includes/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 /**
  25  * List of query page classes and their associated special pages,
  26  * for periodic updates.
  27  *
  28  * DO NOT CHANGE THIS LIST without testing that
  29  * maintenance/updateSpecialPages.php still works.
  30  */
  31 global $wgQueryPages; // not redundant
  32 $wgQueryPages = array(
  33 //         QueryPage subclass           Special page name         Limit (false for none, none for the default)
  34 // ----------------------------------------------------------------------------
  35         array( 'AncientPagesPage',              'Ancientpages'                  ),
  36         array( 'BrokenRedirectsPage',           'BrokenRedirects'               ),
  37         array( 'DeadendPagesPage',              'Deadendpages'                  ),
  38         array( 'DoubleRedirectsPage',           'DoubleRedirects'               ),
  39         array( 'FileDuplicateSearchPage',       'FileDuplicateSearch'           ),
  40         array( 'LinkSearchPage',                'LinkSearch'                    ),
  41         array( 'ListredirectsPage',             'Listredirects'                 ),
  42         array( 'LonelyPagesPage',               'Lonelypages'                   ),
  43         array( 'LongPagesPage',                 'Longpages'                     ),
  44         array( 'MIMEsearchPage',                'MIMEsearch'                    ),
  45         array( 'MostcategoriesPage',            'Mostcategories'                ),
  46         array( 'MostimagesPage',                'Mostimages'                    ),
  47         array( 'MostinterwikisPage',            'Mostinterwikis'                ),
  48         array( 'MostlinkedCategoriesPage',      'Mostlinkedcategories'          ),
  49         array( 'MostlinkedtemplatesPage',       'Mostlinkedtemplates'           ),
  50         array( 'MostlinkedPage',                'Mostlinked'                    ),
  51         array( 'MostrevisionsPage',             'Mostrevisions'                 ),
  52         array( 'FewestrevisionsPage',           'Fewestrevisions'               ),
  53         array( 'ShortPagesPage',                'Shortpages'                    ),
  54         array( 'UncategorizedCategoriesPage',   'Uncategorizedcategories'       ),
  55         array( 'UncategorizedPagesPage',        'Uncategorizedpages'            ),
  56         array( 'UncategorizedImagesPage',       'Uncategorizedimages'           ),
  57         array( 'UncategorizedTemplatesPage',    'Uncategorizedtemplates'        ),
  58         array( 'UnusedCategoriesPage',          'Unusedcategories'              ),
  59         array( 'UnusedimagesPage',              'Unusedimages'                  ),
  60         array( 'WantedCategoriesPage',          'Wantedcategories'              ),
  61         array( 'WantedFilesPage',               'Wantedfiles'                   ),
  62         array( 'WantedPagesPage',               'Wantedpages'                   ),
  63         array( 'WantedTemplatesPage',           'Wantedtemplates'               ),
  64         array( 'UnwatchedPagesPage',            'Unwatchedpages'                ),
  65         array( 'UnusedtemplatesPage',           'Unusedtemplates'               ),
  66         array( 'WithoutInterwikiPage',          'Withoutinterwiki'              ),
  67 );
  68 wfRunHooks( 'wgQueryPages', array( &$wgQueryPages ) );
  69
  70 global $wgDisableCounters;
  71 if ( !$wgDisableCounters ) {
  72         $wgQueryPages[] = array( 'PopularPagesPage', 'Popularpages' );
  73 }
  74
  75 /**
  76  * This is a class for doing query pages; since they're almost all the same,
  77  * we factor out some of the functionality into a superclass, and let
  78  * subclasses derive from it.
  79  * @ingroup SpecialPage
  80  */
  81 abstract class QueryPage extends SpecialPage {
  82         /**
  83          * Whether or not we want plain listoutput rather than an ordered list
  84          *
  85          * @var bool
  86          */
  87         var $listoutput = false;
  88
  89         /**
  90          * The offset and limit in use, as passed to the query() function
  91          *
  92          * @var int
  93          */
  94         var $offset = 0;
  95         var $limit = 0;
  96
  97         /**
  98          * The number of rows returned by the query. Reading this variable
  99          * only makes sense in functions that are run after the query has been
 100          * done, such as preprocessResults() and formatRow().
 101          */
 102         protected $numRows;
 103
 104         protected $cachedTimestamp = null;
 105
 106         /**
 107          * Wheter to show prev/next links
 108          */
 109         protected $shownavigation = true;
 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         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 getQuery() properly" );
 159         }
 160
 161         /**
 162          * Subclasses return an array of fields to order by here. Don't append
 163          * DESC to the field names, that'll be done automatically if
 164          * sortDescending() returns true.
 165          * @return array
 166          * @since 1.18
 167          */
 168         function getOrderFields() {
 169                 return array( 'value' );
 170         }
 171
 172         /**
 173          * Does this query return timestamps rather than integers in its
 174          * 'value' field? If true, this class will convert 'value' to a
 175          * UNIX timestamp for caching.
 176          * NOTE: formatRow() may get timestamps in TS_MW (mysql), TS_DB (pgsql)
 177          *       or TS_UNIX (querycache) format, so be sure to always run them
 178          *       through wfTimestamp()
 179          * @return bool
 180          * @since 1.18
 181          */
 182         function usesTimestamps() {
 183                 return false;
 184         }
 185
 186         /**
 187          * Override to sort by increasing values
 188          *
 189          * @return bool
 190          */
 191         function sortDescending() {
 192                 return true;
 193         }
 194
 195         /**
 196          * Is this query expensive (for some definition of expensive)? Then we
 197          * don't let it run in miser mode. $wgDisableQueryPages causes all query
 198          * pages to be declared expensive. Some query pages are always expensive.
 199          *
 200          * @return bool
 201          */
 202         function isExpensive() {
 203                 global $wgDisableQueryPages;
 204                 return $wgDisableQueryPages;
 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         function isCached() {
 225                 global $wgMiserMode;
 226
 227                 return $this->isExpensive() && $wgMiserMode;
 228         }
 229
 230         /**
 231          * Sometime we don't want to build rss / atom feeds.
 232          *
 233          * @return bool
 234          */
 235         function isSyndicated() {
 236                 return true;
 237         }
 238
 239         /**
 240          * Formats the results of the query for display. The skin is the current
 241          * skin; you can use it for making links. The result is a single row of
 242          * result data. You should be able to grab SQL results off of it.
 243          * If the function returns false, the line output will be skipped.
 244          * @param Skin $skin
 245          * @param object $result Result row
 246          * @return string|bool String or false to skip
 247          */
 248         abstract function formatResult( $skin, $result );
 249
 250         /**
 251          * The content returned by this function will be output before any result
 252          *
 253          * @return string
 254          */
 255         function getPageHeader() {
 256                 return '';
 257         }
 258
 259         /**
 260          * If using extra form wheely-dealies, return a set of parameters here
 261          * as an associative array. They will be encoded and added to the paging
 262          * links (prev/next/lengths).
 263          *
 264          * @return array
 265          */
 266         function linkParameters() {
 267                 return array();
 268         }
 269
 270         /**
 271          * Some special pages (for example SpecialListusers) might not return the
 272          * current object formatted, but return the previous one instead.
 273          * Setting this to return true will ensure formatResult() is called
 274          * one more time to make sure that the very last result is formatted
 275          * as well.
 276          * @return bool
 277          */
 278         function tryLastResult() {
 279                 return false;
 280         }
 281
 282         /**
 283          * Clear the cache and save new results
 284          *
 285          * @param int|bool $limit Limit for SQL statement
 286          * @param bool $ignoreErrors Whether to ignore database errors
 287          * @throws DBError|Exception
 288          * @return bool|int
 289          */
 290         function recache( $limit, $ignoreErrors = true ) {
 291                 if ( !$this->isCacheable() ) {
 292                         return 0;
 293                 }
 294
 295                 $fname = get_class( $this ) . '::recache';
 296                 $dbw = wfGetDB( DB_MASTER );
 297                 $dbr = wfGetDB( DB_SLAVE, array( $this->getName(), __METHOD__, 'vslow' ) );
 298                 if ( !$dbw || !$dbr ) {
 299                         return false;
 300                 }
 301
 302                 try {
 303                         # Clear out any old cached data
 304                         $dbw->delete( 'querycache', array( 'qc_type' => $this->getName() ), $fname );
 305                         # Do query
 306                         $res = $this->reallyDoQuery( $limit, false );
 307                         $num = false;
 308                         if ( $res ) {
 309                                 $num = $res->numRows();
 310                                 # Fetch results
 311                                 $vals = array();
 312                                 while ( $res && $row = $dbr->fetchObject( $res ) ) {
 313                                         if ( isset( $row->value ) ) {
 314                                                 if ( $this->usesTimestamps() ) {
 315                                                         $value = wfTimestamp( TS_UNIX,
 316                                                                 $row->value );
 317                                                 } else {
 318                                                         $value = intval( $row->value ); // @bug 14414
 319                                                 }
 320                                         } else {
 321                                                 $value = 0;
 322                                         }
 323
 324                                         $vals[] = array( 'qc_type' => $this->getName(),
 325                                                         'qc_namespace' => $row->namespace,
 326                                                         'qc_title' => $row->title,
 327                                                         'qc_value' => $value );
 328                                 }
 329
 330                                 # Save results into the querycache table on the master
 331                                 if ( count( $vals ) ) {
 332                                         $dbw->insert( 'querycache', $vals, __METHOD__ );
 333                                 }
 334                                 # Update the querycache_info record for the page
 335                                 $dbw->delete( 'querycache_info', array( 'qci_type' => $this->getName() ), $fname );
 336                                 $dbw->insert( 'querycache_info',
 337                                         array( 'qci_type' => $this->getName(), 'qci_timestamp' => $dbw->timestamp() ),
 338                                         $fname );
 339                         }
 340                 } catch ( DBError $e ) {
 341                         if ( !$ignoreErrors ) {
 342                                 throw $e; // report query error
 343                         }
 344                         $num = false; // set result to false to indicate error
 345                 }
 346
 347                 return $num;
 348         }
 349
 350         /**
 351          * Run the query and return the result
 352          * @param int|bool $limit Numerical limit or false for no limit
 353          * @param int|bool $offset Numerical offset or false for no offset
 354          * @return ResultWrapper
 355          * @since 1.18
 356          */
 357         function reallyDoQuery( $limit, $offset = false ) {
 358                 $fname = get_class( $this ) . "::reallyDoQuery";
 359                 $dbr = wfGetDB( DB_SLAVE );
 360                 $query = $this->getQueryInfo();
 361                 $order = $this->getOrderFields();
 362
 363                 if ( $this->sortDescending() ) {
 364                         foreach ( $order as &$field ) {
 365                                 $field .= ' DESC';
 366                         }
 367                 }
 368
 369                 if ( is_array( $query ) ) {
 370                         $tables = isset( $query['tables'] ) ? (array)$query['tables'] : array();
 371                         $fields = isset( $query['fields'] ) ? (array)$query['fields'] : array();
 372                         $conds = isset( $query['conds'] ) ? (array)$query['conds'] : array();
 373                         $options = isset( $query['options'] ) ? (array)$query['options'] : array();
 374                         $join_conds = isset( $query['join_conds'] ) ? (array)$query['join_conds'] : array();
 375
 376                         if ( count( $order ) ) {
 377                                 $options['ORDER BY'] = $order;
 378                         }
 379
 380                         if ( $limit !== false ) {
 381                                 $options['LIMIT'] = intval( $limit );
 382                         }
 383
 384                         if ( $offset !== false ) {
 385                                 $options['OFFSET'] = intval( $offset );
 386                         }
 387
 388                         $res = $dbr->select( $tables, $fields, $conds, $fname,
 389                                         $options, $join_conds
 390                         );
 391                 } else {
 392                         // Old-fashioned raw SQL style, deprecated
 393                         $sql = $this->getSQL();
 394                         $sql .= ' ORDER BY ' . implode( ', ', $order );
 395                         $sql = $dbr->limitResult( $sql, $limit, $offset );
 396                         $res = $dbr->query( $sql, $fname );
 397                 }
 398
 399                 return $dbr->resultObject( $res );
 400         }
 401
 402         /**
 403          * Somewhat deprecated, you probably want to be using execute()
 404          * @param int|bool $offset
 405          * @oaram int|bool $limit
 406          * @return ResultWrapper
 407          */
 408         function doQuery( $offset = false, $limit = false ) {
 409                 if ( $this->isCached() && $this->isCacheable() ) {
 410                         return $this->fetchFromCache( $limit, $offset );
 411                 } else {
 412                         return $this->reallyDoQuery( $limit, $offset );
 413                 }
 414         }
 415
 416         /**
 417          * Fetch the query results from the query cache
 418          * @param int|bool $limit Numerical limit or false for no limit
 419          * @param int|bool $offset Numerical offset or false for no offset
 420          * @return ResultWrapper
 421          * @since 1.18
 422          */
 423         function fetchFromCache( $limit, $offset = false ) {
 424                 $dbr = wfGetDB( DB_SLAVE );
 425                 $options = array();
 426                 if ( $limit !== false ) {
 427                         $options['LIMIT'] = intval( $limit );
 428                 }
 429                 if ( $offset !== false ) {
 430                         $options['OFFSET'] = intval( $offset );
 431                 }
 432                 if ( $this->sortDescending() ) {
 433                         $options['ORDER BY'] = 'qc_value DESC';
 434                 } else {
 435                         $options['ORDER BY'] = 'qc_value ASC';
 436                 }
 437                 $res = $dbr->select( 'querycache', array( 'qc_type',
 438                                 'namespace' => 'qc_namespace',
 439                                 'title' => 'qc_title',
 440                                 'value' => 'qc_value' ),
 441                                 array( 'qc_type' => $this->getName() ),
 442                                 __METHOD__, $options
 443                 );
 444                 return $dbr->resultObject( $res );
 445         }
 446
 447         public function getCachedTimestamp() {
 448                 if ( is_null( $this->cachedTimestamp ) ) {
 449                         $dbr = wfGetDB( DB_SLAVE );
 450                         $fname = get_class( $this ) . '::getCachedTimestamp';
 451                         $this->cachedTimestamp = $dbr->selectField( 'querycache_info', 'qci_timestamp',
 452                                 array( 'qci_type' => $this->getName() ), $fname );
 453                 }
 454                 return $this->cachedTimestamp;
 455         }
 456
 457         /**
 458          * This is the actual workhorse. It does everything needed to make a
 459          * real, honest-to-gosh query page.
 460          * @para $par
 461          * @return int
 462          */
 463         function execute( $par ) {
 464                 global $wgQueryCacheLimit, $wgDisableQueryPageUpdate;
 465
 466                 $user = $this->getUser();
 467                 if ( !$this->userCanExecute( $user ) ) {
 468                         $this->displayRestrictionError();
 469                         return;
 470                 }
 471
 472                 $this->setHeaders();
 473                 $this->outputHeader();
 474
 475                 $out = $this->getOutput();
 476
 477                 if ( $this->isCached() && !$this->isCacheable() ) {
 478                         $out->addWikiMsg( 'querypage-disabled' );
 479                         return 0;
 480                 }
 481
 482                 $out->setSyndicated( $this->isSyndicated() );
 483
 484                 if ( $this->limit == 0 && $this->offset == 0 ) {
 485                         list( $this->limit, $this->offset ) = $this->getRequest()->getLimitOffset();
 486                 }
 487
 488                 // TODO: Use doQuery()
 489                 if ( !$this->isCached() ) {
 490                         # select one extra row for navigation
 491                         $res = $this->reallyDoQuery( $this->limit + 1, $this->offset );
 492                 } else {
 493                         # Get the cached result, select one extra row for navigation
 494                         $res = $this->fetchFromCache( $this->limit + 1, $this->offset );
 495                         if ( !$this->listoutput ) {
 496
 497                                 # Fetch the timestamp of this update
 498                                 $ts = $this->getCachedTimestamp();
 499                                 $lang = $this->getLanguage();
 500                                 $maxResults = $lang->formatNum( $wgQueryCacheLimit );
 501
 502                                 if ( $ts ) {
 503                                         $updated = $lang->userTimeAndDate( $ts, $user );
 504                                         $updateddate = $lang->userDate( $ts, $user );
 505                                         $updatedtime = $lang->userTime( $ts, $user );
 506                                         $out->addMeta( 'Data-Cache-Time', $ts );
 507                                         $out->addJsConfigVars( 'dataCacheTime', $ts );
 508                                         $out->addWikiMsg( 'perfcachedts', $updated, $updateddate, $updatedtime, $maxResults );
 509                                 } else {
 510                                         $out->addWikiMsg( 'perfcached', $maxResults );
 511                                 }
 512
 513                                 # If updates on this page have been disabled, let the user know
 514                                 # that the data set won't be refreshed for now
 515                                 if ( is_array( $wgDisableQueryPageUpdate ) && in_array( $this->getName(), $wgDisableQueryPageUpdate ) ) {
 516                                         $out->wrapWikiMsg( "<div class=\"mw-querypage-no-updates\">\n$1\n</div>", 'querypage-no-updates' );
 517                                 }
 518                         }
 519                 }
 520
 521                 $this->numRows = $res->numRows();
 522
 523                 $dbr = wfGetDB( DB_SLAVE );
 524                 $this->preprocessResults( $dbr, $res );
 525
 526                 $out->addHTML( Xml::openElement( 'div', array( 'class' => 'mw-spcontent' ) ) );
 527
 528                 # Top header and navigation
 529                 if ( $this->shownavigation ) {
 530                         $out->addHTML( $this->getPageHeader() );
 531                         if ( $this->numRows > 0 ) {
 532                                 $out->addHTML( $this->msg( 'showingresults' )->numParams(
 533                                         min( $this->numRows, $this->limit ), # do not show the one extra row, if exist
 534                                         $this->offset + 1 )->parseAsBlock() );
 535                                 # Disable the "next" link when we reach the end
 536                                 $paging = $this->getLanguage()->viewPrevNext( $this->getTitle( $par ), $this->offset,
 537                                         $this->limit, $this->linkParameters(), ( $this->numRows <= $this->limit ) );
 538                                 $out->addHTML( '<p>' . $paging . '</p>' );
 539                         } else {
 540                                 # No results to show, so don't bother with "showing X of Y" etc.
 541                                 # -- just let the user know and give up now
 542                                 $out->addWikiMsg( 'specialpage-empty' );
 543                                 $out->addHTML( Xml::closeElement( 'div' ) );
 544                                 return;
 545                         }
 546                 }
 547
 548                 # The actual results; specialist subclasses will want to handle this
 549                 # with more than a straight list, so we hand them the info, plus
 550                 # an OutputPage, and let them get on with it
 551                 $this->outputResults( $out,
 552                         $this->getSkin(),
 553                         $dbr, # Should use a ResultWrapper for this
 554                         $res,
 555                         min( $this->numRows, $this->limit ), # do not format the one extra row, if exist
 556                         $this->offset );
 557
 558                 # Repeat the paging links at the bottom
 559                 if ( $this->shownavigation ) {
 560                         $out->addHTML( '<p>' . $paging . '</p>' );
 561                 }
 562
 563                 $out->addHTML( Xml::closeElement( 'div' ) );
 564
 565                 return min( $this->numRows, $this->limit ); # do not return the one extra row, if exist
 566         }
 567
 568         /**
 569          * Format and output report results using the given information plus
 570          * OutputPage
 571          *
 572          * @param OutputPage $out OutputPage to print to
 573          * @param Skin $skin User skin to use
 574          * @param DatabaseBase $dbr Database (read) connection to use
 575          * @param int $res Result pointer
 576          * @param int $num Number of available result rows
 577          * @param int $offset Paging offset
 578          */
 579         protected function outputResults( $out, $skin, $dbr, $res, $num, $offset ) {
 580                 global $wgContLang;
 581
 582                 if ( $num > 0 ) {
 583                         $html = array();
 584                         if ( !$this->listoutput ) {
 585                                 $html[] = $this->openList( $offset );
 586                         }
 587
 588                         # $res might contain the whole 1,000 rows, so we read up to
 589                         # $num [should update this to use a Pager]
 590                         for ( $i = 0; $i < $num && $row = $res->fetchObject(); $i++ ) {
 591                                 $line = $this->formatResult( $skin, $row );
 592                                 if ( $line ) {
 593                                         $attr = ( isset( $row->usepatrol ) && $row->usepatrol && $row->patrolled == 0 )
 594                                                 ? ' class="not-patrolled"'
 595                                                 : '';
 596                                         $html[] = $this->listoutput
 597                                                 ? $line
 598                                                 : "<li{$attr}>{$line}</li>\n";
 599                                 }
 600                         }
 601
 602                         # Flush the final result
 603                         if ( $this->tryLastResult() ) {
 604                                 $row = null;
 605                                 $line = $this->formatResult( $skin, $row );
 606                                 if ( $line ) {
 607                                         $attr = ( isset( $row->usepatrol ) && $row->usepatrol && $row->patrolled == 0 )
 608                                                 ? ' class="not-patrolled"'
 609                                                 : '';
 610                                         $html[] = $this->listoutput
 611                                                 ? $line
 612                                                 : "<li{$attr}>{$line}</li>\n";
 613                                 }
 614                         }
 615
 616                         if ( !$this->listoutput ) {
 617                                 $html[] = $this->closeList();
 618                         }
 619
 620                         $html = $this->listoutput
 621                                 ? $wgContLang->listToText( $html )
 622                                 : implode( '', $html );
 623
 624                         $out->addHTML( $html );
 625                 }
 626         }
 627
 628         /**
 629          * @param $offset
 630          * @return string
 631          */
 632         function openList( $offset ) {
 633                 return "\n<ol start='" . ( $offset + 1 ) . "' class='special'>\n";
 634         }
 635
 636         /**
 637          * @return string
 638          */
 639         function closeList() {
 640                 return "</ol>\n";
 641         }
 642
 643         /**
 644          * Do any necessary preprocessing of the result object.
 645          * @param DatabaseBase $db
 646          * @param ResultWrapper $res
 647          */
 648         function preprocessResults( $db, $res ) {}
 649
 650         /**
 651          * Similar to above, but packaging in a syndicated feed instead of a web page
 652          * @param string $class
 653          * @param int $limit
 654          * @return bool
 655          */
 656         function doFeed( $class = '', $limit = 50 ) {
 657                 global $wgFeed, $wgFeedClasses, $wgFeedLimit;
 658
 659                 if ( !$wgFeed ) {
 660                         $this->getOutput()->addWikiMsg( 'feed-unavailable' );
 661                         return false;
 662                 }
 663
 664                 $limit = min( $limit, $wgFeedLimit );
 665
 666                 if ( isset( $wgFeedClasses[$class] ) ) {
 667                         $feed = new $wgFeedClasses[$class](
 668                                 $this->feedTitle(),
 669                                 $this->feedDesc(),
 670                                 $this->feedUrl() );
 671                         $feed->outHeader();
 672
 673                         $res = $this->reallyDoQuery( $limit, 0 );
 674                         foreach ( $res as $obj ) {
 675                                 $item = $this->feedResult( $obj );
 676                                 if ( $item ) {
 677                                         $feed->outItem( $item );
 678                                 }
 679                         }
 680
 681                         $feed->outFooter();
 682                         return true;
 683                 } else {
 684                         return false;
 685                 }
 686         }
 687
 688         /**
 689          * Override for custom handling. If the titles/links are ok, just do
 690          * feedItemDesc()
 691          * @param object $row
 692          * @return FeedItem|null
 693          */
 694         function feedResult( $row ) {
 695                 if ( !isset( $row->title ) ) {
 696                         return null;
 697                 }
 698                 $title = Title::makeTitle( intval( $row->namespace ), $row->title );
 699                 if ( $title ) {
 700                         $date = isset( $row->timestamp ) ? $row->timestamp : '';
 701                         $comments = '';
 702                         if ( $title ) {
 703                                 $talkpage = $title->getTalkPage();
 704                                 $comments = $talkpage->getFullURL();
 705                         }
 706
 707                         return new FeedItem(
 708                                 $title->getPrefixedText(),
 709                                 $this->feedItemDesc( $row ),
 710                                 $title->getFullURL(),
 711                                 $date,
 712                                 $this->feedItemAuthor( $row ),
 713                                 $comments );
 714                 } else {
 715                         return null;
 716                 }
 717         }
 718
 719         function feedItemDesc( $row ) {
 720                 return isset( $row->comment ) ? htmlspecialchars( $row->comment ) : '';
 721         }
 722
 723         function feedItemAuthor( $row ) {
 724                 return isset( $row->user_text ) ? $row->user_text : '';
 725         }
 726
 727         function feedTitle() {
 728                 global $wgLanguageCode, $wgSitename;
 729                 $desc = $this->getDescription();
 730                 return "$wgSitename - $desc [$wgLanguageCode]";
 731         }
 732
 733         function feedDesc() {
 734                 return $this->msg( 'tagline' )->text();
 735         }
 736
 737         function feedUrl() {
 738                 return $this->getTitle()->getFullURL();
 739         }
 740 }
 741
 742 /**
 743  * Class definition for a wanted query page like
 744  * WantedPages, WantedTemplates, etc
 745  */
 746 abstract class WantedQueryPage extends QueryPage {
 747         function isExpensive() {
 748                 return true;
 749         }
 750
 751         function isSyndicated() {
 752                 return false;
 753         }
 754
 755         /**
 756          * Cache page existence for performance
 757          * @param DatabaseBase $db
 758          * @param ResultWrapper $res
 759          */
 760         function preprocessResults( $db, $res ) {
 761                 if ( !$res->numRows() ) {
 762                         return;
 763                 }
 764
 765                 $batch = new LinkBatch;
 766                 foreach ( $res as $row ) {
 767                         $batch->add( $row->namespace, $row->title );
 768                 }
 769                 $batch->execute();
 770
 771                 // Back to start for display
 772                 $res->seek( 0 );
 773         }
 774
 775         /**
 776          * Should formatResult() always check page existence, even if
 777          * the results are fresh?  This is a (hopefully temporary)
 778          * kluge for Special:WantedFiles, which may contain false
 779          * positives for files that exist e.g. in a shared repo (bug
 780          * 6220).
 781          * @return bool
 782          */
 783         function forceExistenceCheck() {
 784                 return false;
 785         }
 786
 787         /**
 788          * Format an individual result
 789          *
 790          * @param Skin $skin Skin to use for UI elements
 791          * @param object $result Result row
 792          * @return string
 793          */
 794         public function formatResult( $skin, $result ) {
 795                 $title = Title::makeTitleSafe( $result->namespace, $result->title );
 796                 if ( $title instanceof Title ) {
 797                         if ( $this->isCached() || $this->forceExistenceCheck() ) {
 798                                 $pageLink = $title->isKnown()
 799                                         ? '<del>' . Linker::link( $title ) . '</del>'
 800                                         : Linker::link(
 801                                                 $title,
 802                                                 null,
 803                                                 array(),
 804                                                 array(),
 805                                                 array( 'broken' )
 806                                         );
 807                         } else {
 808                                 $pageLink = Linker::link(
 809                                         $title,
 810                                         null,
 811                                         array(),
 812                                         array(),
 813                                         array( 'broken' )
 814                                 );
 815                         }
 816                         return $this->getLanguage()->specialList( $pageLink, $this->makeWlhLink( $title, $result ) );
 817                 } else {
 818                         return $this->msg( 'wantedpages-badtitle', $result->title )->escaped();
 819                 }
 820         }
 821
 822         /**
 823          * Make a "what links here" link for a given title
 824          *
 825          * @param Title $title Title to make the link for
 826          * @param object $result Result row
 827          * @return string
 828          */
 829         private function makeWlhLink( $title, $result ) {
 830                 $wlh = SpecialPage::getTitleFor( 'Whatlinkshere', $title->getPrefixedText() );
 831                 $label = $this->msg( 'nlinks' )->numParams( $result->value )->escaped();
 832                 return Linker::link( $wlh, $label );
 833         }
 834 }