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                 $dbw = wfGetDB( DB_MASTER );
 298                 if ( !$dbw ) {
 299                         return false;
 300                 }
 301
 302                 try {
 303                         # Do query
 304                         $res = $this->reallyDoQuery( $limit, false );
 305                         $num = false;
 306                         if ( $res ) {
 307                                 $num = $res->numRows();
 308                                 # Fetch results
 309                                 $vals = array();
 310                                 foreach ( $res as $row ) {
 311                                         if ( isset( $row->value ) ) {
 312                                                 if ( $this->usesTimestamps() ) {
 313                                                         $value = wfTimestamp( TS_UNIX,
 314                                                                 $row->value );
 315                                                 } else {
 316                                                         $value = intval( $row->value ); // @bug 14414
 317                                                 }
 318                                         } else {
 319                                                 $value = 0;
 320                                         }
 321
 322                                         $vals[] = array( 'qc_type' => $this->getName(),
 323                                                         'qc_namespace' => $row->namespace,
 324                                                         'qc_title' => $row->title,
 325                                                         'qc_value' => $value );
 326                                 }
 327
 328                                 $dbw->begin( __METHOD__ );
 329                                 # Clear out any old cached data
 330                                 $dbw->delete( 'querycache', array( 'qc_type' => $this->getName() ), $fname );
 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                                 $dbw->commit( __METHOD__ );
 341                         }
 342                 } catch ( DBError $e ) {
 343                         if ( !$ignoreErrors ) {
 344                                 throw $e; // report query error
 345                         }
 346                         $num = false; // set result to false to indicate error
 347                 }
 348
 349                 return $num;
 350         }
 351
 352         /**
 353          * Get a DB connection to be used for slow recache queries
 354          */
 355         function getRecacheDB() {
 356                 return wfGetDB( DB_SLAVE, array( $this->getName(), 'QueryPage::recache', 'vslow' ) );
 357         }
 358
 359         /**
 360          * Run the query and return the result
 361          * @param int|bool $limit Numerical limit or false for no limit
 362          * @param int|bool $offset Numerical offset or false for no offset
 363          * @return ResultWrapper
 364          * @since 1.18
 365          */
 366         function reallyDoQuery( $limit, $offset = false ) {
 367                 $fname = get_class( $this ) . "::reallyDoQuery";
 368                 $dbr = $this->getRecacheDB();
 369                 $query = $this->getQueryInfo();
 370                 $order = $this->getOrderFields();
 371
 372                 if ( $this->sortDescending() ) {
 373                         foreach ( $order as &$field ) {
 374                                 $field .= ' DESC';
 375                         }
 376                 }
 377
 378                 if ( is_array( $query ) ) {
 379                         $tables = isset( $query['tables'] ) ? (array)$query['tables'] : array();
 380                         $fields = isset( $query['fields'] ) ? (array)$query['fields'] : array();
 381                         $conds = isset( $query['conds'] ) ? (array)$query['conds'] : array();
 382                         $options = isset( $query['options'] ) ? (array)$query['options'] : array();
 383                         $join_conds = isset( $query['join_conds'] ) ? (array)$query['join_conds'] : array();
 384
 385                         if ( count( $order ) ) {
 386                                 $options['ORDER BY'] = $order;
 387                         }
 388
 389                         if ( $limit !== false ) {
 390                                 $options['LIMIT'] = intval( $limit );
 391                         }
 392
 393                         if ( $offset !== false ) {
 394                                 $options['OFFSET'] = intval( $offset );
 395                         }
 396
 397                         $res = $dbr->select( $tables, $fields, $conds, $fname,
 398                                         $options, $join_conds
 399                         );
 400                 } else {
 401                         // Old-fashioned raw SQL style, deprecated
 402                         $sql = $this->getSQL();
 403                         $sql .= ' ORDER BY ' . implode( ', ', $order );
 404                         $sql = $dbr->limitResult( $sql, $limit, $offset );
 405                         $res = $dbr->query( $sql, $fname );
 406                 }
 407
 408                 return $dbr->resultObject( $res );
 409         }
 410
 411         /**
 412          * Somewhat deprecated, you probably want to be using execute()
 413          * @param int|bool $offset
 414          * @param int|bool $limit
 415          * @return ResultWrapper
 416          */
 417         function doQuery( $offset = false, $limit = false ) {
 418                 if ( $this->isCached() && $this->isCacheable() ) {
 419                         return $this->fetchFromCache( $limit, $offset );
 420                 } else {
 421                         return $this->reallyDoQuery( $limit, $offset );
 422                 }
 423         }
 424
 425         /**
 426          * Fetch the query results from the query cache
 427          * @param int|bool $limit Numerical limit or false for no limit
 428          * @param int|bool $offset Numerical offset or false for no offset
 429          * @return ResultWrapper
 430          * @since 1.18
 431          */
 432         function fetchFromCache( $limit, $offset = false ) {
 433                 $dbr = wfGetDB( DB_SLAVE );
 434                 $options = array();
 435                 if ( $limit !== false ) {
 436                         $options['LIMIT'] = intval( $limit );
 437                 }
 438                 if ( $offset !== false ) {
 439                         $options['OFFSET'] = intval( $offset );
 440                 }
 441                 if ( $this->sortDescending() ) {
 442                         $options['ORDER BY'] = 'qc_value DESC';
 443                 } else {
 444                         $options['ORDER BY'] = 'qc_value ASC';
 445                 }
 446                 $res = $dbr->select( 'querycache', array( 'qc_type',
 447                                 'namespace' => 'qc_namespace',
 448                                 'title' => 'qc_title',
 449                                 'value' => 'qc_value' ),
 450                                 array( 'qc_type' => $this->getName() ),
 451                                 __METHOD__, $options
 452                 );
 453                 return $dbr->resultObject( $res );
 454         }
 455
 456         public function getCachedTimestamp() {
 457                 if ( is_null( $this->cachedTimestamp ) ) {
 458                         $dbr = wfGetDB( DB_SLAVE );
 459                         $fname = get_class( $this ) . '::getCachedTimestamp';
 460                         $this->cachedTimestamp = $dbr->selectField( 'querycache_info', 'qci_timestamp',
 461                                 array( 'qci_type' => $this->getName() ), $fname );
 462                 }
 463                 return $this->cachedTimestamp;
 464         }
 465
 466         /**
 467          * This is the actual workhorse. It does everything needed to make a
 468          * real, honest-to-gosh query page.
 469          * @param string $par
 470          * @return int
 471          */
 472         function execute( $par ) {
 473                 global $wgQueryCacheLimit, $wgDisableQueryPageUpdate;
 474
 475                 $user = $this->getUser();
 476                 if ( !$this->userCanExecute( $user ) ) {
 477                         $this->displayRestrictionError();
 478                         return;
 479                 }
 480
 481                 $this->setHeaders();
 482                 $this->outputHeader();
 483
 484                 $out = $this->getOutput();
 485
 486                 if ( $this->isCached() && !$this->isCacheable() ) {
 487                         $out->addWikiMsg( 'querypage-disabled' );
 488                         return 0;
 489                 }
 490
 491                 $out->setSyndicated( $this->isSyndicated() );
 492
 493                 if ( $this->limit == 0 && $this->offset == 0 ) {
 494                         list( $this->limit, $this->offset ) = $this->getRequest()->getLimitOffset();
 495                 }
 496
 497                 // TODO: Use doQuery()
 498                 if ( !$this->isCached() ) {
 499                         # select one extra row for navigation
 500                         $res = $this->reallyDoQuery( $this->limit + 1, $this->offset );
 501                 } else {
 502                         # Get the cached result, select one extra row for navigation
 503                         $res = $this->fetchFromCache( $this->limit + 1, $this->offset );
 504                         if ( !$this->listoutput ) {
 505
 506                                 # Fetch the timestamp of this update
 507                                 $ts = $this->getCachedTimestamp();
 508                                 $lang = $this->getLanguage();
 509                                 $maxResults = $lang->formatNum( $wgQueryCacheLimit );
 510
 511                                 if ( $ts ) {
 512                                         $updated = $lang->userTimeAndDate( $ts, $user );
 513                                         $updateddate = $lang->userDate( $ts, $user );
 514                                         $updatedtime = $lang->userTime( $ts, $user );
 515                                         $out->addMeta( 'Data-Cache-Time', $ts );
 516                                         $out->addJsConfigVars( 'dataCacheTime', $ts );
 517                                         $out->addWikiMsg( 'perfcachedts', $updated, $updateddate, $updatedtime, $maxResults );
 518                                 } else {
 519                                         $out->addWikiMsg( 'perfcached', $maxResults );
 520                                 }
 521
 522                                 # If updates on this page have been disabled, let the user know
 523                                 # that the data set won't be refreshed for now
 524                                 if ( is_array( $wgDisableQueryPageUpdate )
 525                                         && in_array( $this->getName(), $wgDisableQueryPageUpdate )
 526                                 ) {
 527                                         $out->wrapWikiMsg(
 528                                                 "<div class=\"mw-querypage-no-updates\">\n$1\n</div>",
 529                                                 'querypage-no-updates'
 530                                         );
 531                                 }
 532                         }
 533                 }
 534
 535                 $this->numRows = $res->numRows();
 536
 537                 $dbr = wfGetDB( DB_SLAVE );
 538                 $this->preprocessResults( $dbr, $res );
 539
 540                 $out->addHTML( Xml::openElement( 'div', array( 'class' => 'mw-spcontent' ) ) );
 541
 542                 # Top header and navigation
 543                 if ( $this->shownavigation ) {
 544                         $out->addHTML( $this->getPageHeader() );
 545                         if ( $this->numRows > 0 ) {
 546                                 $out->addHTML( $this->msg( 'showingresultsinrange' )->numParams(
 547                                         min( $this->numRows, $this->limit ), # do not show the one extra row, if exist
 548                                         $this->offset + 1, (min( $this->numRows, $this->limit ) + $this->offset) )->parseAsBlock() );
 549                                 # Disable the "next" link when we reach the end
 550                                 $paging = $this->getLanguage()->viewPrevNext( $this->getPageTitle( $par ), $this->offset,
 551                                         $this->limit, $this->linkParameters(), ( $this->numRows <= $this->limit ) );
 552                                 $out->addHTML( '<p>' . $paging . '</p>' );
 553                         } else {
 554                                 # No results to show, so don't bother with "showing X of Y" etc.
 555                                 # -- just let the user know and give up now
 556                                 $out->addWikiMsg( 'specialpage-empty' );
 557                                 $out->addHTML( Xml::closeElement( 'div' ) );
 558                                 return;
 559                         }
 560                 }
 561
 562                 # The actual results; specialist subclasses will want to handle this
 563                 # with more than a straight list, so we hand them the info, plus
 564                 # an OutputPage, and let them get on with it
 565                 $this->outputResults( $out,
 566                         $this->getSkin(),
 567                         $dbr, # Should use a ResultWrapper for this
 568                         $res,
 569                         min( $this->numRows, $this->limit ), # do not format the one extra row, if exist
 570                         $this->offset );
 571
 572                 # Repeat the paging links at the bottom
 573                 if ( $this->shownavigation ) {
 574                         $out->addHTML( '<p>' . $paging . '</p>' );
 575                 }
 576
 577                 $out->addHTML( Xml::closeElement( 'div' ) );
 578
 579                 return min( $this->numRows, $this->limit ); # do not return the one extra row, if exist
 580         }
 581
 582         /**
 583          * Format and output report results using the given information plus
 584          * OutputPage
 585          *
 586          * @param OutputPage $out OutputPage to print to
 587          * @param Skin $skin User skin to use
 588          * @param DatabaseBase $dbr Database (read) connection to use
 589          * @param int $res Result pointer
 590          * @param int $num Number of available result rows
 591          * @param int $offset Paging offset
 592          */
 593         protected function outputResults( $out, $skin, $dbr, $res, $num, $offset ) {
 594                 global $wgContLang;
 595
 596                 if ( $num > 0 ) {
 597                         $html = array();
 598                         if ( !$this->listoutput ) {
 599                                 $html[] = $this->openList( $offset );
 600                         }
 601
 602                         # $res might contain the whole 1,000 rows, so we read up to
 603                         # $num [should update this to use a Pager]
 604                         for ( $i = 0; $i < $num && $row = $res->fetchObject(); $i++ ) {
 605                                 $line = $this->formatResult( $skin, $row );
 606                                 if ( $line ) {
 607                                         $attr = ( isset( $row->usepatrol ) && $row->usepatrol && $row->patrolled == 0 )
 608                                                 ? ' class="not-patrolled"'
 609                                                 : '';
 610                                         $html[] = $this->listoutput
 611                                                 ? $line
 612                                                 : "<li{$attr}>{$line}</li>\n";
 613                                 }
 614                         }
 615
 616                         # Flush the final result
 617                         if ( $this->tryLastResult() ) {
 618                                 $row = null;
 619                                 $line = $this->formatResult( $skin, $row );
 620                                 if ( $line ) {
 621                                         $attr = ( isset( $row->usepatrol ) && $row->usepatrol && $row->patrolled == 0 )
 622                                                 ? ' class="not-patrolled"'
 623                                                 : '';
 624                                         $html[] = $this->listoutput
 625                                                 ? $line
 626                                                 : "<li{$attr}>{$line}</li>\n";
 627                                 }
 628                         }
 629
 630                         if ( !$this->listoutput ) {
 631                                 $html[] = $this->closeList();
 632                         }
 633
 634                         $html = $this->listoutput
 635                                 ? $wgContLang->listToText( $html )
 636                                 : implode( '', $html );
 637
 638                         $out->addHTML( $html );
 639                 }
 640         }
 641
 642         /**
 643          * @param $offset
 644          * @return string
 645          */
 646         function openList( $offset ) {
 647                 return "\n<ol start='" . ( $offset + 1 ) . "' class='special'>\n";
 648         }
 649
 650         /**
 651          * @return string
 652          */
 653         function closeList() {
 654                 return "</ol>\n";
 655         }
 656
 657         /**
 658          * Do any necessary preprocessing of the result object.
 659          * @param DatabaseBase $db
 660          * @param ResultWrapper $res
 661          */
 662         function preprocessResults( $db, $res ) {}
 663
 664         /**
 665          * Similar to above, but packaging in a syndicated feed instead of a web page
 666          * @param string $class
 667          * @param int $limit
 668          * @return bool
 669          */
 670         function doFeed( $class = '', $limit = 50 ) {
 671                 global $wgFeed, $wgFeedClasses, $wgFeedLimit;
 672
 673                 if ( !$wgFeed ) {
 674                         $this->getOutput()->addWikiMsg( 'feed-unavailable' );
 675                         return false;
 676                 }
 677
 678                 $limit = min( $limit, $wgFeedLimit );
 679
 680                 if ( isset( $wgFeedClasses[$class] ) ) {
 681                         $feed = new $wgFeedClasses[$class](
 682                                 $this->feedTitle(),
 683                                 $this->feedDesc(),
 684                                 $this->feedUrl() );
 685                         $feed->outHeader();
 686
 687                         $res = $this->reallyDoQuery( $limit, 0 );
 688                         foreach ( $res as $obj ) {
 689                                 $item = $this->feedResult( $obj );
 690                                 if ( $item ) {
 691                                         $feed->outItem( $item );
 692                                 }
 693                         }
 694
 695                         $feed->outFooter();
 696                         return true;
 697                 } else {
 698                         return false;
 699                 }
 700         }
 701
 702         /**
 703          * Override for custom handling. If the titles/links are ok, just do
 704          * feedItemDesc()
 705          * @param object $row
 706          * @return FeedItem|null
 707          */
 708         function feedResult( $row ) {
 709                 if ( !isset( $row->title ) ) {
 710                         return null;
 711                 }
 712                 $title = Title::makeTitle( intval( $row->namespace ), $row->title );
 713                 if ( $title ) {
 714                         $date = isset( $row->timestamp ) ? $row->timestamp : '';
 715                         $comments = '';
 716                         if ( $title ) {
 717                                 $talkpage = $title->getTalkPage();
 718                                 $comments = $talkpage->getFullURL();
 719                         }
 720
 721                         return new FeedItem(
 722                                 $title->getPrefixedText(),
 723                                 $this->feedItemDesc( $row ),
 724                                 $title->getFullURL(),
 725                                 $date,
 726                                 $this->feedItemAuthor( $row ),
 727                                 $comments );
 728                 } else {
 729                         return null;
 730                 }
 731         }
 732
 733         function feedItemDesc( $row ) {
 734                 return isset( $row->comment ) ? htmlspecialchars( $row->comment ) : '';
 735         }
 736
 737         function feedItemAuthor( $row ) {
 738                 return isset( $row->user_text ) ? $row->user_text : '';
 739         }
 740
 741         function feedTitle() {
 742                 global $wgLanguageCode, $wgSitename;
 743                 $desc = $this->getDescription();
 744                 return "$wgSitename - $desc [$wgLanguageCode]";
 745         }
 746
 747         function feedDesc() {
 748                 return $this->msg( 'tagline' )->text();
 749         }
 750
 751         function feedUrl() {
 752                 return $this->getPageTitle()->getFullURL();
 753         }
 754 }
 755
 756 /**
 757  * Class definition for a wanted query page like
 758  * WantedPages, WantedTemplates, etc
 759  */
 760 abstract class WantedQueryPage extends QueryPage {
 761         function isExpensive() {
 762                 return true;
 763         }
 764
 765         function isSyndicated() {
 766                 return false;
 767         }
 768
 769         /**
 770          * Cache page existence for performance
 771          * @param DatabaseBase $db
 772          * @param ResultWrapper $res
 773          */
 774         function preprocessResults( $db, $res ) {
 775                 if ( !$res->numRows() ) {
 776                         return;
 777                 }
 778
 779                 $batch = new LinkBatch;
 780                 foreach ( $res as $row ) {
 781                         $batch->add( $row->namespace, $row->title );
 782                 }
 783                 $batch->execute();
 784
 785                 // Back to start for display
 786                 $res->seek( 0 );
 787         }
 788
 789         /**
 790          * Should formatResult() always check page existence, even if
 791          * the results are fresh?  This is a (hopefully temporary)
 792          * kluge for Special:WantedFiles, which may contain false
 793          * positives for files that exist e.g. in a shared repo (bug
 794          * 6220).
 795          * @return bool
 796          */
 797         function forceExistenceCheck() {
 798                 return false;
 799         }
 800
 801         /**
 802          * Format an individual result
 803          *
 804          * @param Skin $skin Skin to use for UI elements
 805          * @param object $result Result row
 806          * @return string
 807          */
 808         public function formatResult( $skin, $result ) {
 809                 $title = Title::makeTitleSafe( $result->namespace, $result->title );
 810                 if ( $title instanceof Title ) {
 811                         if ( $this->isCached() || $this->forceExistenceCheck() ) {
 812                                 $pageLink = $title->isKnown()
 813                                         ? '<del>' . Linker::link( $title ) . '</del>'
 814                                         : Linker::link(
 815                                                 $title,
 816                                                 null,
 817                                                 array(),
 818                                                 array(),
 819                                                 array( 'broken' )
 820                                         );
 821                         } else {
 822                                 $pageLink = Linker::link(
 823                                         $title,
 824                                         null,
 825                                         array(),
 826                                         array(),
 827                                         array( 'broken' )
 828                                 );
 829                         }
 830                         return $this->getLanguage()->specialList( $pageLink, $this->makeWlhLink( $title, $result ) );
 831                 } else {
 832                         return $this->msg( 'wantedpages-badtitle', $result->title )->escaped();
 833                 }
 834         }
 835
 836         /**
 837          * Make a "what links here" link for a given title
 838          *
 839          * @param Title $title Title to make the link for
 840          * @param object $result Result row
 841          * @return string
 842          */
 843         private function makeWlhLink( $title, $result ) {
 844                 $wlh = SpecialPage::getTitleFor( 'Whatlinkshere', $title->getPrefixedText() );
 845                 $label = $this->msg( 'nlinks' )->numParams( $result->value )->escaped();
 846                 return Linker::link( $wlh, $label );
 847         }
 848 }