includes/QueryPage.php

   1 <?php
   2 /**
   3  * Contain a class for special pages
   4  * @file
   5  * @ingroup SpecialPages
   6  */
   7
   8 /**
   9  * List of query page classes and their associated special pages,
  10  * for periodic updates.
  11  *
  12  * DO NOT CHANGE THIS LIST without testing that
  13  * maintenance/updateSpecialPages.php still works.
  14  */
  15 global $wgQueryPages; // not redundant
  16 $wgQueryPages = array(
  17 //         QueryPage subclass           Special page name         Limit (false for none, none for the default)
  18 // ----------------------------------------------------------------------------
  19         array( 'AncientPagesPage',              'Ancientpages'                  ),
  20         array( 'BrokenRedirectsPage',           'BrokenRedirects'               ),
  21         array( 'DeadendPagesPage',              'Deadendpages'                  ),
  22         array( 'DisambiguationsPage',           'Disambiguations'               ),
  23         array( 'DoubleRedirectsPage',           'DoubleRedirects'               ),
  24         array( 'FileDuplicateSearchPage',       'FileDuplicateSearch'           ),
  25         array( 'LinkSearchPage',                'LinkSearch'                    ),
  26         array( 'ListredirectsPage',             'Listredirects'                 ),
  27         array( 'LonelyPagesPage',               'Lonelypages'                   ),
  28         array( 'LongPagesPage',                 'Longpages'                     ),
  29         array( 'MIMEsearchPage',                'MIMEsearch'                    ),
  30         array( 'MostcategoriesPage',            'Mostcategories'                ),
  31         array( 'MostimagesPage',                'Mostimages'                    ),
  32         array( 'MostlinkedCategoriesPage',      'Mostlinkedcategories'          ),
  33         array( 'MostlinkedtemplatesPage',       'Mostlinkedtemplates'           ),
  34         array( 'MostlinkedPage',                'Mostlinked'                    ),
  35         array( 'MostrevisionsPage',             'Mostrevisions'                 ),
  36         array( 'FewestrevisionsPage',           'Fewestrevisions'               ),
  37         array( 'ShortPagesPage',                'Shortpages'                    ),
  38         array( 'UncategorizedCategoriesPage',   'Uncategorizedcategories'       ),
  39         array( 'UncategorizedPagesPage',        'Uncategorizedpages'            ),
  40         array( 'UncategorizedImagesPage',       'Uncategorizedimages'           ),
  41         array( 'UncategorizedTemplatesPage',    'Uncategorizedtemplates'        ),
  42         array( 'UnusedCategoriesPage',          'Unusedcategories'              ),
  43         array( 'UnusedimagesPage',              'Unusedimages'                  ),
  44         array( 'WantedCategoriesPage',          'Wantedcategories'              ),
  45         array( 'WantedFilesPage',               'Wantedfiles'                   ),
  46         array( 'WantedPagesPage',               'Wantedpages'                   ),
  47         array( 'WantedTemplatesPage',           'Wantedtemplates'               ),
  48         array( 'UnwatchedPagesPage',            'Unwatchedpages'                ),
  49         array( 'UnusedtemplatesPage',           'Unusedtemplates'               ),
  50         array( 'WithoutInterwikiPage',          'Withoutinterwiki'              ),
  51 );
  52 wfRunHooks( 'wgQueryPages', array( &$wgQueryPages ) );
  53
  54 global $wgDisableCounters;
  55 if ( !$wgDisableCounters )
  56         $wgQueryPages[] = array( 'PopularPagesPage', 'Popularpages' );
  57
  58
  59 /**
  60  * This is a class for doing query pages; since they're almost all the same,
  61  * we factor out some of the functionality into a superclass, and let
  62  * subclasses derive from it.
  63  * @ingroup SpecialPage
  64  */
  65 abstract class QueryPage extends SpecialPage {
  66         /**
  67          * Whether or not we want plain listoutput rather than an ordered list
  68          *
  69          * @var bool
  70          */
  71         var $listoutput = false;
  72
  73         /**
  74          * The offset and limit in use, as passed to the query() function
  75          *
  76          * @var integer
  77          */
  78         var $offset = 0;
  79         var $limit = 0;
  80
  81         /**
  82          * The number of rows returned by the query. Reading this variable
  83          * only makes sense in functions that are run after the query has been
  84          * done, such as preprocessResults() and formatRow().
  85          */
  86         protected $numRows;
  87
  88         protected $cachedTimestamp = null;
  89
  90         /**
  91          * Wheter to show prev/next links
  92          */
  93         protected $shownavigation = true;
  94
  95         /**
  96          * A mutator for $this->listoutput;
  97          *
  98          * @param $bool Boolean
  99          */
 100         function setListoutput( $bool ) {
 101                 $this->listoutput = $bool;
 102         }
 103
 104         /**
 105          * Subclasses return an SQL query here, formatted as an array with the
 106          * following keys:
 107          *    tables => Table(s) for passing to Database::select()
 108          *    fields => Field(s) for passing to Database::select(), may be *
 109          *    conds => WHERE conditions
 110          *    options => options
 111          *    join_conds => JOIN conditions
 112          *
 113          * Note that the query itself should return the following three columns:
 114          * 'namespace', 'title', and 'value'. 'value' is used for sorting.
 115          *
 116          * These may be stored in the querycache table for expensive queries,
 117          * and that cached data will be returned sometimes, so the presence of
 118          * extra fields can't be relied upon. The cached 'value' column will be
 119          * an integer; non-numeric values are useful only for sorting the
 120          * initial query (except if they're timestamps, see usesTimestamps()).
 121          *
 122          * Don't include an ORDER or LIMIT clause, they will be added.
 123          *
 124          * If this function is not overridden or returns something other than
 125          * an array, getSQL() will be used instead. This is for backwards
 126          * compatibility only and is strongly deprecated.
 127          * @return array
 128          * @since 1.18
 129          */
 130         function getQueryInfo() {
 131                 return null;
 132         }
 133
 134         /**
 135          * For back-compat, subclasses may return a raw SQL query here, as a string.
 136          * This is stronly deprecated; getQueryInfo() should be overridden instead.
 137          * @return string
 138          */
 139         function getSQL() {
 140                 /* Implement getQueryInfo() instead */
 141                 throw new MWException( "Bug in a QueryPage: doesn't implement getQueryInfo() nor getQuery() properly" );
 142         }
 143
 144         /**
 145          * Subclasses return an array of fields to order by here. Don't append
 146          * DESC to the field names, that'll be done automatically if
 147          * sortDescending() returns true.
 148          * @return array
 149          * @since 1.18
 150          */
 151         function getOrderFields() {
 152                 return array( 'value' );
 153         }
 154
 155         /**
 156          * Does this query return timestamps rather than integers in its
 157          * 'value' field? If true, this class will convert 'value' to a
 158          * UNIX timestamp for caching.
 159          * NOTE: formatRow() may get timestamps in TS_MW (mysql), TS_DB (pgsql)
 160          *       or TS_UNIX (querycache) format, so be sure to always run them
 161          *       through wfTimestamp()
 162          * @return bool
 163          * @since 1.18
 164          */
 165         function usesTimestamps() {
 166                 return false;
 167         }
 168
 169         /**
 170          * Override to sort by increasing values
 171          *
 172          * @return Boolean
 173          */
 174         function sortDescending() {
 175                 return true;
 176         }
 177
 178         /**
 179          * Is this query expensive (for some definition of expensive)? Then we
 180          * don't let it run in miser mode. $wgDisableQueryPages causes all query
 181          * pages to be declared expensive. Some query pages are always expensive.
 182          *
 183          * @return Boolean
 184          */
 185         function isExpensive() {
 186                 global $wgDisableQueryPages;
 187                 return $wgDisableQueryPages;
 188         }
 189
 190         /**
 191          * Is the output of this query cacheable? Non-cacheable expensive pages
 192          * will be disabled in miser mode and will not have their results written
 193          * to the querycache table.
 194          * @return Boolean
 195          * @since 1.18
 196          */
 197         public function isCacheable() {
 198                 return true;
 199         }
 200
 201         /**
 202          * Whether or not the output of the page in question is retrieved from
 203          * the database cache.
 204          *
 205          * @return Boolean
 206          */
 207         function isCached() {
 208                 global $wgMiserMode;
 209
 210                 return $this->isExpensive() && $wgMiserMode;
 211         }
 212
 213         /**
 214          * Sometime we dont want to build rss / atom feeds.
 215          *
 216          * @return Boolean
 217          */
 218         function isSyndicated() {
 219                 return true;
 220         }
 221
 222         /**
 223          * Formats the results of the query for display. The skin is the current
 224          * skin; you can use it for making links. The result is a single row of
 225          * result data. You should be able to grab SQL results off of it.
 226          * If the function returns false, the line output will be skipped.
 227          * @param $skin Skin
 228          * @param $result object Result row
 229          * @return mixed String or false to skip
 230          *
 231          * @param $skin Skin object
 232          * @param $result Object: database row
 233          */
 234         abstract function formatResult( $skin, $result );
 235
 236         /**
 237          * The content returned by this function will be output before any result
 238          *
 239          * @return String
 240          */
 241         function getPageHeader() {
 242                 return '';
 243         }
 244
 245         /**
 246          * If using extra form wheely-dealies, return a set of parameters here
 247          * as an associative array. They will be encoded and added to the paging
 248          * links (prev/next/lengths).
 249          *
 250          * @return Array
 251          */
 252         function linkParameters() {
 253                 return array();
 254         }
 255
 256         /**
 257          * Some special pages (for example SpecialListusers) might not return the
 258          * current object formatted, but return the previous one instead.
 259          * Setting this to return true will ensure formatResult() is called
 260          * one more time to make sure that the very last result is formatted
 261          * as well.
 262          */
 263         function tryLastResult() {
 264                 return false;
 265         }
 266
 267         /**
 268          * Clear the cache and save new results
 269          *
 270          * @param $limit Integer: limit for SQL statement
 271          * @param $ignoreErrors Boolean: whether to ignore database errors
 272          */
 273         function recache( $limit, $ignoreErrors = true ) {
 274                 if ( !$this->isCacheable() ) {
 275                         return 0;
 276                 }
 277
 278                 $fname = get_class( $this ) . '::recache';
 279                 $dbw = wfGetDB( DB_MASTER );
 280                 $dbr = wfGetDB( DB_SLAVE, array( $this->getName(), __METHOD__, 'vslow' ) );
 281                 if ( !$dbw || !$dbr ) {
 282                         return false;
 283                 }
 284
 285                 if ( $ignoreErrors ) {
 286                         $ignoreW = $dbw->ignoreErrors( true );
 287                         $ignoreR = $dbr->ignoreErrors( true );
 288                 }
 289
 290                 # Clear out any old cached data
 291                 $dbw->delete( 'querycache', array( 'qc_type' => $this->getName() ), $fname );
 292                 # Do query
 293                 $res = $this->reallyDoQuery( $limit, false );
 294                 $num = false;
 295                 if ( $res ) {
 296                         $num = $dbr->numRows( $res );
 297                         # Fetch results
 298                         $vals = array();
 299                         while ( $res && $row = $dbr->fetchObject( $res ) ) {
 300                                 if ( isset( $row->value ) ) {
 301                                         if ( $this->usesTimestamps() ) {
 302                                                 $value = wfTimestamp( TS_UNIX,
 303                                                         $row->value );
 304                                         } else {
 305                                                 $value = intval( $row->value ); // @bug 14414
 306                                         }
 307                                 } else {
 308                                         $value = 0;
 309                                 }
 310
 311                                 $vals[] = array( 'qc_type' => $this->getName(),
 312                                                 'qc_namespace' => $row->namespace,
 313                                                 'qc_title' => $row->title,
 314                                                 'qc_value' => $value );
 315                         }
 316
 317                         # Save results into the querycache table on the master
 318                         if ( count( $vals ) ) {
 319                                 if ( !$dbw->insert( 'querycache', $vals, __METHOD__ ) ) {
 320                                         // Set result to false to indicate error
 321                                         $num = false;
 322                                 }
 323                         }
 324                         if ( $ignoreErrors ) {
 325                                 $dbw->ignoreErrors( $ignoreW );
 326                                 $dbr->ignoreErrors( $ignoreR );
 327                         }
 328
 329                         # Update the querycache_info record for the page
 330                         $dbw->delete( 'querycache_info', array( 'qci_type' => $this->getName() ), $fname );
 331                         $dbw->insert( 'querycache_info', array( 'qci_type' => $this->getName(), 'qci_timestamp' => $dbw->timestamp() ), $fname );
 332
 333                 }
 334                 return $num;
 335         }
 336
 337         /**
 338          * Run the query and return the result
 339          * @param $limit mixed Numerical limit or false for no limit
 340          * @param $offset mixed Numerical offset or false for no offset
 341          * @return ResultWrapper
 342          * @since 1.18
 343          */
 344         function reallyDoQuery( $limit, $offset = false ) {
 345                 $fname = get_class( $this ) . "::reallyDoQuery";
 346                 $dbr = wfGetDB( DB_SLAVE );
 347                 $query = $this->getQueryInfo();
 348                 $order = $this->getOrderFields();
 349                 if ( $this->sortDescending() ) {
 350                         foreach ( $order as &$field ) {
 351                                 $field .= ' DESC';
 352                         }
 353                 }
 354                 if ( is_array( $query ) ) {
 355                         $tables = isset( $query['tables'] ) ? (array)$query['tables'] : array();
 356                         $fields = isset( $query['fields'] ) ? (array)$query['fields'] : array();
 357                         $conds = isset( $query['conds'] ) ? (array)$query['conds'] : array();
 358                         $options = isset( $query['options'] ) ? (array)$query['options'] : array();
 359                         $join_conds = isset( $query['join_conds'] ) ? (array)$query['join_conds'] : array();
 360                         if ( count( $order ) ) {
 361                                 $options['ORDER BY'] = implode( ', ', $order );
 362                         }
 363                         if ( $limit !== false ) {
 364                                 $options['LIMIT'] = intval( $limit );
 365                         }
 366                         if ( $offset !== false ) {
 367                                 $options['OFFSET'] = intval( $offset );
 368                         }
 369
 370                         $res = $dbr->select( $tables, $fields, $conds, $fname,
 371                                         $options, $join_conds
 372                         );
 373                 } else {
 374                         // Old-fashioned raw SQL style, deprecated
 375                         $sql = $this->getSQL();
 376                         $sql .= ' ORDER BY ' . implode( ', ', $order );
 377                         $sql = $dbr->limitResult( $sql, $limit, $offset );
 378                         $res = $dbr->query( $sql, $fname );
 379                 }
 380                 return $dbr->resultObject( $res );
 381         }
 382
 383         /**
 384          * Somewhat deprecated, you probably want to be using execute()
 385          */
 386         function doQuery( $offset = false, $limit = false ) {
 387                 if ( $this->isCached() && $this->isCacheable() ) {
 388                         return $this->fetchFromCache( $limit, $offset );
 389                 } else {
 390                         return $this->reallyDoQuery( $limit, $offset );
 391                 }
 392         }
 393
 394         /**
 395          * Fetch the query results from the query cache
 396          * @param $limit mixed Numerical limit or false for no limit
 397          * @param $offset mixed Numerical offset or false for no offset
 398          * @return ResultWrapper
 399          * @since 1.18
 400          */
 401         function fetchFromCache( $limit, $offset = false ) {
 402                 $dbr = wfGetDB( DB_SLAVE );
 403                 $options = array ();
 404                 if ( $limit !== false ) {
 405                         $options['LIMIT'] = intval( $limit );
 406                 }
 407                 if ( $offset !== false ) {
 408                         $options['OFFSET'] = intval( $offset );
 409                 }
 410                 if ( $this->sortDescending() ) {
 411                         $options['ORDER BY'] = 'qc_value DESC';
 412                 } else {
 413                         $options['ORDER BY'] = 'qc_value ASC';
 414                 }
 415                 $res = $dbr->select( 'querycache', array( 'qc_type',
 416                                 'qc_namespace AS namespace',
 417                                 'qc_title AS title',
 418                                 'qc_value AS value' ),
 419                                 array( 'qc_type' => $this->getName() ),
 420                                 __METHOD__, $options
 421                 );
 422                 return $dbr->resultObject( $res );
 423         }
 424
 425         public function getCachedTimestamp() {
 426                 if ( is_null( $this->cachedTimestamp ) ) {
 427                         $dbr = wfGetDB( DB_SLAVE );
 428                         $fname = get_class( $this ) . '::getCachedTimestamp';
 429                         $this->cachedTimestamp = $dbr->selectField( 'querycache_info', 'qci_timestamp',
 430                                 array( 'qci_type' => $this->getName() ), $fname );
 431                 }
 432                 return $this->cachedTimestamp;
 433         }
 434
 435         /**
 436          * This is the actual workhorse. It does everything needed to make a
 437          * real, honest-to-gosh query page.
 438          */
 439         function execute( $par ) {
 440                 global $wgQueryCacheLimit;
 441                 if ( !$this->userCanExecute( $this->getUser() ) ) {
 442                         $this->displayRestrictionError();
 443                         return;
 444                 }
 445
 446                 if ( $this->limit == 0 && $this->offset == 0 ) {
 447                         list( $this->limit, $this->offset ) = $this->getRequest()->getLimitOffset();
 448                 }
 449                 $dbr = wfGetDB( DB_SLAVE );
 450
 451                 $this->setHeaders();
 452                 $this->outputHeader();
 453
 454                 $out = $this->getOutput();
 455                 $out->setSyndicated( $this->isSyndicated() );
 456
 457                 if ( $this->isCached() && !$this->isCacheable() ) {
 458                         $out->setSyndicated( false );
 459                         $out->addWikiMsg( 'querypage-disabled' );
 460                         return 0;
 461                 }
 462
 463                 // TODO: Use doQuery()
 464                 // $res = null;
 465                 if ( !$this->isCached() ) {
 466                         $res = $this->reallyDoQuery( $this->limit, $this->offset );
 467                 } else {
 468                         # Get the cached result
 469                         $res = $this->fetchFromCache( $this->limit, $this->offset );
 470                         if ( !$this->listoutput ) {
 471
 472                                 # Fetch the timestamp of this update
 473                                 $ts = $this->getCachedTimestamp();
 474                                 $lang = $this->getLanguage();
 475                                 $maxResults = $lang->formatNum( $wgQueryCacheLimit );
 476
 477                                 if ( $ts ) {
 478                                         $updated = $lang->timeanddate( $ts, true, true );
 479                                         $updateddate = $lang->date( $ts, true, true );
 480                                         $updatedtime = $lang->time( $ts, true, true );
 481                                         $out->addMeta( 'Data-Cache-Time', $ts );
 482                                         $out->addInlineScript( "var dataCacheTime = '$ts';" );
 483                                         $out->addWikiMsg( 'perfcachedts', $updated, $updateddate, $updatedtime, $maxResults );
 484                                 } else {
 485                                         $out->addWikiMsg( 'perfcached', $maxResults );
 486                                 }
 487
 488                                 # If updates on this page have been disabled, let the user know
 489                                 # that the data set won't be refreshed for now
 490                                 global $wgDisableQueryPageUpdate;
 491                                 if ( is_array( $wgDisableQueryPageUpdate ) && in_array( $this->getName(), $wgDisableQueryPageUpdate ) ) {
 492                                         $out->addWikiMsg( 'querypage-no-updates' );
 493                                 }
 494
 495                         }
 496
 497                 }
 498
 499                 $this->numRows = $dbr->numRows( $res );
 500
 501                 $this->preprocessResults( $dbr, $res );
 502
 503                 $out->addHTML( Xml::openElement( 'div', array( 'class' => 'mw-spcontent' ) ) );
 504
 505                 # Top header and navigation
 506                 if ( $this->shownavigation ) {
 507                         $out->addHTML( $this->getPageHeader() );
 508                         if ( $this->numRows > 0 ) {
 509                                 $out->addHTML( $this->msg( 'showingresults' )->numParams(
 510                                         $this->numRows, $this->offset + 1 )->parseAsBlock() );
 511                                 # Disable the "next" link when we reach the end
 512                                 $paging = $this->getLanguage()->viewPrevNext( $this->getTitle( $par ), $this->offset,
 513                                         $this->limit, $this->linkParameters(), ( $this->numRows < $this->limit ) );
 514                                 $out->addHTML( '<p>' . $paging . '</p>' );
 515                         } else {
 516                                 # No results to show, so don't bother with "showing X of Y" etc.
 517                                 # -- just let the user know and give up now
 518                                 $out->addWikiMsg( 'specialpage-empty' );
 519                                 $out->addHTML( Xml::closeElement( 'div' ) );
 520                                 return;
 521                         }
 522                 }
 523
 524                 # The actual results; specialist subclasses will want to handle this
 525                 # with more than a straight list, so we hand them the info, plus
 526                 # an OutputPage, and let them get on with it
 527                 $this->outputResults( $out,
 528                         $this->getSkin(),
 529                         $dbr, # Should use a ResultWrapper for this
 530                         $res,
 531                         $this->numRows,
 532                         $this->offset );
 533
 534                 # Repeat the paging links at the bottom
 535                 if ( $this->shownavigation ) {
 536                         $out->addHTML( '<p>' . $paging . '</p>' );
 537                 }
 538
 539                 $out->addHTML( Xml::closeElement( 'div' ) );
 540
 541                 return $this->numRows;
 542         }
 543
 544         /**
 545          * Format and output report results using the given information plus
 546          * OutputPage
 547          *
 548          * @param $out OutputPage to print to
 549          * @param $skin Skin: user skin to use
 550          * @param $dbr Database (read) connection to use
 551          * @param $res Integer: result pointer
 552          * @param $num Integer: number of available result rows
 553          * @param $offset Integer: paging offset
 554          */
 555         protected function outputResults( $out, $skin, $dbr, $res, $num, $offset ) {
 556                 global $wgContLang;
 557
 558                 if ( $num > 0 ) {
 559                         $html = array();
 560                         if ( !$this->listoutput ) {
 561                                 $html[] = $this->openList( $offset );
 562                         }
 563
 564                         # $res might contain the whole 1,000 rows, so we read up to
 565                         # $num [should update this to use a Pager]
 566                         for ( $i = 0; $i < $num && $row = $dbr->fetchObject( $res ); $i++ ) {
 567                                 $line = $this->formatResult( $skin, $row );
 568                                 if ( $line ) {
 569                                         $attr = ( isset( $row->usepatrol ) && $row->usepatrol && $row->patrolled == 0 )
 570                                                 ? ' class="not-patrolled"'
 571                                                 : '';
 572                                         $html[] = $this->listoutput
 573                                                 ? $line
 574                                                 : "<li{$attr}>{$line}</li>\n";
 575                                 }
 576                         }
 577
 578                         # Flush the final result
 579                         if ( $this->tryLastResult() ) {
 580                                 $row = null;
 581                                 $line = $this->formatResult( $skin, $row );
 582                                 if ( $line ) {
 583                                         $attr = ( isset( $row->usepatrol ) && $row->usepatrol && $row->patrolled == 0 )
 584                                                 ? ' class="not-patrolled"'
 585                                                 : '';
 586                                         $html[] = $this->listoutput
 587                                                 ? $line
 588                                                 : "<li{$attr}>{$line}</li>\n";
 589                                 }
 590                         }
 591
 592                         if ( !$this->listoutput ) {
 593                                 $html[] = $this->closeList();
 594                         }
 595
 596                         $html = $this->listoutput
 597                                 ? $wgContLang->listToText( $html )
 598                                 : implode( '', $html );
 599
 600                         $out->addHTML( $html );
 601                 }
 602         }
 603
 604         /**
 605          * @param $offset
 606          * @return string
 607          */
 608         function openList( $offset ) {
 609                 return "\n<ol start='" . ( $offset + 1 ) . "' class='special'>\n";
 610         }
 611
 612         /**
 613          * @return string
 614          */
 615         function closeList() {
 616                 return "</ol>\n";
 617         }
 618
 619         /**
 620          * Do any necessary preprocessing of the result object.
 621          */
 622         function preprocessResults( $db, $res ) {}
 623
 624         /**
 625          * Similar to above, but packaging in a syndicated feed instead of a web page
 626          */
 627         function doFeed( $class = '', $limit = 50 ) {
 628                 global $wgFeed, $wgFeedClasses;
 629
 630                 if ( !$wgFeed ) {
 631                         $this->getOutput()->addWikiMsg( 'feed-unavailable' );
 632                         return;
 633                 }
 634
 635                 global $wgFeedLimit;
 636                 if ( $limit > $wgFeedLimit ) {
 637                         $limit = $wgFeedLimit;
 638                 }
 639
 640                 if ( isset( $wgFeedClasses[$class] ) ) {
 641                         $feed = new $wgFeedClasses[$class](
 642                                 $this->feedTitle(),
 643                                 $this->feedDesc(),
 644                                 $this->feedUrl() );
 645                         $feed->outHeader();
 646
 647                         $res = $this->reallyDoQuery( $limit, 0 );
 648                         foreach ( $res as $obj ) {
 649                                 $item = $this->feedResult( $obj );
 650                                 if ( $item ) {
 651                                         $feed->outItem( $item );
 652                                 }
 653                         }
 654
 655                         $feed->outFooter();
 656                         return true;
 657                 } else {
 658                         return false;
 659                 }
 660         }
 661
 662         /**
 663          * Override for custom handling. If the titles/links are ok, just do
 664          * feedItemDesc()
 665          */
 666         function feedResult( $row ) {
 667                 if ( !isset( $row->title ) ) {
 668                         return null;
 669                 }
 670                 $title = Title::MakeTitle( intval( $row->namespace ), $row->title );
 671                 if ( $title ) {
 672                         $date = isset( $row->timestamp ) ? $row->timestamp : '';
 673                         $comments = '';
 674                         if ( $title ) {
 675                                 $talkpage = $title->getTalkPage();
 676                                 $comments = $talkpage->getFullURL();
 677                         }
 678
 679                         return new FeedItem(
 680                                 $title->getPrefixedText(),
 681                                 $this->feedItemDesc( $row ),
 682                                 $title->getFullURL(),
 683                                 $date,
 684                                 $this->feedItemAuthor( $row ),
 685                                 $comments );
 686                 } else {
 687                         return null;
 688                 }
 689         }
 690
 691         function feedItemDesc( $row ) {
 692                 return isset( $row->comment ) ? htmlspecialchars( $row->comment ) : '';
 693         }
 694
 695         function feedItemAuthor( $row ) {
 696                 return isset( $row->user_text ) ? $row->user_text : '';
 697         }
 698
 699         function feedTitle() {
 700                 global $wgLanguageCode, $wgSitename;
 701                 $desc = $this->getDescription();
 702                 return "$wgSitename - $desc [$wgLanguageCode]";
 703         }
 704
 705         function feedDesc() {
 706                 return $this->msg( 'tagline' )->text();
 707         }
 708
 709         function feedUrl() {
 710                 return $this->getTitle()->getFullURL();
 711         }
 712 }
 713
 714 /**
 715  * Class definition for a wanted query page like
 716  * WantedPages, WantedTemplates, etc
 717  */
 718 abstract class WantedQueryPage extends QueryPage {
 719
 720         function isExpensive() {
 721                 return true;
 722         }
 723
 724         function isSyndicated() {
 725                 return false;
 726         }
 727
 728         /**
 729          * Cache page existence for performance
 730          */
 731         function preprocessResults( $db, $res ) {
 732                 $batch = new LinkBatch;
 733                 foreach ( $res as $row ) {
 734                         $batch->add( $row->namespace, $row->title );
 735                 }
 736                 $batch->execute();
 737
 738                 // Back to start for display
 739                 if ( $db->numRows( $res ) > 0 )
 740                         // If there are no rows we get an error seeking.
 741                         $db->dataSeek( $res, 0 );
 742         }
 743
 744         /**
 745          * Should formatResult() always check page existence, even if
 746          * the results are fresh?  This is a (hopefully temporary)
 747          * kluge for Special:WantedFiles, which may contain false
 748          * positives for files that exist e.g. in a shared repo (bug
 749          * 6220).
 750          */
 751         function forceExistenceCheck() {
 752                 return false;
 753         }
 754
 755         /**
 756          * Format an individual result
 757          *
 758          * @param $skin Skin to use for UI elements
 759          * @param $result Result row
 760          * @return string
 761          */
 762         public function formatResult( $skin, $result ) {
 763                 $title = Title::makeTitleSafe( $result->namespace, $result->title );
 764                 if ( $title instanceof Title ) {
 765                         if ( $this->isCached() || $this->forceExistenceCheck() ) {
 766                                 $pageLink = $title->isKnown()
 767                                         ? '<del>' . Linker::link( $title ) . '</del>'
 768                                         : Linker::link(
 769                                                 $title,
 770                                                 null,
 771                                                 array(),
 772                                                 array(),
 773                                                 array( 'broken' )
 774                                         );
 775                         } else {
 776                                 $pageLink = Linker::link(
 777                                         $title,
 778                                         null,
 779                                         array(),
 780                                         array(),
 781                                         array( 'broken' )
 782                                 );
 783                         }
 784                         return $this->getLanguage()->specialList( $pageLink, $this->makeWlhLink( $title, $result ) );
 785                 } else {
 786                         return $this->msg( 'wantedpages-badtitle', $result->title )->escaped();
 787                 }
 788         }
 789
 790         /**
 791          * Make a "what links here" link for a given title
 792          *
 793          * @param $title Title to make the link for
 794          * @param $result Object: result row
 795          * @return string
 796          */
 797         private function makeWlhLink( $title, $result ) {
 798                 $wlh = SpecialPage::getTitleFor( 'Whatlinkshere', $title->getPrefixedText() );
 799                 $label = $this->msg( 'nlinks' )->numParams( $result->value )->escaped();
 800                 return Linker::link( $wlh, $label );
 801         }
 802 }