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\ResultWrapper;
  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
  35         private $mQueryModule, $mDb, $tables, $where, $fields, $options, $join_conds;
  36
  37         /**
  38          * @param ApiQuery $queryModule
  39          * @param string $moduleName
  40          * @param string $paramPrefix
  41          */
  42         public function __construct( ApiQuery $queryModule, $moduleName, $paramPrefix = '' ) {
  43                 parent::__construct( $queryModule->getMain(), $moduleName, $paramPrefix );
  44                 $this->mQueryModule = $queryModule;
  45                 $this->mDb = null;
  46                 $this->resetQueryParams();
  47         }
  48
  49         /************************************************************************//**
  50          * @name   Methods to implement
  51          * @{
  52          */
  53
  54         /**
  55          * Get the cache mode for the data generated by this module. Override
  56          * this in the module subclass. For possible return values and other
  57          * details about cache modes, see ApiMain::setCacheMode()
  58          *
  59          * Public caching will only be allowed if *all* the modules that supply
  60          * data for a given request return a cache mode of public.
  61          *
  62          * @param array $params
  63          * @return string
  64          */
  65         public function getCacheMode( $params ) {
  66                 return 'private';
  67         }
  68
  69         /**
  70          * Override this method to request extra fields from the pageSet
  71          * using $pageSet->requestField('fieldName')
  72          *
  73          * Note this only makes sense for 'prop' modules, as 'list' and 'meta'
  74          * modules should not be using the pageset.
  75          *
  76          * @param ApiPageSet $pageSet
  77          */
  78         public function requestExtraData( $pageSet ) {
  79         }
  80
  81         /**@}*/
  82
  83         /************************************************************************//**
  84          * @name   Data access
  85          * @{
  86          */
  87
  88         /**
  89          * Get the main Query module
  90          * @return ApiQuery
  91          */
  92         public function getQuery() {
  93                 return $this->mQueryModule;
  94         }
  95
  96         /** @inheritDoc */
  97         public function getParent() {
  98                 return $this->getQuery();
  99         }
 100
 101         /**
 102          * Get the Query database connection (read-only)
 103          * @return IDatabase
 104          */
 105         protected function getDB() {
 106                 if ( is_null( $this->mDb ) ) {
 107                         $this->mDb = $this->getQuery()->getDB();
 108                 }
 109
 110                 return $this->mDb;
 111         }
 112
 113         /**
 114          * Selects the query database connection with the given name.
 115          * See ApiQuery::getNamedDB() for more information
 116          * @param string $name Name to assign to the database connection
 117          * @param int $db One of the DB_* constants
 118          * @param string|string[] $groups Query groups
 119          * @return IDatabase
 120          */
 121         public function selectNamedDB( $name, $db, $groups ) {
 122                 $this->mDb = $this->getQuery()->getNamedDB( $name, $db, $groups );
 123                 return $this->mDb;
 124         }
 125
 126         /**
 127          * Get the PageSet object to work on
 128          * @return ApiPageSet
 129          */
 130         protected function getPageSet() {
 131                 return $this->getQuery()->getPageSet();
 132         }
 133
 134         /**@}*/
 135
 136         /************************************************************************//**
 137          * @name   Querying
 138          * @{
 139          */
 140
 141         /**
 142          * Blank the internal arrays with query parameters
 143          */
 144         protected function resetQueryParams() {
 145                 $this->tables = [];
 146                 $this->where = [];
 147                 $this->fields = [];
 148                 $this->options = [];
 149                 $this->join_conds = [];
 150         }
 151
 152         /**
 153          * Add a set of tables to the internal array
 154          * @param string|string[] $tables Table name or array of table names
 155          * @param string|null $alias Table alias, or null for no alias. Cannot be
 156          *  used with multiple tables
 157          */
 158         protected function addTables( $tables, $alias = null ) {
 159                 if ( is_array( $tables ) ) {
 160                         if ( !is_null( $alias ) ) {
 161                                 ApiBase::dieDebug( __METHOD__, 'Multiple table aliases not supported' );
 162                         }
 163                         $this->tables = array_merge( $this->tables, $tables );
 164                 } else {
 165                         if ( !is_null( $alias ) ) {
 166                                 $this->tables[$alias] = $tables;
 167                         } else {
 168                                 $this->tables[] = $tables;
 169                         }
 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( $value );
 248
 249                         return true;
 250                 }
 251
 252                 return false;
 253         }
 254
 255         /**
 256          * Equivalent to addWhere(array($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          * Add a WHERE clause corresponding to a range, and an ORDER BY
 268          * clause to sort in the right direction
 269          * @param string $field Field name
 270          * @param string $dir If 'newer', sort in ascending order, otherwise
 271          *  sort in descending order
 272          * @param string $start Value to start the list at. If $dir == 'newer'
 273          *  this is the lower boundary, otherwise it's the upper boundary
 274          * @param string $end Value to end the list at. If $dir == 'newer' this
 275          *  is the upper boundary, otherwise it's the lower boundary
 276          * @param bool $sort If false, don't add an ORDER BY clause
 277          */
 278         protected function addWhereRange( $field, $dir, $start, $end, $sort = true ) {
 279                 $isDirNewer = ( $dir === 'newer' );
 280                 $after = ( $isDirNewer ? '>=' : '<=' );
 281                 $before = ( $isDirNewer ? '<=' : '>=' );
 282                 $db = $this->getDB();
 283
 284                 if ( !is_null( $start ) ) {
 285                         $this->addWhere( $field . $after . $db->addQuotes( $start ) );
 286                 }
 287
 288                 if ( !is_null( $end ) ) {
 289                         $this->addWhere( $field . $before . $db->addQuotes( $end ) );
 290                 }
 291
 292                 if ( $sort ) {
 293                         $order = $field . ( $isDirNewer ? '' : ' DESC' );
 294                         // Append ORDER BY
 295                         $optionOrderBy = isset( $this->options['ORDER BY'] )
 296                                 ? (array)$this->options['ORDER BY']
 297                                 : [];
 298                         $optionOrderBy[] = $order;
 299                         $this->addOption( 'ORDER BY', $optionOrderBy );
 300                 }
 301         }
 302
 303         /**
 304          * Add a WHERE clause corresponding to a range, similar to addWhereRange,
 305          * but converts $start and $end to database timestamps.
 306          * @see addWhereRange
 307          * @param string $field
 308          * @param string $dir
 309          * @param string $start
 310          * @param string $end
 311          * @param bool $sort
 312          */
 313         protected function addTimestampWhereRange( $field, $dir, $start, $end, $sort = true ) {
 314                 $db = $this->getDB();
 315                 $this->addWhereRange( $field, $dir,
 316                         $db->timestampOrNull( $start ), $db->timestampOrNull( $end ), $sort );
 317         }
 318
 319         /**
 320          * Add an option such as LIMIT or USE INDEX. If an option was set
 321          * before, the old value will be overwritten
 322          * @param string $name Option name
 323          * @param string|string[] $value Option value
 324          */
 325         protected function addOption( $name, $value = null ) {
 326                 if ( is_null( $value ) ) {
 327                         $this->options[] = $name;
 328                 } else {
 329                         $this->options[$name] = $value;
 330                 }
 331         }
 332
 333         /**
 334          * Execute a SELECT query based on the values in the internal arrays
 335          * @param string $method Function the query should be attributed to.
 336          *  You should usually use __METHOD__ here
 337          * @param array $extraQuery Query data to add but not store in the object
 338          *  Format is [
 339          *    'tables' => ...,
 340          *    'fields' => ...,
 341          *    'where' => ...,
 342          *    'options' => ...,
 343          *    'join_conds' => ...
 344          *  ]
 345          * @param array|null &$hookData If set, the ApiQueryBaseBeforeQuery and
 346          *  ApiQueryBaseAfterQuery hooks will be called, and the
 347          *  ApiQueryBaseProcessRow hook will be expected.
 348          * @return ResultWrapper
 349          */
 350         protected function select( $method, $extraQuery = [], array &$hookData = null ) {
 351                 $tables = array_merge(
 352                         $this->tables,
 353                         isset( $extraQuery['tables'] ) ? (array)$extraQuery['tables'] : []
 354                 );
 355                 $fields = array_merge(
 356                         $this->fields,
 357                         isset( $extraQuery['fields'] ) ? (array)$extraQuery['fields'] : []
 358                 );
 359                 $where = array_merge(
 360                         $this->where,
 361                         isset( $extraQuery['where'] ) ? (array)$extraQuery['where'] : []
 362                 );
 363                 $options = array_merge(
 364                         $this->options,
 365                         isset( $extraQuery['options'] ) ? (array)$extraQuery['options'] : []
 366                 );
 367                 $join_conds = array_merge(
 368                         $this->join_conds,
 369                         isset( $extraQuery['join_conds'] ) ? (array)$extraQuery['join_conds'] : []
 370                 );
 371
 372                 if ( $hookData !== null ) {
 373                         Hooks::run( 'ApiQueryBaseBeforeQuery',
 374                                 [ $this, &$tables, &$fields, &$where, &$options, &$join_conds, &$hookData ]
 375                         );
 376                 }
 377
 378                 $res = $this->getDB()->select( $tables, $fields, $where, $method, $options, $join_conds );
 379
 380                 if ( $hookData !== null ) {
 381                         Hooks::run( 'ApiQueryBaseAfterQuery', [ $this, $res, &$hookData ] );
 382                 }
 383
 384                 return $res;
 385         }
 386
 387         /**
 388          * Call the ApiQueryBaseProcessRow hook
 389          *
 390          * Generally, a module that passed $hookData to self::select() will call
 391          * this just before calling ApiResult::addValue(), and treat a false return
 392          * here in the same way it treats a false return from addValue().
 393          *
 394          * @since 1.28
 395          * @param object $row Database row
 396          * @param array &$data Data to be added to the result
 397          * @param array &$hookData Hook data from ApiQueryBase::select()
 398          * @return bool Return false if row processing should end with continuation
 399          */
 400         protected function processRow( $row, array &$data, array &$hookData ) {
 401                 return Hooks::run( 'ApiQueryBaseProcessRow', [ $this, $row, &$data, &$hookData ] );
 402         }
 403
 404         /**
 405          * @param string $query
 406          * @param string $protocol
 407          * @return null|string
 408          */
 409         public function prepareUrlQuerySearchString( $query = null, $protocol = null ) {
 410                 $db = $this->getDB();
 411                 if ( !is_null( $query ) || $query != '' ) {
 412                         if ( is_null( $protocol ) ) {
 413                                 $protocol = 'http://';
 414                         }
 415
 416                         $likeQuery = LinkFilter::makeLikeArray( $query, $protocol );
 417                         if ( !$likeQuery ) {
 418                                 $this->dieWithError( 'apierror-badquery' );
 419                         }
 420
 421                         $likeQuery = LinkFilter::keepOneWildcard( $likeQuery );
 422
 423                         return 'el_index ' . $db->buildLike( $likeQuery );
 424                 } elseif ( !is_null( $protocol ) ) {
 425                         return 'el_index ' . $db->buildLike( "$protocol", $db->anyString() );
 426                 }
 427
 428                 return null;
 429         }
 430
 431         /**
 432          * Filters hidden users (where the user doesn't have the right to view them)
 433          * Also adds relevant block information
 434          *
 435          * @param bool $showBlockInfo
 436          * @return void
 437          */
 438         public function showHiddenUsersAddBlockInfo( $showBlockInfo ) {
 439                 $this->addTables( 'ipblocks' );
 440                 $this->addJoinConds( [
 441                         'ipblocks' => [ 'LEFT JOIN', 'ipb_user=user_id' ],
 442                 ] );
 443
 444                 $this->addFields( 'ipb_deleted' );
 445
 446                 if ( $showBlockInfo ) {
 447                         $this->addFields( [
 448                                 'ipb_id',
 449                                 'ipb_by',
 450                                 'ipb_by_text',
 451                                 'ipb_expiry',
 452                                 'ipb_timestamp'
 453                         ] );
 454                         $commentQuery = CommentStore::newKey( 'ipb_reason' )->getJoin();
 455                         $this->addTables( $commentQuery['tables'] );
 456                         $this->addFields( $commentQuery['fields'] );
 457                         $this->addJoinConds( $commentQuery['joins'] );
 458                 }
 459
 460                 // Don't show hidden names
 461                 if ( !$this->getUser()->isAllowed( 'hideuser' ) ) {
 462                         $this->addWhere( 'ipb_deleted = 0 OR ipb_deleted IS NULL' );
 463                 }
 464         }
 465
 466         /**@}*/
 467
 468         /************************************************************************//**
 469          * @name   Utility methods
 470          * @{
 471          */
 472
 473         /**
 474          * Add information (title and namespace) about a Title object to a
 475          * result array
 476          * @param array &$arr Result array à la ApiResult
 477          * @param Title $title
 478          * @param string $prefix Module prefix
 479          */
 480         public static function addTitleInfo( &$arr, $title, $prefix = '' ) {
 481                 $arr[$prefix . 'ns'] = intval( $title->getNamespace() );
 482                 $arr[$prefix . 'title'] = $title->getPrefixedText();
 483         }
 484
 485         /**
 486          * Add a sub-element under the page element with the given page ID
 487          * @param int $pageId Page ID
 488          * @param array $data Data array à la ApiResult
 489          * @return bool Whether the element fit in the result
 490          */
 491         protected function addPageSubItems( $pageId, $data ) {
 492                 $result = $this->getResult();
 493                 ApiResult::setIndexedTagName( $data, $this->getModulePrefix() );
 494
 495                 return $result->addValue( [ 'query', 'pages', intval( $pageId ) ],
 496                         $this->getModuleName(),
 497                         $data );
 498         }
 499
 500         /**
 501          * Same as addPageSubItems(), but one element of $data at a time
 502          * @param int $pageId Page ID
 503          * @param array $item Data array à la ApiResult
 504          * @param string $elemname XML element name. If null, getModuleName()
 505          *  is used
 506          * @return bool Whether the element fit in the result
 507          */
 508         protected function addPageSubItem( $pageId, $item, $elemname = null ) {
 509                 if ( is_null( $elemname ) ) {
 510                         $elemname = $this->getModulePrefix();
 511                 }
 512                 $result = $this->getResult();
 513                 $fit = $result->addValue( [ 'query', 'pages', $pageId,
 514                         $this->getModuleName() ], null, $item );
 515                 if ( !$fit ) {
 516                         return false;
 517                 }
 518                 $result->addIndexedTagName( [ 'query', 'pages', $pageId,
 519                         $this->getModuleName() ], $elemname );
 520
 521                 return true;
 522         }
 523
 524         /**
 525          * Set a query-continue value
 526          * @param string $paramName Parameter name
 527          * @param string|array $paramValue Parameter value
 528          */
 529         protected function setContinueEnumParameter( $paramName, $paramValue ) {
 530                 $this->getContinuationManager()->addContinueParam( $this, $paramName, $paramValue );
 531         }
 532
 533         /**
 534          * Convert an input title or title prefix into a dbkey.
 535          *
 536          * $namespace should always be specified in order to handle per-namespace
 537          * capitalization settings.
 538          *
 539          * @param string $titlePart Title part
 540          * @param int $namespace Namespace of the title
 541          * @return string DBkey (no namespace prefix)
 542          */
 543         public function titlePartToKey( $titlePart, $namespace = NS_MAIN ) {
 544                 $t = Title::makeTitleSafe( $namespace, $titlePart . 'x' );
 545                 if ( !$t || $t->hasFragment() ) {
 546                         // Invalid title (e.g. bad chars) or contained a '#'.
 547                         $this->dieWithError( [ 'apierror-invalidtitle', wfEscapeWikiText( $titlePart ) ] );
 548                 }
 549                 if ( $namespace != $t->getNamespace() || $t->isExternal() ) {
 550                         // This can happen in two cases. First, if you call titlePartToKey with a title part
 551                         // that looks like a namespace, but with $defaultNamespace = NS_MAIN. It would be very
 552                         // difficult to handle such a case. Such cases cannot exist and are therefore treated
 553                         // as invalid user input. The second case is when somebody specifies a title interwiki
 554                         // prefix.
 555                         $this->dieWithError( [ 'apierror-invalidtitle', wfEscapeWikiText( $titlePart ) ] );
 556                 }
 557
 558                 return substr( $t->getDBkey(), 0, -1 );
 559         }
 560
 561         /**
 562          * Convert an input title or title prefix into a namespace constant and dbkey.
 563          *
 564          * @since 1.26
 565          * @param string $titlePart Title part
 566          * @param int $defaultNamespace Default namespace if none is given
 567          * @return array (int, string) Namespace number and DBkey
 568          */
 569         public function prefixedTitlePartToKey( $titlePart, $defaultNamespace = NS_MAIN ) {
 570                 $t = Title::newFromText( $titlePart . 'x', $defaultNamespace );
 571                 if ( !$t || $t->hasFragment() || $t->isExternal() ) {
 572                         // Invalid title (e.g. bad chars) or contained a '#'.
 573                         $this->dieWithError( [ 'apierror-invalidtitle', wfEscapeWikiText( $titlePart ) ] );
 574                 }
 575
 576                 return [ $t->getNamespace(), substr( $t->getDBkey(), 0, -1 ) ];
 577         }
 578
 579         /**
 580          * @param string $hash
 581          * @return bool
 582          */
 583         public function validateSha1Hash( $hash ) {
 584                 return (bool)preg_match( '/^[a-f0-9]{40}$/', $hash );
 585         }
 586
 587         /**
 588          * @param string $hash
 589          * @return bool
 590          */
 591         public function validateSha1Base36Hash( $hash ) {
 592                 return (bool)preg_match( '/^[a-z0-9]{31}$/', $hash );
 593         }
 594
 595         /**
 596          * Check whether the current user has permission to view revision-deleted
 597          * fields.
 598          * @return bool
 599          */
 600         public function userCanSeeRevDel() {
 601                 return $this->getUser()->isAllowedAny(
 602                         'deletedhistory',
 603                         'deletedtext',
 604                         'suppressrevision',
 605                         'viewsuppressed'
 606                 );
 607         }
 608
 609         /**@}*/
 610 }