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         protected $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          * @since 1.18
 163          */
 164         function usesTimestamps() {
 165                 return false;
 166         }
 167
 168         /**
 169          * Override to sort by increasing values
 170          *
 171          * @return Boolean
 172          */
 173         function sortDescending() {
 174                 return true;
 175         }
 176
 177         /**
 178          * Is this query expensive (for some definition of expensive)? Then we
 179          * don't let it run in miser mode. $wgDisableQueryPages causes all query
 180          * pages to be declared expensive. Some query pages are always expensive.
 181          *
 182          * @return Boolean
 183          */
 184         function isExpensive() {
 185                 global $wgDisableQueryPages;
 186                 return $wgDisableQueryPages;
 187         }
 188
 189         /**
 190          * Is the output of this query cacheable? Non-cacheable expensive pages
 191          * will be disabled in miser mode and will not have their results written
 192          * to the querycache table.
 193          * @return Boolean
 194          * @since 1.18
 195          */
 196         public function isCacheable() {
 197                 return true;
 198         }
 199
 200         /**
 201          * Whether or not the output of the page in question is retrieved from
 202          * the database cache.
 203          *
 204          * @return Boolean
 205          */
 206         function isCached() {
 207                 global $wgMiserMode;
 208
 209                 return $this->isExpensive() && $wgMiserMode;
 210         }
 211
 212         /**
 213          * Sometime we dont want to build rss / atom feeds.
 214          *
 215          * @return Boolean
 216          */
 217         function isSyndicated() {
 218                 return true;
 219         }
 220
 221         /**
 222          * Formats the results of the query for display. The skin is the current
 223          * skin; you can use it for making links. The result is a single row of
 224          * result data. You should be able to grab SQL results off of it.
 225          * If the function returns false, the line output will be skipped.
 226          * @param $skin Skin
 227          * @param $result object Result row
 228          * @return mixed String or false to skip
 229          *
 230          * @param $skin Skin object
 231          * @param $result Object: database row
 232          */
 233         abstract function formatResult( $skin, $result );
 234
 235         /**
 236          * The content returned by this function will be output before any result
 237          *
 238          * @return String
 239          */
 240         function getPageHeader() {
 241                 return '';
 242         }
 243
 244         /**
 245          * If using extra form wheely-dealies, return a set of parameters here
 246          * as an associative array. They will be encoded and added to the paging
 247          * links (prev/next/lengths).
 248          *
 249          * @return Array
 250          */
 251         function linkParameters() {
 252                 return array();
 253         }
 254
 255         /**
 256          * Some special pages (for example SpecialListusers) might not return the
 257          * current object formatted, but return the previous one instead.
 258          * Setting this to return true will ensure formatResult() is called
 259          * one more time to make sure that the very last result is formatted
 260          * as well.
 261          */
 262         function tryLastResult() {
 263                 return false;
 264         }
 265
 266         /**
 267          * Clear the cache and save new results
 268          *
 269          * @param $limit Integer: limit for SQL statement
 270          * @param $ignoreErrors Boolean: whether to ignore database errors
 271          */
 272         function recache( $limit, $ignoreErrors = true ) {
 273                 if ( !$this->isCacheable() ) {
 274                         return 0;
 275                 }
 276
 277                 $fname = get_class( $this ) . '::recache';
 278                 $dbw = wfGetDB( DB_MASTER );
 279                 $dbr = wfGetDB( DB_SLAVE, array( $this->getName(), __METHOD__, 'vslow' ) );
 280                 if ( !$dbw || !$dbr ) {
 281                         return false;
 282                 }
 283
 284                 if ( $ignoreErrors ) {
 285                         $ignoreW = $dbw->ignoreErrors( true );
 286                         $ignoreR = $dbr->ignoreErrors( true );
 287                 }
 288
 289                 # Clear out any old cached data
 290                 $dbw->delete( 'querycache', array( 'qc_type' => $this->getName() ), $fname );
 291                 # Do query
 292                 $res = $this->reallyDoQuery( $limit, false );
 293                 $num = false;
 294                 if ( $res ) {
 295                         $num = $dbr->numRows( $res );
 296                         # Fetch results
 297                         $vals = array();
 298                         while ( $res && $row = $dbr->fetchObject( $res ) ) {
 299                                 if ( isset( $row->value ) ) {
 300                                         if ( $this->usesTimestamps() ) {
 301                                                 $value = wfTimestamp( TS_UNIX,
 302                                                         $row->value );
 303                                         } else {
 304                                                 $value = intval( $row->value ); // @bug 14414
 305                                         }
 306                                 } else {
 307                                         $value = 0;
 308                                 }
 309
 310                                 $vals[] = array( 'qc_type' => $this->getName(),
 311                                                 'qc_namespace' => $row->namespace,
 312                                                 'qc_title' => $row->title,
 313                                                 'qc_value' => $value );
 314                         }
 315
 316                         # Save results into the querycache table on the master
 317                         if ( count( $vals ) ) {
 318                                 if ( !$dbw->insert( 'querycache', $vals, __METHOD__ ) ) {
 319                                         // Set result to false to indicate error
 320                                         $num = false;
 321                                 }
 322                         }
 323                         if ( $ignoreErrors ) {
 324                                 $dbw->ignoreErrors( $ignoreW );
 325                                 $dbr->ignoreErrors( $ignoreR );
 326                         }
 327
 328                         # Update the querycache_info record for the page
 329                         $dbw->delete( 'querycache_info', array( 'qci_type' => $this->getName() ), $fname );
 330                         $dbw->insert( 'querycache_info', array( 'qci_type' => $this->getName(), 'qci_timestamp' => $dbw->timestamp() ), $fname );
 331
 332                 }
 333                 return $num;
 334         }
 335
 336         /**
 337          * Run the query and return the result
 338          * @param $limit mixed Numerical limit or false for no limit
 339          * @param $offset mixed Numerical offset or false for no offset
 340          * @return ResultWrapper
 341          * @since 1.18
 342          */
 343         function reallyDoQuery( $limit, $offset = false ) {
 344                 $fname = get_class( $this ) . "::reallyDoQuery";
 345                 $query = $this->getQueryInfo();
 346                 $order = $this->getOrderFields();
 347                 if ( $this->sortDescending() ) {
 348                         foreach ( $order as &$field ) {
 349                                 $field .= ' DESC';
 350                         }
 351                 }
 352                 if ( is_array( $query ) ) {
 353                         $tables = isset( $query['tables'] ) ? (array)$query['tables'] : array();
 354                         $fields = isset( $query['fields'] ) ? (array)$query['fields'] : array();
 355                         $conds = isset( $query['conds'] ) ? (array)$query['conds'] : array();
 356                         $options = isset( $query['options'] ) ? (array)$query['options'] : array();
 357                         $join_conds = isset( $query['join_conds'] ) ? (array)$query['join_conds'] : array();
 358                         if ( count( $order ) ) {
 359                                 $options['ORDER BY'] = implode( ', ', $order );
 360                         }
 361                         if ( $limit !== false ) {
 362                                 $options['LIMIT'] = intval( $limit );
 363                         }
 364                         if ( $offset !== false ) {
 365                                 $options['OFFSET'] = intval( $offset );
 366                         }
 367
 368                         $dbr = wfGetDB( DB_SLAVE );
 369                         $res = $dbr->select( $tables, $fields, $conds, $fname,
 370                                         $options, $join_conds
 371                         );
 372                 } else {
 373                         // Old-fashioned raw SQL style, deprecated
 374                         $sql = $this->getSQL();
 375                         $sql .= ' ORDER BY ' . implode( ', ', $order );
 376                         $sql = $dbr->limitResult( $sql, $limit, $offset );
 377                         $res = $dbr->query( $sql );
 378                 }
 379                 return $dbr->resultObject( $res );
 380         }
 381
 382         /**
 383          * Parameters and order changed in 1.18
 384          */
 385         function doQuery( $limit, $offset = false ) {
 386                 if ( $this->isCached() && $this->isCacheable() ) {
 387                         return $this->fetchFromCache( $limit, $offset );
 388                 } else {
 389                         return $this->reallyDoQuery( $limit, $offset );
 390                 }
 391         }
 392
 393         /**
 394          * Fetch the query results from the query cache
 395          * @param $limit mixed Numerical limit or false for no limit
 396          * @param $offset mixed Numerical offset or false for no offset
 397          * @return ResultWrapper
 398          * @since 1.18
 399          */
 400         function fetchFromCache( $limit, $offset = false ) {
 401                 $dbr = wfGetDB( DB_SLAVE );
 402                 $options = array ();
 403                 if ( $limit !== false ) {
 404                         $options['LIMIT'] = intval( $limit );
 405                 }
 406                 if ( $offset !== false ) {
 407                         $options['OFFSET'] = intval( $offset );
 408                 }
 409                 $res = $dbr->select( 'querycache', array( 'qc_type',
 410                                 'qc_namespace AS namespace',
 411                                 'qc_title AS title',
 412                                 'qc_value AS value' ),
 413                                 array( 'qc_type' => $this->getName() ),
 414                                 __METHOD__, $options
 415                 );
 416                 return $dbr->resultObject( $res );
 417         }
 418
 419         /**
 420          * This is the actual workhorse. It does everything needed to make a
 421          * real, honest-to-gosh query page.
 422          */
 423         function execute( $par ) {
 424                 global $wgUser, $wgOut, $wgLang;
 425
 426                 if ( !$this->userCanExecute( $wgUser ) ) {
 427                         $this->displayRestrictionError();
 428                         return;
 429                 }
 430
 431                 if ( $this->limit == 0 && $this->offset == 0 )
 432                         list( $this->limit, $this->offset ) = wfCheckLimits();
 433                 $sname = $this->getName();
 434                 $fname = get_class( $this ) . '::doQuery';
 435                 $dbr = wfGetDB( DB_SLAVE );
 436
 437                 $this->setHeaders();
 438                 $wgOut->setSyndicated( $this->isSyndicated() );
 439
 440                 if ( $this->isCached() && !$this->isCacheable() ) {
 441                         $wgOut->setSyndicated( false );
 442                         $wgOut->addWikiMsg( 'querypage-disabled' );
 443                         return 0;
 444                 }
 445
 446                 // TODO: Use doQuery()
 447                 // $res = null;
 448                 if ( !$this->isCached() ) {
 449                         $res = $this->reallyDoQuery( $this->limit, $this->offset );
 450                 } else {
 451                         # Get the cached result
 452                         $res = $this->fetchFromCache( $this->limit, $this->offset );
 453                         if ( !$this->listoutput ) {
 454
 455                                 # Fetch the timestamp of this update
 456                                 $tRes = $dbr->select( 'querycache_info', array( 'qci_timestamp' ), array( 'qci_type' => $sname ), $fname );
 457                                 $tRow = $dbr->fetchObject( $tRes );
 458
 459                                 if ( $tRow ) {
 460                                         $updated = $wgLang->timeanddate( $tRow->qci_timestamp, true, true );
 461                                         $updateddate = $wgLang->date( $tRow->qci_timestamp, true, true );
 462                                         $updatedtime = $wgLang->time( $tRow->qci_timestamp, true, true );
 463                                         $wgOut->addMeta( 'Data-Cache-Time', $tRow->qci_timestamp );
 464                                         $wgOut->addInlineScript( "var dataCacheTime = '{$tRow->qci_timestamp}';" );
 465                                         $wgOut->addWikiMsg( 'perfcachedts', $updated, $updateddate, $updatedtime );
 466                                 } else {
 467                                         $wgOut->addWikiMsg( 'perfcached' );
 468                                 }
 469
 470                                 # If updates on this page have been disabled, let the user know
 471                                 # that the data set won't be refreshed for now
 472                                 global $wgDisableQueryPageUpdate;
 473                                 if ( is_array( $wgDisableQueryPageUpdate ) && in_array( $this->getName(), $wgDisableQueryPageUpdate ) ) {
 474                                         $wgOut->addWikiMsg( 'querypage-no-updates' );
 475                                 }
 476
 477                         }
 478
 479                 }
 480
 481                 $this->numRows = $dbr->numRows( $res );
 482
 483                 $this->preprocessResults( $dbr, $res );
 484
 485                 $wgOut->addHTML( Xml::openElement( 'div', array( 'class' => 'mw-spcontent' ) ) );
 486
 487                 # Top header and navigation
 488                 if ( $this->shownavigation ) {
 489                         $wgOut->addHTML( $this->getPageHeader() );
 490                         if ( $this->numRows > 0 ) {
 491                                 $wgOut->addHTML( '<p>' . wfShowingResults( $this->offset, $this->numRows ) . '</p>' );
 492                                 # Disable the "next" link when we reach the end
 493                                 $paging = wfViewPrevNext( $this->offset, $this->limit,
 494                                         $this->getTitle( $par ),
 495                                         wfArrayToCGI( $this->linkParameters() ), ( $this->numRows < $this->limit ) );
 496                                 $wgOut->addHTML( '<p>' . $paging . '</p>' );
 497                         } else {
 498                                 # No results to show, so don't bother with "showing X of Y" etc.
 499                                 # -- just let the user know and give up now
 500                                 $wgOut->addHTML( '<p>' . wfMsgHtml( 'specialpage-empty' ) . '</p>' );
 501                                 $wgOut->addHTML( Xml::closeElement( 'div' ) );
 502                                 return;
 503                         }
 504                 }
 505
 506                 # The actual results; specialist subclasses will want to handle this
 507                 # with more than a straight list, so we hand them the info, plus
 508                 # an OutputPage, and let them get on with it
 509                 $this->outputResults( $wgOut,
 510                         $wgUser->getSkin(),
 511                         $dbr, # Should use a ResultWrapper for this
 512                         $res,
 513                         $this->numRows,
 514                         $this->offset );
 515
 516                 # Repeat the paging links at the bottom
 517                 if ( $this->shownavigation ) {
 518                         $wgOut->addHTML( '<p>' . $paging . '</p>' );
 519                 }
 520
 521                 $wgOut->addHTML( Xml::closeElement( 'div' ) );
 522
 523                 return $this->numRows;
 524         }
 525
 526         /**
 527          * Format and output report results using the given information plus
 528          * OutputPage
 529          *
 530          * @param $out OutputPage to print to
 531          * @param $skin Skin: user skin to use
 532          * @param $dbr Database (read) connection to use
 533          * @param $res Integer: result pointer
 534          * @param $num Integer: number of available result rows
 535          * @param $offset Integer: paging offset
 536          */
 537         protected function outputResults( $out, $skin, $dbr, $res, $num, $offset ) {
 538                 global $wgContLang;
 539
 540                 if ( $num > 0 ) {
 541                         $html = array();
 542                         if ( !$this->listoutput )
 543                                 $html[] = $this->openList( $offset );
 544
 545                         # $res might contain the whole 1,000 rows, so we read up to
 546                         # $num [should update this to use a Pager]
 547                         for ( $i = 0; $i < $num && $row = $dbr->fetchObject( $res ); $i++ ) {
 548                                 $line = $this->formatResult( $skin, $row );
 549                                 if ( $line ) {
 550                                         $attr = ( isset( $row->usepatrol ) && $row->usepatrol && $row->patrolled == 0 )
 551                                                 ? ' class="not-patrolled"'
 552                                                 : '';
 553                                         $html[] = $this->listoutput
 554                                                 ? $line
 555                                                 : "<li{$attr}>{$line}</li>\n";
 556                                 }
 557                         }
 558
 559                         # Flush the final result
 560                         if ( $this->tryLastResult() ) {
 561                                 $row = null;
 562                                 $line = $this->formatResult( $skin, $row );
 563                                 if ( $line ) {
 564                                         $attr = ( isset( $row->usepatrol ) && $row->usepatrol && $row->patrolled == 0 )
 565                                                 ? ' class="not-patrolled"'
 566                                                 : '';
 567                                         $html[] = $this->listoutput
 568                                                 ? $line
 569                                                 : "<li{$attr}>{$line}</li>\n";
 570                                 }
 571                         }
 572
 573                         if ( !$this->listoutput )
 574                                 $html[] = $this->closeList();
 575
 576                         $html = $this->listoutput
 577                                 ? $wgContLang->listToText( $html )
 578                                 : implode( '', $html );
 579
 580                         $out->addHTML( $html );
 581                 }
 582         }
 583
 584         function openList( $offset ) {
 585                 return "\n<ol start='" . ( $offset + 1 ) . "' class='special'>\n";
 586         }
 587
 588         function closeList() {
 589                 return "</ol>\n";
 590         }
 591
 592         /**
 593          * Do any necessary preprocessing of the result object.
 594          */
 595         function preprocessResults( $db, $res ) {}
 596
 597         /**
 598          * Similar to above, but packaging in a syndicated feed instead of a web page
 599          */
 600         function doFeed( $class = '', $limit = 50 ) {
 601                 global $wgFeed, $wgFeedClasses;
 602
 603                 if ( !$wgFeed ) {
 604                         global $wgOut;
 605                         $wgOut->addWikiMsg( 'feed-unavailable' );
 606                         return;
 607                 }
 608
 609                 global $wgFeedLimit;
 610                 if ( $limit > $wgFeedLimit ) {
 611                         $limit = $wgFeedLimit;
 612                 }
 613
 614                 if ( isset( $wgFeedClasses[$class] ) ) {
 615                         $feed = new $wgFeedClasses[$class](
 616                                 $this->feedTitle(),
 617                                 $this->feedDesc(),
 618                                 $this->feedUrl() );
 619                         $feed->outHeader();
 620
 621                         $dbr = wfGetDB( DB_SLAVE );
 622                         $res = $this->reallyDoQuery( $limit, 0 );
 623                         foreach ( $res as $obj ) {
 624                                 $item = $this->feedResult( $obj );
 625                                 if ( $item ) {
 626                                         $feed->outItem( $item );
 627                                 }
 628                         }
 629
 630                         $feed->outFooter();
 631                         return true;
 632                 } else {
 633                         return false;
 634                 }
 635         }
 636
 637         /**
 638          * Override for custom handling. If the titles/links are ok, just do
 639          * feedItemDesc()
 640          */
 641         function feedResult( $row ) {
 642                 if ( !isset( $row->title ) ) {
 643                         return null;
 644                 }
 645                 $title = Title::MakeTitle( intval( $row->namespace ), $row->title );
 646                 if ( $title ) {
 647                         $date = isset( $row->timestamp ) ? $row->timestamp : '';
 648                         $comments = '';
 649                         if ( $title ) {
 650                                 $talkpage = $title->getTalkPage();
 651                                 $comments = $talkpage->getFullURL();
 652                         }
 653
 654                         return new FeedItem(
 655                                 $title->getPrefixedText(),
 656                                 $this->feedItemDesc( $row ),
 657                                 $title->getFullURL(),
 658                                 $date,
 659                                 $this->feedItemAuthor( $row ),
 660                                 $comments );
 661                 } else {
 662                         return null;
 663                 }
 664         }
 665
 666         function feedItemDesc( $row ) {
 667                 return isset( $row->comment ) ? htmlspecialchars( $row->comment ) : '';
 668         }
 669
 670         function feedItemAuthor( $row ) {
 671                 return isset( $row->user_text ) ? $row->user_text : '';
 672         }
 673
 674         function feedTitle() {
 675                 global $wgLanguageCode, $wgSitename;
 676                 $page = SpecialPage::getPage( $this->getName() );
 677                 $desc = $page->getDescription();
 678                 return "$wgSitename - $desc [$wgLanguageCode]";
 679         }
 680
 681         function feedDesc() {
 682                 return wfMsgExt( 'tagline', 'parsemag' );
 683         }
 684
 685         function feedUrl() {
 686                 $title = SpecialPage::getTitleFor( $this->getName() );
 687                 return $title->getFullURL();
 688         }
 689 }
 690
 691 /**
 692  * Class definition for a wanted query page like
 693  * WantedPages, WantedTemplates, etc
 694  */
 695 abstract class WantedQueryPage extends QueryPage {
 696
 697         function isExpensive() {
 698                 return true;
 699         }
 700
 701         function isSyndicated() {
 702                 return false;
 703         }
 704
 705         /**
 706          * Cache page existence for performance
 707          */
 708         function preprocessResults( $db, $res ) {
 709                 $batch = new LinkBatch;
 710                 foreach ( $res as $row ) {
 711                         $batch->add( $row->namespace, $row->title );
 712                 }
 713                 $batch->execute();
 714
 715                 // Back to start for display
 716                 if ( $db->numRows( $res ) > 0 )
 717                         // If there are no rows we get an error seeking.
 718                         $db->dataSeek( $res, 0 );
 719         }
 720
 721         /**
 722          * Should formatResult() always check page existence, even if
 723          * the results are fresh?  This is a (hopefully temporary)
 724          * kluge for Special:WantedFiles, which may contain false
 725          * positives for files that exist e.g. in a shared repo (bug
 726          * 6220).
 727          */
 728         function forceExistenceCheck() {
 729                 return false;
 730         }
 731
 732         /**
 733          * Format an individual result
 734          *
 735          * @param $skin Skin to use for UI elements
 736          * @param $result Result row
 737          * @return string
 738          */
 739         public function formatResult( $skin, $result ) {
 740                 $title = Title::makeTitleSafe( $result->namespace, $result->title );
 741                 if ( $title instanceof Title ) {
 742                         if ( $this->isCached() || $this->forceExistenceCheck() ) {
 743                                 $pageLink = $title->isKnown()
 744                                         ? '<del>' . $skin->link( $title ) . '</del>'
 745                                         : $skin->link(
 746                                                 $title,
 747                                                 null,
 748                                                 array(),
 749                                                 array(),
 750                                                 array( 'broken' )
 751                                         );
 752                         } else {
 753                                 $pageLink = $skin->link(
 754                                         $title,
 755                                         null,
 756                                         array(),
 757                                         array(),
 758                                         array( 'broken' )
 759                                 );
 760                         }
 761                         return wfSpecialList( $pageLink, $this->makeWlhLink( $title, $skin, $result ) );
 762                 } else {
 763                         $tsafe = htmlspecialchars( $result->title );
 764                         return wfMsgHtml( 'wantedpages-badtitle', $tsafe );
 765                 }
 766         }
 767
 768         /**
 769          * Make a "what links here" link for a given title
 770          *
 771          * @param $title Title to make the link for
 772          * @param $skin Skin object to use
 773          * @param $result Object: result row
 774          * @return string
 775          */
 776         private function makeWlhLink( $title, $skin, $result ) {
 777                 global $wgLang;
 778                 $wlh = SpecialPage::getTitleFor( 'Whatlinkshere' );
 779                 $label = wfMsgExt( 'nlinks', array( 'parsemag', 'escape' ),
 780                 $wgLang->formatNum( $result->value ) );
 781                 return $skin->link( $wlh, $label, array(), array( 'target' => $title->getPrefixedText() ) );
 782         }
 783 }