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 if ( !defined( 'MEDIAWIKI' ) ) {
  28         // Eclipse helper - will be ignored in production
  29         require_once( 'ApiBase.php' );
  30 }
  31
  32 /**
  33  * This is a base class for all Query modules.
  34  * It provides some common functionality such as constructing various SQL
  35  * queries.
  36  *
  37  * @ingroup API
  38  */
  39 abstract class ApiQueryBase extends ApiBase {
  40
  41         private $mQueryModule, $mDb, $tables, $where, $fields, $options, $join_conds;
  42
  43         public function __construct( ApiBase $query, $moduleName, $paramPrefix = '' ) {
  44                 parent::__construct( $query->getMain(), $moduleName, $paramPrefix );
  45                 $this->mQueryModule = $query;
  46                 $this->mDb = null;
  47                 $this->resetQueryParams();
  48         }
  49
  50         /**
  51          * Get the cache mode for the data generated by this module. Override
  52          * this in the module subclass. For possible return values and other
  53          * details about cache modes, see ApiMain::setCacheMode()
  54          *
  55          * Public caching will only be allowed if *all* the modules that supply
  56          * data for a given request return a cache mode of public.
  57          */
  58         public function getCacheMode( $params ) {
  59                 return 'private';
  60         }
  61
  62         /**
  63          * Blank the internal arrays with query parameters
  64          */
  65         protected function resetQueryParams() {
  66                 $this->tables = array();
  67                 $this->where = array();
  68                 $this->fields = array();
  69                 $this->options = array();
  70                 $this->join_conds = array();
  71         }
  72
  73         /**
  74          * Add a set of tables to the internal array
  75          * @param $tables mixed Table name or array of table names
  76          * @param $alias mixed Table alias, or null for no alias. Cannot be
  77          *  used with multiple tables
  78          */
  79         protected function addTables( $tables, $alias = null ) {
  80                 if ( is_array( $tables ) ) {
  81                         if ( !is_null( $alias ) ) {
  82                                 ApiBase::dieDebug( __METHOD__, 'Multiple table aliases not supported' );
  83                         }
  84                         $this->tables = array_merge( $this->tables, $tables );
  85                 } else {
  86                         if ( !is_null( $alias ) ) {
  87                                 $tables = $this->getAliasedName( $tables, $alias );
  88                         }
  89                         $this->tables[] = $tables;
  90                 }
  91         }
  92
  93         /**
  94          * Get the SQL for a table name with alias
  95          * @param $table string Table name
  96          * @param $alias string Alias
  97          * @return string SQL
  98          */
  99         protected function getAliasedName( $table, $alias ) {
 100                 return $this->getDB()->tableName( $table ) . ' ' . $alias;
 101         }
 102
 103         /**
 104          * Add a set of JOIN conditions to the internal array
 105          *
 106          * JOIN conditions are formatted as array( tablename => array(jointype,
 107          * conditions) e.g. array('page' => array('LEFT JOIN',
 108          * 'page_id=rev_page')) . conditions may be a string or an
 109          * addWhere()-style array
 110          * @param $join_conds array JOIN conditions
 111          */
 112         protected function addJoinConds( $join_conds ) {
 113                 if ( !is_array( $join_conds ) ) {
 114                         ApiBase::dieDebug( __METHOD__, 'Join conditions have to be arrays' );
 115                 }
 116                 $this->join_conds = array_merge( $this->join_conds, $join_conds );
 117         }
 118
 119         /**
 120          * Add a set of fields to select to the internal array
 121          * @param $value mixed Field name or array of field names
 122          */
 123         protected function addFields( $value ) {
 124                 if ( is_array( $value ) ) {
 125                         $this->fields = array_merge( $this->fields, $value );
 126                 } else {
 127                         $this->fields[] = $value;
 128                 }
 129         }
 130
 131         /**
 132          * Same as addFields(), but add the fields only if a condition is met
 133          * @param $value mixed See addFields()
 134          * @param $condition bool If false, do nothing
 135          * @return bool $condition
 136          */
 137         protected function addFieldsIf( $value, $condition ) {
 138                 if ( $condition ) {
 139                         $this->addFields( $value );
 140                         return true;
 141                 }
 142                 return false;
 143         }
 144
 145         /**
 146          * Add a set of WHERE clauses to the internal array.
 147          * Clauses can be formatted as 'foo=bar' or array('foo' => 'bar'),
 148          * the latter only works if the value is a constant (i.e. not another field)
 149          *
 150          * If $value is an empty array, this function does nothing.
 151          *
 152          * For example, array('foo=bar', 'baz' => 3, 'bla' => 'foo') translates
 153          * to "foo=bar AND baz='3' AND bla='foo'"
 154          * @param $value mixed String or array
 155          */
 156         protected function addWhere( $value ) {
 157                 if ( is_array( $value ) ) {
 158                         // Sanity check: don't insert empty arrays,
 159                         // Database::makeList() chokes on them
 160                         if ( count( $value ) ) {
 161                                 $this->where = array_merge( $this->where, $value );
 162                         }
 163                 } else {
 164                         $this->where[] = $value;
 165                 }
 166         }
 167
 168         /**
 169          * Same as addWhere(), but add the WHERE clauses only if a condition is met
 170          * @param $value mixed See addWhere()
 171          * @param $condition bool If false, do nothing
 172          * @return bool $condition
 173          */
 174         protected function addWhereIf( $value, $condition ) {
 175                 if ( $condition ) {
 176                         $this->addWhere( $value );
 177                         return true;
 178                 }
 179                 return false;
 180         }
 181
 182         /**
 183          * Equivalent to addWhere(array($field => $value))
 184          * @param $field string Field name
 185          * @param $value string Value; ignored if null or empty array;
 186          */
 187         protected function addWhereFld( $field, $value ) {
 188                 // Use count() to its full documented capabilities to simultaneously
 189                 // test for null, empty array or empty countable object
 190                 if ( count( $value ) ) {
 191                         $this->where[$field] = $value;
 192                 }
 193         }
 194
 195         /**
 196          * Add a WHERE clause corresponding to a range, and an ORDER BY
 197          * clause to sort in the right direction
 198          * @param $field string Field name
 199          * @param $dir string If 'newer', sort in ascending order, otherwise
 200          *  sort in descending order
 201          * @param $start string Value to start the list at. If $dir == 'newer'
 202          *  this is the lower boundary, otherwise it's the upper boundary
 203          * @param $end string Value to end the list at. If $dir == 'newer' this
 204          *  is the upper boundary, otherwise it's the lower boundary
 205          * @param $sort bool If false, don't add an ORDER BY clause
 206          */
 207         protected function addWhereRange( $field, $dir, $start, $end, $sort = true ) {
 208                 $isDirNewer = ( $dir === 'newer' );
 209                 $after = ( $isDirNewer ? '>=' : '<=' );
 210                 $before = ( $isDirNewer ? '<=' : '>=' );
 211                 $db = $this->getDB();
 212
 213                 if ( !is_null( $start ) ) {
 214                         $this->addWhere( $field . $after . $db->addQuotes( $start ) );
 215                 }
 216
 217                 if ( !is_null( $end ) ) {
 218                         $this->addWhere( $field . $before . $db->addQuotes( $end ) );
 219                 }
 220
 221                 if ( $sort ) {
 222                         $order = $field . ( $isDirNewer ? '' : ' DESC' );
 223                         if ( !isset( $this->options['ORDER BY'] ) ) {
 224                                 $this->addOption( 'ORDER BY', $order );
 225                         } else {
 226                                 $this->addOption( 'ORDER BY', $this->options['ORDER BY'] . ', ' . $order );
 227                         }
 228                 }
 229         }
 230
 231         /**
 232          * Add an option such as LIMIT or USE INDEX. If an option was set
 233          * before, the old value will be overwritten
 234          * @param $name string Option name
 235          * @param $value string Option value
 236          */
 237         protected function addOption( $name, $value = null ) {
 238                 if ( is_null( $value ) ) {
 239                         $this->options[] = $name;
 240                 } else {
 241                         $this->options[$name] = $value;
 242                 }
 243         }
 244
 245         /**
 246          * Execute a SELECT query based on the values in the internal arrays
 247          * @param $method string Function the query should be attributed to.
 248          *  You should usually use __METHOD__ here
 249          * @param $extraQuery array Query data to add but not store in the object
 250          *  Format is array( 'tables' => ..., 'fields' => ..., 'where' => ..., 'options' => ..., 'join_conds' => ... )
 251          * @return ResultWrapper
 252          */
 253         protected function select( $method, $extraQuery = array() ) {
 254                 // Merge $this->tables with $extraQuery['tables'], $this->fields with $extraQuery['fields'], etc.
 255                 foreach ( array( 'tables', 'fields', 'where', 'options', 'join_conds' ) as $var ) {
 256                         $$var = array_merge( $this->{$var}, isset( $extraQuery[$var] ) ? (array)$extraQuery[$var] : array() );
 257                 }
 258
 259                 // getDB has its own profileDBIn/Out calls
 260                 $db = $this->getDB();
 261
 262                 $this->profileDBIn();
 263                 $res = $db->select( $tables, $fields, $where, $method, $options, $join_conds );
 264                 $this->profileDBOut();
 265
 266                 return $res;
 267         }
 268
 269         /**
 270          * Estimate the row count for the SELECT query that would be run if we
 271          * called select() right now, and check if it's acceptable.
 272          * @return bool true if acceptable, false otherwise
 273          */
 274         protected function checkRowCount() {
 275                 $db = $this->getDB();
 276                 $this->profileDBIn();
 277                 $rowcount = $db->estimateRowCount( $this->tables, $this->fields, $this->where, __METHOD__, $this->options );
 278                 $this->profileDBOut();
 279
 280                 global $wgAPIMaxDBRows;
 281                 if ( $rowcount > $wgAPIMaxDBRows ) {
 282                         return false;
 283                 }
 284                 return true;
 285         }
 286
 287         /**
 288          * Add information (title and namespace) about a Title object to a
 289          * result array
 290          * @param $arr array Result array à la ApiResult
 291          * @param $title Title
 292          * @param $prefix string Module prefix
 293          */
 294         public static function addTitleInfo( &$arr, $title, $prefix = '' ) {
 295                 $arr[$prefix . 'ns'] = intval( $title->getNamespace() );
 296                 $arr[$prefix . 'title'] = $title->getPrefixedText();
 297         }
 298
 299         /**
 300          * Override this method to request extra fields from the pageSet
 301          * using $pageSet->requestField('fieldName')
 302          * @param $pageSet ApiPageSet
 303          */
 304         public function requestExtraData( $pageSet ) {
 305         }
 306
 307         /**
 308          * Get the main Query module
 309          * @return ApiQuery
 310          */
 311         public function getQuery() {
 312                 return $this->mQueryModule;
 313         }
 314
 315         /**
 316          * Add a sub-element under the page element with the given page ID
 317          * @param $pageId int Page ID
 318          * @param $data array Data array à la ApiResult
 319          * @return bool Whether the element fit in the result
 320          */
 321         protected function addPageSubItems( $pageId, $data ) {
 322                 $result = $this->getResult();
 323                 $result->setIndexedTagName( $data, $this->getModulePrefix() );
 324                 return $result->addValue( array( 'query', 'pages', intval( $pageId ) ),
 325                         $this->getModuleName(),
 326                         $data );
 327         }
 328
 329         /**
 330          * Same as addPageSubItems(), but one element of $data at a time
 331          * @param $pageId int Page ID
 332          * @param $item array Data array à la ApiResult
 333          * @param $elemname string XML element name. If null, getModuleName()
 334          *  is used
 335          * @return bool Whether the element fit in the result
 336          */
 337         protected function addPageSubItem( $pageId, $item, $elemname = null ) {
 338                 if ( is_null( $elemname ) ) {
 339                         $elemname = $this->getModulePrefix();
 340                 }
 341                 $result = $this->getResult();
 342                 $fit = $result->addValue( array( 'query', 'pages', $pageId,
 343                                          $this->getModuleName() ), null, $item );
 344                 if ( !$fit ) {
 345                         return false;
 346                 }
 347                 $result->setIndexedTagName_internal( array( 'query', 'pages', $pageId,
 348                                 $this->getModuleName() ), $elemname );
 349                 return true;
 350         }
 351
 352         /**
 353          * Set a query-continue value
 354          * @param $paramName string Parameter name
 355          * @param $paramValue string Parameter value
 356          */
 357         protected function setContinueEnumParameter( $paramName, $paramValue ) {
 358                 $paramName = $this->encodeParamName( $paramName );
 359                 $msg = array( $paramName => $paramValue );
 360                 $this->getResult()->disableSizeCheck();
 361                 $this->getResult()->addValue( 'query-continue', $this->getModuleName(), $msg );
 362                 $this->getResult()->enableSizeCheck();
 363         }
 364
 365         /**
 366          * Get the Query database connection (read-only)
 367          * @return Database
 368          */
 369         protected function getDB() {
 370                 if ( is_null( $this->mDb ) ) {
 371                         $apiQuery = $this->getQuery();
 372                         $this->mDb = $apiQuery->getDB();
 373                 }
 374                 return $this->mDb;
 375         }
 376
 377         /**
 378          * Selects the query database connection with the given name.
 379          * See ApiQuery::getNamedDB() for more information
 380          * @param $name string Name to assign to the database connection
 381          * @param $db int One of the DB_* constants
 382          * @param $groups array Query groups
 383          * @return Database
 384          */
 385         public function selectNamedDB( $name, $db, $groups ) {
 386                 $this->mDb = $this->getQuery()->getNamedDB( $name, $db, $groups );
 387         }
 388
 389         /**
 390          * Get the PageSet object to work on
 391          * @return ApiPageSet
 392          */
 393         protected function getPageSet() {
 394                 return $this->getQuery()->getPageSet();
 395         }
 396
 397         /**
 398          * Convert a title to a DB key
 399          * @param $title string Page title with spaces
 400          * @return string Page title with underscores
 401          */
 402         public function titleToKey( $title ) {
 403                 // Don't throw an error if we got an empty string
 404                 if ( trim( $title ) == '' ) {
 405                         return '';
 406                 }
 407                 $t = Title::newFromText( $title );
 408                 if ( !$t ) {
 409                         $this->dieUsageMsg( array( 'invalidtitle', $title ) );
 410                 }
 411                 return $t->getPrefixedDbKey();
 412         }
 413
 414         /**
 415          * The inverse of titleToKey()
 416          * @param $key string Page title with underscores
 417          * @return string Page title with spaces
 418          */
 419         public function keyToTitle( $key ) {
 420                 // Don't throw an error if we got an empty string
 421                 if ( trim( $key ) == '' ) {
 422                         return '';
 423                 }
 424                 $t = Title::newFromDbKey( $key );
 425                 // This really shouldn't happen but we gotta check anyway
 426                 if ( !$t ) {
 427                         $this->dieUsageMsg( array( 'invalidtitle', $key ) );
 428                 }
 429                 return $t->getPrefixedText();
 430         }
 431
 432         /**
 433          * An alternative to titleToKey() that doesn't trim trailing spaces
 434          * @param $titlePart string Title part with spaces
 435          * @return string Title part with underscores
 436          */
 437         public function titlePartToKey( $titlePart ) {
 438                 return substr( $this->titleToKey( $titlePart . 'x' ), 0, - 1 );
 439         }
 440
 441         /**
 442          * An alternative to keyToTitle() that doesn't trim trailing spaces
 443          * @param $keyPart string Key part with spaces
 444          * @return string Key part with underscores
 445          */
 446         public function keyPartToTitle( $keyPart ) {
 447                 return substr( $this->keyToTitle( $keyPart . 'x' ), 0, - 1 );
 448         }
 449
 450         /**
 451          * Gets the personalised direction parameter description
 452          *
 453          * @param string $p ModulePrefix
 454          * @param string $extraDirText Any extra text to be appended on the description
 455          * @return array
 456          */
 457         public function getDirectionDescription( $p = '', $extraDirText = '' ) {
 458                 return array(
 459                                 "In which direction to enumerate{$extraDirText}",
 460                                 " newer          - List oldest first. Note: {$p}start has to be before {$p}end.",
 461                                 " older          - List newest first (default). Note: {$p}start has to be later than {$p}end.",
 462                         );
 463         }
 464
 465         /**
 466          * @param $query String
 467          * @param $protocol String
 468          * @return null|string
 469          */
 470         public function prepareUrlQuerySearchString( $query = null, $protocol = null) {
 471                 $db = $this->getDb();
 472                 if ( !is_null( $query ) || $query != '' ) {
 473                         if ( is_null( $protocol ) ) {
 474                                 $protocol = 'http://';
 475                         }
 476
 477                         $likeQuery = LinkFilter::makeLikeArray( $query, $protocol );
 478                         if ( !$likeQuery ) {
 479                                 $this->dieUsage( 'Invalid query', 'bad_query' );
 480                         }
 481
 482                         $likeQuery = LinkFilter::keepOneWildcard( $likeQuery );
 483                         return 'el_index ' . $db->buildLike( $likeQuery );
 484                 } elseif ( !is_null( $protocol ) ) {
 485                         return 'el_index ' . $db->buildLike( "$protocol", $db->anyString() );
 486                 }
 487
 488                 return null;
 489         }
 490
 491         /**
 492          * Filters hidden users (where the user doesn't have the right to view them)
 493          * Also adds relevant block information
 494          *
 495          * @param bool $showBlockInfo
 496          * @return void
 497          */
 498         public function showHiddenUsersAddBlockInfo( $showBlockInfo ) {
 499                 global $wgUser;
 500                 $userCanViewHiddenUsers = $wgUser->isAllowed( 'hideuser' );
 501
 502                 if ( $showBlockInfo || !$userCanViewHiddenUsers ) {
 503                         $this->addTables( 'ipblocks' );
 504                         $this->addJoinConds( array(
 505                                 'ipblocks' => array( 'LEFT JOIN', 'ipb_user=user_id' ),
 506                         ) );
 507
 508                         $this->addFields( 'ipb_deleted' );
 509
 510                         if ( $showBlockInfo ) {
 511                                 $this->addFields( array( 'ipb_reason', 'ipb_by_text', 'ipb_expiry' ) );
 512                         }
 513
 514                         // Don't show hidden names
 515                         if ( !$userCanViewHiddenUsers ) {
 516                                 $this->addWhere( 'ipb_deleted = 0 OR ipb_deleted IS NULL' );
 517                         }
 518                 }
 519         }
 520
 521         public function getPossibleErrors() {
 522                 return array_merge( parent::getPossibleErrors(), array(
 523                         array( 'invalidtitle', 'title' ),
 524                         array( 'invalidtitle', 'key' ),
 525                 ) );
 526         }
 527
 528         /**
 529          * Get version string for use in the API help output
 530          * @return string
 531          */
 532         public static function getBaseVersion() {
 533                 return __CLASS__ . ': $Id$';
 534         }
 535 }
 536
 537 /**
 538  * @ingroup API
 539  */
 540 abstract class ApiQueryGeneratorBase extends ApiQueryBase {
 541
 542         private $mIsGenerator;
 543
 544         public function __construct( $query, $moduleName, $paramPrefix = '' ) {
 545                 parent::__construct( $query, $moduleName, $paramPrefix );
 546                 $this->mIsGenerator = false;
 547         }
 548
 549         /**
 550          * Switch this module to generator mode. By default, generator mode is
 551          * switched off and the module acts like a normal query module.
 552          */
 553         public function setGeneratorMode() {
 554                 $this->mIsGenerator = true;
 555         }
 556
 557         /**
 558          * Overrides base class to prepend 'g' to every generator parameter
 559          * @param $paramName string Parameter name
 560          * @return string Prefixed parameter name
 561          */
 562         public function encodeParamName( $paramName ) {
 563                 if ( $this->mIsGenerator ) {
 564                         return 'g' . parent::encodeParamName( $paramName );
 565                 } else {
 566                         return parent::encodeParamName( $paramName );
 567                 }
 568         }
 569
 570         /**
 571          * Execute this module as a generator
 572          * @param $resultPageSet ApiPageSet: All output should be appended to
 573          *  this object
 574          */
 575         public abstract function executeGenerator( $resultPageSet );
 576 }