includes/api/ApiBase.php

   1 <?php
   2 /**
   3  *
   4  *
   5  * Created on Sep 5, 2006
   6  *
   7  * Copyright © 2006, 2010 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 abstract class implements many basic API functions, and is the base of
  29  * all API classes.
  30  * The class functions are divided into several areas of functionality:
  31  *
  32  * Module parameters: Derived classes can define getAllowedParams() to specify
  33  *      which parameters to expect, how to parse and validate them.
  34  *
  35  * Profiling: various methods to allow keeping tabs on various tasks and their
  36  *      time costs
  37  *
  38  * Self-documentation: code to allow the API to document its own state
  39  *
  40  * @ingroup API
  41  */
  42 abstract class ApiBase extends ContextSource {
  43
  44         // These constants allow modules to specify exactly how to treat incoming parameters.
  45
  46         const PARAM_DFLT = 0; // Default value of the parameter
  47         const PARAM_ISMULTI = 1; // Boolean, do we accept more than one item for this parameter (e.g.: titles)?
  48         const PARAM_TYPE = 2; // Can be either a string type (e.g.: 'integer') or an array of allowed values
  49         const PARAM_MAX = 3; // Max value allowed for a parameter. Only applies if TYPE='integer'
  50         const PARAM_MAX2 = 4; // Max value allowed for a parameter for bots and sysops. Only applies if TYPE='integer'
  51         const PARAM_MIN = 5; // Lowest value allowed for a parameter. Only applies if TYPE='integer'
  52         const PARAM_ALLOW_DUPLICATES = 6; // Boolean, do we allow the same value to be set more than once when ISMULTI=true
  53         const PARAM_DEPRECATED = 7; // Boolean, is the parameter deprecated (will show a warning)
  54         /// @since 1.17
  55         const PARAM_REQUIRED = 8; // Boolean, is the parameter required?
  56         /// @since 1.17
  57         const PARAM_RANGE_ENFORCE = 9; // Boolean, if MIN/MAX are set, enforce (die) these? Only applies if TYPE='integer' Use with extreme caution
  58
  59         const PROP_ROOT = 'ROOT'; // Name of property group that is on the root element of the result, i.e. not part of a list
  60         const PROP_LIST = 'LIST'; // Boolean, is the result multiple items? Defaults to true for query modules, to false for other modules
  61         const PROP_TYPE = 0; // Type of the property, uses same format as PARAM_TYPE
  62         const PROP_NULLABLE = 1; // Boolean, can the property be not included in the result? Defaults to false
  63
  64         const LIMIT_BIG1 = 500; // Fast query, std user limit
  65         const LIMIT_BIG2 = 5000; // Fast query, bot/sysop limit
  66         const LIMIT_SML1 = 50; // Slow query, std user limit
  67         const LIMIT_SML2 = 500; // Slow query, bot/sysop limit
  68
  69         /**
  70          * getAllowedParams() flag: When set, the result could take longer to generate,
  71          * but should be more thorough. E.g. get the list of generators for ApiSandBox extension
  72          * @since 1.21
  73          */
  74         const GET_VALUES_FOR_HELP = 1;
  75
  76         private $mMainModule, $mModuleName, $mModulePrefix;
  77         private $mSlaveDB = null;
  78         private $mParamCache = array();
  79
  80         /**
  81          * Constructor
  82          * @param $mainModule ApiMain object
  83          * @param string $moduleName Name of this module
  84          * @param string $modulePrefix Prefix to use for parameter names
  85          */
  86         public function __construct( $mainModule, $moduleName, $modulePrefix = '' ) {
  87                 $this->mMainModule = $mainModule;
  88                 $this->mModuleName = $moduleName;
  89                 $this->mModulePrefix = $modulePrefix;
  90
  91                 if ( !$this->isMain() ) {
  92                         $this->setContext( $mainModule->getContext() );
  93                 }
  94         }
  95
  96         /*****************************************************************************
  97          * ABSTRACT METHODS                                                          *
  98          *****************************************************************************/
  99
 100         /**
 101          * Evaluates the parameters, performs the requested query, and sets up
 102          * the result. Concrete implementations of ApiBase must override this
 103          * method to provide whatever functionality their module offers.
 104          * Implementations must not produce any output on their own and are not
 105          * expected to handle any errors.
 106          *
 107          * The execute() method will be invoked directly by ApiMain immediately
 108          * before the result of the module is output. Aside from the
 109          * constructor, implementations should assume that no other methods
 110          * will be called externally on the module before the result is
 111          * processed.
 112          *
 113          * The result data should be stored in the ApiResult object available
 114          * through getResult().
 115          */
 116         abstract public function execute();
 117
 118         /**
 119          * Returns a string that identifies the version of the extending class.
 120          * Typically includes the class name, the svn revision, timestamp, and
 121          * last author. Usually done with SVN's Id keyword
 122          * @return string
 123          * @deprecated since 1.21, version string is no longer supported
 124          */
 125         public function getVersion() {
 126                 wfDeprecated( __METHOD__, '1.21' );
 127                 return '';
 128         }
 129
 130         /**
 131          * Get the name of the module being executed by this instance
 132          * @return string
 133          */
 134         public function getModuleName() {
 135                 return $this->mModuleName;
 136         }
 137
 138         /**
 139          * Get the module manager, or null if this module has no sub-modules
 140          * @since 1.21
 141          * @return ApiModuleManager
 142          */
 143         public function getModuleManager() {
 144                 return null;
 145         }
 146
 147         /**
 148          * Get parameter prefix (usually two letters or an empty string).
 149          * @return string
 150          */
 151         public function getModulePrefix() {
 152                 return $this->mModulePrefix;
 153         }
 154
 155         /**
 156          * Get the name of the module as shown in the profiler log
 157          *
 158          * @param $db DatabaseBase|bool
 159          *
 160          * @return string
 161          */
 162         public function getModuleProfileName( $db = false ) {
 163                 if ( $db ) {
 164                         return 'API:' . $this->mModuleName . '-DB';
 165                 } else {
 166                         return 'API:' . $this->mModuleName;
 167                 }
 168         }
 169
 170         /**
 171          * Get the main module
 172          * @return ApiMain object
 173          */
 174         public function getMain() {
 175                 return $this->mMainModule;
 176         }
 177
 178         /**
 179          * Returns true if this module is the main module ($this === $this->mMainModule),
 180          * false otherwise.
 181          * @return bool
 182          */
 183         public function isMain() {
 184                 return $this === $this->mMainModule;
 185         }
 186
 187         /**
 188          * Get the result object
 189          * @return ApiResult
 190          */
 191         public function getResult() {
 192                 // Main module has getResult() method overridden
 193                 // Safety - avoid infinite loop:
 194                 if ( $this->isMain() ) {
 195                         ApiBase::dieDebug( __METHOD__, 'base method was called on main module. ' );
 196                 }
 197                 return $this->getMain()->getResult();
 198         }
 199
 200         /**
 201          * Get the result data array (read-only)
 202          * @return array
 203          */
 204         public function getResultData() {
 205                 return $this->getResult()->getData();
 206         }
 207
 208         /**
 209          * Create a new RequestContext object to use e.g. for calls to other parts
 210          * the software.
 211          * The object will have the WebRequest and the User object set to the ones
 212          * used in this instance.
 213          *
 214          * @deprecated since 1.19 use getContext to get the current context
 215          * @return DerivativeContext
 216          */
 217         public function createContext() {
 218                 wfDeprecated( __METHOD__, '1.19' );
 219                 return new DerivativeContext( $this->getContext() );
 220         }
 221
 222         /**
 223          * Set warning section for this module. Users should monitor this
 224          * section to notice any changes in API. Multiple calls to this
 225          * function will result in the warning messages being separated by
 226          * newlines
 227          * @param string $warning Warning message
 228          */
 229         public function setWarning( $warning ) {
 230                 $result = $this->getResult();
 231                 $data = $result->getData();
 232                 $moduleName = $this->getModuleName();
 233                 if ( isset( $data['warnings'][$moduleName] ) ) {
 234                         // Don't add duplicate warnings
 235                         $oldWarning = $data['warnings'][$moduleName]['*'];
 236                         $warnPos = strpos( $oldWarning, $warning );
 237                         // If $warning was found in $oldWarning, check if it starts at 0 or after "\n"
 238                         if ( $warnPos !== false && ( $warnPos === 0 || $oldWarning[$warnPos - 1] === "\n" ) ) {
 239                                 // Check if $warning is followed by "\n" or the end of the $oldWarning
 240                                 $warnPos += strlen( $warning );
 241                                 if ( strlen( $oldWarning ) <= $warnPos || $oldWarning[$warnPos] === "\n" ) {
 242                                         return;
 243                                 }
 244                         }
 245                         // If there is a warning already, append it to the existing one
 246                         $warning = "$oldWarning\n$warning";
 247                 }
 248                 $msg = array();
 249                 ApiResult::setContent( $msg, $warning );
 250                 $result->disableSizeCheck();
 251                 $result->addValue( 'warnings', $moduleName,
 252                         $msg, ApiResult::OVERRIDE | ApiResult::ADD_ON_TOP );
 253                 $result->enableSizeCheck();
 254         }
 255
 256         /**
 257          * If the module may only be used with a certain format module,
 258          * it should override this method to return an instance of that formatter.
 259          * A value of null means the default format will be used.
 260          * @return mixed instance of a derived class of ApiFormatBase, or null
 261          */
 262         public function getCustomPrinter() {
 263                 return null;
 264         }
 265
 266         /**
 267          * Generates help message for this module, or false if there is no description
 268          * @return mixed string or false
 269          */
 270         public function makeHelpMsg() {
 271                 static $lnPrfx = "\n  ";
 272
 273                 $msg = $this->getFinalDescription();
 274
 275                 if ( $msg !== false ) {
 276
 277                         if ( !is_array( $msg ) ) {
 278                                 $msg = array(
 279                                         $msg
 280                                 );
 281                         }
 282                         $msg = $lnPrfx . implode( $lnPrfx, $msg ) . "\n";
 283
 284                         $msg .= $this->makeHelpArrayToString( $lnPrfx, false, $this->getHelpUrls() );
 285
 286                         if ( $this->isReadMode() ) {
 287                                 $msg .= "\nThis module requires read rights";
 288                         }
 289                         if ( $this->isWriteMode() ) {
 290                                 $msg .= "\nThis module requires write rights";
 291                         }
 292                         if ( $this->mustBePosted() ) {
 293                                 $msg .= "\nThis module only accepts POST requests";
 294                         }
 295                         if ( $this->isReadMode() || $this->isWriteMode() ||
 296                                         $this->mustBePosted() ) {
 297                                 $msg .= "\n";
 298                         }
 299
 300                         // Parameters
 301                         $paramsMsg = $this->makeHelpMsgParameters();
 302                         if ( $paramsMsg !== false ) {
 303                                 $msg .= "Parameters:\n$paramsMsg";
 304                         }
 305
 306                         $examples = $this->getExamples();
 307                         if ( $examples ) {
 308                                 if ( !is_array( $examples ) ) {
 309                                         $examples = array(
 310                                                 $examples
 311                                         );
 312                                 }
 313                                 $msg .= "Example" . ( count( $examples ) > 1 ? 's' : '' ) . ":\n";
 314                                 foreach ( $examples as $k => $v ) {
 315                                         if ( is_numeric( $k ) ) {
 316                                                 $msg .= "  $v\n";
 317                                         } else {
 318                                                 if ( is_array( $v ) ) {
 319                                                         $msgExample = implode( "\n", array_map( array( $this, 'indentExampleText' ), $v ) );
 320                                                 } else {
 321                                                         $msgExample = "  $v";
 322                                                 }
 323                                                 $msgExample .= ":";
 324                                                 $msg .= wordwrap( $msgExample, 100, "\n" ) . "\n    $k\n";
 325                                         }
 326                                 }
 327                         }
 328                 }
 329
 330                 return $msg;
 331         }
 332
 333         /**
 334          * @param $item string
 335          * @return string
 336          */
 337         private function indentExampleText( $item ) {
 338                 return "  " . $item;
 339         }
 340
 341         /**
 342          * @param string $prefix Text to split output items
 343          * @param string $title What is being output
 344          * @param $input string|array
 345          * @return string
 346          */
 347         protected function makeHelpArrayToString( $prefix, $title, $input ) {
 348                 if ( $input === false ) {
 349                         return '';
 350                 }
 351                 if ( !is_array( $input ) ) {
 352                         $input = array( $input );
 353                 }
 354
 355                 if ( count( $input ) > 0 ) {
 356                         if ( $title ) {
 357                                 $msg = $title . ( count( $input ) > 1 ? 's' : '' ) . ":\n  ";
 358                         } else {
 359                                 $msg = '  ';
 360                         }
 361                         $msg .= implode( $prefix, $input ) . "\n";
 362                         return $msg;
 363                 }
 364                 return '';
 365         }
 366
 367         /**
 368          * Generates the parameter descriptions for this module, to be displayed in the
 369          * module's help.
 370          * @return string or false
 371          */
 372         public function makeHelpMsgParameters() {
 373                 $params = $this->getFinalParams( ApiBase::GET_VALUES_FOR_HELP );
 374                 if ( $params ) {
 375
 376                         $paramsDescription = $this->getFinalParamDescription();
 377                         $msg = '';
 378                         $paramPrefix = "\n" . str_repeat( ' ', 24 );
 379                         $descWordwrap = "\n" . str_repeat( ' ', 28 );
 380                         foreach ( $params as $paramName => $paramSettings ) {
 381                                 $desc = isset( $paramsDescription[$paramName] ) ? $paramsDescription[$paramName] : '';
 382                                 if ( is_array( $desc ) ) {
 383                                         $desc = implode( $paramPrefix, $desc );
 384                                 }
 385
 386                                 //handle shorthand
 387                                 if ( !is_array( $paramSettings ) ) {
 388                                         $paramSettings = array(
 389                                                 self::PARAM_DFLT => $paramSettings,
 390                                         );
 391                                 }
 392
 393                                 //handle missing type
 394                                 if ( !isset( $paramSettings[ApiBase::PARAM_TYPE] ) ) {
 395                                         $dflt = isset( $paramSettings[ApiBase::PARAM_DFLT] ) ? $paramSettings[ApiBase::PARAM_DFLT] : null;
 396                                         if ( is_bool( $dflt ) ) {
 397                                                 $paramSettings[ApiBase::PARAM_TYPE] = 'boolean';
 398                                         } elseif ( is_string( $dflt ) || is_null( $dflt ) ) {
 399                                                 $paramSettings[ApiBase::PARAM_TYPE] = 'string';
 400                                         } elseif ( is_int( $dflt ) ) {
 401                                                 $paramSettings[ApiBase::PARAM_TYPE] = 'integer';
 402                                         }
 403                                 }
 404
 405                                 if ( isset( $paramSettings[self::PARAM_DEPRECATED] ) && $paramSettings[self::PARAM_DEPRECATED] ) {
 406                                         $desc = "DEPRECATED! $desc";
 407                                 }
 408
 409                                 if ( isset( $paramSettings[self::PARAM_REQUIRED] ) && $paramSettings[self::PARAM_REQUIRED] ) {
 410                                         $desc .= $paramPrefix . "This parameter is required";
 411                                 }
 412
 413                                 $type = isset( $paramSettings[self::PARAM_TYPE] ) ? $paramSettings[self::PARAM_TYPE] : null;
 414                                 if ( isset( $type ) ) {
 415                                         $hintPipeSeparated = true;
 416                                         $multi = isset( $paramSettings[self::PARAM_ISMULTI] ) ? $paramSettings[self::PARAM_ISMULTI] : false;
 417                                         if ( $multi ) {
 418                                                 $prompt = 'Values (separate with \'|\'): ';
 419                                         } else {
 420                                                 $prompt = 'One value: ';
 421                                         }
 422
 423                                         if ( is_array( $type ) ) {
 424                                                 $choices = array();
 425                                                 $nothingPrompt = '';
 426                                                 foreach ( $type as $t ) {
 427                                                         if ( $t === '' ) {
 428                                                                 $nothingPrompt = 'Can be empty, or ';
 429                                                         } else {
 430                                                                 $choices[] = $t;
 431                                                         }
 432                                                 }
 433                                                 $desc .= $paramPrefix . $nothingPrompt . $prompt;
 434                                                 $choicesstring = implode( ', ', $choices );
 435                                                 $desc .= wordwrap( $choicesstring, 100, $descWordwrap );
 436                                                 $hintPipeSeparated = false;
 437                                         } else {
 438                                                 switch ( $type ) {
 439                                                         case 'namespace':
 440                                                                 // Special handling because namespaces are type-limited, yet they are not given
 441                                                                 $desc .= $paramPrefix . $prompt;
 442                                                                 $desc .= wordwrap( implode( ', ', MWNamespace::getValidNamespaces() ),
 443                                                                         100, $descWordwrap );
 444                                                                 $hintPipeSeparated = false;
 445                                                                 break;
 446                                                         case 'limit':
 447                                                                 $desc .= $paramPrefix . "No more than {$paramSettings[self::PARAM_MAX]}";
 448                                                                 if ( isset( $paramSettings[self::PARAM_MAX2] ) ) {
 449                                                                         $desc .= " ({$paramSettings[self::PARAM_MAX2]} for bots)";
 450                                                                 }
 451                                                                 $desc .= ' allowed';
 452                                                                 break;
 453                                                         case 'integer':
 454                                                                 $s = $multi ? 's' : '';
 455                                                                 $hasMin = isset( $paramSettings[self::PARAM_MIN] );
 456                                                                 $hasMax = isset( $paramSettings[self::PARAM_MAX] );
 457                                                                 if ( $hasMin || $hasMax ) {
 458                                                                         if ( !$hasMax ) {
 459                                                                                 $intRangeStr = "The value$s must be no less than {$paramSettings[self::PARAM_MIN]}";
 460                                                                         } elseif ( !$hasMin ) {
 461                                                                                 $intRangeStr = "The value$s must be no more than {$paramSettings[self::PARAM_MAX]}";
 462                                                                         } else {
 463                                                                                 $intRangeStr = "The value$s must be between {$paramSettings[self::PARAM_MIN]} and {$paramSettings[self::PARAM_MAX]}";
 464                                                                         }
 465
 466                                                                         $desc .= $paramPrefix . $intRangeStr;
 467                                                                 }
 468                                                                 break;
 469                                                         case 'upload':
 470                                                                 $desc .= $paramPrefix . "Must be posted as a file upload using multipart/form-data";
 471                                                                 break;
 472                                                 }
 473                                         }
 474
 475                                         if ( $multi ) {
 476                                                 if ( $hintPipeSeparated ) {
 477                                                         $desc .= $paramPrefix . "Separate values with '|'";
 478                                                 }
 479
 480                                                 $isArray = is_array( $type );
 481                                                 if ( !$isArray
 482                                                                 || $isArray && count( $type ) > self::LIMIT_SML1 ) {
 483                                                         $desc .= $paramPrefix . "Maximum number of values " .
 484                                                                         self::LIMIT_SML1 . " (" . self::LIMIT_SML2 . " for bots)";
 485                                                 }
 486                                         }
 487                                 }
 488
 489                                 $default = isset( $paramSettings[self::PARAM_DFLT] ) ? $paramSettings[self::PARAM_DFLT] : null;
 490                                 if ( !is_null( $default ) && $default !== false ) {
 491                                         $desc .= $paramPrefix . "Default: $default";
 492                                 }
 493
 494                                 $msg .= sprintf( "  %-19s - %s\n", $this->encodeParamName( $paramName ), $desc );
 495                         }
 496                         return $msg;
 497
 498                 } else {
 499                         return false;
 500                 }
 501         }
 502
 503         /**
 504          * Returns the description string for this module
 505          * @return mixed string or array of strings
 506          */
 507         protected function getDescription() {
 508                 return false;
 509         }
 510
 511         /**
 512          * Returns usage examples for this module. Return false if no examples are available.
 513          * @return bool|string|array
 514          */
 515         protected function getExamples() {
 516                 return false;
 517         }
 518
 519         /**
 520          * Returns an array of allowed parameters (parameter name) => (default
 521          * value) or (parameter name) => (array with PARAM_* constants as keys)
 522          * Don't call this function directly: use getFinalParams() to allow
 523          * hooks to modify parameters as needed.
 524          *
 525          * Some derived classes may choose to handle an integer $flags parameter
 526          * in the overriding methods. Callers of this method can pass zero or
 527          * more OR-ed flags like GET_VALUES_FOR_HELP.
 528          *
 529          * @return array|bool
 530          */
 531         protected function getAllowedParams( /* $flags = 0 */ ) {
 532                 // int $flags is not declared because it causes "Strict standards"
 533                 // warning. Most derived classes do not implement it.
 534                 return false;
 535         }
 536
 537         /**
 538          * Returns an array of parameter descriptions.
 539          * Don't call this function directly: use getFinalParamDescription() to
 540          * allow hooks to modify descriptions as needed.
 541          * @return array|bool False on no parameter descriptions
 542          */
 543         protected function getParamDescription() {
 544                 return false;
 545         }
 546
 547         /**
 548          * Get final list of parameters, after hooks have had a chance to
 549          * tweak it as needed.
 550          *
 551          * @param int $flags Zero or more flags like GET_VALUES_FOR_HELP
 552          * @return array|Bool False on no parameters
 553          * @since 1.21 $flags param added
 554          */
 555         public function getFinalParams( $flags = 0 ) {
 556                 $params = $this->getAllowedParams( $flags );
 557                 wfRunHooks( 'APIGetAllowedParams', array( &$this, &$params, $flags ) );
 558                 return $params;
 559         }
 560
 561         /**
 562          * Get final parameter descriptions, after hooks have had a chance to tweak it as
 563          * needed.
 564          *
 565          * @return array|bool False on no parameter descriptions
 566          */
 567         public function getFinalParamDescription() {
 568                 $desc = $this->getParamDescription();
 569                 wfRunHooks( 'APIGetParamDescription', array( &$this, &$desc ) );
 570                 return $desc;
 571         }
 572
 573         /**
 574          * Returns possible properties in the result, grouped by the value of the prop parameter
 575          * that shows them.
 576          *
 577          * Properties that are shown always are in a group with empty string as a key.
 578          * Properties that can be shown by several values of prop are included multiple times.
 579          * If some properties are part of a list and some are on the root object (see ApiQueryQueryPage),
 580          * those on the root object are under the key PROP_ROOT.
 581          * The array can also contain a boolean under the key PROP_LIST,
 582          * indicating whether the result is a list.
 583          *
 584          * Don't call this function directly: use getFinalResultProperties() to
 585          * allow hooks to modify descriptions as needed.
 586          *
 587          * @return array|bool False on no properties
 588          */
 589         protected function getResultProperties() {
 590                 return false;
 591         }
 592
 593         /**
 594          * Get final possible result properties, after hooks have had a chance to tweak it as
 595          * needed.
 596          *
 597          * @return array
 598          */
 599         public function getFinalResultProperties() {
 600                 $properties = $this->getResultProperties();
 601                 wfRunHooks( 'APIGetResultProperties', array( $this, &$properties ) );
 602                 return $properties;
 603         }
 604
 605         /**
 606          * Add token properties to the array used by getResultProperties,
 607          * based on a token functions mapping.
 608          */
 609         protected static function addTokenProperties( &$props, $tokenFunctions ) {
 610                 foreach ( array_keys( $tokenFunctions ) as $token ) {
 611                         $props[''][$token . 'token'] = array(
 612                                 ApiBase::PROP_TYPE => 'string',
 613                                 ApiBase::PROP_NULLABLE => true
 614                         );
 615                 }
 616         }
 617
 618         /**
 619          * Get final module description, after hooks have had a chance to tweak it as
 620          * needed.
 621          *
 622          * @return array|bool False on no parameters
 623          */
 624         public function getFinalDescription() {
 625                 $desc = $this->getDescription();
 626                 wfRunHooks( 'APIGetDescription', array( &$this, &$desc ) );
 627                 return $desc;
 628         }
 629
 630         /**
 631          * This method mangles parameter name based on the prefix supplied to the constructor.
 632          * Override this method to change parameter name during runtime
 633          * @param string $paramName Parameter name
 634          * @return string Prefixed parameter name
 635          */
 636         public function encodeParamName( $paramName ) {
 637                 return $this->mModulePrefix . $paramName;
 638         }
 639
 640         /**
 641          * Using getAllowedParams(), this function makes an array of the values
 642          * provided by the user, with key being the name of the variable, and
 643          * value - validated value from user or default. limits will not be
 644          * parsed if $parseLimit is set to false; use this when the max
 645          * limit is not definitive yet, e.g. when getting revisions.
 646          * @param $parseLimit Boolean: true by default
 647          * @return array
 648          */
 649         public function extractRequestParams( $parseLimit = true ) {
 650                 // Cache parameters, for performance and to avoid bug 24564.
 651                 if ( !isset( $this->mParamCache[$parseLimit] ) ) {
 652                         $params = $this->getFinalParams();
 653                         $results = array();
 654
 655                         if ( $params ) { // getFinalParams() can return false
 656                                 foreach ( $params as $paramName => $paramSettings ) {
 657                                         $results[$paramName] = $this->getParameterFromSettings(
 658                                                 $paramName, $paramSettings, $parseLimit );
 659                                 }
 660                         }
 661                         $this->mParamCache[$parseLimit] = $results;
 662                 }
 663                 return $this->mParamCache[$parseLimit];
 664         }
 665
 666         /**
 667          * Get a value for the given parameter
 668          * @param string $paramName Parameter name
 669          * @param bool $parseLimit see extractRequestParams()
 670          * @return mixed Parameter value
 671          */
 672         protected function getParameter( $paramName, $parseLimit = true ) {
 673                 $params = $this->getFinalParams();
 674                 $paramSettings = $params[$paramName];
 675                 return $this->getParameterFromSettings( $paramName, $paramSettings, $parseLimit );
 676         }
 677
 678         /**
 679          * Die if none or more than one of a certain set of parameters is set and not false.
 680          * @param array $params of parameter names
 681          */
 682         public function requireOnlyOneParameter( $params ) {
 683                 $required = func_get_args();
 684                 array_shift( $required );
 685                 $p = $this->getModulePrefix();
 686
 687                 $intersection = array_intersect( array_keys( array_filter( $params,
 688                         array( $this, "parameterNotEmpty" ) ) ), $required );
 689
 690                 if ( count( $intersection ) > 1 ) {
 691                         $this->dieUsage( "The parameters {$p}" . implode( ", {$p}", $intersection ) . ' can not be used together', 'invalidparammix' );
 692                 } elseif ( count( $intersection ) == 0 ) {
 693                         $this->dieUsage( "One of the parameters {$p}" . implode( ", {$p}", $required ) . ' is required', 'missingparam' );
 694                 }
 695         }
 696
 697         /**
 698          * Generates the possible errors requireOnlyOneParameter() can die with
 699          *
 700          * @param $params array
 701          * @return array
 702          */
 703         public function getRequireOnlyOneParameterErrorMessages( $params ) {
 704                 $p = $this->getModulePrefix();
 705                 $params = implode( ", {$p}", $params );
 706
 707                 return array(
 708                         array( 'code' => "{$p}missingparam", 'info' => "One of the parameters {$p}{$params} is required" ),
 709                         array( 'code' => "{$p}invalidparammix", 'info' => "The parameters {$p}{$params} can not be used together" )
 710                 );
 711         }
 712
 713         /**
 714          * Die if more than one of a certain set of parameters is set and not false.
 715          *
 716          * @param $params array
 717          */
 718         public function requireMaxOneParameter( $params ) {
 719                 $required = func_get_args();
 720                 array_shift( $required );
 721                 $p = $this->getModulePrefix();
 722
 723                 $intersection = array_intersect( array_keys( array_filter( $params,
 724                         array( $this, "parameterNotEmpty" ) ) ), $required );
 725
 726                 if ( count( $intersection ) > 1 ) {
 727                         $this->dieUsage( "The parameters {$p}" . implode( ", {$p}", $intersection ) . ' can not be used together', 'invalidparammix' );
 728                 }
 729         }
 730
 731         /**
 732          * Generates the possible error requireMaxOneParameter() can die with
 733          *
 734          * @param $params array
 735          * @return array
 736          */
 737         public function getRequireMaxOneParameterErrorMessages( $params ) {
 738                 $p = $this->getModulePrefix();
 739                 $params = implode( ", {$p}", $params );
 740
 741                 return array(
 742                         array( 'code' => "{$p}invalidparammix", 'info' => "The parameters {$p}{$params} can not be used together" )
 743                 );
 744         }
 745
 746         /**
 747          * @param $params array
 748          * @param bool|string $load Whether load the object's state from the database:
 749          *        - false: don't load (if the pageid is given, it will still be loaded)
 750          *        - 'fromdb': load from a slave database
 751          *        - 'fromdbmaster': load from the master database
 752          * @return WikiPage
 753          */
 754         public function getTitleOrPageId( $params, $load = false ) {
 755                 $this->requireOnlyOneParameter( $params, 'title', 'pageid' );
 756
 757                 $pageObj = null;
 758                 if ( isset( $params['title'] ) ) {
 759                         $titleObj = Title::newFromText( $params['title'] );
 760                         if ( !$titleObj || $titleObj->isExternal() ) {
 761                                 $this->dieUsageMsg( array( 'invalidtitle', $params['title'] ) );
 762                         }
 763                         if ( !$titleObj->canExist() ) {
 764                                 $this->dieUsage( "Namespace doesn't allow actual pages", 'pagecannotexist' );
 765                         }
 766                         $pageObj = WikiPage::factory( $titleObj );
 767                         if ( $load !== false ) {
 768                                 $pageObj->loadPageData( $load );
 769                         }
 770                 } elseif ( isset( $params['pageid'] ) ) {
 771                         if ( $load === false ) {
 772                                 $load = 'fromdb';
 773                         }
 774                         $pageObj = WikiPage::newFromID( $params['pageid'], $load );
 775                         if ( !$pageObj ) {
 776                                 $this->dieUsageMsg( array( 'nosuchpageid', $params['pageid'] ) );
 777                         }
 778                 }
 779
 780                 return $pageObj;
 781         }
 782
 783         /**
 784          * @return array
 785          */
 786         public function getTitleOrPageIdErrorMessage() {
 787                 return array_merge(
 788                         $this->getRequireOnlyOneParameterErrorMessages( array( 'title', 'pageid' ) ),
 789                         array(
 790                                 array( 'invalidtitle', 'title' ),
 791                                 array( 'nosuchpageid', 'pageid' ),
 792                         )
 793                 );
 794         }
 795
 796         /**
 797          * Callback function used in requireOnlyOneParameter to check whether required parameters are set
 798          *
 799          * @param  $x object Parameter to check is not null/false
 800          * @return bool
 801          */
 802         private function parameterNotEmpty( $x ) {
 803                 return !is_null( $x ) && $x !== false;
 804         }
 805
 806         /**
 807          * @deprecated since 1.17 use MWNamespace::getValidNamespaces()
 808          *
 809          * @return array
 810          */
 811         public static function getValidNamespaces() {
 812                 wfDeprecated( __METHOD__, '1.17' );
 813                 return MWNamespace::getValidNamespaces();
 814         }
 815
 816         /**
 817          * Return true if we're to watch the page, false if not, null if no change.
 818          * @param string $watchlist Valid values: 'watch', 'unwatch', 'preferences', 'nochange'
 819          * @param $titleObj Title the page under consideration
 820          * @param string $userOption The user option to consider when $watchlist=preferences.
 821          *      If not set will magically default to either watchdefault or watchcreations
 822          * @return bool
 823          */
 824         protected function getWatchlistValue( $watchlist, $titleObj, $userOption = null ) {
 825
 826                 $userWatching = $this->getUser()->isWatched( $titleObj, WatchedItem::IGNORE_USER_RIGHTS );
 827
 828                 switch ( $watchlist ) {
 829                         case 'watch':
 830                                 return true;
 831
 832                         case 'unwatch':
 833                                 return false;
 834
 835                         case 'preferences':
 836                                 # If the user is already watching, don't bother checking
 837                                 if ( $userWatching ) {
 838                                         return true;
 839                                 }
 840                                 # If no user option was passed, use watchdefault or watchcreations
 841                                 if ( is_null( $userOption ) ) {
 842                                         $userOption = $titleObj->exists()
 843                                                         ? 'watchdefault' : 'watchcreations';
 844                                 }
 845                                 # Watch the article based on the user preference
 846                                 return $this->getUser()->getBoolOption( $userOption );
 847
 848                         case 'nochange':
 849                                 return $userWatching;
 850
 851                         default:
 852                                 return $userWatching;
 853                 }
 854         }
 855
 856         /**
 857          * Set a watch (or unwatch) based the based on a watchlist parameter.
 858          * @param string $watch Valid values: 'watch', 'unwatch', 'preferences', 'nochange'
 859          * @param $titleObj Title the article's title to change
 860          * @param string $userOption The user option to consider when $watch=preferences
 861          */
 862         protected function setWatch( $watch, $titleObj, $userOption = null ) {
 863                 $value = $this->getWatchlistValue( $watch, $titleObj, $userOption );
 864                 if ( $value === null ) {
 865                         return;
 866                 }
 867
 868                 WatchAction::doWatchOrUnwatch( $value, $titleObj, $this->getUser() );
 869         }
 870
 871         /**
 872          * Using the settings determine the value for the given parameter
 873          *
 874          * @param string $paramName parameter name
 875          * @param array|mixed $paramSettings default value or an array of settings
 876          *  using PARAM_* constants.
 877          * @param $parseLimit Boolean: parse limit?
 878          * @return mixed Parameter value
 879          */
 880         protected function getParameterFromSettings( $paramName, $paramSettings, $parseLimit ) {
 881                 // Some classes may decide to change parameter names
 882                 $encParamName = $this->encodeParamName( $paramName );
 883
 884                 if ( !is_array( $paramSettings ) ) {
 885                         $default = $paramSettings;
 886                         $multi = false;
 887                         $type = gettype( $paramSettings );
 888                         $dupes = false;
 889                         $deprecated = false;
 890                         $required = false;
 891                 } else {
 892                         $default = isset( $paramSettings[self::PARAM_DFLT] ) ? $paramSettings[self::PARAM_DFLT] : null;
 893                         $multi = isset( $paramSettings[self::PARAM_ISMULTI] ) ? $paramSettings[self::PARAM_ISMULTI] : false;
 894                         $type = isset( $paramSettings[self::PARAM_TYPE] ) ? $paramSettings[self::PARAM_TYPE] : null;
 895                         $dupes = isset( $paramSettings[self::PARAM_ALLOW_DUPLICATES] ) ? $paramSettings[self::PARAM_ALLOW_DUPLICATES] : false;
 896                         $deprecated = isset( $paramSettings[self::PARAM_DEPRECATED] ) ? $paramSettings[self::PARAM_DEPRECATED] : false;
 897                         $required = isset( $paramSettings[self::PARAM_REQUIRED] ) ? $paramSettings[self::PARAM_REQUIRED] : false;
 898
 899                         // When type is not given, and no choices, the type is the same as $default
 900                         if ( !isset( $type ) ) {
 901                                 if ( isset( $default ) ) {
 902                                         $type = gettype( $default );
 903                                 } else {
 904                                         $type = 'NULL'; // allow everything
 905                                 }
 906                         }
 907                 }
 908
 909                 if ( $type == 'boolean' ) {
 910                         if ( isset( $default ) && $default !== false ) {
 911                                 // Having a default value of anything other than 'false' is not allowed
 912                                 ApiBase::dieDebug( __METHOD__, "Boolean param $encParamName's default is set to '$default'. Boolean parameters must default to false." );
 913                         }
 914
 915                         $value = $this->getMain()->getCheck( $encParamName );
 916                 } elseif ( $type == 'upload' ) {
 917                         if ( isset( $default ) ) {
 918                                 // Having a default value is not allowed
 919                                 ApiBase::dieDebug( __METHOD__, "File upload param $encParamName's default is set to '$default'. File upload parameters may not have a default." );
 920                         }
 921                         if ( $multi ) {
 922                                 ApiBase::dieDebug( __METHOD__, "Multi-values not supported for $encParamName" );
 923                         }
 924                         $value = $this->getMain()->getUpload( $encParamName );
 925                         if ( !$value->exists() ) {
 926                                 // This will get the value without trying to normalize it
 927                                 // (because trying to normalize a large binary file
 928                                 // accidentally uploaded as a field fails spectacularly)
 929                                 $value = $this->getMain()->getRequest()->unsetVal( $encParamName );
 930                                 if ( $value !== null ) {
 931                                         $this->dieUsage(
 932                                                 "File upload param $encParamName is not a file upload; " .
 933                                                 "be sure to use multipart/form-data for your POST and include " .
 934                                                 "a filename in the Content-Disposition header.",
 935                                                 "badupload_{$encParamName}"
 936                                         );
 937                                 }
 938                         }
 939                 } else {
 940                         $value = $this->getMain()->getVal( $encParamName, $default );
 941
 942                         if ( isset( $value ) && $type == 'namespace' ) {
 943                                 $type = MWNamespace::getValidNamespaces();
 944                         }
 945                 }
 946
 947                 if ( isset( $value ) && ( $multi || is_array( $type ) ) ) {
 948                         $value = $this->parseMultiValue( $encParamName, $value, $multi, is_array( $type ) ? $type : null );
 949                 }
 950
 951                 // More validation only when choices were not given
 952                 // choices were validated in parseMultiValue()
 953                 if ( isset( $value ) ) {
 954                         if ( !is_array( $type ) ) {
 955                                 switch ( $type ) {
 956                                         case 'NULL': // nothing to do
 957                                                 break;
 958                                         case 'string':
 959                                                 if ( $required && $value === '' ) {
 960                                                         $this->dieUsageMsg( array( 'missingparam', $paramName ) );
 961                                                 }
 962                                                 break;
 963                                         case 'integer': // Force everything using intval() and optionally validate limits
 964                                                 $min = isset( $paramSettings[self::PARAM_MIN] ) ? $paramSettings[self::PARAM_MIN] : null;
 965                                                 $max = isset( $paramSettings[self::PARAM_MAX] ) ? $paramSettings[self::PARAM_MAX] : null;
 966                                                 $enforceLimits = isset( $paramSettings[self::PARAM_RANGE_ENFORCE] )
 967                                                                 ? $paramSettings[self::PARAM_RANGE_ENFORCE] : false;
 968
 969                                                 if ( is_array( $value ) ) {
 970                                                         $value = array_map( 'intval', $value );
 971                                                         if ( !is_null( $min ) || !is_null( $max ) ) {
 972                                                                 foreach ( $value as &$v ) {
 973                                                                         $this->validateLimit( $paramName, $v, $min, $max, null, $enforceLimits );
 974                                                                 }
 975                                                         }
 976                                                 } else {
 977                                                         $value = intval( $value );
 978                                                         if ( !is_null( $min ) || !is_null( $max ) ) {
 979                                                                 $this->validateLimit( $paramName, $value, $min, $max, null, $enforceLimits );
 980                                                         }
 981                                                 }
 982                                                 break;
 983                                         case 'limit':
 984                                                 if ( !$parseLimit ) {
 985                                                         // Don't do any validation whatsoever
 986                                                         break;
 987                                                 }
 988                                                 if ( !isset( $paramSettings[self::PARAM_MAX] ) || !isset( $paramSettings[self::PARAM_MAX2] ) ) {
 989                                                         ApiBase::dieDebug( __METHOD__, "MAX1 or MAX2 are not defined for the limit $encParamName" );
 990                                                 }
 991                                                 if ( $multi ) {
 992                                                         ApiBase::dieDebug( __METHOD__, "Multi-values not supported for $encParamName" );
 993                                                 }
 994                                                 $min = isset( $paramSettings[self::PARAM_MIN] ) ? $paramSettings[self::PARAM_MIN] : 0;
 995                                                 if ( $value == 'max' ) {
 996                                                         $value = $this->getMain()->canApiHighLimits() ? $paramSettings[self::PARAM_MAX2] : $paramSettings[self::PARAM_MAX];
 997                                                         $this->getResult()->setParsedLimit( $this->getModuleName(), $value );
 998                                                 } else {
 999                                                         $value = intval( $value );
1000                                                         $this->validateLimit( $paramName, $value, $min, $paramSettings[self::PARAM_MAX], $paramSettings[self::PARAM_MAX2] );
1001                                                 }
1002                                                 break;
1003                                         case 'boolean':
1004                                                 if ( $multi ) {
1005                                                         ApiBase::dieDebug( __METHOD__, "Multi-values not supported for $encParamName" );
1006                                                 }
1007                                                 break;
1008                                         case 'timestamp':
1009                                                 if ( is_array( $value ) ) {
1010                                                         foreach ( $value as $key => $val ) {
1011                                                                 $value[$key] = $this->validateTimestamp( $val, $encParamName );
1012                                                         }
1013                                                 } else {
1014                                                         $value = $this->validateTimestamp( $value, $encParamName );
1015                                                 }
1016                                                 break;
1017                                         case 'user':
1018                                                 if ( is_array( $value ) ) {
1019                                                         foreach ( $value as $key => $val ) {
1020                                                                 $value[$key] = $this->validateUser( $val, $encParamName );
1021                                                         }
1022                                                 } else {
1023                                                         $value = $this->validateUser( $value, $encParamName );
1024                                                 }
1025                                                 break;
1026                                         case 'upload': // nothing to do
1027                                                 break;
1028                                         default:
1029                                                 ApiBase::dieDebug( __METHOD__, "Param $encParamName's type is unknown - $type" );
1030                                 }
1031                         }
1032
1033                         // Throw out duplicates if requested
1034                         if ( !$dupes && is_array( $value ) ) {
1035                                 $value = array_unique( $value );
1036                         }
1037
1038                         // Set a warning if a deprecated parameter has been passed
1039                         if ( $deprecated && $value !== false ) {
1040                                 $this->setWarning( "The $encParamName parameter has been deprecated." );
1041                         }
1042                 } elseif ( $required ) {
1043                         $this->dieUsageMsg( array( 'missingparam', $paramName ) );
1044                 }
1045
1046                 return $value;
1047         }
1048
1049         /**
1050          * Return an array of values that were given in a 'a|b|c' notation,
1051          * after it optionally validates them against the list allowed values.
1052          *
1053          * @param string $valueName The name of the parameter (for error
1054          *  reporting)
1055          * @param $value mixed The value being parsed
1056          * @param bool $allowMultiple Can $value contain more than one value
1057          *  separated by '|'?
1058          * @param $allowedValues mixed An array of values to check against. If
1059          *  null, all values are accepted.
1060          * @return mixed (allowMultiple ? an_array_of_values : a_single_value)
1061          */
1062         protected function parseMultiValue( $valueName, $value, $allowMultiple, $allowedValues ) {
1063                 if ( trim( $value ) === '' && $allowMultiple ) {
1064                         return array();
1065                 }
1066
1067                 // This is a bit awkward, but we want to avoid calling canApiHighLimits() because it unstubs $wgUser
1068                 $valuesList = explode( '|', $value, self::LIMIT_SML2 + 1 );
1069                 $sizeLimit = count( $valuesList ) > self::LIMIT_SML1 && $this->mMainModule->canApiHighLimits() ?
1070                                 self::LIMIT_SML2 : self::LIMIT_SML1;
1071
1072                 if ( self::truncateArray( $valuesList, $sizeLimit ) ) {
1073                         $this->setWarning( "Too many values supplied for parameter '$valueName': the limit is $sizeLimit" );
1074                 }
1075
1076                 if ( !$allowMultiple && count( $valuesList ) != 1 ) {
1077                         // Bug 33482 - Allow entries with | in them for non-multiple values
1078                         if ( in_array( $value, $allowedValues, true ) ) {
1079                                 return $value;
1080                         }
1081
1082                         $possibleValues = is_array( $allowedValues ) ? "of '" . implode( "', '", $allowedValues ) . "'" : '';
1083                         $this->dieUsage( "Only one $possibleValues is allowed for parameter '$valueName'", "multival_$valueName" );
1084                 }
1085
1086                 if ( is_array( $allowedValues ) ) {
1087                         // Check for unknown values
1088                         $unknown = array_diff( $valuesList, $allowedValues );
1089                         if ( count( $unknown ) ) {
1090                                 if ( $allowMultiple ) {
1091                                         $s = count( $unknown ) > 1 ? 's' : '';
1092                                         $vals = implode( ", ", $unknown );
1093                                         $this->setWarning( "Unrecognized value$s for parameter '$valueName': $vals" );
1094                                 } else {
1095                                         $this->dieUsage( "Unrecognized value for parameter '$valueName': {$valuesList[0]}", "unknown_$valueName" );
1096                                 }
1097                         }
1098                         // Now throw them out
1099                         $valuesList = array_intersect( $valuesList, $allowedValues );
1100                 }
1101
1102                 return $allowMultiple ? $valuesList : $valuesList[0];
1103         }
1104
1105         /**
1106          * Validate the value against the minimum and user/bot maximum limits.
1107          * Prints usage info on failure.
1108          * @param string $paramName Parameter name
1109          * @param int $value Parameter value
1110          * @param int|null $min Minimum value
1111          * @param int|null $max Maximum value for users
1112          * @param int $botMax Maximum value for sysops/bots
1113          * @param $enforceLimits Boolean Whether to enforce (die) if value is outside limits
1114          */
1115         function validateLimit( $paramName, &$value, $min, $max, $botMax = null, $enforceLimits = false ) {
1116                 if ( !is_null( $min ) && $value < $min ) {
1117
1118                         $msg = $this->encodeParamName( $paramName ) . " may not be less than $min (set to $value)";
1119                         $this->warnOrDie( $msg, $enforceLimits );
1120                         $value = $min;
1121                 }
1122
1123                 // Minimum is always validated, whereas maximum is checked only if not running in internal call mode
1124                 if ( $this->getMain()->isInternalMode() ) {
1125                         return;
1126                 }
1127
1128                 // Optimization: do not check user's bot status unless really needed -- skips db query
1129                 // assumes $botMax >= $max
1130                 if ( !is_null( $max ) && $value > $max ) {
1131                         if ( !is_null( $botMax ) && $this->getMain()->canApiHighLimits() ) {
1132                                 if ( $value > $botMax ) {
1133                                         $msg = $this->encodeParamName( $paramName ) . " may not be over $botMax (set to $value) for bots or sysops";
1134                                         $this->warnOrDie( $msg, $enforceLimits );
1135                                         $value = $botMax;
1136                                 }
1137                         } else {
1138                                 $msg = $this->encodeParamName( $paramName ) . " may not be over $max (set to $value) for users";
1139                                 $this->warnOrDie( $msg, $enforceLimits );
1140                                 $value = $max;
1141                         }
1142                 }
1143         }
1144
1145         /**
1146          * Validate and normalize of parameters of type 'timestamp'
1147          * @param string $value Parameter value
1148          * @param string $encParamName Parameter name
1149          * @return string Validated and normalized parameter
1150          */
1151         function validateTimestamp( $value, $encParamName ) {
1152                 $unixTimestamp = wfTimestamp( TS_UNIX, $value );
1153                 if ( $unixTimestamp === false ) {
1154                         $this->dieUsage( "Invalid value '$value' for timestamp parameter $encParamName", "badtimestamp_{$encParamName}" );
1155                 }
1156                 return wfTimestamp( TS_MW, $unixTimestamp );
1157         }
1158
1159         /**
1160          * Validate and normalize of parameters of type 'user'
1161          * @param string $value Parameter value
1162          * @param string $encParamName Parameter name
1163          * @return string Validated and normalized parameter
1164          */
1165         private function validateUser( $value, $encParamName ) {
1166                 $title = Title::makeTitleSafe( NS_USER, $value );
1167                 if ( $title === null ) {
1168                         $this->dieUsage( "Invalid value '$value' for user parameter $encParamName", "baduser_{$encParamName}" );
1169                 }
1170                 return $title->getText();
1171         }
1172
1173         /**
1174          * Adds a warning to the output, else dies
1175          *
1176          * @param  $msg String Message to show as a warning, or error message if dying
1177          * @param  $enforceLimits Boolean Whether this is an enforce (die)
1178          */
1179         private function warnOrDie( $msg, $enforceLimits = false ) {
1180                 if ( $enforceLimits ) {
1181                         $this->dieUsage( $msg, 'integeroutofrange' );
1182                 } else {
1183                         $this->setWarning( $msg );
1184                 }
1185         }
1186
1187         /**
1188          * Truncate an array to a certain length.
1189          * @param array $arr Array to truncate
1190          * @param int $limit Maximum length
1191          * @return bool True if the array was truncated, false otherwise
1192          */
1193         public static function truncateArray( &$arr, $limit ) {
1194                 $modified = false;
1195                 while ( count( $arr ) > $limit ) {
1196                         array_pop( $arr );
1197                         $modified = true;
1198                 }
1199                 return $modified;
1200         }
1201
1202         /**
1203          * Throw a UsageException, which will (if uncaught) call the main module's
1204          * error handler and die with an error message.
1205          *
1206          * @param string $description One-line human-readable description of the
1207          *   error condition, e.g., "The API requires a valid action parameter"
1208          * @param string $errorCode Brief, arbitrary, stable string to allow easy
1209          *   automated identification of the error, e.g., 'unknown_action'
1210          * @param int $httpRespCode HTTP response code
1211          * @param array $extradata Data to add to the "<error>" element; array in ApiResult format
1212          * @throws UsageException
1213          */
1214         public function dieUsage( $description, $errorCode, $httpRespCode = 0, $extradata = null ) {
1215                 Profiler::instance()->close();
1216                 throw new UsageException( $description, $this->encodeParamName( $errorCode ), $httpRespCode, $extradata );
1217         }
1218
1219         /**
1220          * Throw a UsageException based on the errors in the Status object.
1221          *
1222          * @since 1.22
1223          * @param Status $status Status object
1224          * @throws UsageException
1225          */
1226         public function dieStatus( $status ) {
1227                 if ( $status->isGood() ) {
1228                         throw new MWException( 'Successful status passed to ApiBase::dieStatus' );
1229                 }
1230
1231                 $errors = $status->getErrorsArray();
1232                 if ( !$errors ) {
1233                         // No errors? Assume the warnings should be treated as errors
1234                         $errors = $status->getWarningsArray();
1235                 }
1236                 if ( !$errors ) {
1237                         // Still no errors? Punt
1238                         $errors = array( array( 'unknownerror-nocode' ) );
1239                 }
1240
1241                 // Cannot use dieUsageMsg() because extensions might return custom
1242                 // error messages.
1243                 if ( $errors[0] instanceof Message ) {
1244                         $msg = $errors[0];
1245                         $code = $msg->getKey();
1246                 } else {
1247                         $code = array_shift( $errors[0] );
1248                         $msg = wfMessage( $code, $errors[0] );
1249                 }
1250                 if ( isset( ApiBase::$messageMap[$code] ) ) {
1251                         // Translate message to code, for backwards compatability
1252                         $code = ApiBase::$messageMap[$code]['code'];
1253                 }
1254                 $this->dieUsage( $msg->inLanguage( 'en' )->useDatabase( false )->plain(), $code );
1255         }
1256
1257         /**
1258          * Array that maps message keys to error messages. $1 and friends are replaced.
1259          */
1260         public static $messageMap = array(
1261                 // This one MUST be present, or dieUsageMsg() will recurse infinitely
1262                 'unknownerror' => array( 'code' => 'unknownerror', 'info' => "Unknown error: \"\$1\"" ),
1263                 'unknownerror-nocode' => array( 'code' => 'unknownerror', 'info' => 'Unknown error' ),
1264
1265                 // Messages from Title::getUserPermissionsErrors()
1266                 'ns-specialprotected' => array( 'code' => 'unsupportednamespace', 'info' => "Pages in the Special namespace can't be edited" ),
1267                 'protectedinterface' => array( 'code' => 'protectednamespace-interface', 'info' => "You're not allowed to edit interface messages" ),
1268                 'namespaceprotected' => array( 'code' => 'protectednamespace', 'info' => "You're not allowed to edit pages in the \"\$1\" namespace" ),
1269                 'customcssprotected' => array( 'code' => 'customcssprotected', 'info' => "You're not allowed to edit custom CSS pages" ),
1270                 'customjsprotected' => array( 'code' => 'customjsprotected', 'info' => "You're not allowed to edit custom JavaScript pages" ),
1271                 'cascadeprotected' => array( 'code' => 'cascadeprotected', 'info' => "The page you're trying to edit is protected because it's included in a cascade-protected page" ),
1272                 'protectedpagetext' => array( 'code' => 'protectedpage', 'info' => "The \"\$1\" right is required to edit this page" ),
1273                 'protect-cantedit' => array( 'code' => 'cantedit', 'info' => "You can't protect this page because you can't edit it" ),
1274                 'badaccess-group0' => array( 'code' => 'permissiondenied', 'info' => "Permission denied" ), // Generic permission denied message
1275                 'badaccess-groups' => array( 'code' => 'permissiondenied', 'info' => "Permission denied" ),
1276                 'titleprotected' => array( 'code' => 'protectedtitle', 'info' => "This title has been protected from creation" ),
1277                 'nocreate-loggedin' => array( 'code' => 'cantcreate', 'info' => "You don't have permission to create new pages" ),
1278                 'nocreatetext' => array( 'code' => 'cantcreate-anon', 'info' => "Anonymous users can't create new pages" ),
1279                 'movenologintext' => array( 'code' => 'cantmove-anon', 'info' => "Anonymous users can't move pages" ),
1280                 'movenotallowed' => array( 'code' => 'cantmove', 'info' => "You don't have permission to move pages" ),
1281                 'confirmedittext' => array( 'code' => 'confirmemail', 'info' => "You must confirm your email address before you can edit" ),
1282                 'blockedtext' => array( 'code' => 'blocked', 'info' => "You have been blocked from editing" ),
1283                 'autoblockedtext' => array( 'code' => 'autoblocked', 'info' => "Your IP address has been blocked automatically, because it was used by a blocked user" ),
1284
1285                 // Miscellaneous interface messages
1286                 'actionthrottledtext' => array( 'code' => 'ratelimited', 'info' => "You've exceeded your rate limit. Please wait some time and try again" ),
1287                 'alreadyrolled' => array( 'code' => 'alreadyrolled', 'info' => "The page you tried to rollback was already rolled back" ),
1288                 'cantrollback' => array( 'code' => 'onlyauthor', 'info' => "The page you tried to rollback only has one author" ),
1289                 'readonlytext' => array( 'code' => 'readonly', 'info' => "The wiki is currently in read-only mode" ),
1290                 'sessionfailure' => array( 'code' => 'badtoken', 'info' => "Invalid token" ),
1291                 'cannotdelete' => array( 'code' => 'cantdelete', 'info' => "Couldn't delete \"\$1\". Maybe it was deleted already by someone else" ),
1292                 'notanarticle' => array( 'code' => 'missingtitle', 'info' => "The page you requested doesn't exist" ),
1293                 'selfmove' => array( 'code' => 'selfmove', 'info' => "Can't move a page to itself" ),
1294                 'immobile_namespace' => array( 'code' => 'immobilenamespace', 'info' => "You tried to move pages from or to a namespace that is protected from moving" ),
1295                 'articleexists' => array( 'code' => 'articleexists', 'info' => "The destination article already exists and is not a redirect to the source article" ),
1296                 'protectedpage' => array( 'code' => 'protectedpage', 'info' => "You don't have permission to perform this move" ),
1297                 'hookaborted' => array( 'code' => 'hookaborted', 'info' => "The modification you tried to make was aborted by an extension hook" ),
1298                 'cantmove-titleprotected' => array( 'code' => 'protectedtitle', 'info' => "The destination article has been protected from creation" ),
1299                 'imagenocrossnamespace' => array( 'code' => 'nonfilenamespace', 'info' => "Can't move a file to a non-file namespace" ),
1300                 'imagetypemismatch' => array( 'code' => 'filetypemismatch', 'info' => "The new file extension doesn't match its type" ),
1301                 // 'badarticleerror' => shouldn't happen
1302                 // 'badtitletext' => shouldn't happen
1303                 'ip_range_invalid' => array( 'code' => 'invalidrange', 'info' => "Invalid IP range" ),
1304                 'range_block_disabled' => array( 'code' => 'rangedisabled', 'info' => "Blocking IP ranges has been disabled" ),
1305                 'nosuchusershort' => array( 'code' => 'nosuchuser', 'info' => "The user you specified doesn't exist" ),
1306                 'badipaddress' => array( 'code' => 'invalidip', 'info' => "Invalid IP address specified" ),
1307                 'ipb_expiry_invalid' => array( 'code' => 'invalidexpiry', 'info' => "Invalid expiry time" ),
1308                 'ipb_already_blocked' => array( 'code' => 'alreadyblocked', 'info' => "The user you tried to block was already blocked" ),
1309                 'ipb_blocked_as_range' => array( 'code' => 'blockedasrange', 'info' => "IP address \"\$1\" was blocked as part of range \"\$2\". You can't unblock the IP individually, but you can unblock the range as a whole." ),
1310                 'ipb_cant_unblock' => array( 'code' => 'cantunblock', 'info' => "The block you specified was not found. It may have been unblocked already" ),
1311                 'mailnologin' => array( 'code' => 'cantsend', 'info' => "You are not logged in, you do not have a confirmed email address, or you are not allowed to send email to other users, so you cannot send email" ),
1312                 'ipbblocked' => array( 'code' => 'ipbblocked', 'info' => 'You cannot block or unblock users while you are yourself blocked' ),
1313                 'ipbnounblockself' => array( 'code' => 'ipbnounblockself', 'info' => 'You are not allowed to unblock yourself' ),
1314                 'usermaildisabled' => array( 'code' => 'usermaildisabled', 'info' => "User email has been disabled" ),
1315                 'blockedemailuser' => array( 'code' => 'blockedfrommail', 'info' => "You have been blocked from sending email" ),
1316                 'notarget' => array( 'code' => 'notarget', 'info' => "You have not specified a valid target for this action" ),
1317                 'noemail' => array( 'code' => 'noemail', 'info' => "The user has not specified a valid email address, or has chosen not to receive email from other users" ),
1318                 'rcpatroldisabled' => array( 'code' => 'patroldisabled', 'info' => "Patrolling is disabled on this wiki" ),
1319                 'markedaspatrollederror-noautopatrol' => array( 'code' => 'noautopatrol', 'info' => "You don't have permission to patrol your own changes" ),
1320                 'delete-toobig' => array( 'code' => 'bigdelete', 'info' => "You can't delete this page because it has more than \$1 revisions" ),
1321                 'movenotallowedfile' => array( 'code' => 'cantmovefile', 'info' => "You don't have permission to move files" ),
1322                 'userrights-no-interwiki' => array( 'code' => 'nointerwikiuserrights', 'info' => "You don't have permission to change user rights on other wikis" ),
1323                 'userrights-nodatabase' => array( 'code' => 'nosuchdatabase', 'info' => "Database \"\$1\" does not exist or is not local" ),
1324                 'nouserspecified' => array( 'code' => 'invaliduser', 'info' => "Invalid username \"\$1\"" ),
1325                 'noname' => array( 'code' => 'invaliduser', 'info' => "Invalid username \"\$1\"" ),
1326                 'summaryrequired' => array( 'code' => 'summaryrequired', 'info' => 'Summary required' ),
1327                 'import-rootpage-invalid' => array( 'code' => 'import-rootpage-invalid', 'info' => 'Root page is an invalid title' ),
1328                 'import-rootpage-nosubpage' => array( 'code' => 'import-rootpage-nosubpage', 'info' => 'Namespace "$1" of the root page does not allow subpages' ),
1329
1330                 // API-specific messages
1331                 'readrequired' => array( 'code' => 'readapidenied', 'info' => "You need read permission to use this module" ),
1332                 'writedisabled' => array( 'code' => 'noapiwrite', 'info' => "Editing of this wiki through the API is disabled. Make sure the \$wgEnableWriteAPI=true; statement is included in the wiki's LocalSettings.php file" ),
1333                 'writerequired' => array( 'code' => 'writeapidenied', 'info' => "You're not allowed to edit this wiki through the API" ),
1334                 'missingparam' => array( 'code' => 'no$1', 'info' => "The \$1 parameter must be set" ),
1335                 'invalidtitle' => array( 'code' => 'invalidtitle', 'info' => "Bad title \"\$1\"" ),
1336                 'nosuchpageid' => array( 'code' => 'nosuchpageid', 'info' => "There is no page with ID \$1" ),
1337                 'nosuchrevid' => array( 'code' => 'nosuchrevid', 'info' => "There is no revision with ID \$1" ),
1338                 'nosuchuser' => array( 'code' => 'nosuchuser', 'info' => "User \"\$1\" doesn't exist" ),
1339                 'invaliduser' => array( 'code' => 'invaliduser', 'info' => "Invalid username \"\$1\"" ),
1340                 'invalidexpiry' => array( 'code' => 'invalidexpiry', 'info' => "Invalid expiry time \"\$1\"" ),
1341                 'pastexpiry' => array( 'code' => 'pastexpiry', 'info' => "Expiry time \"\$1\" is in the past" ),
1342                 'create-titleexists' => array( 'code' => 'create-titleexists', 'info' => "Existing titles can't be protected with 'create'" ),
1343                 'missingtitle-createonly' => array( 'code' => 'missingtitle-createonly', 'info' => "Missing titles can only be protected with 'create'" ),
1344                 'cantblock' => array( 'code' => 'cantblock', 'info' => "You don't have permission to block users" ),
1345                 'canthide' => array( 'code' => 'canthide', 'info' => "You don't have permission to hide user names from the block log" ),
1346                 'cantblock-email' => array( 'code' => 'cantblock-email', 'info' => "You don't have permission to block users from sending email through the wiki" ),
1347                 'unblock-notarget' => array( 'code' => 'notarget', 'info' => "Either the id or the user parameter must be set" ),
1348                 'unblock-idanduser' => array( 'code' => 'idanduser', 'info' => "The id and user parameters can't be used together" ),
1349                 'cantunblock' => array( 'code' => 'permissiondenied', 'info' => "You don't have permission to unblock users" ),
1350                 'cannotundelete' => array( 'code' => 'cantundelete', 'info' => "Couldn't undelete: the requested revisions may not exist, or may have been undeleted already" ),
1351                 'permdenied-undelete' => array( 'code' => 'permissiondenied', 'info' => "You don't have permission to restore deleted revisions" ),
1352                 'createonly-exists' => array( 'code' => 'articleexists', 'info' => "The article you tried to create has been created already" ),
1353                 'nocreate-missing' => array( 'code' => 'missingtitle', 'info' => "The article you tried to edit doesn't exist" ),
1354                 'nosuchrcid' => array( 'code' => 'nosuchrcid', 'info' => "There is no change with rcid \"\$1\"" ),
1355                 'protect-invalidaction' => array( 'code' => 'protect-invalidaction', 'info' => "Invalid protection type \"\$1\"" ),
1356                 'protect-invalidlevel' => array( 'code' => 'protect-invalidlevel', 'info' => "Invalid protection level \"\$1\"" ),
1357                 'toofewexpiries' => array( 'code' => 'toofewexpiries', 'info' => "\$1 expiry timestamps were provided where \$2 were needed" ),
1358                 'cantimport' => array( 'code' => 'cantimport', 'info' => "You don't have permission to import pages" ),
1359                 'cantimport-upload' => array( 'code' => 'cantimport-upload', 'info' => "You don't have permission to import uploaded pages" ),
1360                 'importnofile' => array( 'code' => 'nofile', 'info' => "You didn't upload a file" ),
1361                 'importuploaderrorsize' => array( 'code' => 'filetoobig', 'info' => 'The file you uploaded is bigger than the maximum upload size' ),
1362                 'importuploaderrorpartial' => array( 'code' => 'partialupload', 'info' => 'The file was only partially uploaded' ),
1363                 'importuploaderrortemp' => array( 'code' => 'notempdir', 'info' => 'The temporary upload directory is missing' ),
1364                 'importcantopen' => array( 'code' => 'cantopenfile', 'info' => "Couldn't open the uploaded file" ),
1365                 'import-noarticle' => array( 'code' => 'badinterwiki', 'info' => 'Invalid interwiki title specified' ),
1366                 'importbadinterwiki' => array( 'code' => 'badinterwiki', 'info' => 'Invalid interwiki title specified' ),
1367                 'import-unknownerror' => array( 'code' => 'import-unknownerror', 'info' => "Unknown error on import: \"\$1\"" ),
1368                 'cantoverwrite-sharedfile' => array( 'code' => 'cantoverwrite-sharedfile', 'info' => 'The target file exists on a shared repository and you do not have permission to override it' ),
1369                 'sharedfile-exists' => array( 'code' => 'fileexists-sharedrepo-perm', 'info' => 'The target file exists on a shared repository. Use the ignorewarnings parameter to override it.' ),
1370                 'mustbeposted' => array( 'code' => 'mustbeposted', 'info' => "The \$1 module requires a POST request" ),
1371                 'show' => array( 'code' => 'show', 'info' => 'Incorrect parameter - mutually exclusive values may not be supplied' ),
1372                 'specialpage-cantexecute' => array( 'code' => 'specialpage-cantexecute', 'info' => "You don't have permission to view the results of this special page" ),
1373                 'invalidoldimage' => array( 'code' => 'invalidoldimage', 'info' => 'The oldimage parameter has invalid format' ),
1374                 'nodeleteablefile' => array( 'code' => 'nodeleteablefile', 'info' => 'No such old version of the file' ),
1375                 'fileexists-forbidden' => array( 'code' => 'fileexists-forbidden', 'info' => 'A file with name "$1" already exists, and cannot be overwritten.' ),
1376                 'fileexists-shared-forbidden' => array( 'code' => 'fileexists-shared-forbidden', 'info' => 'A file with name "$1" already exists in the shared file repository, and cannot be overwritten.' ),
1377                 'filerevert-badversion' => array( 'code' => 'filerevert-badversion', 'info' => 'There is no previous local version of this file with the provided timestamp.' ),
1378
1379                 // ApiEditPage messages
1380                 'noimageredirect-anon' => array( 'code' => 'noimageredirect-anon', 'info' => "Anonymous users can't create image redirects" ),
1381                 'noimageredirect-logged' => array( 'code' => 'noimageredirect', 'info' => "You don't have permission to create image redirects" ),
1382                 'spamdetected' => array( 'code' => 'spamdetected', 'info' => "Your edit was refused because it contained a spam fragment: \"\$1\"" ),
1383                 'contenttoobig' => array( 'code' => 'contenttoobig', 'info' => "The content you supplied exceeds the article size limit of \$1 kilobytes" ),
1384                 'noedit-anon' => array( 'code' => 'noedit-anon', 'info' => "Anonymous users can't edit pages" ),
1385                 'noedit' => array( 'code' => 'noedit', 'info' => "You don't have permission to edit pages" ),
1386                 'wasdeleted' => array( 'code' => 'pagedeleted', 'info' => "The page has been deleted since you fetched its timestamp" ),
1387                 'blankpage' => array( 'code' => 'emptypage', 'info' => "Creating new, empty pages is not allowed" ),
1388                 'editconflict' => array( 'code' => 'editconflict', 'info' => "Edit conflict detected" ),
1389                 'hashcheckfailed' => array( 'code' => 'badmd5', 'info' => "The supplied MD5 hash was incorrect" ),
1390                 'missingtext' => array( 'code' => 'notext', 'info' => "One of the text, appendtext, prependtext and undo parameters must be set" ),
1391                 'emptynewsection' => array( 'code' => 'emptynewsection', 'info' => 'Creating empty new sections is not possible.' ),
1392                 'revwrongpage' => array( 'code' => 'revwrongpage', 'info' => "r\$1 is not a revision of \"\$2\"" ),
1393                 'undo-failure' => array( 'code' => 'undofailure', 'info' => 'Undo failed due to conflicting intermediate edits' ),
1394
1395                 // Messages from WikiPage::doEit()
1396                 'edit-hook-aborted' => array( 'code' => 'edit-hook-aborted', 'info' => "Your edit was aborted by an ArticleSave hook" ),
1397                 'edit-gone-missing' => array( 'code' => 'edit-gone-missing', 'info' => "The page you tried to edit doesn't seem to exist anymore" ),
1398                 'edit-conflict' => array( 'code' => 'editconflict', 'info' => "Edit conflict detected" ),
1399                 'edit-already-exists' => array( 'code' => 'edit-already-exists', 'info' => "It seems the page you tried to create already exist" ),
1400
1401                 // uploadMsgs
1402                 'invalid-file-key' => array( 'code' => 'invalid-file-key', 'info' => 'Not a valid file key' ),
1403                 'nouploadmodule' => array( 'code' => 'nouploadmodule', 'info' => 'No upload module set' ),
1404                 'uploaddisabled' => array( 'code' => 'uploaddisabled', 'info' => 'Uploads are not enabled. Make sure $wgEnableUploads is set to true in LocalSettings.php and the PHP ini setting file_uploads is true' ),
1405                 'copyuploaddisabled' => array( 'code' => 'copyuploaddisabled', 'info' => 'Uploads by URL is not enabled. Make sure $wgAllowCopyUploads is set to true in LocalSettings.php.' ),
1406                 'copyuploadbaddomain' => array( 'code' => 'copyuploadbaddomain', 'info' => 'Uploads by URL are not allowed from this domain.' ),
1407                 'copyuploadbadurl' => array( 'code' => 'copyuploadbadurl', 'info' => 'Upload not allowed from this URL.' ),
1408
1409                 'filename-tooshort' => array( 'code' => 'filename-tooshort', 'info' => 'The filename is too short' ),
1410                 'filename-toolong' => array( 'code' => 'filename-toolong', 'info' => 'The filename is too long' ),
1411                 'illegal-filename' => array( 'code' => 'illegal-filename', 'info' => 'The filename is not allowed' ),
1412                 'filetype-missing' => array( 'code' => 'filetype-missing', 'info' => 'The file is missing an extension' ),
1413
1414                 'mustbeloggedin' => array( 'code' => 'mustbeloggedin', 'info' => 'You must be logged in to $1.' )
1415         );
1416
1417         /**
1418          * Helper function for readonly errors
1419          */
1420         public function dieReadOnly() {
1421                 $parsed = $this->parseMsg( array( 'readonlytext' ) );
1422                 $this->dieUsage( $parsed['info'], $parsed['code'], /* http error */ 0,
1423                         array( 'readonlyreason' => wfReadOnlyReason() ) );
1424         }
1425
1426         /**
1427          * Output the error message related to a certain array
1428          * @param $error (array|string) Element of a getUserPermissionsErrors()-style array
1429          */
1430         public function dieUsageMsg( $error ) {
1431                 # most of the time we send a 1 element, so we might as well send it as
1432                 # a string and make this an array here.
1433                 if ( is_string( $error ) ) {
1434                         $error = array( $error );
1435                 }
1436                 $parsed = $this->parseMsg( $error );
1437                 $this->dieUsage( $parsed['info'], $parsed['code'] );
1438         }
1439
1440         /**
1441          * Will only set a warning instead of failing if the global $wgDebugAPI
1442          * is set to true. Otherwise behaves exactly as dieUsageMsg().
1443          * @param $error (array|string) Element of a getUserPermissionsErrors()-style array
1444          * @since 1.21
1445          */
1446         public function dieUsageMsgOrDebug( $error ) {
1447                 global $wgDebugAPI;
1448                 if ( $wgDebugAPI !== true ) {
1449                         $this->dieUsageMsg( $error );
1450                 } else {
1451                         if ( is_string( $error ) ) {
1452                                 $error = array( $error );
1453                         }
1454                         $parsed = $this->parseMsg( $error );
1455                         $this->setWarning( '$wgDebugAPI: ' . $parsed['code']
1456                                 . ' - ' . $parsed['info'] );
1457                 }
1458         }
1459
1460         /**
1461          * Die with the $prefix.'badcontinue' error. This call is common enough to make it into the base method.
1462          * @param $condition boolean will only die if this value is true
1463          * @since 1.21
1464          */
1465         protected function dieContinueUsageIf( $condition ) {
1466                 if ( $condition ) {
1467                         $this->dieUsage(
1468                                 'Invalid continue param. You should pass the original value returned by the previous query',
1469                                 'badcontinue' );
1470                 }
1471         }
1472
1473         /**
1474          * Return the error message related to a certain array
1475          * @param array $error Element of a getUserPermissionsErrors()-style array
1476          * @return array('code' => code, 'info' => info)
1477          */
1478         public function parseMsg( $error ) {
1479                 $error = (array)$error; // It seems strings sometimes make their way in here
1480                 $key = array_shift( $error );
1481
1482                 // Check whether the error array was nested
1483                 // array( array( <code>, <params> ), array( <another_code>, <params> ) )
1484                 if ( is_array( $key ) ) {
1485                         $error = $key;
1486                         $key = array_shift( $error );
1487                 }
1488
1489                 if ( isset( self::$messageMap[$key] ) ) {
1490                         return array(
1491                                 'code' => wfMsgReplaceArgs( self::$messageMap[$key]['code'], $error ),
1492                                 'info' => wfMsgReplaceArgs( self::$messageMap[$key]['info'], $error )
1493                         );
1494                 }
1495
1496                 // If the key isn't present, throw an "unknown error"
1497                 return $this->parseMsg( array( 'unknownerror', $key ) );
1498         }
1499
1500         /**
1501          * Internal code errors should be reported with this method
1502          * @param string $method Method or function name
1503          * @param string $message Error message
1504          */
1505         protected static function dieDebug( $method, $message ) {
1506                 wfDebugDieBacktrace( "Internal error in $method: $message" );
1507         }
1508
1509         /**
1510          * Indicates if this module needs maxlag to be checked
1511          * @return bool
1512          */
1513         public function shouldCheckMaxlag() {
1514                 return true;
1515         }
1516
1517         /**
1518          * Indicates whether this module requires read rights
1519          * @return bool
1520          */
1521         public function isReadMode() {
1522                 return true;
1523         }
1524         /**
1525          * Indicates whether this module requires write mode
1526          * @return bool
1527          */
1528         public function isWriteMode() {
1529                 return false;
1530         }
1531
1532         /**
1533          * Indicates whether this module must be called with a POST request
1534          * @return bool
1535          */
1536         public function mustBePosted() {
1537                 return false;
1538         }
1539
1540         /**
1541          * Returns whether this module requires a token to execute
1542          * It is used to show possible errors in action=paraminfo
1543          * see bug 25248
1544          * @return bool
1545          */
1546         public function needsToken() {
1547                 return false;
1548         }
1549
1550         /**
1551          * Returns the token salt if there is one,
1552          * '' if the module doesn't require a salt,
1553          * else false if the module doesn't need a token
1554          * You have also to override needsToken()
1555          * Value is passed to User::getEditToken
1556          * @return bool|string|array
1557          */
1558         public function getTokenSalt() {
1559                 return false;
1560         }
1561
1562         /**
1563          * Gets the user for whom to get the watchlist
1564          *
1565          * @param $params array
1566          * @return User
1567          */
1568         public function getWatchlistUser( $params ) {
1569                 if ( !is_null( $params['owner'] ) && !is_null( $params['token'] ) ) {
1570                         $user = User::newFromName( $params['owner'], false );
1571                         if ( !( $user && $user->getId() ) ) {
1572                                 $this->dieUsage( 'Specified user does not exist', 'bad_wlowner' );
1573                         }
1574                         $token = $user->getOption( 'watchlisttoken' );
1575                         if ( $token == '' || $token != $params['token'] ) {
1576                                 $this->dieUsage( 'Incorrect watchlist token provided -- please set a correct token in Special:Preferences', 'bad_wltoken' );
1577                         }
1578                 } else {
1579                         if ( !$this->getUser()->isLoggedIn() ) {
1580                                 $this->dieUsage( 'You must be logged-in to have a watchlist', 'notloggedin' );
1581                         }
1582                         if ( !$this->getUser()->isAllowed( 'viewmywatchlist' ) ) {
1583                                 $this->dieUsage( 'You don\'t have permission to view your watchlist', 'permissiondenied' );
1584                         }
1585                         $user = $this->getUser();
1586                 }
1587                 return $user;
1588         }
1589
1590         /**
1591          * @return bool|string|array Returns a false if the module has no help url, else returns a (array of) string
1592          */
1593         public function getHelpUrls() {
1594                 return false;
1595         }
1596
1597         /**
1598          * Returns a list of all possible errors returned by the module
1599          *
1600          * Don't call this function directly: use getFinalPossibleErrors() to allow
1601          * hooks to modify parameters as needed.
1602          *
1603          * @return array in the format of array( key, param1, param2, ... ) or array( 'code' => ..., 'info' => ... )
1604          */
1605         public function getPossibleErrors() {
1606                 $ret = array();
1607
1608                 $params = $this->getFinalParams();
1609                 if ( $params ) {
1610                         foreach ( $params as $paramName => $paramSettings ) {
1611                                 if ( isset( $paramSettings[ApiBase::PARAM_REQUIRED] ) && $paramSettings[ApiBase::PARAM_REQUIRED] ) {
1612                                         $ret[] = array( 'missingparam', $paramName );
1613                                 }
1614                         }
1615                         if ( array_key_exists( 'continue', $params ) ) {
1616                                 $ret[] = array(
1617                                         'code' => 'badcontinue',
1618                                         'info' => 'Invalid continue param. You should pass the original value returned by the previous query'
1619                                 );
1620                         }
1621                 }
1622
1623                 if ( $this->mustBePosted() ) {
1624                         $ret[] = array( 'mustbeposted', $this->getModuleName() );
1625                 }
1626
1627                 if ( $this->isReadMode() ) {
1628                         $ret[] = array( 'readrequired' );
1629                 }
1630
1631                 if ( $this->isWriteMode() ) {
1632                         $ret[] = array( 'writerequired' );
1633                         $ret[] = array( 'writedisabled' );
1634                 }
1635
1636                 if ( $this->needsToken() ) {
1637                         if ( !isset( $params['token'][ApiBase::PARAM_REQUIRED] )
1638                                 || !$params['token'][ApiBase::PARAM_REQUIRED]
1639                         ) {
1640                                 // Add token as possible missing parameter, if not already done
1641                                 $ret[] = array( 'missingparam', 'token' );
1642                         }
1643                         $ret[] = array( 'sessionfailure' );
1644                 }
1645
1646                 return $ret;
1647         }
1648
1649         /**
1650          * Get final list of possible errors, after hooks have had a chance to
1651          * tweak it as needed.
1652          *
1653          * @return array
1654          * @since 1.22
1655          */
1656         public function getFinalPossibleErrors() {
1657                 $possibleErrors = $this->getPossibleErrors();
1658                 wfRunHooks( 'APIGetPossibleErrors', array( $this, &$possibleErrors ) );
1659                 return $possibleErrors;
1660         }
1661
1662         /**
1663          * Parses a list of errors into a standardised format
1664          * @param array $errors List of errors. Items can be in the for array( key, param1, param2, ... ) or array( 'code' => ..., 'info' => ... )
1665          * @return array Parsed list of errors with items in the form array( 'code' => ..., 'info' => ... )
1666          */
1667         public function parseErrors( $errors ) {
1668                 $ret = array();
1669
1670                 foreach ( $errors as $row ) {
1671                         if ( isset( $row['code'] ) && isset( $row['info'] ) ) {
1672                                 $ret[] = $row;
1673                         } else {
1674                                 $ret[] = $this->parseMsg( $row );
1675                         }
1676                 }
1677                 return $ret;
1678         }
1679
1680         /**
1681          * Profiling: total module execution time
1682          */
1683         private $mTimeIn = 0, $mModuleTime = 0;
1684
1685         /**
1686          * Start module profiling
1687          */
1688         public function profileIn() {
1689                 if ( $this->mTimeIn !== 0 ) {
1690                         ApiBase::dieDebug( __METHOD__, 'called twice without calling profileOut()' );
1691                 }
1692                 $this->mTimeIn = microtime( true );
1693                 wfProfileIn( $this->getModuleProfileName() );
1694         }
1695
1696         /**
1697          * End module profiling
1698          */
1699         public function profileOut() {
1700                 if ( $this->mTimeIn === 0 ) {
1701                         ApiBase::dieDebug( __METHOD__, 'called without calling profileIn() first' );
1702                 }
1703                 if ( $this->mDBTimeIn !== 0 ) {
1704                         ApiBase::dieDebug( __METHOD__, 'must be called after database profiling is done with profileDBOut()' );
1705                 }
1706
1707                 $this->mModuleTime += microtime( true ) - $this->mTimeIn;
1708                 $this->mTimeIn = 0;
1709                 wfProfileOut( $this->getModuleProfileName() );
1710         }
1711
1712         /**
1713          * When modules crash, sometimes it is needed to do a profileOut() regardless
1714          * of the profiling state the module was in. This method does such cleanup.
1715          */
1716         public function safeProfileOut() {
1717                 if ( $this->mTimeIn !== 0 ) {
1718                         if ( $this->mDBTimeIn !== 0 ) {
1719                                 $this->profileDBOut();
1720                         }
1721                         $this->profileOut();
1722                 }
1723         }
1724
1725         /**
1726          * Total time the module was executed
1727          * @return float
1728          */
1729         public function getProfileTime() {
1730                 if ( $this->mTimeIn !== 0 ) {
1731                         ApiBase::dieDebug( __METHOD__, 'called without calling profileOut() first' );
1732                 }
1733                 return $this->mModuleTime;
1734         }
1735
1736         /**
1737          * Profiling: database execution time
1738          */
1739         private $mDBTimeIn = 0, $mDBTime = 0;
1740
1741         /**
1742          * Start module profiling
1743          */
1744         public function profileDBIn() {
1745                 if ( $this->mTimeIn === 0 ) {
1746                         ApiBase::dieDebug( __METHOD__, 'must be called while profiling the entire module with profileIn()' );
1747                 }
1748                 if ( $this->mDBTimeIn !== 0 ) {
1749                         ApiBase::dieDebug( __METHOD__, 'called twice without calling profileDBOut()' );
1750                 }
1751                 $this->mDBTimeIn = microtime( true );
1752                 wfProfileIn( $this->getModuleProfileName( true ) );
1753         }
1754
1755         /**
1756          * End database profiling
1757          */
1758         public function profileDBOut() {
1759                 if ( $this->mTimeIn === 0 ) {
1760                         ApiBase::dieDebug( __METHOD__, 'must be called while profiling the entire module with profileIn()' );
1761                 }
1762                 if ( $this->mDBTimeIn === 0 ) {
1763                         ApiBase::dieDebug( __METHOD__, 'called without calling profileDBIn() first' );
1764                 }
1765
1766                 $time = microtime( true ) - $this->mDBTimeIn;
1767                 $this->mDBTimeIn = 0;
1768
1769                 $this->mDBTime += $time;
1770                 $this->getMain()->mDBTime += $time;
1771                 wfProfileOut( $this->getModuleProfileName( true ) );
1772         }
1773
1774         /**
1775          * Total time the module used the database
1776          * @return float
1777          */
1778         public function getProfileDBTime() {
1779                 if ( $this->mDBTimeIn !== 0 ) {
1780                         ApiBase::dieDebug( __METHOD__, 'called without calling profileDBOut() first' );
1781                 }
1782                 return $this->mDBTime;
1783         }
1784
1785         /**
1786          * Gets a default slave database connection object
1787          * @return DatabaseBase
1788          */
1789         protected function getDB() {
1790                 if ( !isset( $this->mSlaveDB ) ) {
1791                         $this->profileDBIn();
1792                         $this->mSlaveDB = wfGetDB( DB_SLAVE, 'api' );
1793                         $this->profileDBOut();
1794                 }
1795                 return $this->mSlaveDB;
1796         }
1797
1798         /**
1799          * Debugging function that prints a value and an optional backtrace
1800          * @param $value mixed Value to print
1801          * @param string $name Description of the printed value
1802          * @param bool $backtrace If true, print a backtrace
1803          */
1804         public static function debugPrint( $value, $name = 'unknown', $backtrace = false ) {
1805                 print "\n\n<pre><b>Debugging value '$name':</b>\n\n";
1806                 var_export( $value );
1807                 if ( $backtrace ) {
1808                         print "\n" . wfBacktrace();
1809                 }
1810                 print "\n</pre>\n";
1811         }
1812 }