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         /**
 101          * @see ApiBase::getParent()
 102          */
 103         public function getParent() {
 104                 return $this->getQuery();
 105         }
 106
 107         /**
 108          * Get the Query database connection (read-only)
 109          * @return IDatabase
 110          */
 111         protected function getDB() {
 112                 if ( is_null( $this->mDb ) ) {
 113                         $this->mDb = $this->getQuery()->getDB();
 114                 }
 115
 116                 return $this->mDb;
 117         }
 118
 119         /**
 120          * Selects the query database connection with the given name.
 121          * See ApiQuery::getNamedDB() for more information
 122          * @param string $name Name to assign to the database connection
 123          * @param int $db One of the DB_* constants
 124          * @param array $groups Query groups
 125          * @return IDatabase
 126          */
 127         public function selectNamedDB( $name, $db, $groups ) {
 128                 $this->mDb = $this->getQuery()->getNamedDB( $name, $db, $groups );
 129                 return $this->mDb;
 130         }
 131
 132         /**
 133          * Get the PageSet object to work on
 134          * @return ApiPageSet
 135          */
 136         protected function getPageSet() {
 137                 return $this->getQuery()->getPageSet();
 138         }
 139
 140         /**@}*/
 141
 142         /************************************************************************//**
 143          * @name   Querying
 144          * @{
 145          */
 146
 147         /**
 148          * Blank the internal arrays with query parameters
 149          */
 150         protected function resetQueryParams() {
 151                 $this->tables = [];
 152                 $this->where = [];
 153                 $this->fields = [];
 154                 $this->options = [];
 155                 $this->join_conds = [];
 156         }
 157
 158         /**
 159          * Add a set of tables to the internal array
 160          * @param string|string[] $tables Table name or array of table names
 161          * @param string|null $alias Table alias, or null for no alias. Cannot be
 162          *  used with multiple tables
 163          */
 164         protected function addTables( $tables, $alias = null ) {
 165                 if ( is_array( $tables ) ) {
 166                         if ( !is_null( $alias ) ) {
 167                                 ApiBase::dieDebug( __METHOD__, 'Multiple table aliases not supported' );
 168                         }
 169                         $this->tables = array_merge( $this->tables, $tables );
 170                 } else {
 171                         if ( !is_null( $alias ) ) {
 172                                 $this->tables[$alias] = $tables;
 173                         } else {
 174                                 $this->tables[] = $tables;
 175                         }
 176                 }
 177         }
 178
 179         /**
 180          * Add a set of JOIN conditions to the internal array
 181          *
 182          * JOIN conditions are formatted as [ tablename => [ jointype, conditions ] ]
 183          * e.g. [ 'page' => [ 'LEFT JOIN', 'page_id=rev_page' ] ].
 184          * Conditions may be a string or an addWhere()-style array.
 185          * @param array $join_conds JOIN conditions
 186          */
 187         protected function addJoinConds( $join_conds ) {
 188                 if ( !is_array( $join_conds ) ) {
 189                         ApiBase::dieDebug( __METHOD__, 'Join conditions have to be arrays' );
 190                 }
 191                 $this->join_conds = array_merge( $this->join_conds, $join_conds );
 192         }
 193
 194         /**
 195          * Add a set of fields to select to the internal array
 196          * @param array|string $value Field name or array of field names
 197          */
 198         protected function addFields( $value ) {
 199                 if ( is_array( $value ) ) {
 200                         $this->fields = array_merge( $this->fields, $value );
 201                 } else {
 202                         $this->fields[] = $value;
 203                 }
 204         }
 205
 206         /**
 207          * Same as addFields(), but add the fields only if a condition is met
 208          * @param array|string $value See addFields()
 209          * @param bool $condition If false, do nothing
 210          * @return bool $condition
 211          */
 212         protected function addFieldsIf( $value, $condition ) {
 213                 if ( $condition ) {
 214                         $this->addFields( $value );
 215
 216                         return true;
 217                 }
 218
 219                 return false;
 220         }
 221
 222         /**
 223          * Add a set of WHERE clauses to the internal array.
 224          * Clauses can be formatted as 'foo=bar' or [ 'foo' => 'bar' ],
 225          * the latter only works if the value is a constant (i.e. not another field)
 226          *
 227          * If $value is an empty array, this function does nothing.
 228          *
 229          * For example, [ 'foo=bar', 'baz' => 3, 'bla' => 'foo' ] translates
 230          * to "foo=bar AND baz='3' AND bla='foo'"
 231          * @param string|array $value
 232          */
 233         protected function addWhere( $value ) {
 234                 if ( is_array( $value ) ) {
 235                         // Sanity check: don't insert empty arrays,
 236                         // Database::makeList() chokes on them
 237                         if ( count( $value ) ) {
 238                                 $this->where = array_merge( $this->where, $value );
 239                         }
 240                 } else {
 241                         $this->where[] = $value;
 242                 }
 243         }
 244
 245         /**
 246          * Same as addWhere(), but add the WHERE clauses only if a condition is met
 247          * @param string|array $value
 248          * @param bool $condition If false, do nothing
 249          * @return bool $condition
 250          */
 251         protected function addWhereIf( $value, $condition ) {
 252                 if ( $condition ) {
 253                         $this->addWhere( $value );
 254
 255                         return true;
 256                 }
 257
 258                 return false;
 259         }
 260
 261         /**
 262          * Equivalent to addWhere(array($field => $value))
 263          * @param string $field Field name
 264          * @param string|string[] $value Value; ignored if null or empty array;
 265          */
 266         protected function addWhereFld( $field, $value ) {
 267                 // Use count() to its full documented capabilities to simultaneously
 268                 // test for null, empty array or empty countable object
 269                 if ( count( $value ) ) {
 270                         $this->where[$field] = $value;
 271                 }
 272         }
 273
 274         /**
 275          * Add a WHERE clause corresponding to a range, and an ORDER BY
 276          * clause to sort in the right direction
 277          * @param string $field Field name
 278          * @param string $dir If 'newer', sort in ascending order, otherwise
 279          *  sort in descending order
 280          * @param string $start Value to start the list at. If $dir == 'newer'
 281          *  this is the lower boundary, otherwise it's the upper boundary
 282          * @param string $end Value to end the list at. If $dir == 'newer' this
 283          *  is the upper boundary, otherwise it's the lower boundary
 284          * @param bool $sort If false, don't add an ORDER BY clause
 285          */
 286         protected function addWhereRange( $field, $dir, $start, $end, $sort = true ) {
 287                 $isDirNewer = ( $dir === 'newer' );
 288                 $after = ( $isDirNewer ? '>=' : '<=' );
 289                 $before = ( $isDirNewer ? '<=' : '>=' );
 290                 $db = $this->getDB();
 291
 292                 if ( !is_null( $start ) ) {
 293                         $this->addWhere( $field . $after . $db->addQuotes( $start ) );
 294                 }
 295
 296                 if ( !is_null( $end ) ) {
 297                         $this->addWhere( $field . $before . $db->addQuotes( $end ) );
 298                 }
 299
 300                 if ( $sort ) {
 301                         $order = $field . ( $isDirNewer ? '' : ' DESC' );
 302                         // Append ORDER BY
 303                         $optionOrderBy = isset( $this->options['ORDER BY'] )
 304                                 ? (array)$this->options['ORDER BY']
 305                                 : [];
 306                         $optionOrderBy[] = $order;
 307                         $this->addOption( 'ORDER BY', $optionOrderBy );
 308                 }
 309         }
 310
 311         /**
 312          * Add a WHERE clause corresponding to a range, similar to addWhereRange,
 313          * but converts $start and $end to database timestamps.
 314          * @see addWhereRange
 315          * @param string $field
 316          * @param string $dir
 317          * @param string $start
 318          * @param string $end
 319          * @param bool $sort
 320          */
 321         protected function addTimestampWhereRange( $field, $dir, $start, $end, $sort = true ) {
 322                 $db = $this->getDB();
 323                 $this->addWhereRange( $field, $dir,
 324                         $db->timestampOrNull( $start ), $db->timestampOrNull( $end ), $sort );
 325         }
 326
 327         /**
 328          * Add an option such as LIMIT or USE INDEX. If an option was set
 329          * before, the old value will be overwritten
 330          * @param string $name Option name
 331          * @param string|string[] $value Option value
 332          */
 333         protected function addOption( $name, $value = null ) {
 334                 if ( is_null( $value ) ) {
 335                         $this->options[] = $name;
 336                 } else {
 337                         $this->options[$name] = $value;
 338                 }
 339         }
 340
 341         /**
 342          * Execute a SELECT query based on the values in the internal arrays
 343          * @param string $method Function the query should be attributed to.
 344          *  You should usually use __METHOD__ here
 345          * @param array $extraQuery Query data to add but not store in the object
 346          *  Format is [
 347          *    'tables' => ...,
 348          *    'fields' => ...,
 349          *    'where' => ...,
 350          *    'options' => ...,
 351          *    'join_conds' => ...
 352          *  ]
 353          * @param array|null &$hookData If set, the ApiQueryBaseBeforeQuery and
 354          *  ApiQueryBaseAfterQuery hooks will be called, and the
 355          *  ApiQueryBaseProcessRow hook will be expected.
 356          * @return ResultWrapper
 357          */
 358         protected function select( $method, $extraQuery = [], array &$hookData = null ) {
 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 }