includes/CategoryViewer.php

   1 <?php
   2 /**
   3  * List and paging of category members.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  */
  22
  23 class CategoryViewer extends ContextSource {
  24         /** @var int */
  25         public $limit;
  26
  27         /** @var array */
  28         public $from;
  29
  30         /** @var array */
  31         public $until;
  32
  33         /** @var string[] */
  34         public $articles;
  35
  36         /** @var array */
  37         public $articles_start_char;
  38
  39         /** @var array */
  40         public $children;
  41
  42         /** @var array */
  43         public $children_start_char;
  44
  45         /** @var bool */
  46         public $showGallery;
  47
  48         /** @var array */
  49         public $imgsNoGallery_start_char;
  50
  51         /** @var array */
  52         public $imgsNoGallery;
  53
  54         /** @var array */
  55         public $nextPage;
  56
  57         /** @var array */
  58         protected $prevPage;
  59
  60         /** @var array */
  61         public $flip;
  62
  63         /** @var Title */
  64         public $title;
  65
  66         /** @var Collation */
  67         public $collation;
  68
  69         /** @var ImageGallery */
  70         public $gallery;
  71
  72         /** @var Category Category object for this page. */
  73         private $cat;
  74
  75         /** @var array The original query array, to be used in generating paging links. */
  76         private $query;
  77
  78         /**
  79          * @since 1.19 $context is a second, required parameter
  80          * @param Title $title
  81          * @param IContextSource $context
  82          * @param array $from An array with keys page, subcat,
  83          *        and file for offset of results of each section (since 1.17)
  84          * @param array $until An array with 3 keys for until of each section (since 1.17)
  85          * @param array $query
  86          */
  87         function __construct( $title, IContextSource $context, $from = array(),
  88                 $until = array(), $query = array()
  89         ) {
  90                 $this->title = $title;
  91                 $this->setContext( $context );
  92                 $this->from = $from;
  93                 $this->until = $until;
  94                 $this->limit = $context->getConfig()->get( 'CategoryPagingLimit' );
  95                 $this->cat = Category::newFromTitle( $title );
  96                 $this->query = $query;
  97                 $this->collation = Collation::singleton();
  98                 unset( $this->query['title'] );
  99         }
 100
 101         /**
 102          * Format the category data list.
 103          *
 104          * @return string HTML output
 105          */
 106         public function getHTML() {
 107
 108                 $this->showGallery = $this->getConfig()->get( 'CategoryMagicGallery' )
 109                         && !$this->getOutput()->mNoGallery;
 110
 111                 $this->clearCategoryState();
 112                 $this->doCategoryQuery();
 113                 $this->finaliseCategoryState();
 114
 115                 $r = $this->getSubcategorySection() .
 116                         $this->getPagesSection() .
 117                         $this->getImageSection();
 118
 119                 if ( $r == '' ) {
 120                         // If there is no category content to display, only
 121                         // show the top part of the navigation links.
 122                         // @todo FIXME: Cannot be completely suppressed because it
 123                         //        is unknown if 'until' or 'from' makes this
 124                         //        give 0 results.
 125                         $r = $r . $this->getCategoryTop();
 126                 } else {
 127                         $r = $this->getCategoryTop() .
 128                                 $r .
 129                                 $this->getCategoryBottom();
 130                 }
 131
 132                 // Give a proper message if category is empty
 133                 if ( $r == '' ) {
 134                         $r = $this->msg( 'category-empty' )->parseAsBlock();
 135                 }
 136
 137                 $lang = $this->getLanguage();
 138                 $langAttribs = array( 'lang' => $lang->getHtmlCode(), 'dir' => $lang->getDir() );
 139                 # put a div around the headings which are in the user language
 140                 $r = Html::openElement( 'div', $langAttribs ) . $r . '</div>';
 141
 142                 return $r;
 143         }
 144
 145         function clearCategoryState() {
 146                 $this->articles = array();
 147                 $this->articles_start_char = array();
 148                 $this->children = array();
 149                 $this->children_start_char = array();
 150                 if ( $this->showGallery ) {
 151                         // Note that null for mode is taken to mean use default.
 152                         $mode = $this->getRequest()->getVal( 'gallerymode', null );
 153                         try {
 154                                 $this->gallery = ImageGalleryBase::factory( $mode, $this->getContext() );
 155                         } catch ( Exception $e ) {
 156                                 // User specified something invalid, fallback to default.
 157                                 $this->gallery = ImageGalleryBase::factory( false, $this->getContext() );
 158                         }
 159
 160                         $this->gallery->setHideBadImages();
 161                 } else {
 162                         $this->imgsNoGallery = array();
 163                         $this->imgsNoGallery_start_char = array();
 164                 }
 165         }
 166
 167         /**
 168          * Add a subcategory to the internal lists, using a Category object
 169          * @param Category $cat
 170          * @param string $sortkey
 171          * @param int $pageLength
 172          */
 173         function addSubcategoryObject( Category $cat, $sortkey, $pageLength ) {
 174                 // Subcategory; strip the 'Category' namespace from the link text.
 175                 $title = $cat->getTitle();
 176
 177                 $link = Linker::link( $title, htmlspecialchars( $title->getText() ) );
 178                 if ( $title->isRedirect() ) {
 179                         // This didn't used to add redirect-in-category, but might
 180                         // as well be consistent with the rest of the sections
 181                         // on a category page.
 182                         $link = '<span class="redirect-in-category">' . $link . '</span>';
 183                 }
 184                 $this->children[] = $link;
 185
 186                 $this->children_start_char[] =
 187                         $this->getSubcategorySortChar( $cat->getTitle(), $sortkey );
 188         }
 189
 190         /**
 191          * Get the character to be used for sorting subcategories.
 192          * If there's a link from Category:A to Category:B, the sortkey of the resulting
 193          * entry in the categorylinks table is Category:A, not A, which it SHOULD be.
 194          * Workaround: If sortkey == "Category:".$title, than use $title for sorting,
 195          * else use sortkey...
 196          *
 197          * @param Title $title
 198          * @param string $sortkey The human-readable sortkey (before transforming to icu or whatever).
 199          * @return string
 200          */
 201         function getSubcategorySortChar( $title, $sortkey ) {
 202                 global $wgContLang;
 203
 204                 if ( $title->getPrefixedText() == $sortkey ) {
 205                         $word = $title->getDBkey();
 206                 } else {
 207                         $word = $sortkey;
 208                 }
 209
 210                 $firstChar = $this->collation->getFirstLetter( $word );
 211
 212                 return $wgContLang->convert( $firstChar );
 213         }
 214
 215         /**
 216          * Add a page in the image namespace
 217          * @param Title $title
 218          * @param string $sortkey
 219          * @param int $pageLength
 220          * @param bool $isRedirect
 221          */
 222         function addImage( Title $title, $sortkey, $pageLength, $isRedirect = false ) {
 223                 global $wgContLang;
 224                 if ( $this->showGallery ) {
 225                         $flip = $this->flip['file'];
 226                         if ( $flip ) {
 227                                 $this->gallery->insert( $title );
 228                         } else {
 229                                 $this->gallery->add( $title );
 230                         }
 231                 } else {
 232                         $link = Linker::link( $title );
 233                         if ( $isRedirect ) {
 234                                 // This seems kind of pointless given 'mw-redirect' class,
 235                                 // but keeping for back-compatibility with user css.
 236                                 $link = '<span class="redirect-in-category">' . $link . '</span>';
 237                         }
 238                         $this->imgsNoGallery[] = $link;
 239
 240                         $this->imgsNoGallery_start_char[] = $wgContLang->convert(
 241                                 $this->collation->getFirstLetter( $sortkey ) );
 242                 }
 243         }
 244
 245         /**
 246          * Add a miscellaneous page
 247          * @param Title $title
 248          * @param string $sortkey
 249          * @param int $pageLength
 250          * @param bool $isRedirect
 251          */
 252         function addPage( $title, $sortkey, $pageLength, $isRedirect = false ) {
 253                 global $wgContLang;
 254
 255                 $link = Linker::link( $title );
 256                 if ( $isRedirect ) {
 257                         // This seems kind of pointless given 'mw-redirect' class,
 258                         // but keeping for back-compatibility with user css.
 259                         $link = '<span class="redirect-in-category">' . $link . '</span>';
 260                 }
 261                 $this->articles[] = $link;
 262
 263                 $this->articles_start_char[] = $wgContLang->convert(
 264                         $this->collation->getFirstLetter( $sortkey ) );
 265         }
 266
 267         function finaliseCategoryState() {
 268                 if ( $this->flip['subcat'] ) {
 269                         $this->children = array_reverse( $this->children );
 270                         $this->children_start_char = array_reverse( $this->children_start_char );
 271                 }
 272                 if ( $this->flip['page'] ) {
 273                         $this->articles = array_reverse( $this->articles );
 274                         $this->articles_start_char = array_reverse( $this->articles_start_char );
 275                 }
 276                 if ( !$this->showGallery && $this->flip['file'] ) {
 277                         $this->imgsNoGallery = array_reverse( $this->imgsNoGallery );
 278                         $this->imgsNoGallery_start_char = array_reverse( $this->imgsNoGallery_start_char );
 279                 }
 280         }
 281
 282         function doCategoryQuery() {
 283                 $dbr = wfGetDB( DB_SLAVE, 'category' );
 284
 285                 $this->nextPage = array(
 286                         'page' => null,
 287                         'subcat' => null,
 288                         'file' => null,
 289                 );
 290                 $this->prevPage = array(
 291                         'page' => null,
 292                         'subcat' => null,
 293                         'file' => null,
 294                 );
 295
 296                 $this->flip = array( 'page' => false, 'subcat' => false, 'file' => false );
 297
 298                 foreach ( array( 'page', 'subcat', 'file' ) as $type ) {
 299                         # Get the sortkeys for start/end, if applicable.  Note that if
 300                         # the collation in the database differs from the one
 301                         # set in $wgCategoryCollation, pagination might go totally haywire.
 302                         $extraConds = array( 'cl_type' => $type );
 303                         if ( isset( $this->from[$type] ) && $this->from[$type] !== null ) {
 304                                 $extraConds[] = 'cl_sortkey >= '
 305                                         . $dbr->addQuotes( $this->collation->getSortKey( $this->from[$type] ) );
 306                         } elseif ( isset( $this->until[$type] ) && $this->until[$type] !== null ) {
 307                                 $extraConds[] = 'cl_sortkey < '
 308                                         . $dbr->addQuotes( $this->collation->getSortKey( $this->until[$type] ) );
 309                                 $this->flip[$type] = true;
 310                         }
 311
 312                         $res = $dbr->select(
 313                                 array( 'page', 'categorylinks', 'category' ),
 314                                 array( 'page_id', 'page_title', 'page_namespace', 'page_len',
 315                                         'page_is_redirect', 'cl_sortkey', 'cat_id', 'cat_title',
 316                                         'cat_subcats', 'cat_pages', 'cat_files',
 317                                         'cl_sortkey_prefix', 'cl_collation' ),
 318                                 array_merge( array( 'cl_to' => $this->title->getDBkey() ), $extraConds ),
 319                                 __METHOD__,
 320                                 array(
 321                                         'USE INDEX' => array( 'categorylinks' => 'cl_sortkey' ),
 322                                         'LIMIT' => $this->limit + 1,
 323                                         'ORDER BY' => $this->flip[$type] ? 'cl_sortkey DESC' : 'cl_sortkey',
 324                                 ),
 325                                 array(
 326                                         'categorylinks' => array( 'INNER JOIN', 'cl_from = page_id' ),
 327                                         'category' => array( 'LEFT JOIN', array(
 328                                                 'cat_title = page_title',
 329                                                 'page_namespace' => NS_CATEGORY
 330                                         ))
 331                                 )
 332                         );
 333
 334                         $count = 0;
 335                         foreach ( $res as $row ) {
 336                                 $title = Title::newFromRow( $row );
 337                                 if ( $row->cl_collation === '' ) {
 338                                         // Hack to make sure that while updating from 1.16 schema
 339                                         // and db is inconsistent, that the sky doesn't fall.
 340                                         // See r83544. Could perhaps be removed in a couple decades...
 341                                         $humanSortkey = $row->cl_sortkey;
 342                                 } else {
 343                                         $humanSortkey = $title->getCategorySortkey( $row->cl_sortkey_prefix );
 344                                 }
 345
 346                                 if ( ++$count > $this->limit ) {
 347                                         # We've reached the one extra which shows that there
 348                                         # are additional pages to be had. Stop here...
 349                                         $this->nextPage[$type] = $humanSortkey;
 350                                         break;
 351                                 }
 352                                 if ( $count == $this->limit ) {
 353                                         $this->prevPage[$type] = $humanSortkey;
 354                                 }
 355
 356                                 if ( $title->getNamespace() == NS_CATEGORY ) {
 357                                         $cat = Category::newFromRow( $row, $title );
 358                                         $this->addSubcategoryObject( $cat, $humanSortkey, $row->page_len );
 359                                 } elseif ( $title->getNamespace() == NS_FILE ) {
 360                                         $this->addImage( $title, $humanSortkey, $row->page_len, $row->page_is_redirect );
 361                                 } else {
 362                                         $this->addPage( $title, $humanSortkey, $row->page_len, $row->page_is_redirect );
 363                                 }
 364                         }
 365                 }
 366         }
 367
 368         /**
 369          * @return string
 370          */
 371         function getCategoryTop() {
 372                 $r = $this->getCategoryBottom();
 373                 return $r === ''
 374                         ? $r
 375                         : "<br style=\"clear:both;\"/>\n" . $r;
 376         }
 377
 378         /**
 379          * @return string
 380          */
 381         function getSubcategorySection() {
 382                 # Don't show subcategories section if there are none.
 383                 $r = '';
 384                 $rescnt = count( $this->children );
 385                 $dbcnt = $this->cat->getSubcatCount();
 386                 $countmsg = $this->getCountMessage( $rescnt, $dbcnt, 'subcat' );
 387
 388                 if ( $rescnt > 0 ) {
 389                         # Showing subcategories
 390                         $r .= Html::openElement( 'div', array( 'id' => 'mw-subcategories' ) );
 391                         $r .= "\n";
 392                         $r .= Html::element( 'h2', array(), $this->msg( 'subcategories' )->text() );
 393                         $r .= "\n";
 394                         $r .= $countmsg;
 395                         $r .= $this->getSectionPagingLinks( 'subcat' );
 396                         $r .= $this->formatList( $this->children, $this->children_start_char );
 397                         $r .= $this->getSectionPagingLinks( 'subcat' );
 398                         $r .= "\n";
 399                         $r .= Html::closeElement( 'div' );
 400                 }
 401                 return $r;
 402         }
 403
 404         /**
 405          * @return string
 406          */
 407         function getPagesSection() {
 408                 $ti = wfEscapeWikiText( $this->title->getText() );
 409                 # Don't show articles section if there are none.
 410                 $r = '';
 411
 412                 # @todo FIXME: Here and in the other two sections: we don't need to bother
 413                 # with this rigmarole if the entire category contents fit on one page
 414                 # and have already been retrieved.  We can just use $rescnt in that
 415                 # case and save a query and some logic.
 416                 $dbcnt = $this->cat->getPageCount() - $this->cat->getSubcatCount()
 417                         - $this->cat->getFileCount();
 418                 $rescnt = count( $this->articles );
 419                 $countmsg = $this->getCountMessage( $rescnt, $dbcnt, 'article' );
 420
 421                 if ( $rescnt > 0 ) {
 422                         $r .= Html::openElement( 'div', array( 'id' => 'mw-pages' ) );
 423                         $r .= "\n";
 424                         $r .= Html::element( 'h2', array(), $this->msg( 'category_header', $ti )->text() );
 425                         $r .= "\n";
 426                         $r .= $countmsg;
 427                         $r .= $this->getSectionPagingLinks( 'page' );
 428                         $r .= $this->formatList( $this->articles, $this->articles_start_char );
 429                         $r .= $this->getSectionPagingLinks( 'page' );
 430                         $r .= "\n";
 431                         $r .= Html::closeElement( '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                 if ( $rescnt > 0 ) {
 443                         $dbcnt = $this->cat->getFileCount();
 444                         $countmsg = $this->getCountMessage( $rescnt, $dbcnt, 'file' );
 445
 446                         $r .= "<div id=\"mw-category-media\">\n";
 447                         $r .= '<h2>' .
 448                                 $this->msg(
 449                                         'category-media-header',
 450                                         wfEscapeWikiText( $this->title->getText() )
 451                                 )->text() .
 452                                 "</h2>\n";
 453                         $r .= $countmsg;
 454                         $r .= $this->getSectionPagingLinks( 'file' );
 455                         if ( $this->showGallery ) {
 456                                 $r .= $this->gallery->toHTML();
 457                         } else {
 458                                 $r .= $this->formatList( $this->imgsNoGallery, $this->imgsNoGallery_start_char );
 459                         }
 460                         $r .= $this->getSectionPagingLinks( 'file' );
 461                         $r .= "\n</div>";
 462                 }
 463                 return $r;
 464         }
 465
 466         /**
 467          * Get the paging links for a section (subcats/pages/files), to go at the top and bottom
 468          * of the output.
 469          *
 470          * @param string $type 'page', 'subcat', or 'file'
 471          * @return string HTML output, possibly empty if there are no other pages
 472          */
 473         private function getSectionPagingLinks( $type ) {
 474                 if ( isset( $this->until[$type] ) && $this->until[$type] !== null ) {
 475                         // The new value for the until parameter should be pointing to the first
 476                         // result displayed on the page which is the second last result retrieved
 477                         // from the database.The next link should have a from parameter pointing
 478                         // to the until parameter of the current page.
 479                         if ( $this->nextPage[$type] !== null ) {
 480                                 return $this->pagingLinks( $this->prevPage[$type], $this->until[$type], $type );
 481                         } else {
 482                                 // If the nextPage variable is null, it means that we have reached the first page
 483                                 // and therefore the previous link should be disabled.
 484                                 return $this->pagingLinks( null, $this->until[$type], $type );
 485                         }
 486                 } elseif ( $this->nextPage[$type] !== null
 487                         || ( isset( $this->from[$type] ) && $this->from[$type] !== null )
 488                 ) {
 489                         return $this->pagingLinks( $this->from[$type], $this->nextPage[$type], $type );
 490                 } else {
 491                         return '';
 492                 }
 493         }
 494
 495         /**
 496          * @return string
 497          */
 498         function getCategoryBottom() {
 499                 return '';
 500         }
 501
 502         /**
 503          * Format a list of articles chunked by letter, either as a
 504          * bullet list or a columnar format, depending on the length.
 505          *
 506          * @param array $articles
 507          * @param array $articles_start_char
 508          * @param int $cutoff
 509          * @return string
 510          * @private
 511          */
 512         function formatList( $articles, $articles_start_char, $cutoff = 6 ) {
 513                 $list = '';
 514                 if ( count( $articles ) > $cutoff ) {
 515                         $list = self::columnList( $articles, $articles_start_char );
 516                 } elseif ( count( $articles ) > 0 ) {
 517                         // for short lists of articles in categories.
 518                         $list = self::shortList( $articles, $articles_start_char );
 519                 }
 520
 521                 $pageLang = $this->title->getPageLanguage();
 522                 $attribs = array( 'lang' => $pageLang->getHtmlCode(), 'dir' => $pageLang->getDir(),
 523                         'class' => 'mw-content-' . $pageLang->getDir() );
 524                 $list = Html::rawElement( 'div', $attribs, $list );
 525
 526                 return $list;
 527         }
 528
 529         /**
 530          * Format a list of articles chunked by letter in a three-column
 531          * list, ordered vertically.
 532          *
 533          * TODO: Take the headers into account when creating columns, so they're
 534          * more visually equal.
 535          *
 536          * More distant TODO: Scrap this and use CSS columns, whenever IE finally
 537          * supports those.
 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                 # Split into three columns
 547                 $columns = array_chunk( $columns, ceil( count( $columns ) / 3 ), true /* preserve keys */ );
 548
 549                 $ret = '<table style="width: 100%;"><tr style="vertical-align: top;">';
 550                 $prevchar = null;
 551
 552                 foreach ( $columns as $column ) {
 553                         $ret .= '<td style="width: 33.3%;">';
 554                         $colContents = array();
 555
 556                         # Kind of like array_flip() here, but we keep duplicates in an
 557                         # array instead of dropping them.
 558                         foreach ( $column as $article => $char ) {
 559                                 if ( !isset( $colContents[$char] ) ) {
 560                                         $colContents[$char] = array();
 561                                 }
 562                                 $colContents[$char][] = $article;
 563                         }
 564
 565                         $first = true;
 566                         foreach ( $colContents as $char => $articles ) {
 567                                 # Change space to non-breaking space to keep headers aligned
 568                                 $h3char = $char === ' ' ? '&#160;' : htmlspecialchars( $char );
 569
 570                                 $ret .= '<h3>' . $h3char;
 571                                 if ( $first && $char === $prevchar ) {
 572                                         # We're continuing a previous chunk at the top of a new
 573                                         # column, so add " cont." after the letter.
 574                                         $ret .= ' ' . wfMessage( 'listingcontinuesabbrev' )->escaped();
 575                                 }
 576                                 $ret .= "</h3>\n";
 577
 578                                 $ret .= '<ul><li>';
 579                                 $ret .= implode( "</li>\n<li>", $articles );
 580                                 $ret .= '</li></ul>';
 581
 582                                 $first = false;
 583                                 $prevchar = $char;
 584                         }
 585
 586                         $ret .= "</td>\n";
 587                 }
 588
 589                 $ret .= '</tr></table>';
 590                 return $ret;
 591         }
 592
 593         /**
 594          * Format a list of articles chunked by letter in a bullet list.
 595          * @param array $articles
 596          * @param string[] $articles_start_char
 597          * @return string
 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( 'prevn' )->numParams( $this->limit )->escaped();
 626
 627                 if ( $first != '' ) {
 628                         $prevQuery = $this->query;
 629                         $prevQuery["{$type}until"] = $first;
 630                         unset( $prevQuery["{$type}from"] );
 631                         $prevLink = Linker::linkKnown(
 632                                 $this->addFragmentToTitle( $this->title, $type ),
 633                                 $prevLink,
 634                                 array(),
 635                                 $prevQuery
 636                         );
 637                 }
 638
 639                 $nextLink = $this->msg( 'nextn' )->numParams( $this->limit )->escaped();
 640
 641                 if ( $last != '' ) {
 642                         $lastQuery = $this->query;
 643                         $lastQuery["{$type}from"] = $last;
 644                         unset( $lastQuery["{$type}until"] );
 645                         $nextLink = Linker::linkKnown(
 646                                 $this->addFragmentToTitle( $this->title, $type ),
 647                                 $nextLink,
 648                                 array(),
 649                                 $lastQuery
 650                         );
 651                 }
 652
 653                 return $this->msg( 'categoryviewer-pagedlinks' )->rawParams( $prevLink, $nextLink )->escaped();
 654         }
 655
 656         /**
 657          * Takes a title, and adds the fragment identifier that
 658          * corresponds to the correct segment of the category.
 659          *
 660          * @param Title $title The title (usually $this->title)
 661          * @param string $section Which section
 662          * @throws MWException
 663          * @return Title
 664          */
 665         private function addFragmentToTitle( $title, $section ) {
 666                 switch ( $section ) {
 667                         case 'page':
 668                                 $fragment = 'mw-pages';
 669                                 break;
 670                         case 'subcat':
 671                                 $fragment = 'mw-subcategories';
 672                                 break;
 673                         case 'file':
 674                                 $fragment = 'mw-category-media';
 675                                 break;
 676                         default:
 677                                 throw new MWException( __METHOD__ .
 678                                         " Invalid section $section." );
 679                 }
 680
 681                 return Title::makeTitle( $title->getNamespace(),
 682                         $title->getDBkey(), $fragment );
 683         }
 684
 685         /**
 686          * What to do if the category table conflicts with the number of results
 687          * returned?  This function says what. Each type is considered independently
 688          * of the other types.
 689          *
 690          * @param int $rescnt The number of items returned by our database query.
 691          * @param int $dbcnt The number of items according to the category table.
 692          * @param string $type 'subcat', 'article', or 'file'
 693          * @return string A message giving the number of items, to output to HTML.
 694          */
 695         private function getCountMessage( $rescnt, $dbcnt, $type ) {
 696                 // There are three cases:
 697                 //   1) The category table figure seems sane.  It might be wrong, but
 698                 //      we can't do anything about it if we don't recalculate it on ev-
 699                 //      ery category view.
 700                 //   2) The category table figure isn't sane, like it's smaller than the
 701                 //      number of actual results, *but* the number of results is less
 702                 //      than $this->limit and there's no offset.  In this case we still
 703                 //      know the right figure.
 704                 //   3) We have no idea.
 705
 706                 // Check if there's a "from" or "until" for anything
 707
 708                 // This is a little ugly, but we seem to use different names
 709                 // for the paging types then for the messages.
 710                 if ( $type === 'article' ) {
 711                         $pagingType = 'page';
 712                 } else {
 713                         $pagingType = $type;
 714                 }
 715
 716                 $fromOrUntil = false;
 717                 if ( ( isset( $this->from[$pagingType] ) && $this->from[$pagingType] !== null ) ||
 718                         ( isset( $this->until[$pagingType] ) && $this->until[$pagingType] !== null )
 719                 ) {
 720                         $fromOrUntil = true;
 721                 }
 722
 723                 if ( $dbcnt == $rescnt ||
 724                         ( ( $rescnt == $this->limit || $fromOrUntil ) && $dbcnt > $rescnt )
 725                 ) {
 726                         // Case 1: seems sane.
 727                         $totalcnt = $dbcnt;
 728                 } elseif ( $rescnt < $this->limit && !$fromOrUntil ) {
 729                         // Case 2: not sane, but salvageable.  Use the number of results.
 730                         // Since there are fewer than 200, we can also take this opportunity
 731                         // to refresh the incorrect category table entry -- which should be
 732                         // quick due to the small number of entries.
 733                         $totalcnt = $rescnt;
 734                         $category = $this->cat;
 735                         wfGetDB( DB_MASTER )->onTransactionIdle( function () use ( $category ) {
 736                                 $category->refreshCounts();
 737                         } );
 738                 } else {
 739                         // Case 3: hopeless.  Don't give a total count at all.
 740                         // Messages: category-subcat-count-limited, category-article-count-limited,
 741                         // category-file-count-limited
 742                         return $this->msg( "category-$type-count-limited" )->numParams( $rescnt )->parseAsBlock();
 743                 }
 744                 // Messages: category-subcat-count, category-article-count, category-file-count
 745                 return $this->msg( "category-$type-count" )->numParams( $rescnt, $totalcnt )->parseAsBlock();
 746         }
 747 }