includes/api/ApiQueryBase.php

   1 <?php
   2 /**
   3  * Copyright © 2006 Yuri Astrakhan "<Firstname><Lastname>@gmail.com"
   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  */
  22
  23 use MediaWiki\MediaWikiServices;
  24 use Wikimedia\Rdbms\IDatabase;
  25 use Wikimedia\Rdbms\IResultWrapper;
  26
  27 /**
  28  * This is a base class for all Query modules.
  29  * It provides some common functionality such as constructing various SQL
  30  * queries.
  31  *
  32  * @ingroup API
  33  */
  34 abstract class ApiQueryBase extends ApiBase {
  35         use ApiQueryBlockInfoTrait;
  36
  37         private $mQueryModule, $mDb, $tables, $where, $fields, $options, $join_conds;
  38
  39         /**
  40          * @param ApiQuery $queryModule
  41          * @param string $moduleName
  42          * @param string $paramPrefix
  43          */
  44         public function __construct( ApiQuery $queryModule, $moduleName, $paramPrefix = '' ) {
  45                 parent::__construct( $queryModule->getMain(), $moduleName, $paramPrefix );
  46                 $this->mQueryModule = $queryModule;
  47                 $this->mDb = null;
  48                 $this->resetQueryParams();
  49         }
  50
  51         /************************************************************************//**
  52          * @name   Methods to implement
  53          * @{
  54          */
  55
  56         /**
  57          * Get the cache mode for the data generated by this module. Override
  58          * this in the module subclass. For possible return values and other
  59          * details about cache modes, see ApiMain::setCacheMode()
  60          *
  61          * Public caching will only be allowed if *all* the modules that supply
  62          * data for a given request return a cache mode of public.
  63          *
  64          * @param array $params
  65          * @return string
  66          */
  67         public function getCacheMode( $params ) {
  68                 return 'private';
  69         }
  70
  71         /**
  72          * Override this method to request extra fields from the pageSet
  73          * using $pageSet->requestField('fieldName')
  74          *
  75          * Note this only makes sense for 'prop' modules, as 'list' and 'meta'
  76          * modules should not be using the pageset.
  77          *
  78          * @param ApiPageSet $pageSet
  79          */
  80         public function requestExtraData( $pageSet ) {
  81         }
  82
  83         /** @} */
  84
  85         /************************************************************************//**
  86          * @name   Data access
  87          * @{
  88          */
  89
  90         /**
  91          * Get the main Query module
  92          * @return ApiQuery
  93          */
  94         public function getQuery() {
  95                 return $this->mQueryModule;
  96         }
  97
  98         /** @inheritDoc */
  99         public function getParent() {
 100                 return $this->getQuery();
 101         }
 102
 103         /**
 104          * Get the Query database connection (read-only)
 105          * @return IDatabase
 106          */
 107         protected function getDB() {
 108                 if ( is_null( $this->mDb ) ) {
 109                         $this->mDb = $this->getQuery()->getDB();
 110                 }
 111
 112                 return $this->mDb;
 113         }
 114
 115         /**
 116          * Selects the query database connection with the given name.
 117          * See ApiQuery::getNamedDB() for more information
 118          * @param string $name Name to assign to the database connection
 119          * @param int $db One of the DB_* constants
 120          * @param string|string[] $groups Query groups
 121          * @return IDatabase
 122          */
 123         public function selectNamedDB( $name, $db, $groups ) {
 124                 $this->mDb = $this->getQuery()->getNamedDB( $name, $db, $groups );
 125                 return $this->mDb;
 126         }
 127
 128         /**
 129          * Get the PageSet object to work on
 130          * @return ApiPageSet
 131          */
 132         protected function getPageSet() {
 133                 return $this->getQuery()->getPageSet();
 134         }
 135
 136         /** @} */
 137
 138         /************************************************************************//**
 139          * @name   Querying
 140          * @{
 141          */
 142
 143         /**
 144          * Blank the internal arrays with query parameters
 145          */
 146         protected function resetQueryParams() {
 147                 $this->tables = [];
 148                 $this->where = [];
 149                 $this->fields = [];
 150                 $this->options = [];
 151                 $this->join_conds = [];
 152         }
 153
 154         /**
 155          * Add a set of tables to the internal array
 156          * @param string|array $tables Table name or array of table names
 157          *  or nested arrays for joins using parentheses for grouping
 158          * @param string|null $alias Table alias, or null for no alias. Cannot be
 159          *  used with multiple tables
 160          */
 161         protected function addTables( $tables, $alias = null ) {
 162                 if ( is_array( $tables ) ) {
 163                         if ( $alias !== null ) {
 164                                 ApiBase::dieDebug( __METHOD__, 'Multiple table aliases not supported' );
 165                         }
 166                         $this->tables = array_merge( $this->tables, $tables );
 167                 } elseif ( $alias !== null ) {
 168                         $this->tables[$alias] = $tables;
 169                 } else {
 170                         $this->tables[] = $tables;
 171                 }
 172         }
 173
 174         /**
 175          * Add a set of JOIN conditions to the internal array
 176          *
 177          * JOIN conditions are formatted as [ tablename => [ jointype, conditions ] ]
 178          * e.g. [ 'page' => [ 'LEFT JOIN', 'page_id=rev_page' ] ].
 179          * Conditions may be a string or an addWhere()-style array.
 180          * @param array $join_conds JOIN conditions
 181          */
 182         protected function addJoinConds( $join_conds ) {
 183                 if ( !is_array( $join_conds ) ) {
 184                         ApiBase::dieDebug( __METHOD__, 'Join conditions have to be arrays' );
 185                 }
 186                 $this->join_conds = array_merge( $this->join_conds, $join_conds );
 187         }
 188
 189         /**
 190          * Add a set of fields to select to the internal array
 191          * @param array|string $value Field name or array of field names
 192          */
 193         protected function addFields( $value ) {
 194                 if ( is_array( $value ) ) {
 195                         $this->fields = array_merge( $this->fields, $value );
 196                 } else {
 197                         $this->fields[] = $value;
 198                 }
 199         }
 200
 201         /**
 202          * Same as addFields(), but add the fields only if a condition is met
 203          * @param array|string $value See addFields()
 204          * @param bool $condition If false, do nothing
 205          * @return bool $condition
 206          */
 207         protected function addFieldsIf( $value, $condition ) {
 208                 if ( $condition ) {
 209                         $this->addFields( $value );
 210
 211                         return true;
 212                 }
 213
 214                 return false;
 215         }
 216
 217         /**
 218          * Add a set of WHERE clauses to the internal array.
 219          * Clauses can be formatted as 'foo=bar' or [ 'foo' => 'bar' ],
 220          * the latter only works if the value is a constant (i.e. not another field)
 221          *
 222          * If $value is an empty array, this function does nothing.
 223          *
 224          * For example, [ 'foo=bar', 'baz' => 3, 'bla' => 'foo' ] translates
 225          * to "foo=bar AND baz='3' AND bla='foo'"
 226          * @param string|array $value
 227          */
 228         protected function addWhere( $value ) {
 229                 if ( is_array( $value ) ) {
 230                         // Sanity check: don't insert empty arrays,
 231                         // Database::makeList() chokes on them
 232                         if ( count( $value ) ) {
 233                                 $this->where = array_merge( $this->where, $value );
 234                         }
 235                 } else {
 236                         $this->where[] = $value;
 237                 }
 238         }
 239
 240         /**
 241          * Same as addWhere(), but add the WHERE clauses only if a condition is met
 242          * @param string|array $value
 243          * @param bool $condition If false, do nothing
 244          * @return bool $condition
 245          */
 246         protected function addWhereIf( $value, $condition ) {
 247                 if ( $condition ) {
 248                         $this->addWhere( $value );
 249
 250                         return true;
 251                 }
 252
 253                 return false;
 254         }
 255
 256         /**
 257          * Equivalent to addWhere( [ $field => $value ] )
 258          * @param string $field Field name
 259          * @param string|string[] $value Value; ignored if null or empty array
 260          */
 261         protected function addWhereFld( $field, $value ) {
 262                 if ( $value !== null && !( is_array( $value ) && !$value ) ) {
 263                         $this->where[$field] = $value;
 264                 }
 265         }
 266
 267         /**
 268          * Like addWhereFld for an integer list of IDs
 269          * @since 1.33
 270          * @param string $table Table name
 271          * @param string $field Field name
 272          * @param int[] $ids IDs
 273          * @return int Count of IDs actually included
 274          */
 275         protected function addWhereIDsFld( $table, $field, $ids ) {
 276                 // Use count() to its full documented capabilities to simultaneously
 277                 // test for null, empty array or empty countable object
 278                 if ( count( $ids ) ) {
 279                         $ids = $this->filterIDs( [ [ $table, $field ] ], $ids );
 280
 281                         if ( $ids === [] ) {
 282                                 // Return nothing, no IDs are valid
 283                                 $this->where[] = '0 = 1';
 284                         } else {
 285                                 $this->where[$field] = $ids;
 286                         }
 287                 }
 288                 return count( $ids );
 289         }
 290
 291         /**
 292          * Add a WHERE clause corresponding to a range, and an ORDER BY
 293          * clause to sort in the right direction
 294          * @param string $field Field name
 295          * @param string $dir If 'newer', sort in ascending order, otherwise
 296          *  sort in descending order
 297          * @param string $start Value to start the list at. If $dir == 'newer'
 298          *  this is the lower boundary, otherwise it's the upper boundary
 299          * @param string $end Value to end the list at. If $dir == 'newer' this
 300          *  is the upper boundary, otherwise it's the lower boundary
 301          * @param bool $sort If false, don't add an ORDER BY clause
 302          */
 303         protected function addWhereRange( $field, $dir, $start, $end, $sort = true ) {
 304                 $isDirNewer = ( $dir === 'newer' );
 305                 $after = ( $isDirNewer ? '>=' : '<=' );
 306                 $before = ( $isDirNewer ? '<=' : '>=' );
 307                 $db = $this->getDB();
 308
 309                 if ( !is_null( $start ) ) {
 310                         $this->addWhere( $field . $after . $db->addQuotes( $start ) );
 311                 }
 312
 313                 if ( !is_null( $end ) ) {
 314                         $this->addWhere( $field . $before . $db->addQuotes( $end ) );
 315                 }
 316
 317                 if ( $sort ) {
 318                         $order = $field . ( $isDirNewer ? '' : ' DESC' );
 319                         // Append ORDER BY
 320                         $optionOrderBy = isset( $this->options['ORDER BY'] )
 321                                 ? (array)$this->options['ORDER BY']
 322                                 : [];
 323                         $optionOrderBy[] = $order;
 324                         $this->addOption( 'ORDER BY', $optionOrderBy );
 325                 }
 326         }
 327
 328         /**
 329          * Add a WHERE clause corresponding to a range, similar to addWhereRange,
 330          * but converts $start and $end to database timestamps.
 331          * @see addWhereRange
 332          * @param string $field
 333          * @param string $dir
 334          * @param string $start
 335          * @param string $end
 336          * @param bool $sort
 337          */
 338         protected function addTimestampWhereRange( $field, $dir, $start, $end, $sort = true ) {
 339                 $db = $this->getDB();
 340                 $this->addWhereRange( $field, $dir,
 341                         $db->timestampOrNull( $start ), $db->timestampOrNull( $end ), $sort );
 342         }
 343
 344         /**
 345          * Add an option such as LIMIT or USE INDEX. If an option was set
 346          * before, the old value will be overwritten
 347          * @param string $name Option name
 348          * @param string|string[]|null $value Option value
 349          */
 350         protected function addOption( $name, $value = null ) {
 351                 if ( is_null( $value ) ) {
 352                         $this->options[] = $name;
 353                 } else {
 354                         $this->options[$name] = $value;
 355                 }
 356         }
 357
 358         /**
 359          * Execute a SELECT query based on the values in the internal arrays
 360          * @param string $method Function the query should be attributed to.
 361          *  You should usually use __METHOD__ here
 362          * @param array $extraQuery Query data to add but not store in the object
 363          *  Format is [
 364          *    'tables' => ...,
 365          *    'fields' => ...,
 366          *    'where' => ...,
 367          *    'options' => ...,
 368          *    'join_conds' => ...
 369          *  ]
 370          * @param array|null &$hookData If set, the ApiQueryBaseBeforeQuery and
 371          *  ApiQueryBaseAfterQuery hooks will be called, and the
 372          *  ApiQueryBaseProcessRow hook will be expected.
 373          * @return IResultWrapper
 374          */
 375         protected function select( $method, $extraQuery = [], array &$hookData = null ) {
 376                 $tables = array_merge(
 377                         $this->tables,
 378                         isset( $extraQuery['tables'] ) ? (array)$extraQuery['tables'] : []
 379                 );
 380                 $fields = array_merge(
 381                         $this->fields,
 382                         isset( $extraQuery['fields'] ) ? (array)$extraQuery['fields'] : []
 383                 );
 384                 $where = array_merge(
 385                         $this->where,
 386                         isset( $extraQuery['where'] ) ? (array)$extraQuery['where'] : []
 387                 );
 388                 $options = array_merge(
 389                         $this->options,
 390                         isset( $extraQuery['options'] ) ? (array)$extraQuery['options'] : []
 391                 );
 392                 $join_conds = array_merge(
 393                         $this->join_conds,
 394                         isset( $extraQuery['join_conds'] ) ? (array)$extraQuery['join_conds'] : []
 395                 );
 396
 397                 if ( $hookData !== null ) {
 398                         Hooks::run( 'ApiQueryBaseBeforeQuery',
 399                                 [ $this, &$tables, &$fields, &$where, &$options, &$join_conds, &$hookData ]
 400                         );
 401                 }
 402
 403                 $res = $this->getDB()->select( $tables, $fields, $where, $method, $options, $join_conds );
 404
 405                 if ( $hookData !== null ) {
 406                         Hooks::run( 'ApiQueryBaseAfterQuery', [ $this, $res, &$hookData ] );
 407                 }
 408
 409                 return $res;
 410         }
 411
 412         /**
 413          * Call the ApiQueryBaseProcessRow hook
 414          *
 415          * Generally, a module that passed $hookData to self::select() will call
 416          * this just before calling ApiResult::addValue(), and treat a false return
 417          * here in the same way it treats a false return from addValue().
 418          *
 419          * @since 1.28
 420          * @param object $row Database row
 421          * @param array &$data Data to be added to the result
 422          * @param array &$hookData Hook data from ApiQueryBase::select()
 423          * @return bool Return false if row processing should end with continuation
 424          */
 425         protected function processRow( $row, array &$data, array &$hookData ) {
 426                 return Hooks::run( 'ApiQueryBaseProcessRow', [ $this, $row, &$data, &$hookData ] );
 427         }
 428
 429         /** @} */
 430
 431         /************************************************************************//**
 432          * @name   Utility methods
 433          * @{
 434          */
 435
 436         /**
 437          * Add information (title and namespace) about a Title object to a
 438          * result array
 439          * @param array &$arr Result array à la ApiResult
 440          * @param Title $title
 441          * @param string $prefix Module prefix
 442          */
 443         public static function addTitleInfo( &$arr, $title, $prefix = '' ) {
 444                 $arr[$prefix . 'ns'] = (int)$title->getNamespace();
 445                 $arr[$prefix . 'title'] = $title->getPrefixedText();
 446         }
 447
 448         /**
 449          * Add a sub-element under the page element with the given page ID
 450          * @param int $pageId Page ID
 451          * @param array $data Data array à la ApiResult
 452          * @return bool Whether the element fit in the result
 453          */
 454         protected function addPageSubItems( $pageId, $data ) {
 455                 $result = $this->getResult();
 456                 ApiResult::setIndexedTagName( $data, $this->getModulePrefix() );
 457
 458                 return $result->addValue( [ 'query', 'pages', (int)$pageId ],
 459                         $this->getModuleName(),
 460                         $data );
 461         }
 462
 463         /**
 464          * Same as addPageSubItems(), but one element of $data at a time
 465          * @param int $pageId Page ID
 466          * @param mixed $item Data à la ApiResult
 467          * @param string|null $elemname XML element name. If null, getModuleName()
 468          *  is used
 469          * @return bool Whether the element fit in the result
 470          */
 471         protected function addPageSubItem( $pageId, $item, $elemname = null ) {
 472                 if ( is_null( $elemname ) ) {
 473                         $elemname = $this->getModulePrefix();
 474                 }
 475                 $result = $this->getResult();
 476                 $fit = $result->addValue( [ 'query', 'pages', $pageId,
 477                         $this->getModuleName() ], null, $item );
 478                 if ( !$fit ) {
 479                         return false;
 480                 }
 481                 $result->addIndexedTagName( [ 'query', 'pages', $pageId,
 482                         $this->getModuleName() ], $elemname );
 483
 484                 return true;
 485         }
 486
 487         /**
 488          * Set a query-continue value
 489          * @param string $paramName Parameter name
 490          * @param string|array $paramValue Parameter value
 491          */
 492         protected function setContinueEnumParameter( $paramName, $paramValue ) {
 493                 $this->getContinuationManager()->addContinueParam( $this, $paramName, $paramValue );
 494         }
 495
 496         /**
 497          * Convert an input title or title prefix into a dbkey.
 498          *
 499          * $namespace should always be specified in order to handle per-namespace
 500          * capitalization settings.
 501          *
 502          * @param string $titlePart Title part
 503          * @param int $namespace Namespace of the title
 504          * @return string DBkey (no namespace prefix)
 505          */
 506         public function titlePartToKey( $titlePart, $namespace = NS_MAIN ) {
 507                 $t = Title::makeTitleSafe( $namespace, $titlePart . 'x' );
 508                 if ( !$t || $t->hasFragment() ) {
 509                         // Invalid title (e.g. bad chars) or contained a '#'.
 510                         $this->dieWithError( [ 'apierror-invalidtitle', wfEscapeWikiText( $titlePart ) ] );
 511                 }
 512                 if ( $namespace != $t->getNamespace() || $t->isExternal() ) {
 513                         // This can happen in two cases. First, if you call titlePartToKey with a title part
 514                         // that looks like a namespace, but with $defaultNamespace = NS_MAIN. It would be very
 515                         // difficult to handle such a case. Such cases cannot exist and are therefore treated
 516                         // as invalid user input. The second case is when somebody specifies a title interwiki
 517                         // prefix.
 518                         $this->dieWithError( [ 'apierror-invalidtitle', wfEscapeWikiText( $titlePart ) ] );
 519                 }
 520
 521                 return substr( $t->getDBkey(), 0, -1 );
 522         }
 523
 524         /**
 525          * Convert an input title or title prefix into a namespace constant and dbkey.
 526          *
 527          * @since 1.26
 528          * @param string $titlePart Title part
 529          * @param int $defaultNamespace Default namespace if none is given
 530          * @return array (int, string) Namespace number and DBkey
 531          */
 532         public function prefixedTitlePartToKey( $titlePart, $defaultNamespace = NS_MAIN ) {
 533                 $t = Title::newFromText( $titlePart . 'x', $defaultNamespace );
 534                 if ( !$t || $t->hasFragment() || $t->isExternal() ) {
 535                         // Invalid title (e.g. bad chars) or contained a '#'.
 536                         $this->dieWithError( [ 'apierror-invalidtitle', wfEscapeWikiText( $titlePart ) ] );
 537                 }
 538
 539                 return [ $t->getNamespace(), substr( $t->getDBkey(), 0, -1 ) ];
 540         }
 541
 542         /**
 543          * @param string $hash
 544          * @return bool
 545          */
 546         public function validateSha1Hash( $hash ) {
 547                 return (bool)preg_match( '/^[a-f0-9]{40}$/', $hash );
 548         }
 549
 550         /**
 551          * @param string $hash
 552          * @return bool
 553          */
 554         public function validateSha1Base36Hash( $hash ) {
 555                 return (bool)preg_match( '/^[a-z0-9]{31}$/', $hash );
 556         }
 557
 558         /**
 559          * Check whether the current user has permission to view revision-deleted
 560          * fields.
 561          * @return bool
 562          */
 563         public function userCanSeeRevDel() {
 564                 return $this->getPermissionManager()->userHasAnyRight(
 565                         $this->getUser(),
 566                         'deletedhistory',
 567                         'deletedtext',
 568                         'suppressrevision',
 569                         'viewsuppressed'
 570                 );
 571         }
 572
 573         /**
 574          * Preprocess the result set to fill the GenderCache with the necessary information
 575          * before using self::addTitleInfo
 576          *
 577          * @param IResultWrapper $res Result set to work on.
 578          *  The result set must have _namespace and _title fields with the provided field prefix
 579          * @param string $fname The caller function name, always use __METHOD__
 580          * @param string $fieldPrefix Prefix for fields to check gender for
 581          */
 582         protected function executeGenderCacheFromResultWrapper(
 583                 IResultWrapper $res, $fname = __METHOD__, $fieldPrefix = 'page'
 584         ) {
 585                 if ( !$res->numRows() ) {
 586                         return;
 587                 }
 588
 589                 $services = MediaWikiServices::getInstance();
 590                 $nsInfo = $services->getNamespaceInfo();
 591                 $namespaceField = $fieldPrefix . '_namespace';
 592                 $titleField = $fieldPrefix . '_title';
 593
 594                 $usernames = [];
 595                 foreach ( $res as $row ) {
 596                         if ( $nsInfo->hasGenderDistinction( $row->$namespaceField ) ) {
 597                                 $usernames[] = $row->$titleField;
 598                         }
 599                 }
 600
 601                 if ( $usernames === [] ) {
 602                         return;
 603                 }
 604
 605                 $genderCache = $services->getGenderCache();
 606                 $genderCache->doQuery( $usernames, $fname );
 607         }
 608
 609         /** @} */
 610
 611         /************************************************************************//**
 612          * @name   Deprecated methods
 613          * @{
 614          */
 615
 616         /**
 617          * Filters hidden users (where the user doesn't have the right to view them)
 618          * Also adds relevant block information
 619          *
 620          * @deprecated since 1.34, use ApiQueryBlockInfoTrait instead
 621          * @param bool $showBlockInfo
 622          * @return void
 623          */
 624         public function showHiddenUsersAddBlockInfo( $showBlockInfo ) {
 625                 wfDeprecated( __METHOD__, '1.34' );
 626                 return $this->addBlockInfoToQuery( $showBlockInfo );
 627         }
 628
 629         /** @} */
 630 }