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 DatabaseBase
 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 DatabaseBase
 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 array( tablename => array(jointype,
 180          * conditions) e.g. array('page' => array('LEFT JOIN',
 181          * 'page_id=rev_page')) . conditions may be a string or an
 182          * 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 array('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, array('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 $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 $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 array(
 345          *    'tables' => ...,
 346          *    'fields' => ...,
 347          *    'where' => ...,
 348          *    'options' => ...,
 349          *    'join_conds' => ...
 350          *  )
 351          * @return ResultWrapper
 352          */
 353         protected function select( $method, $extraQuery = [] ) {
 354
 355                 $tables = array_merge(
 356                         $this->tables,
 357                         isset( $extraQuery['tables'] ) ? (array)$extraQuery['tables'] : []
 358                 );
 359                 $fields = array_merge(
 360                         $this->fields,
 361                         isset( $extraQuery['fields'] ) ? (array)$extraQuery['fields'] : []
 362                 );
 363                 $where = array_merge(
 364                         $this->where,
 365                         isset( $extraQuery['where'] ) ? (array)$extraQuery['where'] : []
 366                 );
 367                 $options = array_merge(
 368                         $this->options,
 369                         isset( $extraQuery['options'] ) ? (array)$extraQuery['options'] : []
 370                 );
 371                 $join_conds = array_merge(
 372                         $this->join_conds,
 373                         isset( $extraQuery['join_conds'] ) ? (array)$extraQuery['join_conds'] : []
 374                 );
 375
 376                 $res = $this->getDB()->select( $tables, $fields, $where, $method, $options, $join_conds );
 377
 378                 return $res;
 379         }
 380
 381         /**
 382          * @param string $query
 383          * @param string $protocol
 384          * @return null|string
 385          */
 386         public function prepareUrlQuerySearchString( $query = null, $protocol = null ) {
 387                 $db = $this->getDB();
 388                 if ( !is_null( $query ) || $query != '' ) {
 389                         if ( is_null( $protocol ) ) {
 390                                 $protocol = 'http://';
 391                         }
 392
 393                         $likeQuery = LinkFilter::makeLikeArray( $query, $protocol );
 394                         if ( !$likeQuery ) {
 395                                 $this->dieUsage( 'Invalid query', 'bad_query' );
 396                         }
 397
 398                         $likeQuery = LinkFilter::keepOneWildcard( $likeQuery );
 399
 400                         return 'el_index ' . $db->buildLike( $likeQuery );
 401                 } elseif ( !is_null( $protocol ) ) {
 402                         return 'el_index ' . $db->buildLike( "$protocol", $db->anyString() );
 403                 }
 404
 405                 return null;
 406         }
 407
 408         /**
 409          * Filters hidden users (where the user doesn't have the right to view them)
 410          * Also adds relevant block information
 411          *
 412          * @param bool $showBlockInfo
 413          * @return void
 414          */
 415         public function showHiddenUsersAddBlockInfo( $showBlockInfo ) {
 416                 $this->addTables( 'ipblocks' );
 417                 $this->addJoinConds( [
 418                         'ipblocks' => [ 'LEFT JOIN', 'ipb_user=user_id' ],
 419                 ] );
 420
 421                 $this->addFields( 'ipb_deleted' );
 422
 423                 if ( $showBlockInfo ) {
 424                         $this->addFields( [
 425                                 'ipb_id',
 426                                 'ipb_by',
 427                                 'ipb_by_text',
 428                                 'ipb_reason',
 429                                 'ipb_expiry',
 430                                 'ipb_timestamp'
 431                         ] );
 432                 }
 433
 434                 // Don't show hidden names
 435                 if ( !$this->getUser()->isAllowed( 'hideuser' ) ) {
 436                         $this->addWhere( 'ipb_deleted = 0 OR ipb_deleted IS NULL' );
 437                 }
 438         }
 439
 440         /**@}*/
 441
 442         /************************************************************************//**
 443          * @name   Utility methods
 444          * @{
 445          */
 446
 447         /**
 448          * Add information (title and namespace) about a Title object to a
 449          * result array
 450          * @param array $arr Result array à la ApiResult
 451          * @param Title $title
 452          * @param string $prefix Module prefix
 453          */
 454         public static function addTitleInfo( &$arr, $title, $prefix = '' ) {
 455                 $arr[$prefix . 'ns'] = intval( $title->getNamespace() );
 456                 $arr[$prefix . 'title'] = $title->getPrefixedText();
 457         }
 458
 459         /**
 460          * Add a sub-element under the page element with the given page ID
 461          * @param int $pageId Page ID
 462          * @param array $data Data array à la ApiResult
 463          * @return bool Whether the element fit in the result
 464          */
 465         protected function addPageSubItems( $pageId, $data ) {
 466                 $result = $this->getResult();
 467                 ApiResult::setIndexedTagName( $data, $this->getModulePrefix() );
 468
 469                 return $result->addValue( [ 'query', 'pages', intval( $pageId ) ],
 470                         $this->getModuleName(),
 471                         $data );
 472         }
 473
 474         /**
 475          * Same as addPageSubItems(), but one element of $data at a time
 476          * @param int $pageId Page ID
 477          * @param array $item Data array à la ApiResult
 478          * @param string $elemname XML element name. If null, getModuleName()
 479          *  is used
 480          * @return bool Whether the element fit in the result
 481          */
 482         protected function addPageSubItem( $pageId, $item, $elemname = null ) {
 483                 if ( is_null( $elemname ) ) {
 484                         $elemname = $this->getModulePrefix();
 485                 }
 486                 $result = $this->getResult();
 487                 $fit = $result->addValue( [ 'query', 'pages', $pageId,
 488                         $this->getModuleName() ], null, $item );
 489                 if ( !$fit ) {
 490                         return false;
 491                 }
 492                 $result->addIndexedTagName( [ 'query', 'pages', $pageId,
 493                         $this->getModuleName() ], $elemname );
 494
 495                 return true;
 496         }
 497
 498         /**
 499          * Set a query-continue value
 500          * @param string $paramName Parameter name
 501          * @param string|array $paramValue Parameter value
 502          */
 503         protected function setContinueEnumParameter( $paramName, $paramValue ) {
 504                 $this->getContinuationManager()->addContinueParam( $this, $paramName, $paramValue );
 505         }
 506
 507         /**
 508          * Convert an input title or title prefix into a dbkey.
 509          *
 510          * $namespace should always be specified in order to handle per-namespace
 511          * capitalization settings.
 512          *
 513          * @param string $titlePart Title part
 514          * @param int $namespace Namespace of the title
 515          * @return string DBkey (no namespace prefix)
 516          */
 517         public function titlePartToKey( $titlePart, $namespace = NS_MAIN ) {
 518                 $t = Title::makeTitleSafe( $namespace, $titlePart . 'x' );
 519                 if ( !$t || $t->hasFragment() ) {
 520                         // Invalid title (e.g. bad chars) or contained a '#'.
 521                         $this->dieUsageMsg( [ 'invalidtitle', $titlePart ] );
 522                 }
 523                 if ( $namespace != $t->getNamespace() || $t->isExternal() ) {
 524                         // This can happen in two cases. First, if you call titlePartToKey with a title part
 525                         // that looks like a namespace, but with $defaultNamespace = NS_MAIN. It would be very
 526                         // difficult to handle such a case. Such cases cannot exist and are therefore treated
 527                         // as invalid user input. The second case is when somebody specifies a title interwiki
 528                         // prefix.
 529                         $this->dieUsageMsg( [ 'invalidtitle', $titlePart ] );
 530                 }
 531
 532                 return substr( $t->getDBkey(), 0, -1 );
 533         }
 534
 535         /**
 536          * Convert an input title or title prefix into a namespace constant and dbkey.
 537          *
 538          * @since 1.26
 539          * @param string $titlePart Title part
 540          * @param int $defaultNamespace Default namespace if none is given
 541          * @return array (int, string) Namespace number and DBkey
 542          */
 543         public function prefixedTitlePartToKey( $titlePart, $defaultNamespace = NS_MAIN ) {
 544                 $t = Title::newFromText( $titlePart . 'x', $defaultNamespace );
 545                 if ( !$t || $t->hasFragment() || $t->isExternal() ) {
 546                         // Invalid title (e.g. bad chars) or contained a '#'.
 547                         $this->dieUsageMsg( [ 'invalidtitle', $titlePart ] );
 548                 }
 549
 550                 return [ $t->getNamespace(), substr( $t->getDBkey(), 0, -1 ) ];
 551         }
 552
 553         /**
 554          * @param string $hash
 555          * @return bool
 556          */
 557         public function validateSha1Hash( $hash ) {
 558                 return preg_match( '/^[a-f0-9]{40}$/', $hash );
 559         }
 560
 561         /**
 562          * @param string $hash
 563          * @return bool
 564          */
 565         public function validateSha1Base36Hash( $hash ) {
 566                 return preg_match( '/^[a-z0-9]{31}$/', $hash );
 567         }
 568
 569         /**
 570          * Check whether the current user has permission to view revision-deleted
 571          * fields.
 572          * @return bool
 573          */
 574         public function userCanSeeRevDel() {
 575                 return $this->getUser()->isAllowedAny(
 576                         'deletedhistory',
 577                         'deletedtext',
 578                         'suppressrevision',
 579                         'viewsuppressed'
 580                 );
 581         }
 582
 583         /**@}*/
 584 }