includes/QueryPage.php

   1 <?php
   2 /**
   3  * Base code for "query" special pages.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup SpecialPage
  22  */
  23
  24 /**
  25  * List of query page classes and their associated special pages,
  26  * for periodic updates.
  27  *
  28  * DO NOT CHANGE THIS LIST without testing that
  29  * maintenance/updateSpecialPages.php still works.
  30  */
  31 global $wgQueryPages; // not redundant
  32 $wgQueryPages = array(
  33 //         QueryPage subclass, Special page name, Limit (false for none, none for the default)
  34 // ----------------------------------------------------------------------------
  35         array( 'AncientPagesPage', 'Ancientpages' ),
  36         array( 'BrokenRedirectsPage', 'BrokenRedirects' ),
  37         array( 'DeadendPagesPage', 'Deadendpages' ),
  38         array( 'DoubleRedirectsPage', 'DoubleRedirects' ),
  39         array( 'FileDuplicateSearchPage', 'FileDuplicateSearch' ),
  40         array( 'LinkSearchPage', 'LinkSearch' ),
  41         array( 'ListredirectsPage', 'Listredirects' ),
  42         array( 'LonelyPagesPage', 'Lonelypages' ),
  43         array( 'LongPagesPage', 'Longpages' ),
  44         array( 'MIMEsearchPage', 'MIMEsearch' ),
  45         array( 'MostcategoriesPage', 'Mostcategories' ),
  46         array( 'MostimagesPage', 'Mostimages' ),
  47         array( 'MostinterwikisPage', 'Mostinterwikis' ),
  48         array( 'MostlinkedCategoriesPage', 'Mostlinkedcategories' ),
  49         array( 'MostlinkedtemplatesPage', 'Mostlinkedtemplates' ),
  50         array( 'MostlinkedPage', 'Mostlinked' ),
  51         array( 'MostrevisionsPage', 'Mostrevisions' ),
  52         array( 'FewestrevisionsPage', 'Fewestrevisions' ),
  53         array( 'ShortPagesPage', 'Shortpages' ),
  54         array( 'UncategorizedCategoriesPage', 'Uncategorizedcategories' ),
  55         array( 'UncategorizedPagesPage', 'Uncategorizedpages' ),
  56         array( 'UncategorizedImagesPage', 'Uncategorizedimages' ),
  57         array( 'UncategorizedTemplatesPage', 'Uncategorizedtemplates' ),
  58         array( 'UnusedCategoriesPage', 'Unusedcategories' ),
  59         array( 'UnusedimagesPage', 'Unusedimages' ),
  60         array( 'WantedCategoriesPage', 'Wantedcategories' ),
  61         array( 'WantedFilesPage', 'Wantedfiles' ),
  62         array( 'WantedPagesPage', 'Wantedpages' ),
  63         array( 'WantedTemplatesPage', 'Wantedtemplates' ),
  64         array( 'UnwatchedPagesPage', 'Unwatchedpages' ),
  65         array( 'UnusedtemplatesPage', 'Unusedtemplates' ),
  66         array( 'WithoutInterwikiPage', 'Withoutinterwiki' ),
  67 );
  68 wfRunHooks( 'wgQueryPages', array( &$wgQueryPages ) );
  69
  70 global $wgDisableCounters;
  71 if ( !$wgDisableCounters ) {
  72         $wgQueryPages[] = array( 'PopularPagesPage', 'Popularpages' );
  73 }
  74
  75 /**
  76  * This is a class for doing query pages; since they're almost all the same,
  77  * we factor out some of the functionality into a superclass, and let
  78  * subclasses derive from it.
  79  * @ingroup SpecialPage
  80  */
  81 abstract class QueryPage extends SpecialPage {
  82         /**
  83          * Whether or not we want plain listoutput rather than an ordered list
  84          *
  85          * @var bool
  86          */
  87         var $listoutput = false;
  88
  89         /**
  90          * The offset and limit in use, as passed to the query() function
  91          *
  92          * @var int
  93          */
  94         var $offset = 0;
  95         var $limit = 0;
  96
  97         /**
  98          * The number of rows returned by the query. Reading this variable
  99          * only makes sense in functions that are run after the query has been
 100          * done, such as preprocessResults() and formatRow().
 101          */
 102         protected $numRows;
 103
 104         protected $cachedTimestamp = null;
 105
 106         /**
 107          * Wheter to show prev/next links
 108          */
 109         protected $shownavigation = true;
 110
 111         /**
 112          * A mutator for $this->listoutput;
 113          *
 114          * @param bool $bool
 115          */
 116         function setListoutput( $bool ) {
 117                 $this->listoutput = $bool;
 118         }
 119
 120         /**
 121          * Subclasses return an SQL query here, formatted as an array with the
 122          * following keys:
 123          *    tables => Table(s) for passing to Database::select()
 124          *    fields => Field(s) for passing to Database::select(), may be *
 125          *    conds => WHERE conditions
 126          *    options => options
 127          *    join_conds => JOIN conditions
 128          *
 129          * Note that the query itself should return the following three columns:
 130          * 'namespace', 'title', and 'value'. 'value' is used for sorting.
 131          *
 132          * These may be stored in the querycache table for expensive queries,
 133          * and that cached data will be returned sometimes, so the presence of
 134          * extra fields can't be relied upon. The cached 'value' column will be
 135          * an integer; non-numeric values are useful only for sorting the
 136          * initial query (except if they're timestamps, see usesTimestamps()).
 137          *
 138          * Don't include an ORDER or LIMIT clause, they will be added.
 139          *
 140          * If this function is not overridden or returns something other than
 141          * an array, getSQL() will be used instead. This is for backwards
 142          * compatibility only and is strongly deprecated.
 143          * @return array
 144          * @since 1.18
 145          */
 146         function getQueryInfo() {
 147                 return null;
 148         }
 149
 150         /**
 151          * For back-compat, subclasses may return a raw SQL query here, as a string.
 152          * This is strongly deprecated; getQueryInfo() should be overridden instead.
 153          * @throws MWException
 154          * @return string
 155          */
 156         function getSQL() {
 157                 /* Implement getQueryInfo() instead */
 158                 throw new MWException( "Bug in a QueryPage: doesn't implement getQueryInfo() nor "
 159                         . "getQuery() properly" );
 160         }
 161
 162         /**
 163          * Subclasses return an array of fields to order by here. Don't append
 164          * DESC to the field names, that'll be done automatically if
 165          * sortDescending() returns true.
 166          * @return array
 167          * @since 1.18
 168          */
 169         function getOrderFields() {
 170                 return array( 'value' );
 171         }
 172
 173         /**
 174          * Does this query return timestamps rather than integers in its
 175          * 'value' field? If true, this class will convert 'value' to a
 176          * UNIX timestamp for caching.
 177          * NOTE: formatRow() may get timestamps in TS_MW (mysql), TS_DB (pgsql)
 178          *       or TS_UNIX (querycache) format, so be sure to always run them
 179          *       through wfTimestamp()
 180          * @return bool
 181          * @since 1.18
 182          */
 183         function usesTimestamps() {
 184                 return false;
 185         }
 186
 187         /**
 188          * Override to sort by increasing values
 189          *
 190          * @return bool
 191          */
 192         function sortDescending() {
 193                 return true;
 194         }
 195
 196         /**
 197          * Is this query expensive (for some definition of expensive)? Then we
 198          * don't let it run in miser mode. $wgDisableQueryPages causes all query
 199          * pages to be declared expensive. Some query pages are always expensive.
 200          *
 201          * @return bool
 202          */
 203         function isExpensive() {
 204                 global $wgDisableQueryPages;
 205                 return $wgDisableQueryPages;
 206         }
 207
 208         /**
 209          * Is the output of this query cacheable? Non-cacheable expensive pages
 210          * will be disabled in miser mode and will not have their results written
 211          * to the querycache table.
 212          * @return bool
 213          * @since 1.18
 214          */
 215         public function isCacheable() {
 216                 return true;
 217         }
 218
 219         /**
 220          * Whether or not the output of the page in question is retrieved from
 221          * the database cache.
 222          *
 223          * @return bool
 224          */
 225         function isCached() {
 226                 global $wgMiserMode;
 227
 228                 return $this->isExpensive() && $wgMiserMode;
 229         }
 230
 231         /**
 232          * Sometime we don't want to build rss / atom feeds.
 233          *
 234          * @return bool
 235          */
 236         function isSyndicated() {
 237                 return true;
 238         }
 239
 240         /**
 241          * Formats the results of the query for display. The skin is the current
 242          * skin; you can use it for making links. The result is a single row of
 243          * result data. You should be able to grab SQL results off of it.
 244          * If the function returns false, the line output will be skipped.
 245          * @param Skin $skin
 246          * @param object $result Result row
 247          * @return string|bool String or false to skip
 248          */
 249         abstract function formatResult( $skin, $result );
 250
 251         /**
 252          * The content returned by this function will be output before any result
 253          *
 254          * @return string
 255          */
 256         function getPageHeader() {
 257                 return '';
 258         }
 259
 260         /**
 261          * If using extra form wheely-dealies, return a set of parameters here
 262          * as an associative array. They will be encoded and added to the paging
 263          * links (prev/next/lengths).
 264          *
 265          * @return array
 266          */
 267         function linkParameters() {
 268                 return array();
 269         }
 270
 271         /**
 272          * Some special pages (for example SpecialListusers) might not return the
 273          * current object formatted, but return the previous one instead.
 274          * Setting this to return true will ensure formatResult() is called
 275          * one more time to make sure that the very last result is formatted
 276          * as well.
 277          * @return bool
 278          */
 279         function tryLastResult() {
 280                 return false;
 281         }
 282
 283         /**
 284          * Clear the cache and save new results
 285          *
 286          * @param int|bool $limit Limit for SQL statement
 287          * @param bool $ignoreErrors Whether to ignore database errors
 288          * @throws DBError|Exception
 289          * @return bool|int
 290          */
 291         function recache( $limit, $ignoreErrors = true ) {
 292                 if ( !$this->isCacheable() ) {
 293                         return 0;
 294                 }
 295
 296                 $fname = get_class( $this ) . '::recache';
 297                 $dbw = wfGetDB( DB_MASTER );
 298                 $dbr = wfGetDB( DB_SLAVE, array( $this->getName(), __METHOD__, 'vslow' ) );
 299                 if ( !$dbw || !$dbr ) {
 300                         return false;
 301                 }
 302
 303                 try {
 304                         # Clear out any old cached data
 305                         $dbw->delete( 'querycache', array( 'qc_type' => $this->getName() ), $fname );
 306                         # Do query
 307                         $res = $this->reallyDoQuery( $limit, false );
 308                         $num = false;
 309                         if ( $res ) {
 310                                 $num = $res->numRows();
 311                                 # Fetch results
 312                                 $vals = array();
 313                                 while ( $res && $row = $dbr->fetchObject( $res ) ) {
 314                                         if ( isset( $row->value ) ) {
 315                                                 if ( $this->usesTimestamps() ) {
 316                                                         $value = wfTimestamp( TS_UNIX,
 317                                                                 $row->value );
 318                                                 } else {
 319                                                         $value = intval( $row->value ); // @bug 14414
 320                                                 }
 321                                         } else {
 322                                                 $value = 0;
 323                                         }
 324
 325                                         $vals[] = array( 'qc_type' => $this->getName(),
 326                                                         'qc_namespace' => $row->namespace,
 327                                                         'qc_title' => $row->title,
 328                                                         'qc_value' => $value );
 329                                 }
 330
 331                                 # Save results into the querycache table on the master
 332                                 if ( count( $vals ) ) {
 333                                         $dbw->insert( 'querycache', $vals, __METHOD__ );
 334                                 }
 335                                 # Update the querycache_info record for the page
 336                                 $dbw->delete( 'querycache_info', array( 'qci_type' => $this->getName() ), $fname );
 337                                 $dbw->insert( 'querycache_info',
 338                                         array( 'qci_type' => $this->getName(), 'qci_timestamp' => $dbw->timestamp() ),
 339                                         $fname );
 340                         }
 341                 } catch ( DBError $e ) {
 342                         if ( !$ignoreErrors ) {
 343                                 throw $e; // report query error
 344                         }
 345                         $num = false; // set result to false to indicate error
 346                 }
 347
 348                 return $num;
 349         }
 350
 351         /**
 352          * Run the query and return the result
 353          * @param int|bool $limit Numerical limit or false for no limit
 354          * @param int|bool $offset Numerical offset or false for no offset
 355          * @return ResultWrapper
 356          * @since 1.18
 357          */
 358         function reallyDoQuery( $limit, $offset = false ) {
 359                 $fname = get_class( $this ) . "::reallyDoQuery";
 360                 $dbr = wfGetDB( DB_SLAVE );
 361                 $query = $this->getQueryInfo();
 362                 $order = $this->getOrderFields();
 363
 364                 if ( $this->sortDescending() ) {
 365                         foreach ( $order as &$field ) {
 366                                 $field .= ' DESC';
 367                         }
 368                 }
 369
 370                 if ( is_array( $query ) ) {
 371                         $tables = isset( $query['tables'] ) ? (array)$query['tables'] : array();
 372                         $fields = isset( $query['fields'] ) ? (array)$query['fields'] : array();
 373                         $conds = isset( $query['conds'] ) ? (array)$query['conds'] : array();
 374                         $options = isset( $query['options'] ) ? (array)$query['options'] : array();
 375                         $join_conds = isset( $query['join_conds'] ) ? (array)$query['join_conds'] : array();
 376
 377                         if ( count( $order ) ) {
 378                                 $options['ORDER BY'] = $order;
 379                         }
 380
 381                         if ( $limit !== false ) {
 382                                 $options['LIMIT'] = intval( $limit );
 383                         }
 384
 385                         if ( $offset !== false ) {
 386                                 $options['OFFSET'] = intval( $offset );
 387                         }
 388
 389                         $res = $dbr->select( $tables, $fields, $conds, $fname,
 390                                         $options, $join_conds
 391                         );
 392                 } else {
 393                         // Old-fashioned raw SQL style, deprecated
 394                         $sql = $this->getSQL();
 395                         $sql .= ' ORDER BY ' . implode( ', ', $order );
 396                         $sql = $dbr->limitResult( $sql, $limit, $offset );
 397                         $res = $dbr->query( $sql, $fname );
 398                 }
 399
 400                 return $dbr->resultObject( $res );
 401         }
 402
 403         /**
 404          * Somewhat deprecated, you probably want to be using execute()
 405          * @param int|bool $offset
 406          * @oaram int|bool $limit
 407          * @return ResultWrapper
 408          */
 409         function doQuery( $offset = false, $limit = false ) {
 410                 if ( $this->isCached() && $this->isCacheable() ) {
 411                         return $this->fetchFromCache( $limit, $offset );
 412                 } else {
 413                         return $this->reallyDoQuery( $limit, $offset );
 414                 }
 415         }
 416
 417         /**
 418          * Fetch the query results from the query cache
 419          * @param int|bool $limit Numerical limit or false for no limit
 420          * @param int|bool $offset Numerical offset or false for no offset
 421          * @return ResultWrapper
 422          * @since 1.18
 423          */
 424         function fetchFromCache( $limit, $offset = false ) {
 425                 $dbr = wfGetDB( DB_SLAVE );
 426                 $options = array();
 427                 if ( $limit !== false ) {
 428                         $options['LIMIT'] = intval( $limit );
 429                 }
 430                 if ( $offset !== false ) {
 431                         $options['OFFSET'] = intval( $offset );
 432                 }
 433                 if ( $this->sortDescending() ) {
 434                         $options['ORDER BY'] = 'qc_value DESC';
 435                 } else {
 436                         $options['ORDER BY'] = 'qc_value ASC';
 437                 }
 438                 $res = $dbr->select( 'querycache', array( 'qc_type',
 439                                 'namespace' => 'qc_namespace',
 440                                 'title' => 'qc_title',
 441                                 'value' => 'qc_value' ),
 442                                 array( 'qc_type' => $this->getName() ),
 443                                 __METHOD__, $options
 444                 );
 445                 return $dbr->resultObject( $res );
 446         }
 447
 448         public function getCachedTimestamp() {
 449                 if ( is_null( $this->cachedTimestamp ) ) {
 450                         $dbr = wfGetDB( DB_SLAVE );
 451                         $fname = get_class( $this ) . '::getCachedTimestamp';
 452                         $this->cachedTimestamp = $dbr->selectField( 'querycache_info', 'qci_timestamp',
 453                                 array( 'qci_type' => $this->getName() ), $fname );
 454                 }
 455                 return $this->cachedTimestamp;
 456         }
 457
 458         /**
 459          * This is the actual workhorse. It does everything needed to make a
 460          * real, honest-to-gosh query page.
 461          * @para $par
 462          * @return int
 463          */
 464         function execute( $par ) {
 465                 global $wgQueryCacheLimit, $wgDisableQueryPageUpdate;
 466
 467                 $user = $this->getUser();
 468                 if ( !$this->userCanExecute( $user ) ) {
 469                         $this->displayRestrictionError();
 470                         return;
 471                 }
 472
 473                 $this->setHeaders();
 474                 $this->outputHeader();
 475
 476                 $out = $this->getOutput();
 477
 478                 if ( $this->isCached() && !$this->isCacheable() ) {
 479                         $out->addWikiMsg( 'querypage-disabled' );
 480                         return 0;
 481                 }
 482
 483                 $out->setSyndicated( $this->isSyndicated() );
 484
 485                 if ( $this->limit == 0 && $this->offset == 0 ) {
 486                         list( $this->limit, $this->offset ) = $this->getRequest()->getLimitOffset();
 487                 }
 488
 489                 // TODO: Use doQuery()
 490                 if ( !$this->isCached() ) {
 491                         # select one extra row for navigation
 492                         $res = $this->reallyDoQuery( $this->limit + 1, $this->offset );
 493                 } else {
 494                         # Get the cached result, select one extra row for navigation
 495                         $res = $this->fetchFromCache( $this->limit + 1, $this->offset );
 496                         if ( !$this->listoutput ) {
 497
 498                                 # Fetch the timestamp of this update
 499                                 $ts = $this->getCachedTimestamp();
 500                                 $lang = $this->getLanguage();
 501                                 $maxResults = $lang->formatNum( $wgQueryCacheLimit );
 502
 503                                 if ( $ts ) {
 504                                         $updated = $lang->userTimeAndDate( $ts, $user );
 505                                         $updateddate = $lang->userDate( $ts, $user );
 506                                         $updatedtime = $lang->userTime( $ts, $user );
 507                                         $out->addMeta( 'Data-Cache-Time', $ts );
 508                                         $out->addJsConfigVars( 'dataCacheTime', $ts );
 509                                         $out->addWikiMsg( 'perfcachedts', $updated, $updateddate, $updatedtime, $maxResults );
 510                                 } else {
 511                                         $out->addWikiMsg( 'perfcached', $maxResults );
 512                                 }
 513
 514                                 # If updates on this page have been disabled, let the user know
 515                                 # that the data set won't be refreshed for now
 516                                 if ( is_array( $wgDisableQueryPageUpdate )
 517                                         && in_array( $this->getName(), $wgDisableQueryPageUpdate )
 518                                 ) {
 519                                         $out->wrapWikiMsg(
 520                                                 "<div class=\"mw-querypage-no-updates\">\n$1\n</div>",
 521                                                 'querypage-no-updates'
 522                                         );
 523                                 }
 524                         }
 525                 }
 526
 527                 $this->numRows = $res->numRows();
 528
 529                 $dbr = wfGetDB( DB_SLAVE );
 530                 $this->preprocessResults( $dbr, $res );
 531
 532                 $out->addHTML( Xml::openElement( 'div', array( 'class' => 'mw-spcontent' ) ) );
 533
 534                 # Top header and navigation
 535                 if ( $this->shownavigation ) {
 536                         $out->addHTML( $this->getPageHeader() );
 537                         if ( $this->numRows > 0 ) {
 538                                 $out->addHTML( $this->msg( 'showingresults' )->numParams(
 539                                         min( $this->numRows, $this->limit ), # do not show the one extra row, if exist
 540                                         $this->offset + 1 )->parseAsBlock() );
 541                                 # Disable the "next" link when we reach the end
 542                                 $paging = $this->getLanguage()->viewPrevNext( $this->getTitle( $par ), $this->offset,
 543                                         $this->limit, $this->linkParameters(), ( $this->numRows <= $this->limit ) );
 544                                 $out->addHTML( '<p>' . $paging . '</p>' );
 545                         } else {
 546                                 # No results to show, so don't bother with "showing X of Y" etc.
 547                                 # -- just let the user know and give up now
 548                                 $out->addWikiMsg( 'specialpage-empty' );
 549                                 $out->addHTML( Xml::closeElement( 'div' ) );
 550                                 return;
 551                         }
 552                 }
 553
 554                 # The actual results; specialist subclasses will want to handle this
 555                 # with more than a straight list, so we hand them the info, plus
 556                 # an OutputPage, and let them get on with it
 557                 $this->outputResults( $out,
 558                         $this->getSkin(),
 559                         $dbr, # Should use a ResultWrapper for this
 560                         $res,
 561                         min( $this->numRows, $this->limit ), # do not format the one extra row, if exist
 562                         $this->offset );
 563
 564                 # Repeat the paging links at the bottom
 565                 if ( $this->shownavigation ) {
 566                         $out->addHTML( '<p>' . $paging . '</p>' );
 567                 }
 568
 569                 $out->addHTML( Xml::closeElement( 'div' ) );
 570
 571                 return min( $this->numRows, $this->limit ); # do not return the one extra row, if exist
 572         }
 573
 574         /**
 575          * Format and output report results using the given information plus
 576          * OutputPage
 577          *
 578          * @param OutputPage $out OutputPage to print to
 579          * @param Skin $skin User skin to use
 580          * @param DatabaseBase $dbr Database (read) connection to use
 581          * @param int $res Result pointer
 582          * @param int $num Number of available result rows
 583          * @param int $offset Paging offset
 584          */
 585         protected function outputResults( $out, $skin, $dbr, $res, $num, $offset ) {
 586                 global $wgContLang;
 587
 588                 if ( $num > 0 ) {
 589                         $html = array();
 590                         if ( !$this->listoutput ) {
 591                                 $html[] = $this->openList( $offset );
 592                         }
 593
 594                         # $res might contain the whole 1,000 rows, so we read up to
 595                         # $num [should update this to use a Pager]
 596                         for ( $i = 0; $i < $num && $row = $res->fetchObject(); $i++ ) {
 597                                 $line = $this->formatResult( $skin, $row );
 598                                 if ( $line ) {
 599                                         $attr = ( isset( $row->usepatrol ) && $row->usepatrol && $row->patrolled == 0 )
 600                                                 ? ' class="not-patrolled"'
 601                                                 : '';
 602                                         $html[] = $this->listoutput
 603                                                 ? $line
 604                                                 : "<li{$attr}>{$line}</li>\n";
 605                                 }
 606                         }
 607
 608                         # Flush the final result
 609                         if ( $this->tryLastResult() ) {
 610                                 $row = null;
 611                                 $line = $this->formatResult( $skin, $row );
 612                                 if ( $line ) {
 613                                         $attr = ( isset( $row->usepatrol ) && $row->usepatrol && $row->patrolled == 0 )
 614                                                 ? ' class="not-patrolled"'
 615                                                 : '';
 616                                         $html[] = $this->listoutput
 617                                                 ? $line
 618                                                 : "<li{$attr}>{$line}</li>\n";
 619                                 }
 620                         }
 621
 622                         if ( !$this->listoutput ) {
 623                                 $html[] = $this->closeList();
 624                         }
 625
 626                         $html = $this->listoutput
 627                                 ? $wgContLang->listToText( $html )
 628                                 : implode( '', $html );
 629
 630                         $out->addHTML( $html );
 631                 }
 632         }
 633
 634         /**
 635          * @param $offset
 636          * @return string
 637          */
 638         function openList( $offset ) {
 639                 return "\n<ol start='" . ( $offset + 1 ) . "' class='special'>\n";
 640         }
 641
 642         /**
 643          * @return string
 644          */
 645         function closeList() {
 646                 return "</ol>\n";
 647         }
 648
 649         /**
 650          * Do any necessary preprocessing of the result object.
 651          * @param DatabaseBase $db
 652          * @param ResultWrapper $res
 653          */
 654         function preprocessResults( $db, $res ) {}
 655
 656         /**
 657          * Similar to above, but packaging in a syndicated feed instead of a web page
 658          * @param string $class
 659          * @param int $limit
 660          * @return bool
 661          */
 662         function doFeed( $class = '', $limit = 50 ) {
 663                 global $wgFeed, $wgFeedClasses, $wgFeedLimit;
 664
 665                 if ( !$wgFeed ) {
 666                         $this->getOutput()->addWikiMsg( 'feed-unavailable' );
 667                         return false;
 668                 }
 669
 670                 $limit = min( $limit, $wgFeedLimit );
 671
 672                 if ( isset( $wgFeedClasses[$class] ) ) {
 673                         $feed = new $wgFeedClasses[$class](
 674                                 $this->feedTitle(),
 675                                 $this->feedDesc(),
 676                                 $this->feedUrl() );
 677                         $feed->outHeader();
 678
 679                         $res = $this->reallyDoQuery( $limit, 0 );
 680                         foreach ( $res as $obj ) {
 681                                 $item = $this->feedResult( $obj );
 682                                 if ( $item ) {
 683                                         $feed->outItem( $item );
 684                                 }
 685                         }
 686
 687                         $feed->outFooter();
 688                         return true;
 689                 } else {
 690                         return false;
 691                 }
 692         }
 693
 694         /**
 695          * Override for custom handling. If the titles/links are ok, just do
 696          * feedItemDesc()
 697          * @param object $row
 698          * @return FeedItem|null
 699          */
 700         function feedResult( $row ) {
 701                 if ( !isset( $row->title ) ) {
 702                         return null;
 703                 }
 704                 $title = Title::makeTitle( intval( $row->namespace ), $row->title );
 705                 if ( $title ) {
 706                         $date = isset( $row->timestamp ) ? $row->timestamp : '';
 707                         $comments = '';
 708                         if ( $title ) {
 709                                 $talkpage = $title->getTalkPage();
 710                                 $comments = $talkpage->getFullURL();
 711                         }
 712
 713                         return new FeedItem(
 714                                 $title->getPrefixedText(),
 715                                 $this->feedItemDesc( $row ),
 716                                 $title->getFullURL(),
 717                                 $date,
 718                                 $this->feedItemAuthor( $row ),
 719                                 $comments );
 720                 } else {
 721                         return null;
 722                 }
 723         }
 724
 725         function feedItemDesc( $row ) {
 726                 return isset( $row->comment ) ? htmlspecialchars( $row->comment ) : '';
 727         }
 728
 729         function feedItemAuthor( $row ) {
 730                 return isset( $row->user_text ) ? $row->user_text : '';
 731         }
 732
 733         function feedTitle() {
 734                 global $wgLanguageCode, $wgSitename;
 735                 $desc = $this->getDescription();
 736                 return "$wgSitename - $desc [$wgLanguageCode]";
 737         }
 738
 739         function feedDesc() {
 740                 return $this->msg( 'tagline' )->text();
 741         }
 742
 743         function feedUrl() {
 744                 return $this->getTitle()->getFullURL();
 745         }
 746 }
 747
 748 /**
 749  * Class definition for a wanted query page like
 750  * WantedPages, WantedTemplates, etc
 751  */
 752 abstract class WantedQueryPage extends QueryPage {
 753         function isExpensive() {
 754                 return true;
 755         }
 756
 757         function isSyndicated() {
 758                 return false;
 759         }
 760
 761         /**
 762          * Cache page existence for performance
 763          * @param DatabaseBase $db
 764          * @param ResultWrapper $res
 765          */
 766         function preprocessResults( $db, $res ) {
 767                 if ( !$res->numRows() ) {
 768                         return;
 769                 }
 770
 771                 $batch = new LinkBatch;
 772                 foreach ( $res as $row ) {
 773                         $batch->add( $row->namespace, $row->title );
 774                 }
 775                 $batch->execute();
 776
 777                 // Back to start for display
 778                 $res->seek( 0 );
 779         }
 780
 781         /**
 782          * Should formatResult() always check page existence, even if
 783          * the results are fresh?  This is a (hopefully temporary)
 784          * kluge for Special:WantedFiles, which may contain false
 785          * positives for files that exist e.g. in a shared repo (bug
 786          * 6220).
 787          * @return bool
 788          */
 789         function forceExistenceCheck() {
 790                 return false;
 791         }
 792
 793         /**
 794          * Format an individual result
 795          *
 796          * @param Skin $skin Skin to use for UI elements
 797          * @param object $result Result row
 798          * @return string
 799          */
 800         public function formatResult( $skin, $result ) {
 801                 $title = Title::makeTitleSafe( $result->namespace, $result->title );
 802                 if ( $title instanceof Title ) {
 803                         if ( $this->isCached() || $this->forceExistenceCheck() ) {
 804                                 $pageLink = $title->isKnown()
 805                                         ? '<del>' . Linker::link( $title ) . '</del>'
 806                                         : Linker::link(
 807                                                 $title,
 808                                                 null,
 809                                                 array(),
 810                                                 array(),
 811                                                 array( 'broken' )
 812                                         );
 813                         } else {
 814                                 $pageLink = Linker::link(
 815                                         $title,
 816                                         null,
 817                                         array(),
 818                                         array(),
 819                                         array( 'broken' )
 820                                 );
 821                         }
 822                         return $this->getLanguage()->specialList( $pageLink, $this->makeWlhLink( $title, $result ) );
 823                 } else {
 824                         return $this->msg( 'wantedpages-badtitle', $result->title )->escaped();
 825                 }
 826         }
 827
 828         /**
 829          * Make a "what links here" link for a given title
 830          *
 831          * @param Title $title Title to make the link for
 832          * @param object $result Result row
 833          * @return string
 834          */
 835         private function makeWlhLink( $title, $result ) {
 836                 $wlh = SpecialPage::getTitleFor( 'Whatlinkshere', $title->getPrefixedText() );
 837                 $label = $this->msg( 'nlinks' )->numParams( $result->value )->escaped();
 838                 return Linker::link( $wlh, $label );
 839         }
 840 }