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