includes/specialpage/QueryPage.php

   1 <?php
   2 /**
   3  * Base code for "query" special pages.
   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  * @ingroup SpecialPage
  22  */
  23
  24 use Wikimedia\Rdbms\ResultWrapper;
  25
  26 /**
  27  * This is a class for doing query pages; since they're almost all the same,
  28  * we factor out some of the functionality into a superclass, and let
  29  * subclasses derive from it.
  30  * @ingroup SpecialPage
  31  */
  32 abstract class QueryPage extends SpecialPage {
  33         /** @var bool Whether or not we want plain listoutput rather than an ordered list */
  34         protected $listoutput = false;
  35
  36         /** @var int The offset and limit in use, as passed to the query() function */
  37         protected $offset = 0;
  38
  39         /** @var int */
  40         protected $limit = 0;
  41
  42         /**
  43          * The number of rows returned by the query. Reading this variable
  44          * only makes sense in functions that are run after the query has been
  45          * done, such as preprocessResults() and formatRow().
  46          */
  47         protected $numRows;
  48
  49         protected $cachedTimestamp = null;
  50
  51         /**
  52          * Whether to show prev/next links
  53          */
  54         protected $shownavigation = true;
  55
  56         /**
  57          * Get a list of query page classes and their associated special pages,
  58          * for periodic updates.
  59          *
  60          * DO NOT CHANGE THIS LIST without testing that
  61          * maintenance/updateSpecialPages.php still works.
  62          * @return array
  63          */
  64         public static function getPages() {
  65                 static $qp = null;
  66
  67                 if ( $qp === null ) {
  68                         // QueryPage subclass, Special page name
  69                         $qp = [
  70                                 [ 'AncientPagesPage', 'Ancientpages' ],
  71                                 [ 'BrokenRedirectsPage', 'BrokenRedirects' ],
  72                                 [ 'DeadendPagesPage', 'Deadendpages' ],
  73                                 [ 'DoubleRedirectsPage', 'DoubleRedirects' ],
  74                                 [ 'FileDuplicateSearchPage', 'FileDuplicateSearch' ],
  75                                 [ 'ListDuplicatedFilesPage', 'ListDuplicatedFiles' ],
  76                                 [ 'LinkSearchPage', 'LinkSearch' ],
  77                                 [ 'ListredirectsPage', 'Listredirects' ],
  78                                 [ 'LonelyPagesPage', 'Lonelypages' ],
  79                                 [ 'LongPagesPage', 'Longpages' ],
  80                                 [ 'MediaStatisticsPage', 'MediaStatistics' ],
  81                                 [ 'MIMEsearchPage', 'MIMEsearch' ],
  82                                 [ 'MostcategoriesPage', 'Mostcategories' ],
  83                                 [ 'MostimagesPage', 'Mostimages' ],
  84                                 [ 'MostinterwikisPage', 'Mostinterwikis' ],
  85                                 [ 'MostlinkedCategoriesPage', 'Mostlinkedcategories' ],
  86                                 [ 'MostlinkedTemplatesPage', 'Mostlinkedtemplates' ],
  87                                 [ 'MostlinkedPage', 'Mostlinked' ],
  88                                 [ 'MostrevisionsPage', 'Mostrevisions' ],
  89                                 [ 'FewestrevisionsPage', 'Fewestrevisions' ],
  90                                 [ 'ShortPagesPage', 'Shortpages' ],
  91                                 [ 'UncategorizedCategoriesPage', 'Uncategorizedcategories' ],
  92                                 [ 'UncategorizedPagesPage', 'Uncategorizedpages' ],
  93                                 [ 'UncategorizedImagesPage', 'Uncategorizedimages' ],
  94                                 [ 'UncategorizedTemplatesPage', 'Uncategorizedtemplates' ],
  95                                 [ 'UnusedCategoriesPage', 'Unusedcategories' ],
  96                                 [ 'UnusedimagesPage', 'Unusedimages' ],
  97                                 [ 'WantedCategoriesPage', 'Wantedcategories' ],
  98                                 [ 'WantedFilesPage', 'Wantedfiles' ],
  99                                 [ 'WantedPagesPage', 'Wantedpages' ],
 100                                 [ 'WantedTemplatesPage', 'Wantedtemplates' ],
 101                                 [ 'UnwatchedpagesPage', 'Unwatchedpages' ],
 102                                 [ 'UnusedtemplatesPage', 'Unusedtemplates' ],
 103                                 [ 'WithoutInterwikiPage', 'Withoutinterwiki' ],
 104                         ];
 105                         Hooks::run( 'wgQueryPages', [ &$qp ] );
 106                 }
 107
 108                 return $qp;
 109         }
 110
 111         /**
 112          * A mutator for $this->listoutput;
 113          *
 114          * @param bool $bool
 115          */
 116         function setListoutput( $bool ) {
 117                 $this->listoutput = $bool;
 118         }
 119
 120         /**
 121          * Subclasses return an SQL query here, formatted as an array with the
 122          * following keys:
 123          *    tables => Table(s) for passing to Database::select()
 124          *    fields => Field(s) for passing to Database::select(), may be *
 125          *    conds => WHERE conditions
 126          *    options => options
 127          *    join_conds => JOIN conditions
 128          *
 129          * Note that the query itself should return the following three columns:
 130          * 'namespace', 'title', and 'value'. 'value' is used for sorting.
 131          *
 132          * These may be stored in the querycache table for expensive queries,
 133          * and that cached data will be returned sometimes, so the presence of
 134          * extra fields can't be relied upon. The cached 'value' column will be
 135          * an integer; non-numeric values are useful only for sorting the
 136          * initial query (except if they're timestamps, see usesTimestamps()).
 137          *
 138          * Don't include an ORDER or LIMIT clause, they will be added.
 139          *
 140          * If this function is not overridden or returns something other than
 141          * an array, getSQL() will be used instead. This is for backwards
 142          * compatibility only and is strongly deprecated.
 143          * @return array
 144          * @since 1.18
 145          */
 146         public function getQueryInfo() {
 147                 return null;
 148         }
 149
 150         /**
 151          * For back-compat, subclasses may return a raw SQL query here, as a string.
 152          * This is strongly deprecated; getQueryInfo() should be overridden instead.
 153          * @throws MWException
 154          * @return string
 155          */
 156         function getSQL() {
 157                 /* Implement getQueryInfo() instead */
 158                 throw new MWException( "Bug in a QueryPage: doesn't implement getQueryInfo() nor "
 159                         . "getQuery() properly" );
 160         }
 161
 162         /**
 163          * Subclasses return an array of fields to order by here. Don't append
 164          * DESC to the field names, that'll be done automatically if
 165          * sortDescending() returns true.
 166          * @return array
 167          * @since 1.18
 168          */
 169         function getOrderFields() {
 170                 return [ 'value' ];
 171         }
 172
 173         /**
 174          * Does this query return timestamps rather than integers in its
 175          * 'value' field? If true, this class will convert 'value' to a
 176          * UNIX timestamp for caching.
 177          * NOTE: formatRow() may get timestamps in TS_MW (mysql), TS_DB (pgsql)
 178          *       or TS_UNIX (querycache) format, so be sure to always run them
 179          *       through wfTimestamp()
 180          * @return bool
 181          * @since 1.18
 182          */
 183         public function usesTimestamps() {
 184                 return false;
 185         }
 186
 187         /**
 188          * Override to sort by increasing values
 189          *
 190          * @return bool
 191          */
 192         function sortDescending() {
 193                 return true;
 194         }
 195
 196         /**
 197          * Is this query expensive (for some definition of expensive)? Then we
 198          * don't let it run in miser mode. $wgDisableQueryPages causes all query
 199          * pages to be declared expensive. Some query pages are always expensive.
 200          *
 201          * @return bool
 202          */
 203         public function isExpensive() {
 204                 return $this->getConfig()->get( 'DisableQueryPages' );
 205         }
 206
 207         /**
 208          * Is the output of this query cacheable? Non-cacheable expensive pages
 209          * will be disabled in miser mode and will not have their results written
 210          * to the querycache table.
 211          * @return bool
 212          * @since 1.18
 213          */
 214         public function isCacheable() {
 215                 return true;
 216         }
 217
 218         /**
 219          * Whether or not the output of the page in question is retrieved from
 220          * the database cache.
 221          *
 222          * @return bool
 223          */
 224         public function isCached() {
 225                 return $this->isExpensive() && $this->getConfig()->get( 'MiserMode' );
 226         }
 227
 228         /**
 229          * Sometime we don't want to build rss / atom feeds.
 230          *
 231          * @return bool
 232          */
 233         function isSyndicated() {
 234                 return true;
 235         }
 236
 237         /**
 238          * Formats the results of the query for display. The skin is the current
 239          * skin; you can use it for making links. The result is a single row of
 240          * result data. You should be able to grab SQL results off of it.
 241          * If the function returns false, the line output will be skipped.
 242          * @param Skin $skin
 243          * @param object $result Result row
 244          * @return string|bool String or false to skip
 245          */
 246         abstract function formatResult( $skin, $result );
 247
 248         /**
 249          * The content returned by this function will be output before any result
 250          *
 251          * @return string
 252          */
 253         function getPageHeader() {
 254                 return '';
 255         }
 256
 257         /**
 258          * Outputs some kind of an informative message (via OutputPage) to let the
 259          * user know that the query returned nothing and thus there's nothing to
 260          * show.
 261          *
 262          * @since 1.26
 263          */
 264         protected function showEmptyText() {
 265                 $this->getOutput()->addWikiMsg( 'specialpage-empty' );
 266         }
 267
 268         /**
 269          * If using extra form wheely-dealies, return a set of parameters here
 270          * as an associative array. They will be encoded and added to the paging
 271          * links (prev/next/lengths).
 272          *
 273          * @return array
 274          */
 275         function linkParameters() {
 276                 return [];
 277         }
 278
 279         /**
 280          * Some special pages (for example SpecialListusers used to) might not return the
 281          * current object formatted, but return the previous one instead.
 282          * Setting this to return true will ensure formatResult() is called
 283          * one more time to make sure that the very last result is formatted
 284          * as well.
 285          *
 286          * @deprecated since 1.27
 287          *
 288          * @return bool
 289          */
 290         function tryLastResult() {
 291                 return false;
 292         }
 293
 294         /**
 295          * Clear the cache and save new results
 296          *
 297          * @param int|bool $limit Limit for SQL statement
 298          * @param bool $ignoreErrors Whether to ignore database errors
 299          * @throws DBError|Exception
 300          * @return bool|int
 301          */
 302         public function recache( $limit, $ignoreErrors = true ) {
 303                 if ( !$this->isCacheable() ) {
 304                         return 0;
 305                 }
 306
 307                 $fname = static::class . '::recache';
 308                 $dbw = wfGetDB( DB_MASTER );
 309                 if ( !$dbw ) {
 310                         return false;
 311                 }
 312
 313                 try {
 314                         # Do query
 315                         $res = $this->reallyDoQuery( $limit, false );
 316                         $num = false;
 317                         if ( $res ) {
 318                                 $num = $res->numRows();
 319                                 # Fetch results
 320                                 $vals = [];
 321                                 foreach ( $res as $row ) {
 322                                         if ( isset( $row->value ) ) {
 323                                                 if ( $this->usesTimestamps() ) {
 324                                                         $value = wfTimestamp( TS_UNIX,
 325                                                                 $row->value );
 326                                                 } else {
 327                                                         $value = intval( $row->value ); // T16414
 328                                                 }
 329                                         } else {
 330                                                 $value = 0;
 331                                         }
 332
 333                                         $vals[] = [
 334                                                 'qc_type' => $this->getName(),
 335                                                 'qc_namespace' => $row->namespace,
 336                                                 'qc_title' => $row->title,
 337                                                 'qc_value' => $value
 338                                         ];
 339                                 }
 340
 341                                 $dbw->doAtomicSection(
 342                                         __METHOD__,
 343                                         function ( IDatabase $dbw, $fname ) use ( $vals ) {
 344                                                 # Clear out any old cached data
 345                                                 $dbw->delete( 'querycache',
 346                                                         [ 'qc_type' => $this->getName() ],
 347                                                         $fname
 348                                                 );
 349                                                 # Save results into the querycache table on the master
 350                                                 if ( count( $vals ) ) {
 351                                                         $dbw->insert( 'querycache', $vals, $fname );
 352                                                 }
 353                                                 # Update the querycache_info record for the page
 354                                                 $dbw->delete( 'querycache_info',
 355                                                         [ 'qci_type' => $this->getName() ],
 356                                                         $fname
 357                                                 );
 358                                                 $dbw->insert( 'querycache_info',
 359                                                         [ 'qci_type' => $this->getName(),
 360                                                                 'qci_timestamp' => $dbw->timestamp() ],
 361                                                         $fname
 362                                                 );
 363                                         }
 364                                 );
 365                         }
 366                 } catch ( DBError $e ) {
 367                         if ( !$ignoreErrors ) {
 368                                 throw $e; // report query error
 369                         }
 370                         $num = false; // set result to false to indicate error
 371                 }
 372
 373                 return $num;
 374         }
 375
 376         /**
 377          * Get a DB connection to be used for slow recache queries
 378          * @return IDatabase
 379          */
 380         function getRecacheDB() {
 381                 return wfGetDB( DB_REPLICA, [ $this->getName(), 'QueryPage::recache', 'vslow' ] );
 382         }
 383
 384         /**
 385          * Run the query and return the result
 386          * @param int|bool $limit Numerical limit or false for no limit
 387          * @param int|bool $offset Numerical offset or false for no offset
 388          * @return ResultWrapper
 389          * @since 1.18
 390          */
 391         public function reallyDoQuery( $limit, $offset = false ) {
 392                 $fname = static::class . '::reallyDoQuery';
 393                 $dbr = $this->getRecacheDB();
 394                 $query = $this->getQueryInfo();
 395                 $order = $this->getOrderFields();
 396
 397                 if ( $this->sortDescending() ) {
 398                         foreach ( $order as &$field ) {
 399                                 $field .= ' DESC';
 400                         }
 401                 }
 402
 403                 if ( is_array( $query ) ) {
 404                         $tables = isset( $query['tables'] ) ? (array)$query['tables'] : [];
 405                         $fields = isset( $query['fields'] ) ? (array)$query['fields'] : [];
 406                         $conds = isset( $query['conds'] ) ? (array)$query['conds'] : [];
 407                         $options = isset( $query['options'] ) ? (array)$query['options'] : [];
 408                         $join_conds = isset( $query['join_conds'] ) ? (array)$query['join_conds'] : [];
 409
 410                         if ( $order ) {
 411                                 $options['ORDER BY'] = $order;
 412                         }
 413
 414                         if ( $limit !== false ) {
 415                                 $options['LIMIT'] = intval( $limit );
 416                         }
 417
 418                         if ( $offset !== false ) {
 419                                 $options['OFFSET'] = intval( $offset );
 420                         }
 421
 422                         $res = $dbr->select( $tables, $fields, $conds, $fname,
 423                                         $options, $join_conds
 424                         );
 425                 } else {
 426                         // Old-fashioned raw SQL style, deprecated
 427                         $sql = $this->getSQL();
 428                         $sql .= ' ORDER BY ' . implode( ', ', $order );
 429                         $sql = $dbr->limitResult( $sql, $limit, $offset );
 430                         $res = $dbr->query( $sql, $fname );
 431                 }
 432
 433                 return $res;
 434         }
 435
 436         /**
 437          * Somewhat deprecated, you probably want to be using execute()
 438          * @param int|bool $offset
 439          * @param int|bool $limit
 440          * @return ResultWrapper
 441          */
 442         public function doQuery( $offset = false, $limit = false ) {
 443                 if ( $this->isCached() && $this->isCacheable() ) {
 444                         return $this->fetchFromCache( $limit, $offset );
 445                 } else {
 446                         return $this->reallyDoQuery( $limit, $offset );
 447                 }
 448         }
 449
 450         /**
 451          * Fetch the query results from the query cache
 452          * @param int|bool $limit Numerical limit or false for no limit
 453          * @param int|bool $offset Numerical offset or false for no offset
 454          * @return ResultWrapper
 455          * @since 1.18
 456          */
 457         public function fetchFromCache( $limit, $offset = false ) {
 458                 $dbr = wfGetDB( DB_REPLICA );
 459                 $options = [];
 460
 461                 if ( $limit !== false ) {
 462                         $options['LIMIT'] = intval( $limit );
 463                 }
 464
 465                 if ( $offset !== false ) {
 466                         $options['OFFSET'] = intval( $offset );
 467                 }
 468
 469                 $order = $this->getCacheOrderFields();
 470                 if ( $this->sortDescending() ) {
 471                         foreach ( $order as &$field ) {
 472                                 $field .= " DESC";
 473                         }
 474                 }
 475                 if ( $order ) {
 476                         $options['ORDER BY'] = $order;
 477                 }
 478
 479                 return $dbr->select( 'querycache',
 480                                 [ 'qc_type',
 481                                 'namespace' => 'qc_namespace',
 482                                 'title' => 'qc_title',
 483                                 'value' => 'qc_value' ],
 484                                 [ 'qc_type' => $this->getName() ],
 485                                 __METHOD__,
 486                                 $options
 487                 );
 488         }
 489
 490         /**
 491          * Return the order fields for fetchFromCache. Default is to always use
 492          * "ORDER BY value" which was the default prior to this function.
 493          * @return array
 494          * @since 1.29
 495          */
 496         function getCacheOrderFields() {
 497                 return [ 'value' ];
 498         }
 499
 500         public function getCachedTimestamp() {
 501                 if ( is_null( $this->cachedTimestamp ) ) {
 502                         $dbr = wfGetDB( DB_REPLICA );
 503                         $fname = static::class . '::getCachedTimestamp';
 504                         $this->cachedTimestamp = $dbr->selectField( 'querycache_info', 'qci_timestamp',
 505                                 [ 'qci_type' => $this->getName() ], $fname );
 506                 }
 507                 return $this->cachedTimestamp;
 508         }
 509
 510         /**
 511          * Returns limit and offset, as returned by $this->getRequest()->getLimitOffset().
 512          * Subclasses may override this to further restrict or modify limit and offset.
 513          *
 514          * @note Restricts the offset parameter, as most query pages have inefficient paging
 515          *
 516          * Its generally expected that the returned limit will not be 0, and the returned
 517          * offset will be less than the max results.
 518          *
 519          * @since 1.26
 520          * @return int[] list( $limit, $offset )
 521          */
 522         protected function getLimitOffset() {
 523                 list( $limit, $offset ) = $this->getRequest()->getLimitOffset();
 524                 if ( $this->getConfig()->get( 'MiserMode' ) ) {
 525                         $maxResults = $this->getMaxResults();
 526                         // Can't display more than max results on a page
 527                         $limit = min( $limit, $maxResults );
 528                         // Can't skip over more than the end of $maxResults
 529                         $offset = min( $offset, $maxResults + 1 );
 530                 }
 531                 return [ $limit, $offset ];
 532         }
 533
 534         /**
 535          * What is limit to fetch from DB
 536          *
 537          * Used to make it appear the DB stores less results then it actually does
 538          * @param int $uiLimit Limit from UI
 539          * @param int $uiOffset Offset from UI
 540          * @return int Limit to use for DB (not including extra row to see if at end)
 541          */
 542         protected function getDBLimit( $uiLimit, $uiOffset ) {
 543                 $maxResults = $this->getMaxResults();
 544                 if ( $this->getConfig()->get( 'MiserMode' ) ) {
 545                         $limit = min( $uiLimit + 1, $maxResults - $uiOffset );
 546                         return max( $limit, 0 );
 547                 } else {
 548                         return $uiLimit + 1;
 549                 }
 550         }
 551
 552         /**
 553          * Get max number of results we can return in miser mode.
 554          *
 555          * Most QueryPage subclasses use inefficient paging, so limit the max amount we return
 556          * This matters for uncached query pages that might otherwise accept an offset of 3 million
 557          *
 558          * @since 1.27
 559          * @return int
 560          */
 561         protected function getMaxResults() {
 562                 // Max of 10000, unless we store more than 10000 in query cache.
 563                 return max( $this->getConfig()->get( 'QueryCacheLimit' ), 10000 );
 564         }
 565
 566         /**
 567          * This is the actual workhorse. It does everything needed to make a
 568          * real, honest-to-gosh query page.
 569          * @param string $par
 570          */
 571         public function execute( $par ) {
 572                 $user = $this->getUser();
 573                 if ( !$this->userCanExecute( $user ) ) {
 574                         $this->displayRestrictionError();
 575                         return;
 576                 }
 577
 578                 $this->setHeaders();
 579                 $this->outputHeader();
 580
 581                 $out = $this->getOutput();
 582
 583                 if ( $this->isCached() && !$this->isCacheable() ) {
 584                         $out->addWikiMsg( 'querypage-disabled' );
 585                         return;
 586                 }
 587
 588                 $out->setSyndicated( $this->isSyndicated() );
 589
 590                 if ( $this->limit == 0 && $this->offset == 0 ) {
 591                         list( $this->limit, $this->offset ) = $this->getLimitOffset();
 592                 }
 593                 $dbLimit = $this->getDBLimit( $this->limit, $this->offset );
 594                 // @todo Use doQuery()
 595                 if ( !$this->isCached() ) {
 596                         # select one extra row for navigation
 597                         $res = $this->reallyDoQuery( $dbLimit, $this->offset );
 598                 } else {
 599                         # Get the cached result, select one extra row for navigation
 600                         $res = $this->fetchFromCache( $dbLimit, $this->offset );
 601                         if ( !$this->listoutput ) {
 602
 603                                 # Fetch the timestamp of this update
 604                                 $ts = $this->getCachedTimestamp();
 605                                 $lang = $this->getLanguage();
 606                                 $maxResults = $lang->formatNum( $this->getConfig()->get( 'QueryCacheLimit' ) );
 607
 608                                 if ( $ts ) {
 609                                         $updated = $lang->userTimeAndDate( $ts, $user );
 610                                         $updateddate = $lang->userDate( $ts, $user );
 611                                         $updatedtime = $lang->userTime( $ts, $user );
 612                                         $out->addMeta( 'Data-Cache-Time', $ts );
 613                                         $out->addJsConfigVars( 'dataCacheTime', $ts );
 614                                         $out->addWikiMsg( 'perfcachedts', $updated, $updateddate, $updatedtime, $maxResults );
 615                                 } else {
 616                                         $out->addWikiMsg( 'perfcached', $maxResults );
 617                                 }
 618
 619                                 # If updates on this page have been disabled, let the user know
 620                                 # that the data set won't be refreshed for now
 621                                 if ( is_array( $this->getConfig()->get( 'DisableQueryPageUpdate' ) )
 622                                         && in_array( $this->getName(), $this->getConfig()->get( 'DisableQueryPageUpdate' ) )
 623                                 ) {
 624                                         $out->wrapWikiMsg(
 625                                                 "<div class=\"mw-querypage-no-updates\">\n$1\n</div>",
 626                                                 'querypage-no-updates'
 627                                         );
 628                                 }
 629                         }
 630                 }
 631
 632                 $this->numRows = $res->numRows();
 633
 634                 $dbr = $this->getRecacheDB();
 635                 $this->preprocessResults( $dbr, $res );
 636
 637                 $out->addHTML( Xml::openElement( 'div', [ 'class' => 'mw-spcontent' ] ) );
 638
 639                 # Top header and navigation
 640                 if ( $this->shownavigation ) {
 641                         $out->addHTML( $this->getPageHeader() );
 642                         if ( $this->numRows > 0 ) {
 643                                 $out->addHTML( $this->msg( 'showingresultsinrange' )->numParams(
 644                                         min( $this->numRows, $this->limit ), # do not show the one extra row, if exist
 645                                         $this->offset + 1, ( min( $this->numRows, $this->limit ) + $this->offset ) )->parseAsBlock() );
 646                                 # Disable the "next" link when we reach the end
 647                                 $miserMaxResults = $this->getConfig()->get( 'MiserMode' )
 648                                         && ( $this->offset + $this->limit >= $this->getMaxResults() );
 649                                 $atEnd = ( $this->numRows <= $this->limit ) || $miserMaxResults;
 650                                 $paging = $this->getLanguage()->viewPrevNext( $this->getPageTitle( $par ), $this->offset,
 651                                         $this->limit, $this->linkParameters(), $atEnd );
 652                                 $out->addHTML( '<p>' . $paging . '</p>' );
 653                         } else {
 654                                 # No results to show, so don't bother with "showing X of Y" etc.
 655                                 # -- just let the user know and give up now
 656                                 $this->showEmptyText();
 657                                 $out->addHTML( Xml::closeElement( 'div' ) );
 658                                 return;
 659                         }
 660                 }
 661
 662                 # The actual results; specialist subclasses will want to handle this
 663                 # with more than a straight list, so we hand them the info, plus
 664                 # an OutputPage, and let them get on with it
 665                 $this->outputResults( $out,
 666                         $this->getSkin(),
 667                         $dbr, # Should use a ResultWrapper for this
 668                         $res,
 669                         min( $this->numRows, $this->limit ), # do not format the one extra row, if exist
 670                         $this->offset );
 671
 672                 # Repeat the paging links at the bottom
 673                 if ( $this->shownavigation ) {
 674                         $out->addHTML( '<p>' . $paging . '</p>' );
 675                 }
 676
 677                 $out->addHTML( Xml::closeElement( 'div' ) );
 678         }
 679
 680         /**
 681          * Format and output report results using the given information plus
 682          * OutputPage
 683          *
 684          * @param OutputPage $out OutputPage to print to
 685          * @param Skin $skin User skin to use
 686          * @param IDatabase $dbr Database (read) connection to use
 687          * @param ResultWrapper $res Result pointer
 688          * @param int $num Number of available result rows
 689          * @param int $offset Paging offset
 690          */
 691         protected function outputResults( $out, $skin, $dbr, $res, $num, $offset ) {
 692                 global $wgContLang;
 693
 694                 if ( $num > 0 ) {
 695                         $html = [];
 696                         if ( !$this->listoutput ) {
 697                                 $html[] = $this->openList( $offset );
 698                         }
 699
 700                         # $res might contain the whole 1,000 rows, so we read up to
 701                         # $num [should update this to use a Pager]
 702                         // @codingStandardsIgnoreStart Generic.CodeAnalysis.ForLoopWithTestFunctionCall.NotAllowed
 703                         for ( $i = 0; $i < $num && $row = $res->fetchObject(); $i++ ) {
 704                                 // @codingStandardsIgnoreEnd
 705                                 $line = $this->formatResult( $skin, $row );
 706                                 if ( $line ) {
 707                                         $html[] = $this->listoutput
 708                                                 ? $line
 709                                                 : "<li>{$line}</li>\n";
 710                                 }
 711                         }
 712
 713                         # Flush the final result
 714                         if ( $this->tryLastResult() ) {
 715                                 $row = null;
 716                                 $line = $this->formatResult( $skin, $row );
 717                                 if ( $line ) {
 718                                         $html[] = $this->listoutput
 719                                                 ? $line
 720                                                 : "<li>{$line}</li>\n";
 721                                 }
 722                         }
 723
 724                         if ( !$this->listoutput ) {
 725                                 $html[] = $this->closeList();
 726                         }
 727
 728                         $html = $this->listoutput
 729                                 ? $wgContLang->listToText( $html )
 730                                 : implode( '', $html );
 731
 732                         $out->addHTML( $html );
 733                 }
 734         }
 735
 736         /**
 737          * @param int $offset
 738          * @return string
 739          */
 740         function openList( $offset ) {
 741                 return "\n<ol start='" . ( $offset + 1 ) . "' class='special'>\n";
 742         }
 743
 744         /**
 745          * @return string
 746          */
 747         function closeList() {
 748                 return "</ol>\n";
 749         }
 750
 751         /**
 752          * Do any necessary preprocessing of the result object.
 753          * @param IDatabase $db
 754          * @param ResultWrapper $res
 755          */
 756         function preprocessResults( $db, $res ) {
 757         }
 758
 759         /**
 760          * Similar to above, but packaging in a syndicated feed instead of a web page
 761          * @param string $class
 762          * @param int $limit
 763          * @return bool
 764          */
 765         function doFeed( $class = '', $limit = 50 ) {
 766                 if ( !$this->getConfig()->get( 'Feed' ) ) {
 767                         $this->getOutput()->addWikiMsg( 'feed-unavailable' );
 768                         return false;
 769                 }
 770
 771                 $limit = min( $limit, $this->getConfig()->get( 'FeedLimit' ) );
 772
 773                 $feedClasses = $this->getConfig()->get( 'FeedClasses' );
 774                 if ( isset( $feedClasses[$class] ) ) {
 775                         /** @var RSSFeed|AtomFeed $feed */
 776                         $feed = new $feedClasses[$class](
 777                                 $this->feedTitle(),
 778                                 $this->feedDesc(),
 779                                 $this->feedUrl() );
 780                         $feed->outHeader();
 781
 782                         $res = $this->reallyDoQuery( $limit, 0 );
 783                         foreach ( $res as $obj ) {
 784                                 $item = $this->feedResult( $obj );
 785                                 if ( $item ) {
 786                                         $feed->outItem( $item );
 787                                 }
 788                         }
 789
 790                         $feed->outFooter();
 791                         return true;
 792                 } else {
 793                         return false;
 794                 }
 795         }
 796
 797         /**
 798          * Override for custom handling. If the titles/links are ok, just do
 799          * feedItemDesc()
 800          * @param object $row
 801          * @return FeedItem|null
 802          */
 803         function feedResult( $row ) {
 804                 if ( !isset( $row->title ) ) {
 805                         return null;
 806                 }
 807                 $title = Title::makeTitle( intval( $row->namespace ), $row->title );
 808                 if ( $title ) {
 809                         $date = isset( $row->timestamp ) ? $row->timestamp : '';
 810                         $comments = '';
 811                         if ( $title ) {
 812                                 $talkpage = $title->getTalkPage();
 813                                 $comments = $talkpage->getFullURL();
 814                         }
 815
 816                         return new FeedItem(
 817                                 $title->getPrefixedText(),
 818                                 $this->feedItemDesc( $row ),
 819                                 $title->getFullURL(),
 820                                 $date,
 821                                 $this->feedItemAuthor( $row ),
 822                                 $comments );
 823                 } else {
 824                         return null;
 825                 }
 826         }
 827
 828         function feedItemDesc( $row ) {
 829                 return isset( $row->comment ) ? htmlspecialchars( $row->comment ) : '';
 830         }
 831
 832         function feedItemAuthor( $row ) {
 833                 return isset( $row->user_text ) ? $row->user_text : '';
 834         }
 835
 836         function feedTitle() {
 837                 $desc = $this->getDescription();
 838                 $code = $this->getConfig()->get( 'LanguageCode' );
 839                 $sitename = $this->getConfig()->get( 'Sitename' );
 840                 return "$sitename - $desc [$code]";
 841         }
 842
 843         function feedDesc() {
 844                 return $this->msg( 'tagline' )->text();
 845         }
 846
 847         function feedUrl() {
 848                 return $this->getPageTitle()->getFullURL();
 849         }
 850
 851         /**
 852          * Creates a new LinkBatch object, adds all pages from the passed ResultWrapper (MUST include
 853          * title and optional the namespace field) and executes the batch. This operation will pre-cache
 854          * LinkCache information like page existence and information for stub color and redirect hints.
 855          *
 856          * @param ResultWrapper $res The ResultWrapper object to process. Needs to include the title
 857          *  field and namespace field, if the $ns parameter isn't set.
 858          * @param null $ns Use this namespace for the given titles in the ResultWrapper object,
 859          *  instead of the namespace value of $res.
 860          */
 861         protected function executeLBFromResultWrapper( ResultWrapper $res, $ns = null ) {
 862                 if ( !$res->numRows() ) {
 863                         return;
 864                 }
 865
 866                 $batch = new LinkBatch;
 867                 foreach ( $res as $row ) {
 868                         $batch->add( $ns !== null ? $ns : $row->namespace, $row->title );
 869                 }
 870                 $batch->execute();
 871
 872                 $res->seek( 0 );
 873         }
 874 }