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