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