includes/api/ApiQueryBacklinksprop.php

   1 <?php
   2 /**
   3  * API module to handle links table back-queries
   4  *
   5  * Created on Aug 19, 2014
   6  *
   7  * Copyright © 2014 Brad Jorsch <bjorsch@wikimedia.org>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License along
  20  * with this program; if not, write to the Free Software Foundation, Inc.,
  21  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  22  * http://www.gnu.org/copyleft/gpl.html
  23  *
  24  * @file
  25  * @since 1.24
  26  */
  27
  28 /**
  29  * This implements prop=redirects, prop=linkshere, prop=catmembers,
  30  * prop=transcludedin, and prop=fileusage
  31  *
  32  * @ingroup API
  33  * @since 1.24
  34  */
  35 class ApiQueryBacklinksprop extends ApiQueryGeneratorBase {
  36
  37         // Data for the various modules implemented by this class
  38         private static $settings = array(
  39                 'redirects' => array(
  40                         'code' => 'rd',
  41                         'prefix' => 'rd',
  42                         'linktable' => 'redirect',
  43                         'what' => 'redirects to',
  44                         'description' => 'Returns all redirects to the given pages.',
  45                         'props' => array(
  46                                 'fragment' => 'Fragment of each redirect, if any',
  47                         ),
  48                         'showredirects' => false,
  49                         'show' => array(
  50                                 'fragment' => 'Only show redirects with a fragment',
  51                                 '!fragment' => 'Only show redirects without a fragment',
  52                         ),
  53                 ),
  54                 'linkshere' => array(
  55                         'code' => 'lh',
  56                         'prefix' => 'pl',
  57                         'linktable' => 'pagelinks',
  58                         'from_namespace' => true,
  59                         'what' => 'pages linking to',
  60                         'description' => 'Find all pages that link to the given pages.',
  61                         'showredirects' => true,
  62                 ),
  63                 'transcludedin' => array(
  64                         'code' => 'ti',
  65                         'prefix' => 'tl',
  66                         'linktable' => 'templatelinks',
  67                         'from_namespace' => true,
  68                         'what' => 'pages transcluding',
  69                         'description' => 'Find all pages that transclude the given pages.',
  70                         'showredirects' => true,
  71                 ),
  72                 'fileusage' => array(
  73                         'code' => 'fu',
  74                         'prefix' => 'il',
  75                         'linktable' => 'imagelinks',
  76                         'from_namespace' => true,
  77                         'to_namespace' => NS_FILE,
  78                         'what' => 'pages using',
  79                         'exampletitle' => 'File:Example.jpg',
  80                         'description' => 'Find all pages that use the given files.',
  81                         'showredirects' => true,
  82                 ),
  83         );
  84
  85         public function __construct( ApiQuery $query, $moduleName ) {
  86                 parent::__construct( $query, $moduleName, self::$settings[$moduleName]['code'] );
  87         }
  88
  89         public function execute() {
  90                 $this->run();
  91         }
  92
  93         public function executeGenerator( $resultPageSet ) {
  94                 $this->run( $resultPageSet );
  95         }
  96
  97         /**
  98          * @param ApiPageSet $resultPageSet
  99          */
 100         private function run( ApiPageSet $resultPageSet = null ) {
 101                 $settings = self::$settings[$this->getModuleName()];
 102
 103                 $db = $this->getDB();
 104                 $params = $this->extractRequestParams();
 105                 $prop = array_flip( $params['prop'] );
 106                 $emptyString = $db->addQuotes( '' );
 107
 108                 $pageSet = $this->getPageSet();
 109                 $titles = $pageSet->getGoodAndMissingTitles();
 110                 $map = $pageSet->getGoodAndMissingTitlesByNamespace();
 111
 112                 // Determine our fields to query on
 113                 $p = $settings['prefix'];
 114                 $hasNS = !isset( $settings['to_namespace'] );
 115                 if ( $hasNS ) {
 116                         $bl_namespace = "{$p}_namespace";
 117                         $bl_title = "{$p}_title";
 118                 } else {
 119                         $bl_namespace = $settings['to_namespace'];
 120                         $bl_title = "{$p}_to";
 121
 122                         $titles = array_filter( $titles, function ( $t ) use ( $bl_namespace ) {
 123                                 return $t->getNamespace() === $bl_namespace;
 124                         } );
 125                         $map = array_intersect_key( $map, array( $bl_namespace => true ) );
 126                 }
 127                 $bl_from = "{$p}_from";
 128
 129                 if ( !$titles ) {
 130                         return; // nothing to do
 131                 }
 132
 133                 // Figure out what we're sorting by, and add associated WHERE clauses.
 134                 // MySQL's query planner screws up if we include a field in ORDER BY
 135                 // when it's constant in WHERE, so we have to test that for each field.
 136                 $sortby = array();
 137                 if ( $hasNS && count( $map ) > 1 ) {
 138                         $sortby[$bl_namespace] = 'ns';
 139                 }
 140                 $theTitle = null;
 141                 foreach ( $map as $nsTitles ) {
 142                         reset( $nsTitles );
 143                         $key = key( $nsTitles );
 144                         if ( $theTitle === null ) {
 145                                 $theTitle = $key;
 146                         }
 147                         if ( count( $nsTitles ) > 1 || $key !== $theTitle ) {
 148                                 $sortby[$bl_title] = 'title';
 149                                 break;
 150                         }
 151                 }
 152                 $miser_ns = null;
 153                 if ( $params['namespace'] !== null ) {
 154                         if ( empty( $settings['from_namespace'] ) && $this->getConfig()->get( 'MiserMode' ) ) {
 155                                 $miser_ns = $params['namespace'];
 156                         } else {
 157                                 $this->addWhereFld( "{$p}_from_namespace", $params['namespace'] );
 158                                 if ( !empty( $settings['from_namespace'] ) && count( $params['namespace'] ) > 1 ) {
 159                                         $sortby["{$p}_from_namespace"] = 'int';
 160                                 }
 161                         }
 162                 }
 163                 $sortby[$bl_from] = 'int';
 164
 165                 // Now use the $sortby to figure out the continuation
 166                 if ( !is_null( $params['continue'] ) ) {
 167                         $cont = explode( '|', $params['continue'] );
 168                         $this->dieContinueUsageIf( count( $cont ) != count( $sortby ) );
 169                         $where = '';
 170                         $i = count( $sortby ) - 1;
 171                         $cont_ns = 0;
 172                         $cont_title = '';
 173                         foreach ( array_reverse( $sortby, true ) as $field => $type ) {
 174                                 $v = $cont[$i];
 175                                 switch ( $type ) {
 176                                         case 'ns':
 177                                                 $cont_ns = (int)$v;
 178                                                 /* fall through */
 179                                         case 'int':
 180                                                 $v = (int)$v;
 181                                                 $this->dieContinueUsageIf( $v != $cont[$i] );
 182                                                 break;
 183
 184                                         case 'title':
 185                                                 $cont_title = $v;
 186                                                 /* fall through */
 187                                         default:
 188                                                 $v = $db->addQuotes( $v );
 189                                                 break;
 190                                 }
 191
 192                                 if ( $where === '' ) {
 193                                         $where = "$field >= $v";
 194                                 } else {
 195                                         $where = "$field > $v OR ($field = $v AND ($where))";
 196                                 }
 197
 198                                 $i--;
 199                         }
 200                         $this->addWhere( $where );
 201                 }
 202
 203                 // Populate the rest of the query
 204                 $this->addTables( array( $settings['linktable'], 'page' ) );
 205                 $this->addWhere( "$bl_from = page_id" );
 206
 207                 if ( $this->getModuleName() === 'redirects' ) {
 208                         $this->addWhere( "rd_interwiki = $emptyString OR rd_interwiki IS NULL" );
 209                 }
 210
 211                 $this->addFields( array_keys( $sortby ) );
 212                 $this->addFields( array( 'bl_namespace' => $bl_namespace, 'bl_title' => $bl_title ) );
 213                 if ( is_null( $resultPageSet ) ) {
 214                         $fld_pageid = isset( $prop['pageid'] );
 215                         $fld_title = isset( $prop['title'] );
 216                         $fld_redirect = isset( $prop['redirect'] );
 217
 218                         $this->addFieldsIf( 'page_id', $fld_pageid );
 219                         $this->addFieldsIf( array( 'page_title', 'page_namespace' ), $fld_title );
 220                         $this->addFieldsIf( 'page_is_redirect', $fld_redirect );
 221
 222                         // prop=redirects
 223                         $fld_fragment = isset( $prop['fragment'] );
 224                         $this->addFieldsIf( 'rd_fragment', $fld_fragment );
 225                 } else {
 226                         $this->addFields( $resultPageSet->getPageTableFields() );
 227                 }
 228
 229                 $this->addFieldsIf( 'page_namespace', $miser_ns !== null );
 230
 231                 if ( $hasNS ) {
 232                         $lb = new LinkBatch( $titles );
 233                         $this->addWhere( $lb->constructSet( $p, $db ) );
 234                 } else {
 235                         $where = array();
 236                         foreach ( $titles as $t ) {
 237                                 if ( $t->getNamespace() == $bl_namespace ) {
 238                                         $where[] = "$bl_title = " . $db->addQuotes( $t->getDBkey() );
 239                                 }
 240                         }
 241                         $this->addWhere( $db->makeList( $where, LIST_OR ) );
 242                 }
 243
 244                 if ( $params['show'] !== null ) {
 245                         // prop=redirects only
 246                         $show = array_flip( $params['show'] );
 247                         if ( isset( $show['fragment'] ) && isset( $show['!fragment'] ) ||
 248                                 isset( $show['redirect'] ) && isset( $show['!redirect'] )
 249                         ) {
 250                                 $this->dieUsageMsg( 'show' );
 251                         }
 252                         $this->addWhereIf( "rd_fragment != $emptyString", isset( $show['fragment'] ) );
 253                         $this->addWhereIf(
 254                                 "rd_fragment = $emptyString OR rd_fragment IS NULL",
 255                                 isset( $show['!fragment'] )
 256                         );
 257                         $this->addWhereIf( array( 'page_is_redirect' => 1 ), isset( $show['redirect'] ) );
 258                         $this->addWhereIf( array( 'page_is_redirect' => 0 ), isset( $show['!redirect'] ) );
 259                 }
 260
 261                 // Override any ORDER BY from above with what we calculated earlier.
 262                 $this->addOption( 'ORDER BY', array_keys( $sortby ) );
 263
 264                 $this->addOption( 'LIMIT', $params['limit'] + 1 );
 265
 266                 $res = $this->select( __METHOD__ );
 267
 268                 if ( is_null( $resultPageSet ) ) {
 269                         $count = 0;
 270                         foreach ( $res as $row ) {
 271                                 if ( ++$count > $params['limit'] ) {
 272                                         // We've reached the one extra which shows that
 273                                         // there are additional pages to be had. Stop here...
 274                                         $this->setContinue( $row, $sortby );
 275                                         break;
 276                                 }
 277
 278                                 if ( $miser_ns !== null && !in_array( $row->page_namespace, $miser_ns ) ) {
 279                                         // Miser mode namespace check
 280                                         continue;
 281                                 }
 282
 283                                 // Get the ID of the current page
 284                                 $id = $map[$row->bl_namespace][$row->bl_title];
 285
 286                                 $vals = array();
 287                                 if ( $fld_pageid ) {
 288                                         $vals['pageid'] = $row->page_id;
 289                                 }
 290                                 if ( $fld_title ) {
 291                                         ApiQueryBase::addTitleInfo( $vals,
 292                                                 Title::makeTitle( $row->page_namespace, $row->page_title )
 293                                         );
 294                                 }
 295                                 if ( $fld_fragment && $row->rd_fragment !== null && $row->rd_fragment !== '' ) {
 296                                         $vals['fragment'] = $row->rd_fragment;
 297                                 }
 298                                 if ( $fld_redirect && $row->page_is_redirect ) {
 299                                         $vals['redirect'] = '';
 300                                 }
 301                                 $fit = $this->addPageSubItem( $id, $vals );
 302                                 if ( !$fit ) {
 303                                         $this->setContinue( $row, $sortby );
 304                                         break;
 305                                 }
 306                         }
 307                 } else {
 308                         $titles = array();
 309                         $count = 0;
 310                         foreach ( $res as $row ) {
 311                                 if ( ++$count > $params['limit'] ) {
 312                                         // We've reached the one extra which shows that
 313                                         // there are additional pages to be had. Stop here...
 314                                         $this->setContinue( $row, $sortby );
 315                                         break;
 316                                 }
 317                                 $titles[] = Title::makeTitle( $row->page_namespace, $row->page_title );
 318                         }
 319                         $resultPageSet->populateFromTitles( $titles );
 320                 }
 321         }
 322
 323         private function setContinue( $row, $sortby ) {
 324                 $cont = array();
 325                 foreach ( $sortby as $field => $v ) {
 326                         $cont[] = $row->$field;
 327                 }
 328                 $this->setContinueEnumParameter( 'continue', join( '|', $cont ) );
 329         }
 330
 331         public function getCacheMode( $params ) {
 332                 return 'public';
 333         }
 334
 335         public function getAllowedParams() {
 336                 $settings = self::$settings[$this->getModuleName()];
 337
 338                 $ret = array(
 339                         'prop' => array(
 340                                 ApiBase::PARAM_TYPE => array(
 341                                         'pageid',
 342                                         'title',
 343                                 ),
 344                                 ApiBase::PARAM_ISMULTI => true,
 345                                 ApiBase::PARAM_DFLT => 'pageid|title',
 346                         ),
 347                         'namespace' => array(
 348                                 ApiBase::PARAM_ISMULTI => true,
 349                                 ApiBase::PARAM_TYPE => 'namespace',
 350                         ),
 351                         'limit' => array(
 352                                 ApiBase::PARAM_DFLT => 10,
 353                                 ApiBase::PARAM_TYPE => 'limit',
 354                                 ApiBase::PARAM_MIN => 1,
 355                                 ApiBase::PARAM_MAX => ApiBase::LIMIT_BIG1,
 356                                 ApiBase::PARAM_MAX2 => ApiBase::LIMIT_BIG2
 357                         ),
 358                         'continue' => null,
 359                 );
 360
 361                 if ( !empty( $settings['showredirects'] ) ) {
 362                         $ret['prop'][ApiBase::PARAM_TYPE][] = 'redirect';
 363                         $ret['prop'][ApiBase::PARAM_DFLT] .= '|redirect';
 364                 }
 365                 if ( isset( $settings['props'] ) ) {
 366                         $ret['prop'][ApiBase::PARAM_TYPE] = array_merge(
 367                                 $ret['prop'][ApiBase::PARAM_TYPE], array_keys( $settings['props'] )
 368                         );
 369                 }
 370
 371                 $show = array();
 372                 if ( !empty( $settings['showredirects'] ) ) {
 373                         $show[] = 'redirect';
 374                         $show[] = '!redirect';
 375                 }
 376                 if ( isset( $settings['show'] ) ) {
 377                         $show = array_merge( $show, array_keys( $settings['show'] ) );
 378                 }
 379                 if ( $show ) {
 380                         $ret['show'] = array(
 381                                 ApiBase::PARAM_TYPE => $show,
 382                                 ApiBase::PARAM_ISMULTI => true,
 383                         );
 384                 }
 385
 386                 return $ret;
 387         }
 388
 389         public function getParamDescription() {
 390                 $settings = self::$settings[$this->getModuleName()];
 391                 $p = $this->getModulePrefix();
 392
 393                 $ret = array(
 394                         'prop' => array(
 395                                 'Which properties to get:',
 396                         ),
 397                         'show' => array(
 398                                 'Show only items that meet this criteria.',
 399                         ),
 400                         'namespace' => 'Only include pages in these namespaces',
 401                         'limit' => 'How many to return',
 402                         'continue' => 'When more results are available, use this to continue',
 403                 );
 404
 405                 if ( empty( $settings['from_namespace'] ) && $this->getConfig()->get( 'MiserMode' ) ) {
 406                         $ret['namespace'] = array(
 407                                 $ret['namespace'],
 408                                 "NOTE: Due to \$wgMiserMode, using this may result in fewer than \"{$p}limit\" results",
 409                                 'returned before continuing; in extreme cases, zero results may be returned.',
 410                         );
 411                         if ( isset( $ret['type'] ) ) {
 412                                 $ret['namespace'][] = "Note that you can use {$p}type=subcat or {$p}type=file " .
 413                                         "instead of {$p}namespace=14 or 6.";
 414                         }
 415                 }
 416
 417                 $props = array(
 418                         'pageid' => 'Adds the ID of page',
 419                         'title' => 'Adds the title and namespace ID of the page',
 420                 );
 421                 if ( !empty( $settings['showredirects'] ) ) {
 422                         $props['redirect'] = 'Indicate if the page is a redirect';
 423                 }
 424                 if ( isset( $settings['props'] ) ) {
 425                         $props += $settings['props'];
 426                 }
 427                 foreach ( $props as $k => $v ) {
 428                         $ret['props'][] = sprintf( "%-9s - %s", $k, $v );
 429                 }
 430
 431                 $show = array();
 432                 if ( !empty( $settings['showredirects'] ) ) {
 433                         $show += array(
 434                                 'redirect' => 'Only show redirects',
 435                                 '!redirect' => 'Only show non-redirects',
 436                         );
 437                 }
 438                 if ( isset( $settings['show'] ) ) {
 439                         $show += $settings['show'];
 440                 }
 441                 foreach ( $show as $k => $v ) {
 442                         $ret['show'][] = sprintf( "%-9s - %s", $k, $v );
 443                 }
 444
 445                 return $ret;
 446         }
 447
 448         public function getDescription() {
 449                 return self::$settings[$this->getModuleName()]['description'];
 450         }
 451
 452         public function getExamples() {
 453                 $settings = self::$settings[$this->getModuleName()];
 454                 $name = $this->getModuleName();
 455                 $what = $settings['what'];
 456                 $title = isset( $settings['exampletitle'] ) ? $settings['exampletitle'] : 'Main Page';
 457                 $etitle = rawurlencode( $title );
 458
 459                 return array(
 460                         "api.php?action=query&prop={$name}&titles={$etitle}"
 461                                 => "Get a list of $what [[$title]]",
 462                         "api.php?action=query&generator={$name}&titles={$etitle}&prop=info"
 463                                 => "Get information about $what [[$title]]",
 464                 );
 465         }
 466
 467         public function getHelpUrls() {
 468                 $name = $this->getModuleName();
 469                 $prefix = $this->getModulePrefix();
 470                 return "https://www.mediawiki.org/wiki/API:Properties#{$name}_.2F_{$prefix}";
 471         }
 472 }