includes/api/ApiQueryBase.php

   1 <?php
   2 /**
   3  *
   4  *
   5  * Created on Sep 7, 2006
   6  *
   7  * Copyright © 2006 Yuri Astrakhan "<Firstname><Lastname>@gmail.com"
   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  */
  26
  27 use Wikimedia\Rdbms\IDatabase;
  28 use Wikimedia\Rdbms\ResultWrapper;
  29
  30 /**
  31  * This is a base class for all Query modules.
  32  * It provides some common functionality such as constructing various SQL
  33  * queries.
  34  *
  35  * @ingroup API
  36  */
  37 abstract class ApiQueryBase extends ApiBase {
  38
  39         private $mQueryModule, $mDb, $tables, $where, $fields, $options, $join_conds;
  40
  41         /**
  42          * @param ApiQuery $queryModule
  43          * @param string $moduleName
  44          * @param string $paramPrefix
  45          */
  46         public function __construct( ApiQuery $queryModule, $moduleName, $paramPrefix = '' ) {
  47                 parent::__construct( $queryModule->getMain(), $moduleName, $paramPrefix );
  48                 $this->mQueryModule = $queryModule;
  49                 $this->mDb = null;
  50                 $this->resetQueryParams();
  51         }
  52
  53         /************************************************************************//**
  54          * @name   Methods to implement
  55          * @{
  56          */
  57
  58         /**
  59          * Get the cache mode for the data generated by this module. Override
  60          * this in the module subclass. For possible return values and other
  61          * details about cache modes, see ApiMain::setCacheMode()
  62          *
  63          * Public caching will only be allowed if *all* the modules that supply
  64          * data for a given request return a cache mode of public.
  65          *
  66          * @param array $params
  67          * @return string
  68          */
  69         public function getCacheMode( $params ) {
  70                 return 'private';
  71         }
  72
  73         /**
  74          * Override this method to request extra fields from the pageSet
  75          * using $pageSet->requestField('fieldName')
  76          *
  77          * Note this only makes sense for 'prop' modules, as 'list' and 'meta'
  78          * modules should not be using the pageset.
  79          *
  80          * @param ApiPageSet $pageSet
  81          */
  82         public function requestExtraData( $pageSet ) {
  83         }
  84
  85         /**@}*/
  86
  87         /************************************************************************//**
  88          * @name   Data access
  89          * @{
  90          */
  91
  92         /**
  93          * Get the main Query module
  94          * @return ApiQuery
  95          */
  96         public function getQuery() {
  97                 return $this->mQueryModule;
  98         }
  99
 100         /** @inheritDoc */
 101         public function getParent() {
 102                 return $this->getQuery();
 103         }
 104
 105         /**
 106          * Get the Query database connection (read-only)
 107          * @return IDatabase
 108          */
 109         protected function getDB() {
 110                 if ( is_null( $this->mDb ) ) {
 111                         $this->mDb = $this->getQuery()->getDB();
 112                 }
 113
 114                 return $this->mDb;
 115         }
 116
 117         /**
 118          * Selects the query database connection with the given name.
 119          * See ApiQuery::getNamedDB() for more information
 120          * @param string $name Name to assign to the database connection
 121          * @param int $db One of the DB_* constants
 122          * @param string|string[] $groups Query groups
 123          * @return IDatabase
 124          */
 125         public function selectNamedDB( $name, $db, $groups ) {
 126                 $this->mDb = $this->getQuery()->getNamedDB( $name, $db, $groups );
 127                 return $this->mDb;
 128         }
 129
 130         /**
 131          * Get the PageSet object to work on
 132          * @return ApiPageSet
 133          */
 134         protected function getPageSet() {
 135                 return $this->getQuery()->getPageSet();
 136         }
 137
 138         /**@}*/
 139
 140         /************************************************************************//**
 141          * @name   Querying
 142          * @{
 143          */
 144
 145         /**
 146          * Blank the internal arrays with query parameters
 147          */
 148         protected function resetQueryParams() {
 149                 $this->tables = [];
 150                 $this->where = [];
 151                 $this->fields = [];
 152                 $this->options = [];
 153                 $this->join_conds = [];
 154         }
 155
 156         /**
 157          * Add a set of tables to the internal array
 158          * @param string|string[] $tables Table name or array of table names
 159          * @param string|null $alias Table alias, or null for no alias. Cannot be
 160          *  used with multiple tables
 161          */
 162         protected function addTables( $tables, $alias = null ) {
 163                 if ( is_array( $tables ) ) {
 164                         if ( !is_null( $alias ) ) {
 165                                 ApiBase::dieDebug( __METHOD__, 'Multiple table aliases not supported' );
 166                         }
 167                         $this->tables = array_merge( $this->tables, $tables );
 168                 } else {
 169                         if ( !is_null( $alias ) ) {
 170                                 $this->tables[$alias] = $tables;
 171                         } else {
 172                                 $this->tables[] = $tables;
 173                         }
 174                 }
 175         }
 176
 177         /**
 178          * Add a set of JOIN conditions to the internal array
 179          *
 180          * JOIN conditions are formatted as [ tablename => [ jointype, conditions ] ]
 181          * e.g. [ 'page' => [ 'LEFT JOIN', 'page_id=rev_page' ] ].
 182          * Conditions may be a string or an addWhere()-style array.
 183          * @param array $join_conds JOIN conditions
 184          */
 185         protected function addJoinConds( $join_conds ) {
 186                 if ( !is_array( $join_conds ) ) {
 187                         ApiBase::dieDebug( __METHOD__, 'Join conditions have to be arrays' );
 188                 }
 189                 $this->join_conds = array_merge( $this->join_conds, $join_conds );
 190         }
 191
 192         /**
 193          * Add a set of fields to select to the internal array
 194          * @param array|string $value Field name or array of field names
 195          */
 196         protected function addFields( $value ) {
 197                 if ( is_array( $value ) ) {
 198                         $this->fields = array_merge( $this->fields, $value );
 199                 } else {
 200                         $this->fields[] = $value;
 201                 }
 202         }
 203
 204         /**
 205          * Same as addFields(), but add the fields only if a condition is met
 206          * @param array|string $value See addFields()
 207          * @param bool $condition If false, do nothing
 208          * @return bool $condition
 209          */
 210         protected function addFieldsIf( $value, $condition ) {
 211                 if ( $condition ) {
 212                         $this->addFields( $value );
 213
 214                         return true;
 215                 }
 216
 217                 return false;
 218         }
 219
 220         /**
 221          * Add a set of WHERE clauses to the internal array.
 222          * Clauses can be formatted as 'foo=bar' or [ 'foo' => 'bar' ],
 223          * the latter only works if the value is a constant (i.e. not another field)
 224          *
 225          * If $value is an empty array, this function does nothing.
 226          *
 227          * For example, [ 'foo=bar', 'baz' => 3, 'bla' => 'foo' ] translates
 228          * to "foo=bar AND baz='3' AND bla='foo'"
 229          * @param string|array $value
 230          */
 231         protected function addWhere( $value ) {
 232                 if ( is_array( $value ) ) {
 233                         // Sanity check: don't insert empty arrays,
 234                         // Database::makeList() chokes on them
 235                         if ( count( $value ) ) {
 236                                 $this->where = array_merge( $this->where, $value );
 237                         }
 238                 } else {
 239                         $this->where[] = $value;
 240                 }
 241         }
 242
 243         /**
 244          * Same as addWhere(), but add the WHERE clauses only if a condition is met
 245          * @param string|array $value
 246          * @param bool $condition If false, do nothing
 247          * @return bool $condition
 248          */
 249         protected function addWhereIf( $value, $condition ) {
 250                 if ( $condition ) {
 251                         $this->addWhere( $value );
 252
 253                         return true;
 254                 }
 255
 256                 return false;
 257         }
 258
 259         /**
 260          * Equivalent to addWhere(array($field => $value))
 261          * @param string $field Field name
 262          * @param string|string[] $value Value; ignored if null or empty array;
 263          */
 264         protected function addWhereFld( $field, $value ) {
 265                 // Use count() to its full documented capabilities to simultaneously
 266                 // test for null, empty array or empty countable object
 267                 if ( count( $value ) ) {
 268                         $this->where[$field] = $value;
 269                 }
 270         }
 271
 272         /**
 273          * Add a WHERE clause corresponding to a range, and an ORDER BY
 274          * clause to sort in the right direction
 275          * @param string $field Field name
 276          * @param string $dir If 'newer', sort in ascending order, otherwise
 277          *  sort in descending order
 278          * @param string $start Value to start the list at. If $dir == 'newer'
 279          *  this is the lower boundary, otherwise it's the upper boundary
 280          * @param string $end Value to end the list at. If $dir == 'newer' this
 281          *  is the upper boundary, otherwise it's the lower boundary
 282          * @param bool $sort If false, don't add an ORDER BY clause
 283          */
 284         protected function addWhereRange( $field, $dir, $start, $end, $sort = true ) {
 285                 $isDirNewer = ( $dir === 'newer' );
 286                 $after = ( $isDirNewer ? '>=' : '<=' );
 287                 $before = ( $isDirNewer ? '<=' : '>=' );
 288                 $db = $this->getDB();
 289
 290                 if ( !is_null( $start ) ) {
 291                         $this->addWhere( $field . $after . $db->addQuotes( $start ) );
 292                 }
 293
 294                 if ( !is_null( $end ) ) {
 295                         $this->addWhere( $field . $before . $db->addQuotes( $end ) );
 296                 }
 297
 298                 if ( $sort ) {
 299                         $order = $field . ( $isDirNewer ? '' : ' DESC' );
 300                         // Append ORDER BY
 301                         $optionOrderBy = isset( $this->options['ORDER BY'] )
 302                                 ? (array)$this->options['ORDER BY']
 303                                 : [];
 304                         $optionOrderBy[] = $order;
 305                         $this->addOption( 'ORDER BY', $optionOrderBy );
 306                 }
 307         }
 308
 309         /**
 310          * Add a WHERE clause corresponding to a range, similar to addWhereRange,
 311          * but converts $start and $end to database timestamps.
 312          * @see addWhereRange
 313          * @param string $field
 314          * @param string $dir
 315          * @param string $start
 316          * @param string $end
 317          * @param bool $sort
 318          */
 319         protected function addTimestampWhereRange( $field, $dir, $start, $end, $sort = true ) {
 320                 $db = $this->getDB();
 321                 $this->addWhereRange( $field, $dir,
 322                         $db->timestampOrNull( $start ), $db->timestampOrNull( $end ), $sort );
 323         }
 324
 325         /**
 326          * Add an option such as LIMIT or USE INDEX. If an option was set
 327          * before, the old value will be overwritten
 328          * @param string $name Option name
 329          * @param string|string[] $value Option value
 330          */
 331         protected function addOption( $name, $value = null ) {
 332                 if ( is_null( $value ) ) {
 333                         $this->options[] = $name;
 334                 } else {
 335                         $this->options[$name] = $value;
 336                 }
 337         }
 338
 339         /**
 340          * Execute a SELECT query based on the values in the internal arrays
 341          * @param string $method Function the query should be attributed to.
 342          *  You should usually use __METHOD__ here
 343          * @param array $extraQuery Query data to add but not store in the object
 344          *  Format is [
 345          *    'tables' => ...,
 346          *    'fields' => ...,
 347          *    'where' => ...,
 348          *    'options' => ...,
 349          *    'join_conds' => ...
 350          *  ]
 351          * @param array|null &$hookData If set, the ApiQueryBaseBeforeQuery and
 352          *  ApiQueryBaseAfterQuery hooks will be called, and the
 353          *  ApiQueryBaseProcessRow hook will be expected.
 354          * @return ResultWrapper
 355          */
 356         protected function select( $method, $extraQuery = [], array &$hookData = null ) {
 357                 $tables = array_merge(
 358                         $this->tables,
 359                         isset( $extraQuery['tables'] ) ? (array)$extraQuery['tables'] : []
 360                 );
 361                 $fields = array_merge(
 362                         $this->fields,
 363                         isset( $extraQuery['fields'] ) ? (array)$extraQuery['fields'] : []
 364                 );
 365                 $where = array_merge(
 366                         $this->where,
 367                         isset( $extraQuery['where'] ) ? (array)$extraQuery['where'] : []
 368                 );
 369                 $options = array_merge(
 370                         $this->options,
 371                         isset( $extraQuery['options'] ) ? (array)$extraQuery['options'] : []
 372                 );
 373                 $join_conds = array_merge(
 374                         $this->join_conds,
 375                         isset( $extraQuery['join_conds'] ) ? (array)$extraQuery['join_conds'] : []
 376                 );
 377
 378                 if ( $hookData !== null ) {
 379                         Hooks::run( 'ApiQueryBaseBeforeQuery',
 380                                 [ $this, &$tables, &$fields, &$where, &$options, &$join_conds, &$hookData ]
 381                         );
 382                 }
 383
 384                 $res = $this->getDB()->select( $tables, $fields, $where, $method, $options, $join_conds );
 385
 386                 if ( $hookData !== null ) {
 387                         Hooks::run( 'ApiQueryBaseAfterQuery', [ $this, $res, &$hookData ] );
 388                 }
 389
 390                 return $res;
 391         }
 392
 393         /**
 394          * Call the ApiQueryBaseProcessRow hook
 395          *
 396          * Generally, a module that passed $hookData to self::select() will call
 397          * this just before calling ApiResult::addValue(), and treat a false return
 398          * here in the same way it treats a false return from addValue().
 399          *
 400          * @since 1.28
 401          * @param object $row Database row
 402          * @param array &$data Data to be added to the result
 403          * @param array &$hookData Hook data from ApiQueryBase::select()
 404          * @return bool Return false if row processing should end with continuation
 405          */
 406         protected function processRow( $row, array &$data, array &$hookData ) {
 407                 return Hooks::run( 'ApiQueryBaseProcessRow', [ $this, $row, &$data, &$hookData ] );
 408         }
 409
 410         /**
 411          * @param string $query
 412          * @param string $protocol
 413          * @return null|string
 414          */
 415         public function prepareUrlQuerySearchString( $query = null, $protocol = null ) {
 416                 $db = $this->getDB();
 417                 if ( !is_null( $query ) || $query != '' ) {
 418                         if ( is_null( $protocol ) ) {
 419                                 $protocol = 'http://';
 420                         }
 421
 422                         $likeQuery = LinkFilter::makeLikeArray( $query, $protocol );
 423                         if ( !$likeQuery ) {
 424                                 $this->dieWithError( 'apierror-badquery' );
 425                         }
 426
 427                         $likeQuery = LinkFilter::keepOneWildcard( $likeQuery );
 428
 429                         return 'el_index ' . $db->buildLike( $likeQuery );
 430                 } elseif ( !is_null( $protocol ) ) {
 431                         return 'el_index ' . $db->buildLike( "$protocol", $db->anyString() );
 432                 }
 433
 434                 return null;
 435         }
 436
 437         /**
 438          * Filters hidden users (where the user doesn't have the right to view them)
 439          * Also adds relevant block information
 440          *
 441          * @param bool $showBlockInfo
 442          * @return void
 443          */
 444         public function showHiddenUsersAddBlockInfo( $showBlockInfo ) {
 445                 $this->addTables( 'ipblocks' );
 446                 $this->addJoinConds( [
 447                         'ipblocks' => [ 'LEFT JOIN', 'ipb_user=user_id' ],
 448                 ] );
 449
 450                 $this->addFields( 'ipb_deleted' );
 451
 452                 if ( $showBlockInfo ) {
 453                         $this->addFields( [
 454                                 'ipb_id',
 455                                 'ipb_by',
 456                                 'ipb_by_text',
 457                                 'ipb_expiry',
 458                                 'ipb_timestamp'
 459                         ] );
 460                         $commentQuery = CommentStore::newKey( 'ipb_reason' )->getJoin();
 461                         $this->addTables( $commentQuery['tables'] );
 462                         $this->addFields( $commentQuery['fields'] );
 463                         $this->addJoinConds( $commentQuery['joins'] );
 464                 }
 465
 466                 // Don't show hidden names
 467                 if ( !$this->getUser()->isAllowed( 'hideuser' ) ) {
 468                         $this->addWhere( 'ipb_deleted = 0 OR ipb_deleted IS NULL' );
 469                 }
 470         }
 471
 472         /**@}*/
 473
 474         /************************************************************************//**
 475          * @name   Utility methods
 476          * @{
 477          */
 478
 479         /**
 480          * Add information (title and namespace) about a Title object to a
 481          * result array
 482          * @param array &$arr Result array à la ApiResult
 483          * @param Title $title
 484          * @param string $prefix Module prefix
 485          */
 486         public static function addTitleInfo( &$arr, $title, $prefix = '' ) {
 487                 $arr[$prefix . 'ns'] = intval( $title->getNamespace() );
 488                 $arr[$prefix . 'title'] = $title->getPrefixedText();
 489         }
 490
 491         /**
 492          * Add a sub-element under the page element with the given page ID
 493          * @param int $pageId Page ID
 494          * @param array $data Data array à la ApiResult
 495          * @return bool Whether the element fit in the result
 496          */
 497         protected function addPageSubItems( $pageId, $data ) {
 498                 $result = $this->getResult();
 499                 ApiResult::setIndexedTagName( $data, $this->getModulePrefix() );
 500
 501                 return $result->addValue( [ 'query', 'pages', intval( $pageId ) ],
 502                         $this->getModuleName(),
 503                         $data );
 504         }
 505
 506         /**
 507          * Same as addPageSubItems(), but one element of $data at a time
 508          * @param int $pageId Page ID
 509          * @param array $item Data array à la ApiResult
 510          * @param string $elemname XML element name. If null, getModuleName()
 511          *  is used
 512          * @return bool Whether the element fit in the result
 513          */
 514         protected function addPageSubItem( $pageId, $item, $elemname = null ) {
 515                 if ( is_null( $elemname ) ) {
 516                         $elemname = $this->getModulePrefix();
 517                 }
 518                 $result = $this->getResult();
 519                 $fit = $result->addValue( [ 'query', 'pages', $pageId,
 520                         $this->getModuleName() ], null, $item );
 521                 if ( !$fit ) {
 522                         return false;
 523                 }
 524                 $result->addIndexedTagName( [ 'query', 'pages', $pageId,
 525                         $this->getModuleName() ], $elemname );
 526
 527                 return true;
 528         }
 529
 530         /**
 531          * Set a query-continue value
 532          * @param string $paramName Parameter name
 533          * @param string|array $paramValue Parameter value
 534          */
 535         protected function setContinueEnumParameter( $paramName, $paramValue ) {
 536                 $this->getContinuationManager()->addContinueParam( $this, $paramName, $paramValue );
 537         }
 538
 539         /**
 540          * Convert an input title or title prefix into a dbkey.
 541          *
 542          * $namespace should always be specified in order to handle per-namespace
 543          * capitalization settings.
 544          *
 545          * @param string $titlePart Title part
 546          * @param int $namespace Namespace of the title
 547          * @return string DBkey (no namespace prefix)
 548          */
 549         public function titlePartToKey( $titlePart, $namespace = NS_MAIN ) {
 550                 $t = Title::makeTitleSafe( $namespace, $titlePart . 'x' );
 551                 if ( !$t || $t->hasFragment() ) {
 552                         // Invalid title (e.g. bad chars) or contained a '#'.
 553                         $this->dieWithError( [ 'apierror-invalidtitle', wfEscapeWikiText( $titlePart ) ] );
 554                 }
 555                 if ( $namespace != $t->getNamespace() || $t->isExternal() ) {
 556                         // This can happen in two cases. First, if you call titlePartToKey with a title part
 557                         // that looks like a namespace, but with $defaultNamespace = NS_MAIN. It would be very
 558                         // difficult to handle such a case. Such cases cannot exist and are therefore treated
 559                         // as invalid user input. The second case is when somebody specifies a title interwiki
 560                         // prefix.
 561                         $this->dieWithError( [ 'apierror-invalidtitle', wfEscapeWikiText( $titlePart ) ] );
 562                 }
 563
 564                 return substr( $t->getDBkey(), 0, -1 );
 565         }
 566
 567         /**
 568          * Convert an input title or title prefix into a namespace constant and dbkey.
 569          *
 570          * @since 1.26
 571          * @param string $titlePart Title part
 572          * @param int $defaultNamespace Default namespace if none is given
 573          * @return array (int, string) Namespace number and DBkey
 574          */
 575         public function prefixedTitlePartToKey( $titlePart, $defaultNamespace = NS_MAIN ) {
 576                 $t = Title::newFromText( $titlePart . 'x', $defaultNamespace );
 577                 if ( !$t || $t->hasFragment() || $t->isExternal() ) {
 578                         // Invalid title (e.g. bad chars) or contained a '#'.
 579                         $this->dieWithError( [ 'apierror-invalidtitle', wfEscapeWikiText( $titlePart ) ] );
 580                 }
 581
 582                 return [ $t->getNamespace(), substr( $t->getDBkey(), 0, -1 ) ];
 583         }
 584
 585         /**
 586          * @param string $hash
 587          * @return bool
 588          */
 589         public function validateSha1Hash( $hash ) {
 590                 return (bool)preg_match( '/^[a-f0-9]{40}$/', $hash );
 591         }
 592
 593         /**
 594          * @param string $hash
 595          * @return bool
 596          */
 597         public function validateSha1Base36Hash( $hash ) {
 598                 return (bool)preg_match( '/^[a-z0-9]{31}$/', $hash );
 599         }
 600
 601         /**
 602          * Check whether the current user has permission to view revision-deleted
 603          * fields.
 604          * @return bool
 605          */
 606         public function userCanSeeRevDel() {
 607                 return $this->getUser()->isAllowedAny(
 608                         'deletedhistory',
 609                         'deletedtext',
 610                         'suppressrevision',
 611                         'viewsuppressed'
 612                 );
 613         }
 614
 615         /**@}*/
 616 }