includes/QueryPage.php

   1 <?php
   2 /**
   3  * Contain a class for special pages
   4  * @file
   5  * @ingroup SpecialPage
   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          * @return bool
 263          */
 264         function tryLastResult() {
 265                 return false;
 266         }
 267
 268         /**
 269          * Clear the cache and save new results
 270          *
 271          * @param $limit Integer: limit for SQL statement
 272          * @param $ignoreErrors Boolean: whether to ignore database errors
 273          * @return bool|int
 274          */
 275         function recache( $limit, $ignoreErrors = true ) {
 276                 if ( !$this->isCacheable() ) {
 277                         return 0;
 278                 }
 279
 280                 $fname = get_class( $this ) . '::recache';
 281                 $dbw = wfGetDB( DB_MASTER );
 282                 $dbr = wfGetDB( DB_SLAVE, array( $this->getName(), __METHOD__, 'vslow' ) );
 283                 if ( !$dbw || !$dbr ) {
 284                         return false;
 285                 }
 286
 287                 if ( $ignoreErrors ) {
 288                         $ignoreW = $dbw->ignoreErrors( true );
 289                         $ignoreR = $dbr->ignoreErrors( true );
 290                 }
 291
 292                 # Clear out any old cached data
 293                 $dbw->delete( 'querycache', array( 'qc_type' => $this->getName() ), $fname );
 294                 # Do query
 295                 $res = $this->reallyDoQuery( $limit, false );
 296                 $num = false;
 297                 if ( $res ) {
 298                         $num = $res->numRows();
 299                         # Fetch results
 300                         $vals = array();
 301                         while ( $res && $row = $dbr->fetchObject( $res ) ) {
 302                                 if ( isset( $row->value ) ) {
 303                                         if ( $this->usesTimestamps() ) {
 304                                                 $value = wfTimestamp( TS_UNIX,
 305                                                         $row->value );
 306                                         } else {
 307                                                 $value = intval( $row->value ); // @bug 14414
 308                                         }
 309                                 } else {
 310                                         $value = 0;
 311                                 }
 312
 313                                 $vals[] = array( 'qc_type' => $this->getName(),
 314                                                 'qc_namespace' => $row->namespace,
 315                                                 'qc_title' => $row->title,
 316                                                 'qc_value' => $value );
 317                         }
 318
 319                         # Save results into the querycache table on the master
 320                         if ( count( $vals ) ) {
 321                                 if ( !$dbw->insert( 'querycache', $vals, __METHOD__ ) ) {
 322                                         // Set result to false to indicate error
 323                                         $num = false;
 324                                 }
 325                         }
 326                         if ( $ignoreErrors ) {
 327                                 $dbw->ignoreErrors( $ignoreW );
 328                                 $dbr->ignoreErrors( $ignoreR );
 329                         }
 330
 331                         # Update the querycache_info record for the page
 332                         $dbw->delete( 'querycache_info', array( 'qci_type' => $this->getName() ), $fname );
 333                         $dbw->insert( 'querycache_info', array( 'qci_type' => $this->getName(), 'qci_timestamp' => $dbw->timestamp() ), $fname );
 334
 335                 }
 336                 return $num;
 337         }
 338
 339         /**
 340          * Run the query and return the result
 341          * @param $limit mixed Numerical limit or false for no limit
 342          * @param $offset mixed Numerical offset or false for no offset
 343          * @return ResultWrapper
 344          * @since 1.18
 345          */
 346         function reallyDoQuery( $limit, $offset = false ) {
 347                 $fname = get_class( $this ) . "::reallyDoQuery";
 348                 $dbr = wfGetDB( DB_SLAVE );
 349                 $query = $this->getQueryInfo();
 350                 $order = $this->getOrderFields();
 351                 if ( $this->sortDescending() ) {
 352                         foreach ( $order as &$field ) {
 353                                 $field .= ' DESC';
 354                         }
 355                 }
 356                 if ( is_array( $query ) ) {
 357                         $tables = isset( $query['tables'] ) ? (array)$query['tables'] : array();
 358                         $fields = isset( $query['fields'] ) ? (array)$query['fields'] : array();
 359                         $conds = isset( $query['conds'] ) ? (array)$query['conds'] : array();
 360                         $options = isset( $query['options'] ) ? (array)$query['options'] : array();
 361                         $join_conds = isset( $query['join_conds'] ) ? (array)$query['join_conds'] : array();
 362                         if ( count( $order ) ) {
 363                                 $options['ORDER BY'] = implode( ', ', $order );
 364                         }
 365                         if ( $limit !== false ) {
 366                                 $options['LIMIT'] = intval( $limit );
 367                         }
 368                         if ( $offset !== false ) {
 369                                 $options['OFFSET'] = intval( $offset );
 370                         }
 371
 372                         $res = $dbr->select( $tables, $fields, $conds, $fname,
 373                                         $options, $join_conds
 374                         );
 375                 } else {
 376                         // Old-fashioned raw SQL style, deprecated
 377                         $sql = $this->getSQL();
 378                         $sql .= ' ORDER BY ' . implode( ', ', $order );
 379                         $sql = $dbr->limitResult( $sql, $limit, $offset );
 380                         $res = $dbr->query( $sql, $fname );
 381                 }
 382                 return $dbr->resultObject( $res );
 383         }
 384
 385         /**
 386          * Somewhat deprecated, you probably want to be using execute()
 387          * @return ResultWrapper
 388          */
 389         function doQuery( $offset = false, $limit = false ) {
 390                 if ( $this->isCached() && $this->isCacheable() ) {
 391                         return $this->fetchFromCache( $limit, $offset );
 392                 } else {
 393                         return $this->reallyDoQuery( $limit, $offset );
 394                 }
 395         }
 396
 397         /**
 398          * Fetch the query results from the query cache
 399          * @param $limit mixed Numerical limit or false for no limit
 400          * @param $offset mixed Numerical offset or false for no offset
 401          * @return ResultWrapper
 402          * @since 1.18
 403          */
 404         function fetchFromCache( $limit, $offset = false ) {
 405                 $dbr = wfGetDB( DB_SLAVE );
 406                 $options = array ();
 407                 if ( $limit !== false ) {
 408                         $options['LIMIT'] = intval( $limit );
 409                 }
 410                 if ( $offset !== false ) {
 411                         $options['OFFSET'] = intval( $offset );
 412                 }
 413                 if ( $this->sortDescending() ) {
 414                         $options['ORDER BY'] = 'qc_value DESC';
 415                 } else {
 416                         $options['ORDER BY'] = 'qc_value ASC';
 417                 }
 418                 $res = $dbr->select( 'querycache', array( 'qc_type',
 419                                 'qc_namespace AS namespace',
 420                                 'qc_title AS title',
 421                                 'qc_value AS value' ),
 422                                 array( 'qc_type' => $this->getName() ),
 423                                 __METHOD__, $options
 424                 );
 425                 return $dbr->resultObject( $res );
 426         }
 427
 428         public function getCachedTimestamp() {
 429                 if ( is_null( $this->cachedTimestamp ) ) {
 430                         $dbr = wfGetDB( DB_SLAVE );
 431                         $fname = get_class( $this ) . '::getCachedTimestamp';
 432                         $this->cachedTimestamp = $dbr->selectField( 'querycache_info', 'qci_timestamp',
 433                                 array( 'qci_type' => $this->getName() ), $fname );
 434                 }
 435                 return $this->cachedTimestamp;
 436         }
 437
 438         /**
 439          * This is the actual workhorse. It does everything needed to make a
 440          * real, honest-to-gosh query page.
 441          * @return int
 442          */
 443         function execute( $par ) {
 444                 global $wgQueryCacheLimit, $wgDisableQueryPageUpdate;
 445
 446                 $user = $this->getUser();
 447                 if ( !$this->userCanExecute( $user ) ) {
 448                         $this->displayRestrictionError();
 449                         return;
 450                 }
 451
 452                 $this->setHeaders();
 453                 $this->outputHeader();
 454
 455                 $out = $this->getOutput();
 456
 457                 if ( $this->isCached() && !$this->isCacheable() ) {
 458                         $out->addWikiMsg( 'querypage-disabled' );
 459                         return 0;
 460                 }
 461
 462                 $out->setSyndicated( $this->isSyndicated() );
 463
 464                 if ( $this->limit == 0 && $this->offset == 0 ) {
 465                         list( $this->limit, $this->offset ) = $this->getRequest()->getLimitOffset();
 466                 }
 467
 468                 // TODO: Use doQuery()
 469                 if ( !$this->isCached() ) {
 470                         $res = $this->reallyDoQuery( $this->limit, $this->offset );
 471                 } else {
 472                         # Get the cached result
 473                         $res = $this->fetchFromCache( $this->limit, $this->offset );
 474                         if ( !$this->listoutput ) {
 475
 476                                 # Fetch the timestamp of this update
 477                                 $ts = $this->getCachedTimestamp();
 478                                 $lang = $this->getLanguage();
 479                                 $maxResults = $lang->formatNum( $wgQueryCacheLimit );
 480
 481                                 if ( $ts ) {
 482                                         $updated = $lang->userTimeAndDate( $ts, $user );
 483                                         $updateddate = $lang->userDate( $ts, $user );
 484                                         $updatedtime = $lang->userTime( $ts, $user );
 485                                         $out->addMeta( 'Data-Cache-Time', $ts );
 486                                         $out->addInlineScript( "var dataCacheTime = '$ts';" );
 487                                         $out->addWikiMsg( 'perfcachedts', $updated, $updateddate, $updatedtime, $maxResults );
 488                                 } else {
 489                                         $out->addWikiMsg( 'perfcached', $maxResults );
 490                                 }
 491
 492                                 # If updates on this page have been disabled, let the user know
 493                                 # that the data set won't be refreshed for now
 494                                 if ( is_array( $wgDisableQueryPageUpdate ) && in_array( $this->getName(), $wgDisableQueryPageUpdate ) ) {
 495                                         $out->addWikiMsg( 'querypage-no-updates' );
 496                                 }
 497                         }
 498                 }
 499
 500                 $this->numRows = $res->numRows();
 501
 502                 $dbr = wfGetDB( DB_SLAVE );
 503                 $this->preprocessResults( $dbr, $res );
 504
 505                 $out->addHTML( Xml::openElement( 'div', array( 'class' => 'mw-spcontent' ) ) );
 506
 507                 # Top header and navigation
 508                 if ( $this->shownavigation ) {
 509                         $out->addHTML( $this->getPageHeader() );
 510                         if ( $this->numRows > 0 ) {
 511                                 $out->addHTML( $this->msg( 'showingresults' )->numParams(
 512                                         $this->numRows, $this->offset + 1 )->parseAsBlock() );
 513                                 # Disable the "next" link when we reach the end
 514                                 $paging = $this->getLanguage()->viewPrevNext( $this->getTitle( $par ), $this->offset,
 515                                         $this->limit, $this->linkParameters(), ( $this->numRows < $this->limit ) );
 516                                 $out->addHTML( '<p>' . $paging . '</p>' );
 517                         } else {
 518                                 # No results to show, so don't bother with "showing X of Y" etc.
 519                                 # -- just let the user know and give up now
 520                                 $out->addWikiMsg( 'specialpage-empty' );
 521                                 $out->addHTML( Xml::closeElement( 'div' ) );
 522                                 return;
 523                         }
 524                 }
 525
 526                 # The actual results; specialist subclasses will want to handle this
 527                 # with more than a straight list, so we hand them the info, plus
 528                 # an OutputPage, and let them get on with it
 529                 $this->outputResults( $out,
 530                         $this->getSkin(),
 531                         $dbr, # Should use a ResultWrapper for this
 532                         $res,
 533                         $this->numRows,
 534                         $this->offset );
 535
 536                 # Repeat the paging links at the bottom
 537                 if ( $this->shownavigation ) {
 538                         $out->addHTML( '<p>' . $paging . '</p>' );
 539                 }
 540
 541                 $out->addHTML( Xml::closeElement( 'div' ) );
 542
 543                 return $this->numRows;
 544         }
 545
 546         /**
 547          * Format and output report results using the given information plus
 548          * OutputPage
 549          *
 550          * @param $out OutputPage to print to
 551          * @param $skin Skin: user skin to use
 552          * @param $dbr Database (read) connection to use
 553          * @param $res Integer: result pointer
 554          * @param $num Integer: number of available result rows
 555          * @param $offset Integer: paging offset
 556          */
 557         protected function outputResults( $out, $skin, $dbr, $res, $num, $offset ) {
 558                 global $wgContLang;
 559
 560                 if ( $num > 0 ) {
 561                         $html = array();
 562                         if ( !$this->listoutput ) {
 563                                 $html[] = $this->openList( $offset );
 564                         }
 565
 566                         # $res might contain the whole 1,000 rows, so we read up to
 567                         # $num [should update this to use a Pager]
 568                         for ( $i = 0; $i < $num && $row = $dbr->fetchObject( $res ); $i++ ) {
 569                                 $line = $this->formatResult( $skin, $row );
 570                                 if ( $line ) {
 571                                         $attr = ( isset( $row->usepatrol ) && $row->usepatrol && $row->patrolled == 0 )
 572                                                 ? ' class="not-patrolled"'
 573                                                 : '';
 574                                         $html[] = $this->listoutput
 575                                                 ? $line
 576                                                 : "<li{$attr}>{$line}</li>\n";
 577                                 }
 578                         }
 579
 580                         # Flush the final result
 581                         if ( $this->tryLastResult() ) {
 582                                 $row = null;
 583                                 $line = $this->formatResult( $skin, $row );
 584                                 if ( $line ) {
 585                                         $attr = ( isset( $row->usepatrol ) && $row->usepatrol && $row->patrolled == 0 )
 586                                                 ? ' class="not-patrolled"'
 587                                                 : '';
 588                                         $html[] = $this->listoutput
 589                                                 ? $line
 590                                                 : "<li{$attr}>{$line}</li>\n";
 591                                 }
 592                         }
 593
 594                         if ( !$this->listoutput ) {
 595                                 $html[] = $this->closeList();
 596                         }
 597
 598                         $html = $this->listoutput
 599                                 ? $wgContLang->listToText( $html )
 600                                 : implode( '', $html );
 601
 602                         $out->addHTML( $html );
 603                 }
 604         }
 605
 606         /**
 607          * @param $offset
 608          * @return string
 609          */
 610         function openList( $offset ) {
 611                 return "\n<ol start='" . ( $offset + 1 ) . "' class='special'>\n";
 612         }
 613
 614         /**
 615          * @return string
 616          */
 617         function closeList() {
 618                 return "</ol>\n";
 619         }
 620
 621         /**
 622          * Do any necessary preprocessing of the result object.
 623          */
 624         function preprocessResults( $db, $res ) {}
 625
 626         /**
 627          * Similar to above, but packaging in a syndicated feed instead of a web page
 628          * @return bool
 629          */
 630         function doFeed( $class = '', $limit = 50 ) {
 631                 global $wgFeed, $wgFeedClasses;
 632
 633                 if ( !$wgFeed ) {
 634                         $this->getOutput()->addWikiMsg( 'feed-unavailable' );
 635                         return;
 636                 }
 637
 638                 global $wgFeedLimit;
 639                 if ( $limit > $wgFeedLimit ) {
 640                         $limit = $wgFeedLimit;
 641                 }
 642
 643                 if ( isset( $wgFeedClasses[$class] ) ) {
 644                         $feed = new $wgFeedClasses[$class](
 645                                 $this->feedTitle(),
 646                                 $this->feedDesc(),
 647                                 $this->feedUrl() );
 648                         $feed->outHeader();
 649
 650                         $res = $this->reallyDoQuery( $limit, 0 );
 651                         foreach ( $res as $obj ) {
 652                                 $item = $this->feedResult( $obj );
 653                                 if ( $item ) {
 654                                         $feed->outItem( $item );
 655                                 }
 656                         }
 657
 658                         $feed->outFooter();
 659                         return true;
 660                 } else {
 661                         return false;
 662                 }
 663         }
 664
 665         /**
 666          * Override for custom handling. If the titles/links are ok, just do
 667          * feedItemDesc()
 668          * @return FeedItem|null
 669          */
 670         function feedResult( $row ) {
 671                 if ( !isset( $row->title ) ) {
 672                         return null;
 673                 }
 674                 $title = Title::makeTitle( intval( $row->namespace ), $row->title );
 675                 if ( $title ) {
 676                         $date = isset( $row->timestamp ) ? $row->timestamp : '';
 677                         $comments = '';
 678                         if ( $title ) {
 679                                 $talkpage = $title->getTalkPage();
 680                                 $comments = $talkpage->getFullURL();
 681                         }
 682
 683                         return new FeedItem(
 684                                 $title->getPrefixedText(),
 685                                 $this->feedItemDesc( $row ),
 686                                 $title->getFullURL(),
 687                                 $date,
 688                                 $this->feedItemAuthor( $row ),
 689                                 $comments );
 690                 } else {
 691                         return null;
 692                 }
 693         }
 694
 695         function feedItemDesc( $row ) {
 696                 return isset( $row->comment ) ? htmlspecialchars( $row->comment ) : '';
 697         }
 698
 699         function feedItemAuthor( $row ) {
 700                 return isset( $row->user_text ) ? $row->user_text : '';
 701         }
 702
 703         function feedTitle() {
 704                 global $wgLanguageCode, $wgSitename;
 705                 $desc = $this->getDescription();
 706                 return "$wgSitename - $desc [$wgLanguageCode]";
 707         }
 708
 709         function feedDesc() {
 710                 return $this->msg( 'tagline' )->text();
 711         }
 712
 713         function feedUrl() {
 714                 return $this->getTitle()->getFullURL();
 715         }
 716 }
 717
 718 /**
 719  * Class definition for a wanted query page like
 720  * WantedPages, WantedTemplates, etc
 721  */
 722 abstract class WantedQueryPage extends QueryPage {
 723
 724         function isExpensive() {
 725                 return true;
 726         }
 727
 728         function isSyndicated() {
 729                 return false;
 730         }
 731
 732         /**
 733          * Cache page existence for performance
 734          */
 735         function preprocessResults( $db, $res ) {
 736                 if ( !$res->numRows() ) {
 737                         return;
 738                 }
 739
 740                 $batch = new LinkBatch;
 741                 foreach ( $res as $row ) {
 742                         $batch->add( $row->namespace, $row->title );
 743                 }
 744                 $batch->execute();
 745
 746                 // Back to start for display
 747                 $res->seek( 0 );
 748         }
 749
 750         /**
 751          * Should formatResult() always check page existence, even if
 752          * the results are fresh?  This is a (hopefully temporary)
 753          * kluge for Special:WantedFiles, which may contain false
 754          * positives for files that exist e.g. in a shared repo (bug
 755          * 6220).
 756          * @return bool
 757          */
 758         function forceExistenceCheck() {
 759                 return false;
 760         }
 761
 762         /**
 763          * Format an individual result
 764          *
 765          * @param $skin Skin to use for UI elements
 766          * @param $result Result row
 767          * @return string
 768          */
 769         public function formatResult( $skin, $result ) {
 770                 $title = Title::makeTitleSafe( $result->namespace, $result->title );
 771                 if ( $title instanceof Title ) {
 772                         if ( $this->isCached() || $this->forceExistenceCheck() ) {
 773                                 $pageLink = $title->isKnown()
 774                                         ? '<del>' . Linker::link( $title ) . '</del>'
 775                                         : Linker::link(
 776                                                 $title,
 777                                                 null,
 778                                                 array(),
 779                                                 array(),
 780                                                 array( 'broken' )
 781                                         );
 782                         } else {
 783                                 $pageLink = Linker::link(
 784                                         $title,
 785                                         null,
 786                                         array(),
 787                                         array(),
 788                                         array( 'broken' )
 789                                 );
 790                         }
 791                         return $this->getLanguage()->specialList( $pageLink, $this->makeWlhLink( $title, $result ) );
 792                 } else {
 793                         return $this->msg( 'wantedpages-badtitle', $result->title )->escaped();
 794                 }
 795         }
 796
 797         /**
 798          * Make a "what links here" link for a given title
 799          *
 800          * @param $title Title to make the link for
 801          * @param $result Object: result row
 802          * @return string
 803          */
 804         private function makeWlhLink( $title, $result ) {
 805                 $wlh = SpecialPage::getTitleFor( 'Whatlinkshere', $title->getPrefixedText() );
 806                 $label = $this->msg( 'nlinks' )->numParams( $result->value )->escaped();
 807                 return Linker::link( $wlh, $label );
 808         }
 809 }