includes/api/ApiResult.php

   1 <?php
   2 /**
   3  *
   4  *
   5  * Created on Sep 4, 2006
   6  *
   7  * Copyright © 2006 Yuri Astrakhan "<Firstname><Lastname>@gmail.com"
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License along
  20  * with this program; if not, write to the Free Software Foundation, Inc.,
  21  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  22  * http://www.gnu.org/copyleft/gpl.html
  23  *
  24  * @file
  25  */
  26
  27 /**
  28  * This class represents the result of the API operations.
  29  * It simply wraps a nested array() structure, adding some functions to simplify
  30  * array's modifications. As various modules execute, they add different pieces
  31  * of information to this result, structuring it as it will be given to the client.
  32  *
  33  * Each subarray may either be a dictionary - key-value pairs with unique keys,
  34  * or lists, where the items are added using $data[] = $value notation.
  35  *
  36  * There are three special key values that change how XML output is generated:
  37  *   '_element'     This key sets the tag name for the rest of the elements in the current array.
  38  *                  It is only inserted if the formatter returned true for getNeedsRawData()
  39  *   '_subelements' This key causes the specified elements to be returned as subelements rather than attributes.
  40  *                  It is only inserted if the formatter returned true for getNeedsRawData()
  41  *   '*'            This key has special meaning only to the XML formatter, and is outputted as is
  42  *                  for all others. In XML it becomes the content of the current element.
  43  *
  44  * @ingroup API
  45  */
  46 class ApiResult extends ApiBase {
  47
  48         /**
  49          * override existing value in addValue() and setElement()
  50          * @since 1.21
  51          */
  52         const OVERRIDE = 1;
  53
  54         /**
  55          * For addValue() and setElement(), if the value does not exist, add it as the first element.
  56          * In case the new value has no name (numerical index), all indexes will be renumbered.
  57          * @since 1.21
  58          */
  59         const ADD_ON_TOP = 2;
  60
  61         /**
  62          * For addValue() and setElement(), do not check size while adding a value
  63          * Don't use this unless you REALLY know what you're doing.
  64          * Values added while the size checking was disabled will never be counted
  65          * @since 1.24
  66          */
  67         const NO_SIZE_CHECK = 4;
  68
  69         private $mData, $mIsRawMode, $mSize, $mCheckingSize;
  70
  71         private $continueAllModules = array();
  72         private $continueGeneratedModules = array();
  73         private $continuationData = array();
  74         private $generatorContinuationData = array();
  75         private $generatorParams = array();
  76         private $generatorDone = false;
  77
  78         /**
  79          * @param ApiMain $main
  80          */
  81         public function __construct( ApiMain $main ) {
  82                 parent::__construct( $main, 'result' );
  83                 $this->mIsRawMode = false;
  84                 $this->mCheckingSize = true;
  85                 $this->reset();
  86         }
  87
  88         /**
  89          * Clear the current result data.
  90          */
  91         public function reset() {
  92                 $this->mData = array();
  93                 $this->mSize = 0;
  94         }
  95
  96         /**
  97          * Call this function when special elements such as '_element'
  98          * are needed by the formatter, for example in XML printing.
  99          * @since 1.23 $flag parameter added
 100          * @param bool $flag Set the raw mode flag to this state
 101          */
 102         public function setRawMode( $flag = true ) {
 103                 $this->mIsRawMode = $flag;
 104         }
 105
 106         /**
 107          * Returns true whether the formatter requested raw data.
 108          * @return bool
 109          */
 110         public function getIsRawMode() {
 111                 return $this->mIsRawMode;
 112         }
 113
 114         /**
 115          * Get the result's internal data array (read-only)
 116          * @return array
 117          */
 118         public function getData() {
 119                 return $this->mData;
 120         }
 121
 122         /**
 123          * Get the 'real' size of a result item. This means the strlen() of the item,
 124          * or the sum of the strlen()s of the elements if the item is an array.
 125          * @param mixed $value
 126          * @return int
 127          */
 128         public static function size( $value ) {
 129                 $s = 0;
 130                 if ( is_array( $value ) ) {
 131                         foreach ( $value as $v ) {
 132                                 $s += self::size( $v );
 133                         }
 134                 } elseif ( !is_object( $value ) ) {
 135                         // Objects can't always be cast to string
 136                         $s = strlen( $value );
 137                 }
 138
 139                 return $s;
 140         }
 141
 142         /**
 143          * Get the size of the result, i.e. the amount of bytes in it
 144          * @return int
 145          */
 146         public function getSize() {
 147                 return $this->mSize;
 148         }
 149
 150         /**
 151          * Disable size checking in addValue(). Don't use this unless you
 152          * REALLY know what you're doing. Values added while size checking
 153          * was disabled will not be counted (ever)
 154          * @deprecated since 1.24, use ApiResult::NO_SIZE_CHECK
 155          */
 156         public function disableSizeCheck() {
 157                 $this->mCheckingSize = false;
 158         }
 159
 160         /**
 161          * Re-enable size checking in addValue()
 162          * @deprecated since 1.24, use ApiResult::NO_SIZE_CHECK
 163          */
 164         public function enableSizeCheck() {
 165                 $this->mCheckingSize = true;
 166         }
 167
 168         /**
 169          * Add an output value to the array by name.
 170          * Verifies that value with the same name has not been added before.
 171          * @param array $arr To add $value to
 172          * @param string $name Index of $arr to add $value at
 173          * @param mixed $value
 174          * @param int $flags Zero or more OR-ed flags like OVERRIDE | ADD_ON_TOP.
 175          *    This parameter used to be boolean, and the value of OVERRIDE=1 was
 176          *    specifically chosen so that it would be backwards compatible with the
 177          *    new method signature.
 178          *
 179          * @since 1.21 int $flags replaced boolean $override
 180          */
 181         public static function setElement( &$arr, $name, $value, $flags = 0 ) {
 182                 if ( $arr === null || $name === null || $value === null
 183                         || !is_array( $arr ) || is_array( $name )
 184                 ) {
 185                         ApiBase::dieDebug( __METHOD__, 'Bad parameter' );
 186                 }
 187
 188                 $exists = isset( $arr[$name] );
 189                 if ( !$exists || ( $flags & ApiResult::OVERRIDE ) ) {
 190                         if ( !$exists && ( $flags & ApiResult::ADD_ON_TOP ) ) {
 191                                 $arr = array( $name => $value ) + $arr;
 192                         } else {
 193                                 $arr[$name] = $value;
 194                         }
 195                 } elseif ( is_array( $arr[$name] ) && is_array( $value ) ) {
 196                         $merged = array_intersect_key( $arr[$name], $value );
 197                         if ( !count( $merged ) ) {
 198                                 $arr[$name] += $value;
 199                         } else {
 200                                 ApiBase::dieDebug( __METHOD__, "Attempting to merge element $name" );
 201                         }
 202                 } else {
 203                         ApiBase::dieDebug(
 204                                 __METHOD__,
 205                                 "Attempting to add element $name=$value, existing value is {$arr[$name]}"
 206                         );
 207                 }
 208         }
 209
 210         /**
 211          * Adds a content element to an array.
 212          * Use this function instead of hardcoding the '*' element.
 213          * @param array $arr To add the content element to
 214          * @param mixed $value
 215          * @param string $subElemName When present, content element is created
 216          *  as a sub item of $arr. Use this parameter to create elements in
 217          *  format "<elem>text</elem>" without attributes.
 218          */
 219         public static function setContent( &$arr, $value, $subElemName = null ) {
 220                 if ( is_array( $value ) ) {
 221                         ApiBase::dieDebug( __METHOD__, 'Bad parameter' );
 222                 }
 223                 if ( is_null( $subElemName ) ) {
 224                         ApiResult::setElement( $arr, '*', $value );
 225                 } else {
 226                         if ( !isset( $arr[$subElemName] ) ) {
 227                                 $arr[$subElemName] = array();
 228                         }
 229                         ApiResult::setElement( $arr[$subElemName], '*', $value );
 230                 }
 231         }
 232
 233         /**
 234          * Causes the elements with the specified names to be output as
 235          * subelements rather than attributes.
 236          * @param array $arr
 237          * @param array|string $names The element name(s) to be output as subelements
 238          */
 239         public function setSubelements( &$arr, $names ) {
 240                 // In raw mode, add the '_subelements', otherwise just ignore
 241                 if ( !$this->getIsRawMode() ) {
 242                         return;
 243                 }
 244                 if ( $arr === null || $names === null || !is_array( $arr ) ) {
 245                         ApiBase::dieDebug( __METHOD__, 'Bad parameter' );
 246                 }
 247                 if ( !is_array( $names ) ) {
 248                         $names = array( $names );
 249                 }
 250                 if ( !isset( $arr['_subelements'] ) ) {
 251                         $arr['_subelements'] = $names;
 252                 } else {
 253                         $arr['_subelements'] = array_merge( $arr['_subelements'], $names );
 254                 }
 255         }
 256
 257         /**
 258          * In case the array contains indexed values (in addition to named),
 259          * give all indexed values the given tag name. This function MUST be
 260          * called on every array that has numerical indexes.
 261          * @param array $arr
 262          * @param string $tag Tag name
 263          */
 264         public function setIndexedTagName( &$arr, $tag ) {
 265                 // In raw mode, add the '_element', otherwise just ignore
 266                 if ( !$this->getIsRawMode() ) {
 267                         return;
 268                 }
 269                 if ( $arr === null || $tag === null || !is_array( $arr ) || is_array( $tag ) ) {
 270                         ApiBase::dieDebug( __METHOD__, 'Bad parameter' );
 271                 }
 272                 // Do not use setElement() as it is ok to call this more than once
 273                 $arr['_element'] = $tag;
 274         }
 275
 276         /**
 277          * Calls setIndexedTagName() on each sub-array of $arr
 278          * @param array $arr
 279          * @param string $tag Tag name
 280          */
 281         public function setIndexedTagName_recursive( &$arr, $tag ) {
 282                 if ( !is_array( $arr ) ) {
 283                         return;
 284                 }
 285                 foreach ( $arr as &$a ) {
 286                         if ( !is_array( $a ) ) {
 287                                 continue;
 288                         }
 289                         $this->setIndexedTagName( $a, $tag );
 290                         $this->setIndexedTagName_recursive( $a, $tag );
 291                 }
 292         }
 293
 294         /**
 295          * Calls setIndexedTagName() on an array already in the result.
 296          * Don't specify a path to a value that's not in the result, or
 297          * you'll get nasty errors.
 298          * @param array $path Path to the array, like addValue()'s $path
 299          * @param string $tag
 300          */
 301         public function setIndexedTagName_internal( $path, $tag ) {
 302                 $data = &$this->mData;
 303                 foreach ( (array)$path as $p ) {
 304                         if ( !isset( $data[$p] ) ) {
 305                                 $data[$p] = array();
 306                         }
 307                         $data = &$data[$p];
 308                 }
 309                 if ( is_null( $data ) ) {
 310                         return;
 311                 }
 312                 $this->setIndexedTagName( $data, $tag );
 313         }
 314
 315         /**
 316          * Add value to the output data at the given path.
 317          * Path can be an indexed array, each element specifying the branch at which to add the new
 318          * value. Setting $path to array('a','b','c') is equivalent to data['a']['b']['c'] = $value.
 319          * If $path is null, the value will be inserted at the data root.
 320          * If $name is empty, the $value is added as a next list element data[] = $value.
 321          *
 322          * @param array|string|null $path
 323          * @param string $name
 324          * @param mixed $value
 325          * @param int $flags Zero or more OR-ed flags like OVERRIDE | ADD_ON_TOP.
 326          *   This parameter used to be boolean, and the value of OVERRIDE=1 was specifically
 327          *   chosen so that it would be backwards compatible with the new method signature.
 328          * @return bool True if $value fits in the result, false if not
 329          *
 330          * @since 1.21 int $flags replaced boolean $override
 331          */
 332         public function addValue( $path, $name, $value, $flags = 0 ) {
 333                 $data = &$this->mData;
 334                 if ( $this->mCheckingSize && !( $flags & ApiResult::NO_SIZE_CHECK ) ) {
 335                         $newsize = $this->mSize + self::size( $value );
 336                         $maxResultSize = $this->getConfig()->get( 'APIMaxResultSize' );
 337                         if ( $newsize > $maxResultSize ) {
 338                                 $this->setWarning(
 339                                         "This result was truncated because it would otherwise be larger than the " .
 340                                                 "limit of {$maxResultSize} bytes" );
 341
 342                                 return false;
 343                         }
 344                         $this->mSize = $newsize;
 345                 }
 346
 347                 $addOnTop = $flags & ApiResult::ADD_ON_TOP;
 348                 if ( $path !== null ) {
 349                         foreach ( (array)$path as $p ) {
 350                                 if ( !isset( $data[$p] ) ) {
 351                                         if ( $addOnTop ) {
 352                                                 $data = array( $p => array() ) + $data;
 353                                                 $addOnTop = false;
 354                                         } else {
 355                                                 $data[$p] = array();
 356                                         }
 357                                 }
 358                                 $data = &$data[$p];
 359                         }
 360                 }
 361
 362                 if ( !$name ) {
 363                         // Add list element
 364                         if ( $addOnTop ) {
 365                                 // This element needs to be inserted in the beginning
 366                                 // Numerical indexes will be renumbered
 367                                 array_unshift( $data, $value );
 368                         } else {
 369                                 // Add new value at the end
 370                                 $data[] = $value;
 371                         }
 372                 } else {
 373                         // Add named element
 374                         self::setElement( $data, $name, $value, $flags );
 375                 }
 376
 377                 return true;
 378         }
 379
 380         /**
 381          * Add a parsed limit=max to the result.
 382          *
 383          * @param string $moduleName
 384          * @param int $limit
 385          */
 386         public function setParsedLimit( $moduleName, $limit ) {
 387                 // Add value, allowing overwriting
 388                 $this->addValue( 'limits', $moduleName, $limit, ApiResult::OVERRIDE );
 389         }
 390
 391         /**
 392          * Unset a value previously added to the result set.
 393          * Fails silently if the value isn't found.
 394          * For parameters, see addValue()
 395          * @param array|null $path
 396          * @param string $name
 397          */
 398         public function unsetValue( $path, $name ) {
 399                 $data = &$this->mData;
 400                 if ( $path !== null ) {
 401                         foreach ( (array)$path as $p ) {
 402                                 if ( !isset( $data[$p] ) ) {
 403                                         return;
 404                                 }
 405                                 $data = &$data[$p];
 406                         }
 407                 }
 408                 $this->mSize -= self::size( $data[$name] );
 409                 unset( $data[$name] );
 410         }
 411
 412         /**
 413          * Ensure all values in this result are valid UTF-8.
 414          */
 415         public function cleanUpUTF8() {
 416                 array_walk_recursive( $this->mData, array( 'ApiResult', 'cleanUp_helper' ) );
 417         }
 418
 419         /**
 420          * Callback function for cleanUpUTF8()
 421          *
 422          * @param string $s
 423          */
 424         private static function cleanUp_helper( &$s ) {
 425                 if ( !is_string( $s ) ) {
 426                         return;
 427                 }
 428                 global $wgContLang;
 429                 $s = $wgContLang->normalize( $s );
 430         }
 431
 432         /**
 433          * Converts a Status object to an array suitable for addValue
 434          * @param Status $status
 435          * @param string $errorType
 436          * @return array
 437          */
 438         public function convertStatusToArray( $status, $errorType = 'error' ) {
 439                 if ( $status->isGood() ) {
 440                         return array();
 441                 }
 442
 443                 $result = array();
 444                 foreach ( $status->getErrorsByType( $errorType ) as $error ) {
 445                         $this->setIndexedTagName( $error['params'], 'param' );
 446                         $result[] = $error;
 447                 }
 448                 $this->setIndexedTagName( $result, $errorType );
 449
 450                 return $result;
 451         }
 452
 453         public function execute() {
 454                 ApiBase::dieDebug( __METHOD__, 'execute() is not supported on Result object' );
 455         }
 456
 457         /**
 458          * Parse a 'continue' parameter and return status information.
 459          *
 460          * This must be balanced by a call to endContinuation().
 461          *
 462          * @since 1.24
 463          * @param string|null $continue The "continue" parameter, if any
 464          * @param ApiBase[] $allModules Contains ApiBase instances that will be executed
 465          * @param array $generatedModules Names of modules that depend on the generator
 466          * @return array Two elements: a boolean indicating if the generator is done,
 467          *   and an array of modules to actually execute.
 468          */
 469         public function beginContinuation(
 470                 $continue, array $allModules = array(), array $generatedModules = array()
 471         ) {
 472                 $this->continueGeneratedModules = $generatedModules
 473                         ? array_combine( $generatedModules, $generatedModules )
 474                         : array();
 475                 $this->continuationData = array();
 476                 $this->generatorContinuationData = array();
 477                 $this->generatorParams = array();
 478
 479                 $skip = array();
 480                 if ( is_string( $continue ) && $continue !== '' ) {
 481                         $continue = explode( '||', $continue );
 482                         $this->dieContinueUsageIf( count( $continue ) !== 2 );
 483                         $this->generatorDone = ( $continue[0] === '-' );
 484                         $skip = explode( '|', $continue[1] );
 485                         if ( !$this->generatorDone ) {
 486                                 $this->generatorParams = explode( '|', $continue[0] );
 487                         } else {
 488                                 // When the generator is complete, don't run any modules that
 489                                 // depend on it.
 490                                 $skip += $this->continueGeneratedModules;
 491                         }
 492                 }
 493
 494                 $this->continueAllModules = array();
 495                 $runModules = array();
 496                 foreach ( $allModules as $module ) {
 497                         $name = $module->getModuleName();
 498                         if ( in_array( $name, $skip ) ) {
 499                                 $this->continueAllModules[$name] = false;
 500                                 // Prevent spurious "unused parameter" warnings
 501                                 $module->extractRequestParams();
 502                         } else {
 503                                 $this->continueAllModules[$name] = true;
 504                                 $runModules[] = $module;
 505                         }
 506                 }
 507
 508                 return array(
 509                         $this->generatorDone,
 510                         $runModules,
 511                 );
 512         }
 513
 514         /**
 515          * Set the continuation parameter for a module
 516          *
 517          * @since 1.24
 518          * @param ApiBase $module
 519          * @param string $paramName
 520          * @param string|array $paramValue
 521          */
 522         public function setContinueParam( ApiBase $module, $paramName, $paramValue ) {
 523                 $name = $module->getModuleName();
 524                 if ( !isset( $this->continueAllModules[$name] ) ) {
 525                         throw new MWException(
 526                                 "Module '$name' called ApiResult::setContinueParam but was not " .
 527                                 'passed to ApiResult::beginContinuation'
 528                         );
 529                 }
 530                 if ( !$this->continueAllModules[$name] ) {
 531                         throw new MWException(
 532                                 "Module '$name' was not supposed to have been executed, but " .
 533                                 'it was executed anyway'
 534                         );
 535                 }
 536                 $paramName = $module->encodeParamName( $paramName );
 537                 if ( is_array( $paramValue ) ) {
 538                         $paramValue = join( '|', $paramValue );
 539                 }
 540                 $this->continuationData[$name][$paramName] = $paramValue;
 541         }
 542
 543         /**
 544          * Set the continuation parameter for the generator module
 545          *
 546          * @since 1.24
 547          * @param ApiBase $module
 548          * @param string $paramName
 549          * @param string|array $paramValue
 550          */
 551         public function setGeneratorContinueParam( ApiBase $module, $paramName, $paramValue ) {
 552                 $name = $module->getModuleName();
 553                 $paramName = $module->encodeParamName( $paramName );
 554                 if ( is_array( $paramValue ) ) {
 555                         $paramValue = join( '|', $paramValue );
 556                 }
 557                 $this->generatorContinuationData[$name][$paramName] = $paramValue;
 558         }
 559
 560         /**
 561          * Close continuation, writing the data into the result
 562          *
 563          * @since 1.24
 564          * @param string $style 'standard' for the new style since 1.21, 'raw' for
 565          *   the style used in 1.20 and earlier.
 566          */
 567         public function endContinuation( $style = 'standard' ) {
 568                 if ( $style === 'raw' ) {
 569                         $key = 'query-continue';
 570                         $data = array_merge_recursive(
 571                                 $this->continuationData, $this->generatorContinuationData
 572                         );
 573                 } else {
 574                         $key = 'continue';
 575                         $data = array();
 576                         $batchcomplete = false;
 577
 578                         $finishedModules = array_diff(
 579                                 array_keys( $this->continueAllModules ),
 580                                 array_keys( $this->continuationData )
 581                         );
 582
 583                         // First, grab the non-generator-using continuation data
 584                         $continuationData = array_diff_key(
 585                                 $this->continuationData, $this->continueGeneratedModules
 586                         );
 587                         foreach ( $continuationData as $module => $kvp ) {
 588                                 $data += $kvp;
 589                         }
 590
 591                         // Next, handle the generator-using continuation data
 592                         $continuationData = array_intersect_key(
 593                                 $this->continuationData, $this->continueGeneratedModules
 594                         );
 595                         if ( $continuationData ) {
 596                                 // Some modules are unfinished: include those params, and copy
 597                                 // the generator params.
 598                                 foreach ( $continuationData as $module => $kvp ) {
 599                                         $data += $kvp;
 600                                 }
 601                                 $data += array_intersect_key(
 602                                         $this->getMain()->getRequest()->getValues(),
 603                                         array_flip( $this->generatorParams )
 604                                 );
 605                         } elseif ( $this->generatorContinuationData ) {
 606                                 // All the generator-using modules are complete, but the
 607                                 // generator isn't. Continue the generator and restart the
 608                                 // generator-using modules
 609                                 $this->generatorParams = array();
 610                                 foreach ( $this->generatorContinuationData as $kvp ) {
 611                                         $this->generatorParams = array_merge(
 612                                                 $this->generatorParams, array_keys( $kvp )
 613                                         );
 614                                         $data += $kvp;
 615                                 }
 616                                 $finishedModules = array_diff(
 617                                         $finishedModules, $this->continueGeneratedModules
 618                                 );
 619                                 $batchcomplete = true;
 620                         } else {
 621                                 // Generator and prop modules are all done. Mark it so.
 622                                 $this->generatorDone = true;
 623                                 $batchcomplete = true;
 624                         }
 625
 626                         // Set 'continue' if any continuation data is set or if the generator
 627                         // still needs to run
 628                         if ( $data || !$this->generatorDone ) {
 629                                 $data['continue'] =
 630                                         ( $this->generatorDone ? '-' : join( '|', $this->generatorParams ) ) .
 631                                         '||' . join( '|', $finishedModules );
 632                         }
 633
 634                         if ( $batchcomplete ) {
 635                                 $this->addValue( null, 'batchcomplete', '', ApiResult::ADD_ON_TOP | ApiResult::NO_SIZE_CHECK );
 636                         }
 637                 }
 638                 if ( $data ) {
 639                         $this->addValue( null, $key, $data, ApiResult::ADD_ON_TOP | ApiResult::NO_SIZE_CHECK );
 640                 }
 641         }
 642 }