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