextPage[$type] !== null ) {
 496                                 return $this->pagingLinks( $this->prevPage[$type], $this->until[$type], $type );
 497                         } else {
 498                                 // If the nextPage variable is null, it means that we have reached the first page
 499                                 // and therefore the previous link should be disabled.
 500                                 return $this->pagingLinks( null, $this->until[$type], $type );
 501                         }
 502                 } elseif ( $this->nextPage[$type] !== null
 503                         || ( isset( $this->from[$type] ) && $this->from[$type] !== null )
 504                 ) {
 505                         return $this->pagingLinks( $this->from[$type], $this->nextPage[$type], $type );
 506                 } else {
 507                         return '';
 508                 }
 509         }
 510
 511         /**
 512          * @return string
 513          */
 514         function getCategoryBottom() {
 515                 return '';
 516         }
 517
 518         /**
 519          * Format a list of articles chunked by letter, either as a
 520          * bullet list or a columnar format, depending on the length.
 521          *
 522          * @param array $articles
 523          * @param array $articles_start_char
 524          * @param int $cutoff
 525          * @return string
 526          * @private
 527          */
 528         function formatList( $articles, $articles_start_char, $cutoff = 6 ) {
 529                 $list = '';
 530                 if ( count( $articles ) > $cutoff ) {
 531                         $list = self::columnList( $articles, $articles_start_char );
 532                 } elseif ( count( $articles ) > 0 ) {
 533                         // for short lists of articles in categories.
 534                         $list = self::shortList( $articles, $articles_start_char );
 535                 }
 536
 537                 $pageLang = $this->title->getPageLanguage();
 538                 $attribs = [ 'lang' => $pageLang->getHtmlCode(), 'dir' => $pageLang->getDir(),
 539                         'class' => 'mw-content-' . $pageLang->getDir() ];
 540                 $list = Html::rawElement( 'div', $attribs, $list );
 541
 542                 return $list;
 543         }
 544
 545         /**
 546          * Format a list of articles chunked by letter in a three-column list, ordered
 547          * vertically. This is used for categories with a significant number of pages.
 548          *
 549          * TODO: Take the headers into account when creating columns, so they're
 550          * more visually equal.
 551          *
 552          * TODO: shortList and columnList are similar, need merging
 553          *
 554          * @param string[] $articles HTML links to each article
 555          * @param string[] $articles_start_char The header characters for each article
 556          * @return string HTML to output
 557          * @private
 558          */
 559         static function columnList( $articles, $articles_start_char ) {
 560                 $columns = array_combine( $articles, $articles_start_char );
 561
 562                 $ret = Html::openElement( 'div', [ 'class' => 'mw-category' ] );
 563
 564                 $colContents = [];
 565
 566                 # Kind of like array_flip() here, but we keep duplicates in an
 567                 # array instead of dropping them.
 568                 foreach ( $columns as $article => $char ) {
 569                         if ( !isset( $colContents[$char] ) ) {
 570                                 $colContents[$char] = [];
 571                         }
 572                         $colContents[$char][] = $article;
 573                 }
 574
 575                 foreach ( $colContents as $char => $articles ) {
 576                         # Change space to non-breaking space to keep headers aligned
 577                         $h3char = $char === ' ' ? "\u{00A0}" : htmlspecialchars( $char );
 578
 579                         $ret .= '<div class="mw-category-group"><h3>' . $h3char;
 580                         $ret .= "</h3>\n";
 581
 582                         $ret .= '<ul><li>';
 583                         $ret .= implode( "</li>\n<li>", $articles );
 584                         $ret .= '</li></ul></div>';
 585
 586                 }
 587
 588                 $ret .= Html::closeElement( 'div' );
 589                 return $ret;
 590         }
 591
 592         /**
 593          * Format a list of articles chunked by letter in a bullet list. This is used
 594          * for categories with a small number of pages (when columns aren't needed).
 595          * @param string[] $articles HTML links to each article
 596          * @param string[] $articles_start_char The header characters for each article
 597          * @return string HTML to output
 598          * @private
 599          */
 600         static function shortList( $articles, $articles_start_char ) {
 601                 $r = '<h3>' . htmlspecialchars( $articles_start_char[0] ) . "</h3>\n";
 602                 $r .= '<ul><li>' . $articles[0] . '</li>';
 603                 $articleCount = count( $articles );
 604                 for ( $index = 1; $index < $articleCount; $index++ ) {
 605                         if ( $articles_start_char[$index] != $articles_start_char[$index - 1] ) {
 606                                 $r .= "</ul><h3>" . htmlspecialchars( $articles_start_char[$index] ) . "</h3>\n<ul>";
 607                         }
 608
 609                         $r .= "<li>{$articles[$index]}</li>";
 610                 }
 611                 $r .= '</ul>';
 612                 return $r;
 613         }
 614
 615         /**
 616          * Create paging links, as a helper method to getSectionPagingLinks().
 617          *
 618          * @param string $first The 'until' parameter for the generated URL
 619          * @param string $last The 'from' parameter for the generated URL
 620          * @param string $type A prefix for parameters, 'page' or 'subcat' or
 621          *     'file'
 622          * @return string HTML
 623          */
 624         private function pagingLinks( $first, $last, $type = '' ) {
 625                 $prevLink = $this->msg( 'prev-page' )->escaped();
 626
 627                 $linkRenderer = MediaWikiServices::getInstance()->getLinkRenderer();
 628                 if ( $first != '' ) {
 629                         $prevQuery = $this->query;
 630                         $prevQuery["{$type}until"] = $first;
 631                         unset( $prevQuery["{$type}from"] );
 632                         $prevLink = $linkRenderer->makeKnownLink(
 633                                 $this->addFragmentToTitle( $this->title, $type ),
 634                                 new HtmlArmor( $prevLink ),
 635                                 [],
 636                                 $prevQuery
 637                         );
 638                 }
 639
 640                 $nextLink = $this->msg( 'next-page' )->escaped();
 641
 642                 if ( $last != '' ) {
 643                         $lastQuery = $this->query;
 644                         $lastQuery["{$type}from"] = $last;
 645                         unset( $lastQuery["{$type}until"] );
 646                         $nextLink = $linkRenderer->makeKnownLink(
 647                                 $this->addFragmentToTitle( $this->title, $type ),
 648                                 new HtmlArmor( $nextLink ),
 649                                 [],
 650                                 $lastQuery
 651                         );
 652                 }
 653
 654                 return $this->msg( 'categoryviewer-pagedlinks' )->rawParams( $prevLink, $nextLink )->escaped();
 655         }
 656
 657         /**
 658          * Takes a title, and adds the fragment identifier that
 659          * corresponds to the correct segment of the category.
 660          *
 661          * @param Title $title The title (usually $this->title)
 662          * @param string $section Which section
 663          * @throws MWException
 664          * @return Title
 665          */
 666         private function addFragmentToTitle( $title, $section ) {
 667                 switch ( $section ) {
 668                         case 'page':
 669                                 $fragment = 'mw-pages';
 670                                 break;
 671                         case 'subcat':
 672                                 $fragment = 'mw-subcategories';
 673                                 break;
 674                         case 'file':
 675                                 $fragment = 'mw-category-media';
 676                                 break;
 677                         default:
 678                                 throw new MWException( __METHOD__ .
 679                                         " Invalid section $section." );
 680                 }
 681
 682                 return Title::makeTitle( $title->getNamespace(),
 683                         $title->getDBkey(), $fragment );
 684         }
 685
 686         /**
 687          * What to do if the category table conflicts with the number of results
 688          * returned?  This function says what. Each type is considered independently
 689          * of the other types.
 690          *
 691          * @param int $rescnt The number of items returned by our database query.
 692          * @param int $dbcnt The number of items according to the category table.
 693          * @param string $type 'subcat', 'article', or 'file'
 694          * @return string A message giving the number of items, to output to HTML.
 695          */
 696         private function getCountMessage( $rescnt, $dbcnt, $type ) {
 697                 // There are three cases:
 698                 //   1) The category table figure seems sane.  It might be wrong, but
 699                 //      we can't do anything about it if we don't recalculate it on ev-
 700                 //      ery category view.
 701                 //   2) The category table figure isn't sane, like it's smaller than the
 702                 //      number of actual results, *but* the number of results is less
 703                 //      than $this->limit and there's no offset.  In this case we still
 704                 //      know the right figure.
 705                 //   3) We have no idea.
 706
 707                 // Check if there's a "from" or "until" for anything
 708
 709                 // This is a little ugly, but we seem to use different names
 710                 // for the paging types then for the messages.
 711                 if ( $type === 'article' ) {
 712                         $pagingType = 'page';
 713                 } else {
 714                         $pagingType = $type;
 715                 }
 716
 717                 $fromOrUntil = false;
 718                 if ( ( isset( $this->from[$pagingType] ) && $this->from[$pagingType] !== null ) ||
 719                         ( isset( $this->until[$pagingType] ) && $this->until[$pagingType] !== null )
 720                 ) {
 721                         $fromOrUntil = true;
 722                 }
 723
 724                 if ( $dbcnt == $rescnt ||
 725                         ( ( $rescnt == $this->limit || $fromOrUntil ) && $dbcnt > $rescnt )
 726                 ) {
 727                         // Case 1: seems sane.
 728                         $totalcnt = $dbcnt;
 729                 } elseif ( $rescnt < $this->limit && !$fromOrUntil ) {
 730                         // Case 2: not sane, but salvageable.  Use the number of results.
 731                         $totalcnt = $rescnt;
 732                 } else {
 733                         // Case 3: hopeless.  Don't give a total count at all.
 734                         // Messages: category-subcat-count-limited, category-article-count-limited,
 735                         // category-file-count-limited
 736                         return $this->msg( "category-$type-count-limited" )->numParams( $rescnt )->parseAsBlock();
 737                 }
 738                 // Messages: category-subcat-count, category-article-count, category-file-count
 739                 return $this->msg( "category-$type-count" )->numParams( $rescnt, $totalcnt )->parseAsBlock();
 740         }
 741 }