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                 wfProfileIn( __METHOD__ );
 108
 109                 $this->showGallery = $this->getConfig()->get( 'CategoryMagicGallery' )
 110                         && !$this->getOutput()->mNoGallery;
 111
 112                 $this->clearCategoryState();
 113                 $this->doCategoryQuery();
 114                 $this->finaliseCategoryState();
 115
 116                 $r = $this->getSubcategorySection() .
 117                         $this->getPagesSection() .
 118                         $this->getImageSection();
 119
 120                 if ( $r == '' ) {
 121                         // If there is no category content to display, only
 122                         // show the top part of the navigation links.
 123                         // @todo FIXME: Cannot be completely suppressed because it
 124                         //        is unknown if 'until' or 'from' makes this
 125                         //        give 0 results.
 126                         $r = $r . $this->getCategoryTop();
 127                 } else {
 128                         $r = $this->getCategoryTop() .
 129                                 $r .
 130                                 $this->getCategoryBottom();
 131                 }
 132
 133                 // Give a proper message if category is empty
 134                 if ( $r == '' ) {
 135                         $r = $this->msg( 'category-empty' )->parseAsBlock();
 136                 }
 137
 138                 $lang = $this->getLanguage();
 139                 $langAttribs = array( 'lang' => $lang->getHtmlCode(), 'dir' => $lang->getDir() );
 140                 # put a div around the headings which are in the user language
 141                 $r = Html::openElement( 'div', $langAttribs ) . $r . '</div>';
 142
 143                 wfProfileOut( __METHOD__ );
 144                 return $r;
 145         }
 146
 147         function clearCategoryState() {
 148                 $this->articles = array();
 149                 $this->articles_start_char = array();
 150                 $this->children = array();
 151                 $this->children_start_char = array();
 152                 if ( $this->showGallery ) {
 153                         // Note that null for mode is taken to mean use default.
 154                         $mode = $this->getRequest()->getVal( 'gallerymode', null );
 155                         try {
 156                                 $this->gallery = ImageGalleryBase::factory( $mode, $this->getContext() );
 157                         } catch ( MWException $e ) {
 158                                 // User specified something invalid, fallback to default.
 159                                 $this->gallery = ImageGalleryBase::factory( false, $this->getContext() );
 160                         }
 161
 162                         $this->gallery->setHideBadImages();
 163                 } else {
 164                         $this->imgsNoGallery = array();
 165                         $this->imgsNoGallery_start_char = array();
 166                 }
 167         }
 168
 169         /**
 170          * Add a subcategory to the internal lists, using a Category object
 171          * @param Category $cat
 172          * @param string $sortkey
 173          * @param int $pageLength
 174          */
 175         function addSubcategoryObject( Category $cat, $sortkey, $pageLength ) {
 176                 // Subcategory; strip the 'Category' namespace from the link text.
 177                 $title = $cat->getTitle();
 178
 179                 $link = Linker::link( $title, htmlspecialchars( $title->getText() ) );
 180                 if ( $title->isRedirect() ) {
 181                         // This didn't used to add redirect-in-category, but might
 182                         // as well be consistent with the rest of the sections
 183                         // on a category page.
 184                         $link = '<span class="redirect-in-category">' . $link . '</span>';
 185                 }
 186                 $this->children[] = $link;
 187
 188                 $this->children_start_char[] =
 189                         $this->getSubcategorySortChar( $cat->getTitle(), $sortkey );
 190         }
 191
 192         /**
 193          * Get the character to be used for sorting subcategories.
 194          * If there's a link from Category:A to Category:B, the sortkey of the resulting
 195          * entry in the categorylinks table is Category:A, not A, which it SHOULD be.
 196          * Workaround: If sortkey == "Category:".$title, than use $title for sorting,
 197          * else use sortkey...
 198          *
 199          * @param Title $title
 200          * @param string $sortkey The human-readable sortkey (before transforming to icu or whatever).
 201          * @return string
 202          */
 203         function getSubcategorySortChar( $title, $sortkey ) {
 204                 global $wgContLang;
 205
 206                 if ( $title->getPrefixedText() == $sortkey ) {
 207                         $word = $title->getDBkey();
 208                 } else {
 209                         $word = $sortkey;
 210                 }
 211
 212                 $firstChar = $this->collation->getFirstLetter( $word );
 213
 214                 return $wgContLang->convert( $firstChar );
 215         }
 216
 217         /**
 218          * Add a page in the image namespace
 219          * @param Title $title
 220          * @param string $sortkey
 221          * @param int $pageLength
 222          * @param bool $isRedirect
 223          */
 224         function addImage( Title $title, $sortkey, $pageLength, $isRedirect = false ) {
 225                 global $wgContLang;
 226                 if ( $this->showGallery ) {
 227                         $flip = $this->flip['file'];
 228                         if ( $flip ) {
 229                                 $this->gallery->insert( $title );
 230                         } else {
 231                                 $this->gallery->add( $title );
 232                         }
 233                 } else {
 234                         $link = Linker::link( $title );
 235                         if ( $isRedirect ) {
 236                                 // This seems kind of pointless given 'mw-redirect' class,
 237                                 // but keeping for back-compatibility with user css.
 238                                 $link = '<span class="redirect-in-category">' . $link . '</span>';
 239                         }
 240                         $this->imgsNoGallery[] = $link;
 241
 242                         $this->imgsNoGallery_start_char[] = $wgContLang->convert(
 243                                 $this->collation->getFirstLetter( $sortkey ) );
 244                 }
 245         }
 246
 247         /**
 248          * Add a miscellaneous page
 249          * @param Title $title
 250          * @param string $sortkey
 251          * @param int $pageLength
 252          * @param bool $isRedirect
 253          */
 254         function addPage( $title, $sortkey, $pageLength, $isRedirect = false ) {
 255                 global $wgContLang;
 256
 257                 $link = Linker::link( $title );
 258                 if ( $isRedirect ) {
 259                         // This seems kind of pointless given 'mw-redirect' class,
 260                         // but keeping for back-compatibility with user css.
 261                         $link = '<span class="redirect-in-category">' . $link . '</span>';
 262                 }
 263                 $this->articles[] = $link;
 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 = array(
 288                         'page' => null,
 289                         'subcat' => null,
 290                         'file' => null,
 291                 );
 292                 $this->prevPage = array(
 293                         'page' => null,
 294                         'subcat' => null,
 295                         'file' => null,
 296                 );
 297
 298                 $this->flip = array( 'page' => false, 'subcat' => false, 'file' => false );
 299
 300                 foreach ( array( '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 = array( '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                                 array( 'page', 'categorylinks', 'category' ),
 316                                 array( '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( array( 'cl_to' => $this->title->getDBkey() ), $extraConds ),
 321                                 __METHOD__,
 322                                 array(
 323                                         'USE INDEX' => array( 'categorylinks' => 'cl_sortkey' ),
 324                                         'LIMIT' => $this->limit + 1,
 325                                         'ORDER BY' => $this->flip[$type] ? 'cl_sortkey DESC' : 'cl_sortkey',
 326                                 ),
 327                                 array(
 328                                         'categorylinks' => array( 'INNER JOIN', 'cl_from = page_id' ),
 329                                         'category' => array( 'LEFT JOIN', array(
 330                                                 'cat_title = page_title',
 331                                                 'page_namespace' => NS_CATEGORY
 332                                         ))
 333                                 )
 334                         );
 335
 336                         $count = 0;
 337                         foreach ( $res as $row ) {
 338                                 $title = Title::newFromRow( $row );
 339                                 if ( $row->cl_collation === '' ) {
 340                                         // Hack to make sure that while updating from 1.16 schema
 341                                         // and db is inconsistent, that the sky doesn't fall.
 342                                         // See r83544. Could perhaps be removed in a couple decades...
 343                                         $humanSortkey = $row->cl_sortkey;
 344                                 } else {
 345                                         $humanSortkey = $title->getCategorySortkey( $row->cl_sortkey_prefix );
 346                                 }
 347
 348                                 if ( ++$count > $this->limit ) {
 349                                         # We've reached the one extra which shows that there
 350                                         # are additional pages to be had. Stop here...
 351                                         $this->nextPage[$type] = $humanSortkey;
 352                                         break;
 353                                 }
 354                                 if ( $count == $this->limit ) {
 355                                         $this->prevPage[$type] = $humanSortkey;
 356                                 }
 357
 358                                 if ( $title->getNamespace() == NS_CATEGORY ) {
 359                                         $cat = Category::newFromRow( $row, $title );
 360                                         $this->addSubcategoryObject( $cat, $humanSortkey, $row->page_len );
 361                                 } elseif ( $title->getNamespace() == NS_FILE ) {
 362                                         $this->addImage( $title, $humanSortkey, $row->page_len, $row->page_is_redirect );
 363                                 } else {
 364                                         $this->addPage( $title, $humanSortkey, $row->page_len, $row->page_is_redirect );
 365                                 }
 366                         }
 367                 }
 368         }
 369
 370         /**
 371          * @return string
 372          */
 373         function getCategoryTop() {
 374                 $r = $this->getCategoryBottom();
 375                 return $r === ''
 376                         ? $r
 377                         : "<br style=\"clear:both;\"/>\n" . $r;
 378         }
 379
 380         /**
 381          * @return string
 382          */
 383         function getSubcategorySection() {
 384                 # Don't show subcategories section if there are none.
 385                 $r = '';
 386                 $rescnt = count( $this->children );
 387                 $dbcnt = $this->cat->getSubcatCount();
 388                 $countmsg = $this->getCountMessage( $rescnt, $dbcnt, 'subcat' );
 389
 390                 if ( $rescnt > 0 ) {
 391                         # Showing subcategories
 392                         $r .= "<div id=\"mw-subcategories\">\n";
 393                         $r .= '<h2>' . $this->msg( 'subcategories' )->text() . "</h2>\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</div>";
 399                 }
 400                 return $r;
 401         }
 402
 403         /**
 404          * @return string
 405          */
 406         function getPagesSection() {
 407                 $ti = wfEscapeWikiText( $this->title->getText() );
 408                 # Don't show articles section if there are none.
 409                 $r = '';
 410
 411                 # @todo FIXME: Here and in the other two sections: we don't need to bother
 412                 # with this rigmarole if the entire category contents fit on one page
 413                 # and have already been retrieved.  We can just use $rescnt in that
 414                 # case and save a query and some logic.
 415                 $dbcnt = $this->cat->getPageCount() - $this->cat->getSubcatCount()
 416                         - $this->cat->getFileCount();
 417                 $rescnt = count( $this->articles );
 418                 $countmsg = $this->getCountMessage( $rescnt, $dbcnt, 'article' );
 419
 420                 if ( $rescnt > 0 ) {
 421                         $r = "<div id=\"mw-pages\">\n";
 422                         $r .= '<h2>' . $this->msg( 'category_header', $ti )->text() . "</h2>\n";
 423                         $r .= $countmsg;
 424                         $r .= $this->getSectionPagingLinks( 'page' );
 425                         $r .= $this->formatList( $this->articles, $this->articles_start_char );
 426                         $r .= $this->getSectionPagingLinks( 'page' );
 427                         $r .= "\n</div>";
 428                 }
 429                 return $r;
 430         }
 431
 432         /**
 433          * @return string
 434          */
 435         function getImageSection() {
 436                 $r = '';
 437                 $rescnt = $this->showGallery ? $this->gallery->count() : count( $this->imgsNoGallery );
 438                 if ( $rescnt > 0 ) {
 439                         $dbcnt = $this->cat->getFileCount();
 440                         $countmsg = $this->getCountMessage( $rescnt, $dbcnt, 'file' );
 441
 442                         $r .= "<div id=\"mw-category-media\">\n";
 443                         $r .= '<h2>' .
 444                                 $this->msg(
 445                                         'category-media-header',
 446                                         wfEscapeWikiText( $this->title->getText() )
 447                                 )->text() .
 448                                 "</h2>\n";
 449                         $r .= $countmsg;
 450                         $r .= $this->getSectionPagingLinks( 'file' );
 451                         if ( $this->showGallery ) {
 452                                 $r .= $this->gallery->toHTML();
 453                         } else {
 454                                 $r .= $this->formatList( $this->imgsNoGallery, $this->imgsNoGallery_start_char );
 455                         }
 456                         $r .= $this->getSectionPagingLinks( 'file' );
 457                         $r .= "\n</div>";
 458                 }
 459                 return $r;
 460         }
 461
 462         /**
 463          * Get the paging links for a section (subcats/pages/files), to go at the top and bottom
 464          * of the output.
 465          *
 466          * @param string $type 'page', 'subcat', or 'file'
 467          * @return string HTML output, possibly empty if there are no other pages
 468          */
 469         private function getSectionPagingLinks( $type ) {
 470                 if ( isset( $this->until[$type] ) && $this->until[$type] !== null ) {
 471                         // The new value for the until parameter should be pointing to the first
 472                         // result displayed on the page which is the second last result retrieved
 473                         // from the database.The next link should have a from parameter pointing
 474                         // to the until parameter of the current page.
 475                         if ( $this->nextPage[$type] !== null ) {
 476                                 return $this->pagingLinks( $this->prevPage[$type], $this->until[$type], $type );
 477                         } else {
 478                                 // If the nextPage variable is null, it means that we have reached the first page
 479                                 // and therefore the previous link should be disabled.
 480                                 return $this->pagingLinks( null, $this->until[$type], $type );
 481                         }
 482                 } elseif ( $this->nextPage[$type] !== null
 483                         || ( isset( $this->from[$type] ) && $this->from[$type] !== null )
 484                 ) {
 485                         return $this->pagingLinks( $this->from[$type], $this->nextPage[$type], $type );
 486                 } else {
 487                         return '';
 488                 }
 489         }
 490
 491         /**
 492          * @return string
 493          */
 494         function getCategoryBottom() {
 495                 return '';
 496         }
 497
 498         /**
 499          * Format a list of articles chunked by letter, either as a
 500          * bullet list or a columnar format, depending on the length.
 501          *
 502          * @param array $articles
 503          * @param array $articles_start_char
 504          * @param int $cutoff
 505          * @return string
 506          * @private
 507          */
 508         function formatList( $articles, $articles_start_char, $cutoff = 6 ) {
 509                 $list = '';
 510                 if ( count( $articles ) > $cutoff ) {
 511                         $list = self::columnList( $articles, $articles_start_char );
 512                 } elseif ( count( $articles ) > 0 ) {
 513                         // for short lists of articles in categories.
 514                         $list = self::shortList( $articles, $articles_start_char );
 515                 }
 516
 517                 $pageLang = $this->title->getPageLanguage();
 518                 $attribs = array( 'lang' => $pageLang->getHtmlCode(), 'dir' => $pageLang->getDir(),
 519                         'class' => 'mw-content-' . $pageLang->getDir() );
 520                 $list = Html::rawElement( 'div', $attribs, $list );
 521
 522                 return $list;
 523         }
 524
 525         /**
 526          * Format a list of articles chunked by letter in a three-column
 527          * list, ordered vertically.
 528          *
 529          * TODO: Take the headers into account when creating columns, so they're
 530          * more visually equal.
 531          *
 532          * More distant TODO: Scrap this and use CSS columns, whenever IE finally
 533          * supports those.
 534          *
 535          * @param array $articles
 536          * @param string[] $articles_start_char
 537          * @return string
 538          * @private
 539          */
 540         static function columnList( $articles, $articles_start_char ) {
 541                 $columns = array_combine( $articles, $articles_start_char );
 542                 # Split into three columns
 543                 $columns = array_chunk( $columns, ceil( count( $columns ) / 3 ), true /* preserve keys */ );
 544
 545                 $ret = '<table style="width: 100%;"><tr style="vertical-align: top;">';
 546                 $prevchar = null;
 547
 548                 foreach ( $columns as $column ) {
 549                         $ret .= '<td style="width: 33.3%;">';
 550                         $colContents = array();
 551
 552                         # Kind of like array_flip() here, but we keep duplicates in an
 553                         # array instead of dropping them.
 554                         foreach ( $column as $article => $char ) {
 555                                 if ( !isset( $colContents[$char] ) ) {
 556                                         $colContents[$char] = array();
 557                                 }
 558                                 $colContents[$char][] = $article;
 559                         }
 560
 561                         $first = true;
 562                         foreach ( $colContents as $char => $articles ) {
 563                                 # Change space to non-breaking space to keep headers aligned
 564                                 $h3char = $char === ' ' ? '&#160;' : htmlspecialchars( $char );
 565
 566                                 $ret .= '<h3>' . $h3char;
 567                                 if ( $first && $char === $prevchar ) {
 568                                         # We're continuing a previous chunk at the top of a new
 569                                         # column, so add " cont." after the letter.
 570                                         $ret .= ' ' . wfMessage( 'listingcontinuesabbrev' )->escaped();
 571                                 }
 572                                 $ret .= "</h3>\n";
 573
 574                                 $ret .= '<ul><li>';
 575                                 $ret .= implode( "</li>\n<li>", $articles );
 576                                 $ret .= '</li></ul>';
 577
 578                                 $first = false;
 579                                 $prevchar = $char;
 580                         }
 581
 582                         $ret .= "</td>\n";
 583                 }
 584
 585                 $ret .= '</tr></table>';
 586                 return $ret;
 587         }
 588
 589         /**
 590          * Format a list of articles chunked by letter in a bullet list.
 591          * @param array $articles
 592          * @param string[] $articles_start_char
 593          * @return string
 594          * @private
 595          */
 596         static function shortList( $articles, $articles_start_char ) {
 597                 $r = '<h3>' . htmlspecialchars( $articles_start_char[0] ) . "</h3>\n";
 598                 $r .= '<ul><li>' . $articles[0] . '</li>';
 599                 $articleCount = count( $articles );
 600                 for ( $index = 1; $index < $articleCount; $index++ ) {
 601                         if ( $articles_start_char[$index] != $articles_start_char[$index - 1] ) {
 602                                 $r .= "</ul><h3>" . htmlspecialchars( $articles_start_char[$index] ) . "</h3>\n<ul>";
 603                         }
 604
 605                         $r .= "<li>{$articles[$index]}</li>";
 606                 }
 607                 $r .= '</ul>';
 608                 return $r;
 609         }
 610
 611         /**
 612          * Create paging links, as a helper method to getSectionPagingLinks().
 613          *
 614          * @param string $first The 'until' parameter for the generated URL
 615          * @param string $last The 'from' parameter for the generated URL
 616          * @param string $type A prefix for parameters, 'page' or 'subcat' or
 617          *     'file'
 618          * @return string HTML
 619          */
 620         private function pagingLinks( $first, $last, $type = '' ) {
 621                 $prevLink = $this->msg( 'prevn' )->numParams( $this->limit )->escaped();
 622
 623                 if ( $first != '' ) {
 624                         $prevQuery = $this->query;
 625                         $prevQuery["{$type}until"] = $first;
 626                         unset( $prevQuery["{$type}from"] );
 627                         $prevLink = Linker::linkKnown(
 628                                 $this->addFragmentToTitle( $this->title, $type ),
 629                                 $prevLink,
 630                                 array(),
 631                                 $prevQuery
 632                         );
 633                 }
 634
 635                 $nextLink = $this->msg( 'nextn' )->numParams( $this->limit )->escaped();
 636
 637                 if ( $last != '' ) {
 638                         $lastQuery = $this->query;
 639                         $lastQuery["{$type}from"] = $last;
 640                         unset( $lastQuery["{$type}until"] );
 641                         $nextLink = Linker::linkKnown(
 642                                 $this->addFragmentToTitle( $this->title, $type ),
 643                                 $nextLink,
 644                                 array(),
 645                                 $lastQuery
 646                         );
 647                 }
 648
 649                 return $this->msg( 'categoryviewer-pagedlinks' )->rawParams( $prevLink, $nextLink )->escaped();
 650         }
 651
 652         /**
 653          * Takes a title, and adds the fragment identifier that
 654          * corresponds to the correct segment of the category.
 655          *
 656          * @param Title $title The title (usually $this->title)
 657          * @param string $section Which section
 658          * @throws MWException
 659          * @return Title
 660          */
 661         private function addFragmentToTitle( $title, $section ) {
 662                 switch ( $section ) {
 663                         case 'page':
 664                                 $fragment = 'mw-pages';
 665                                 break;
 666                         case 'subcat':
 667                                 $fragment = 'mw-subcategories';
 668                                 break;
 669                         case 'file':
 670                                 $fragment = 'mw-category-media';
 671                                 break;
 672                         default:
 673                                 throw new MWException( __METHOD__ .
 674                                         " Invalid section $section." );
 675                 }
 676
 677                 return Title::makeTitle( $title->getNamespace(),
 678                         $title->getDBkey(), $fragment );
 679         }
 680
 681         /**
 682          * What to do if the category table conflicts with the number of results
 683          * returned?  This function says what. Each type is considered independently
 684          * of the other types.
 685          *
 686          * @param int $rescnt The number of items returned by our database query.
 687          * @param int $dbcnt The number of items according to the category table.
 688          * @param string $type 'subcat', 'article', or 'file'
 689          * @return string A message giving the number of items, to output to HTML.
 690          */
 691         private function getCountMessage( $rescnt, $dbcnt, $type ) {
 692                 // There are three cases:
 693                 //   1) The category table figure seems sane.  It might be wrong, but
 694                 //      we can't do anything about it if we don't recalculate it on ev-
 695                 //      ery category view.
 696                 //   2) The category table figure isn't sane, like it's smaller than the
 697                 //      number of actual results, *but* the number of results is less
 698                 //      than $this->limit and there's no offset.  In this case we still
 699                 //      know the right figure.
 700                 //   3) We have no idea.
 701
 702                 // Check if there's a "from" or "until" for anything
 703
 704                 // This is a little ugly, but we seem to use different names
 705                 // for the paging types then for the messages.
 706                 if ( $type === 'article' ) {
 707                         $pagingType = 'page';
 708                 } else {
 709                         $pagingType = $type;
 710                 }
 711
 712                 $fromOrUntil = false;
 713                 if ( ( isset( $this->from[$pagingType] ) && $this->from[$pagingType] !== null ) ||
 714                         ( isset( $this->until[$pagingType] ) && $this->until[$pagingType] !== null )
 715                 ) {
 716                         $fromOrUntil = true;
 717                 }
 718
 719                 if ( $dbcnt == $rescnt ||
 720                         ( ( $rescnt == $this->limit || $fromOrUntil ) && $dbcnt > $rescnt )
 721                 ) {
 722                         // Case 1: seems sane.
 723                         $totalcnt = $dbcnt;
 724                 } elseif ( $rescnt < $this->limit && !$fromOrUntil ) {
 725                         // Case 2: not sane, but salvageable.  Use the number of results.
 726                         // Since there are fewer than 200, we can also take this opportunity
 727                         // to refresh the incorrect category table entry -- which should be
 728                         // quick due to the small number of entries.
 729                         $totalcnt = $rescnt;
 730                         $category = $this->cat;
 731                         wfGetDB( DB_MASTER )->onTransactionIdle( function () use ( $category ) {
 732                                 $category->refreshCounts();
 733                         } );
 734                 } else {
 735                         // Case 3: hopeless.  Don't give a total count at all.
 736                         // Messages: category-subcat-count-limited, category-article-count-limited,
 737                         // category-file-count-limited
 738                         return $this->msg( "category-$type-count-limited" )->numParams( $rescnt )->parseAsBlock();
 739                 }
 740                 // Messages: category-subcat-count, category-article-count, category-file-count
 741                 return $this->msg( "category-$type-count" )->numParams( $rescnt, $totalcnt )->parseAsBlock();
 742         }
 743 }