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