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 /**
  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
  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         /**
  98          * @see ApiBase::getParent()
  99          */
 100         public function getParent() {
 101                 return $this->getQuery();
 102         }
 103
 104         /**
 105          * Get the Query database connection (read-only)
 106          * @return Database
 107          */
 108         protected function getDB() {
 109                 if ( is_null( $this->mDb ) ) {
 110                         $this->mDb = $this->getQuery()->getDB();
 111                 }
 112
 113                 return $this->mDb;
 114         }
 115
 116         /**
 117          * Selects the query database connection with the given name.
 118          * See ApiQuery::getNamedDB() for more information
 119          * @param string $name Name to assign to the database connection
 120          * @param int $db One of the DB_* constants
 121          * @param array $groups Query groups
 122          * @return Database
 123          */
 124         public function selectNamedDB( $name, $db, $groups ) {
 125                 $this->mDb = $this->getQuery()->getNamedDB( $name, $db, $groups );
 126                 return $this->mDb;
 127         }
 128
 129         /**
 130          * Get the PageSet object to work on
 131          * @return ApiPageSet
 132          */
 133         protected function getPageSet() {
 134                 return $this->getQuery()->getPageSet();
 135         }
 136
 137         /**@}*/
 138
 139         /************************************************************************//**
 140          * @name   Querying
 141          * @{
 142          */
 143
 144         /**
 145          * Blank the internal arrays with query parameters
 146          */
 147         protected function resetQueryParams() {
 148                 $this->tables = [];
 149                 $this->where = [];
 150                 $this->fields = [];
 151                 $this->options = [];
 152                 $this->join_conds = [];
 153         }
 154
 155         /**
 156          * Add a set of tables to the internal array
 157          * @param string|string[] $tables Table name or array of table names
 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 ( !is_null( $alias ) ) {
 164                                 ApiBase::dieDebug( __METHOD__, 'Multiple table aliases not supported' );
 165                         }
 166                         $this->tables = array_merge( $this->tables, $tables );
 167                 } else {
 168                         if ( !is_null( $alias ) ) {
 169                                 $this->tables[$alias] = $tables;
 170                         } else {
 171                                 $this->tables[] = $tables;
 172                         }
 173                 }
 174         }
 175
 176         /**
 177          * Add a set of JOIN conditions to the internal array
 178          *
 179          * JOIN conditions are formatted as [ tablename => [ jointype, conditions ] ]
 180          * e.g. [ 'page' => [ 'LEFT JOIN', 'page_id=rev_page' ] ].
 181          * Conditions may be a string or an addWhere()-style array.
 182          * @param array $join_conds JOIN conditions
 183          */
 184         protected function addJoinConds( $join_conds ) {
 185                 if ( !is_array( $join_conds ) ) {
 186                         ApiBase::dieDebug( __METHOD__, 'Join conditions have to be arrays' );
 187                 }
 188                 $this->join_conds = array_merge( $this->join_conds, $join_conds );
 189         }
 190
 191         /**
 192          * Add a set of fields to select to the internal array
 193          * @param array|string $value Field name or array of field names
 194          */
 195         protected function addFields( $value ) {
 196                 if ( is_array( $value ) ) {
 197                         $this->fields = array_merge( $this->fields, $value );
 198                 } else {
 199                         $this->fields[] = $value;
 200                 }
 201         }
 202
 203         /**
 204          * Same as addFields(), but add the fields only if a condition is met
 205          * @param array|string $value See addFields()
 206          * @param bool $condition If false, do nothing
 207          * @return bool $condition
 208          */
 209         protected function addFieldsIf( $value, $condition ) {
 210                 if ( $condition ) {
 211                         $this->addFields( $value );
 212
 213                         return true;
 214                 }
 215
 216                 return false;
 217         }
 218
 219         /**
 220          * Add a set of WHERE clauses to the internal array.
 221          * Clauses can be formatted as 'foo=bar' or [ 'foo' => 'bar' ],
 222          * the latter only works if the value is a constant (i.e. not another field)
 223          *
 224          * If $value is an empty array, this function does nothing.
 225          *
 226          * For example, [ 'foo=bar', 'baz' => 3, 'bla' => 'foo' ] translates
 227          * to "foo=bar AND baz='3' AND bla='foo'"
 228          * @param string|array $value
 229          */
 230         protected function addWhere( $value ) {
 231                 if ( is_array( $value ) ) {
 232                         // Sanity check: don't insert empty arrays,
 233                         // Database::makeList() chokes on them
 234                         if ( count( $value ) ) {
 235                                 $this->where = array_merge( $this->where, $value );
 236                         }
 237                 } else {
 238                         $this->where[] = $value;
 239                 }
 240         }
 241
 242         /**
 243          * Same as addWhere(), but add the WHERE clauses only if a condition is met
 244          * @param string|array $value
 245          * @param bool $condition If false, do nothing
 246          * @return bool $condition
 247          */
 248         protected function addWhereIf( $value, $condition ) {
 249                 if ( $condition ) {
 250                         $this->addWhere( $value );
 251
 252                         return true;
 253                 }
 254
 255                 return false;
 256         }
 257
 258         /**
 259          * Equivalent to addWhere(array($field => $value))
 260          * @param string $field Field name
 261          * @param string $value Value; ignored if null or empty array;
 262          */
 263         protected function addWhereFld( $field, $value ) {
 264                 // Use count() to its full documented capabilities to simultaneously
 265                 // test for null, empty array or empty countable object
 266                 if ( count( $value ) ) {
 267                         $this->where[$field] = $value;
 268                 }
 269         }
 270
 271         /**
 272          * Add a WHERE clause corresponding to a range, and an ORDER BY
 273          * clause to sort in the right direction
 274          * @param string $field Field name
 275          * @param string $dir If 'newer', sort in ascending order, otherwise
 276          *  sort in descending order
 277          * @param string $start Value to start the list at. If $dir == 'newer'
 278          *  this is the lower boundary, otherwise it's the upper boundary
 279          * @param string $end Value to end the list at. If $dir == 'newer' this
 280          *  is the upper boundary, otherwise it's the lower boundary
 281          * @param bool $sort If false, don't add an ORDER BY clause
 282          */
 283         protected function addWhereRange( $field, $dir, $start, $end, $sort = true ) {
 284                 $isDirNewer = ( $dir === 'newer' );
 285                 $after = ( $isDirNewer ? '>=' : '<=' );
 286                 $before = ( $isDirNewer ? '<=' : '>=' );
 287                 $db = $this->getDB();
 288
 289                 if ( !is_null( $start ) ) {
 290                         $this->addWhere( $field . $after . $db->addQuotes( $start ) );
 291                 }
 292
 293                 if ( !is_null( $end ) ) {
 294                         $this->addWhere( $field . $before . $db->addQuotes( $end ) );
 295                 }
 296
 297                 if ( $sort ) {
 298                         $order = $field . ( $isDirNewer ? '' : ' DESC' );
 299                         // Append ORDER BY
 300                         $optionOrderBy = isset( $this->options['ORDER BY'] )
 301                                 ? (array)$this->options['ORDER BY']
 302                                 : [];
 303                         $optionOrderBy[] = $order;
 304                         $this->addOption( 'ORDER BY', $optionOrderBy );
 305                 }
 306         }
 307
 308         /**
 309          * Add a WHERE clause corresponding to a range, similar to addWhereRange,
 310          * but converts $start and $end to database timestamps.
 311          * @see addWhereRange
 312          * @param string $field
 313          * @param string $dir
 314          * @param string $start
 315          * @param string $end
 316          * @param bool $sort
 317          */
 318         protected function addTimestampWhereRange( $field, $dir, $start, $end, $sort = true ) {
 319                 $db = $this->getDB();
 320                 $this->addWhereRange( $field, $dir,
 321                         $db->timestampOrNull( $start ), $db->timestampOrNull( $end ), $sort );
 322         }
 323
 324         /**
 325          * Add an option such as LIMIT or USE INDEX. If an option was set
 326          * before, the old value will be overwritten
 327          * @param string $name Option name
 328          * @param string $value Option value
 329          */
 330         protected function addOption( $name, $value = null ) {
 331                 if ( is_null( $value ) ) {
 332                         $this->options[] = $name;
 333                 } else {
 334                         $this->options[$name] = $value;
 335                 }
 336         }
 337
 338         /**
 339          * Execute a SELECT query based on the values in the internal arrays
 340          * @param string $method Function the query should be attributed to.
 341          *  You should usually use __METHOD__ here
 342          * @param array $extraQuery Query data to add but not store in the object
 343          *  Format is [
 344          *    'tables' => ...,
 345          *    'fields' => ...,
 346          *    'where' => ...,
 347          *    'options' => ...,
 348          *    'join_conds' => ...
 349          *  ]
 350          * @param array|null &$hookData If set, the ApiQueryBaseBeforeQuery and
 351          *  ApiQueryBaseAfterQuery hooks will be called, and the
 352          *  ApiQueryBaseProcessRow hook will be expected.
 353          * @return ResultWrapper
 354          */
 355         protected function select( $method, $extraQuery = [], array &$hookData = null ) {
 356
 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                         $this->addFields( [
 454                                 'ipb_id',
 455                                 'ipb_by',
 456                                 'ipb_by_text',
 457                                 'ipb_reason',
 458                                 'ipb_expiry',
 459                                 'ipb_timestamp'
 460                         ] );
 461                 }
 462
 463                 // Don't show hidden names
 464                 if ( !$this->getUser()->isAllowed( 'hideuser' ) ) {
 465                         $this->addWhere( 'ipb_deleted = 0 OR ipb_deleted IS NULL' );
 466                 }
 467         }
 468
 469         /**@}*/
 470
 471         /************************************************************************//**
 472          * @name   Utility methods
 473          * @{
 474          */
 475
 476         /**
 477          * Add information (title and namespace) about a Title object to a
 478          * result array
 479          * @param array $arr Result array à la ApiResult
 480          * @param Title $title
 481          * @param string $prefix Module prefix
 482          */
 483         public static function addTitleInfo( &$arr, $title, $prefix = '' ) {
 484                 $arr[$prefix . 'ns'] = intval( $title->getNamespace() );
 485                 $arr[$prefix . 'title'] = $title->getPrefixedText();
 486         }
 487
 488         /**
 489          * Add a sub-element under the page element with the given page ID
 490          * @param int $pageId Page ID
 491          * @param array $data Data array à la ApiResult
 492          * @return bool Whether the element fit in the result
 493          */
 494         protected function addPageSubItems( $pageId, $data ) {
 495                 $result = $this->getResult();
 496                 ApiResult::setIndexedTagName( $data, $this->getModulePrefix() );
 497
 498                 return $result->addValue( [ 'query', 'pages', intval( $pageId ) ],
 499                         $this->getModuleName(),
 500                         $data );
 501         }
 502
 503         /**
 504          * Same as addPageSubItems(), but one element of $data at a time
 505          * @param int $pageId Page ID
 506          * @param array $item Data array à la ApiResult
 507          * @param string $elemname XML element name. If null, getModuleName()
 508          *  is used
 509          * @return bool Whether the element fit in the result
 510          */
 511         protected function addPageSubItem( $pageId, $item, $elemname = null ) {
 512                 if ( is_null( $elemname ) ) {
 513                         $elemname = $this->getModulePrefix();
 514                 }
 515                 $result = $this->getResult();
 516                 $fit = $result->addValue( [ 'query', 'pages', $pageId,
 517                         $this->getModuleName() ], null, $item );
 518                 if ( !$fit ) {
 519                         return false;
 520                 }
 521                 $result->addIndexedTagName( [ 'query', 'pages', $pageId,
 522                         $this->getModuleName() ], $elemname );
 523
 524                 return true;
 525         }
 526
 527         /**
 528          * Set a query-continue value
 529          * @param string $paramName Parameter name
 530          * @param string|array $paramValue Parameter value
 531          */
 532         protected function setContinueEnumParameter( $paramName, $paramValue ) {
 533                 $this->getContinuationManager()->addContinueParam( $this, $paramName, $paramValue );
 534         }
 535
 536         /**
 537          * Convert an input title or title prefix into a dbkey.
 538          *
 539          * $namespace should always be specified in order to handle per-namespace
 540          * capitalization settings.
 541          *
 542          * @param string $titlePart Title part
 543          * @param int $namespace Namespace of the title
 544          * @return string DBkey (no namespace prefix)
 545          */
 546         public function titlePartToKey( $titlePart, $namespace = NS_MAIN ) {
 547                 $t = Title::makeTitleSafe( $namespace, $titlePart . 'x' );
 548                 if ( !$t || $t->hasFragment() ) {
 549                         // Invalid title (e.g. bad chars) or contained a '#'.
 550                         $this->dieWithError( [ 'apierror-invalidtitle', wfEscapeWikiText( $titlePart ) ] );
 551                 }
 552                 if ( $namespace != $t->getNamespace() || $t->isExternal() ) {
 553                         // This can happen in two cases. First, if you call titlePartToKey with a title part
 554                         // that looks like a namespace, but with $defaultNamespace = NS_MAIN. It would be very
 555                         // difficult to handle such a case. Such cases cannot exist and are therefore treated
 556                         // as invalid user input. The second case is when somebody specifies a title interwiki
 557                         // prefix.
 558                         $this->dieWithError( [ 'apierror-invalidtitle', wfEscapeWikiText( $titlePart ) ] );
 559                 }
 560
 561                 return substr( $t->getDBkey(), 0, -1 );
 562         }
 563
 564         /**
 565          * Convert an input title or title prefix into a namespace constant and dbkey.
 566          *
 567          * @since 1.26
 568          * @param string $titlePart Title part
 569          * @param int $defaultNamespace Default namespace if none is given
 570          * @return array (int, string) Namespace number and DBkey
 571          */
 572         public function prefixedTitlePartToKey( $titlePart, $defaultNamespace = NS_MAIN ) {
 573                 $t = Title::newFromText( $titlePart . 'x', $defaultNamespace );
 574                 if ( !$t || $t->hasFragment() || $t->isExternal() ) {
 575                         // Invalid title (e.g. bad chars) or contained a '#'.
 576                         $this->dieWithError( [ 'apierror-invalidtitle', wfEscapeWikiText( $titlePart ) ] );
 577                 }
 578
 579                 return [ $t->getNamespace(), substr( $t->getDBkey(), 0, -1 ) ];
 580         }
 581
 582         /**
 583          * @param string $hash
 584          * @return bool
 585          */
 586         public function validateSha1Hash( $hash ) {
 587                 return preg_match( '/^[a-f0-9]{40}$/', $hash );
 588         }
 589
 590         /**
 591          * @param string $hash
 592          * @return bool
 593          */
 594         public function validateSha1Base36Hash( $hash ) {
 595                 return preg_match( '/^[a-z0-9]{31}$/', $hash );
 596         }
 597
 598         /**
 599          * Check whether the current user has permission to view revision-deleted
 600          * fields.
 601          * @return bool
 602          */
 603         public function userCanSeeRevDel() {
 604                 return $this->getUser()->isAllowedAny(
 605                         'deletedhistory',
 606                         'deletedtext',
 607                         'suppressrevision',
 608                         'viewsuppressed'
 609                 );
 610         }
 611
 612         /**@}*/
 613 }