includes/language/Message.php

   1 <?php
   2 /**
   3  * Fetching and processing of interface messages.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @author Niklas Laxström
  22  */
  23
  24 use MediaWiki\Logger\LoggerFactory;
  25 use MediaWiki\MediaWikiServices;
  26
  27 /**
  28  * The Message class provides methods which fulfil two basic services:
  29  *  - fetching interface messages
  30  *  - processing messages into a variety of formats
  31  *
  32  * First implemented with MediaWiki 1.17, the Message class is intended to
  33  * replace the old wfMsg* functions that over time grew unusable.
  34  * @see https://www.mediawiki.org/wiki/Manual:Messages_API for equivalences
  35  * between old and new functions.
  36  *
  37  * You should use the wfMessage() global function which acts as a wrapper for
  38  * the Message class. The wrapper let you pass parameters as arguments.
  39  *
  40  * The most basic usage cases would be:
  41  *
  42  * @code
  43  *     // Initialize a Message object using the 'some_key' message key
  44  *     $message = wfMessage( 'some_key' );
  45  *
  46  *     // Using two parameters those values are strings 'value1' and 'value2':
  47  *     $message = wfMessage( 'some_key',
  48  *          'value1', 'value2'
  49  *     );
  50  * @endcode
  51  *
  52  * @section message_global_fn Global function wrapper:
  53  *
  54  * Since wfMessage() returns a Message instance, you can chain its call with
  55  * a method. Some of them return a Message instance too so you can chain them.
  56  * You will find below several examples of wfMessage() usage.
  57  *
  58  * Fetching a message text for interface message:
  59  *
  60  * @code
  61  *    $button = Xml::button(
  62  *         wfMessage( 'submit' )->text()
  63  *    );
  64  * @endcode
  65  *
  66  * A Message instance can be passed parameters after it has been constructed,
  67  * use the params() method to do so:
  68  *
  69  * @code
  70  *     wfMessage( 'welcome-to' )
  71  *         ->params( $wgSitename )
  72  *         ->text();
  73  * @endcode
  74  *
  75  * {{GRAMMAR}} and friends work correctly:
  76  *
  77  * @code
  78  *    wfMessage( 'are-friends',
  79  *        $user, $friend
  80  *    );
  81  *    wfMessage( 'bad-message' )
  82  *         ->rawParams( '<script>...</script>' )
  83  *         ->escaped();
  84  * @endcode
  85  *
  86  * @section message_language Changing language:
  87  *
  88  * Messages can be requested in a different language or in whatever current
  89  * content language is being used. The methods are:
  90  *     - Message->inContentLanguage()
  91  *     - Message->inLanguage()
  92  *
  93  * Sometimes the message text ends up in the database, so content language is
  94  * needed:
  95  *
  96  * @code
  97  *    wfMessage( 'file-log',
  98  *        $user, $filename
  99  *    )->inContentLanguage()->text();
 100  * @endcode
 101  *
 102  * Checking whether a message exists:
 103  *
 104  * @code
 105  *    wfMessage( 'mysterious-message' )->exists()
 106  *    // returns a boolean whether the 'mysterious-message' key exist.
 107  * @endcode
 108  *
 109  * If you want to use a different language:
 110  *
 111  * @code
 112  *    $userLanguage = $user->getOption( 'language' );
 113  *    wfMessage( 'email-header' )
 114  *         ->inLanguage( $userLanguage )
 115  *         ->plain();
 116  * @endcode
 117  *
 118  * @note You can parse the text only in the content or interface languages
 119  *
 120  * @section message_compare_old Comparison with old wfMsg* functions:
 121  *
 122  * Use full parsing:
 123  *
 124  * @code
 125  *     // old style:
 126  *     wfMsgExt( 'key', [ 'parseinline' ], 'apple' );
 127  *     // new style:
 128  *     wfMessage( 'key', 'apple' )->parse();
 129  * @endcode
 130  *
 131  * Parseinline is used because it is more useful when pre-building HTML.
 132  * In normal use it is better to use OutputPage::(add|wrap)WikiMsg.
 133  *
 134  * Places where HTML cannot be used. {{-transformation is done.
 135  * @code
 136  *     // old style:
 137  *     wfMsgExt( 'key', [ 'parsemag' ], 'apple', 'pear' );
 138  *     // new style:
 139  *     wfMessage( 'key', 'apple', 'pear' )->text();
 140  * @endcode
 141  *
 142  * Shortcut for escaping the message too, similar to wfMsgHTML(), but
 143  * parameters are not replaced after escaping by default.
 144  * @code
 145  *     $escaped = wfMessage( 'key' )
 146  *          ->rawParams( 'apple' )
 147  *          ->escaped();
 148  * @endcode
 149  *
 150  * @section message_appendix Appendix:
 151  *
 152  * @todo
 153  * - test, can we have tests?
 154  * - this documentation needs to be extended
 155  *
 156  * @see https://www.mediawiki.org/wiki/WfMessage()
 157  * @see https://www.mediawiki.org/wiki/New_messages_API
 158  * @see https://www.mediawiki.org/wiki/Localisation
 159  *
 160  * @since 1.17
 161  */
 162 class Message implements MessageSpecifier, Serializable {
 163         /** Use message text as-is */
 164         const FORMAT_PLAIN = 'plain';
 165         /** Use normal wikitext -> HTML parsing (the result will be wrapped in a block-level HTML tag) */
 166         const FORMAT_BLOCK_PARSE = 'block-parse';
 167         /** Use normal wikitext -> HTML parsing but strip the block-level wrapper */
 168         const FORMAT_PARSE = 'parse';
 169         /** Transform {{..}} constructs but don't transform to HTML */
 170         const FORMAT_TEXT = 'text';
 171         /** Transform {{..}} constructs, HTML-escape the result */
 172         const FORMAT_ESCAPED = 'escaped';
 173
 174         /**
 175          * Mapping from Message::listParam() types to Language methods.
 176          * @var array
 177          */
 178         protected static $listTypeMap = [
 179                 'comma' => 'commaList',
 180                 'semicolon' => 'semicolonList',
 181                 'pipe' => 'pipeList',
 182                 'text' => 'listToText',
 183         ];
 184
 185         /**
 186          * In which language to get this message. True, which is the default,
 187          * means the current user language, false content language.
 188          *
 189          * @var bool
 190          */
 191         protected $interface = true;
 192
 193         /**
 194          * In which language to get this message. Overrides the $interface setting.
 195          *
 196          * @var Language|bool Explicit language object, or false for user language
 197          */
 198         protected $language = false;
 199
 200         /**
 201          * @var string The message key. If $keysToTry has more than one element,
 202          * this may change to one of the keys to try when fetching the message text.
 203          */
 204         protected $key;
 205
 206         /**
 207          * @var string[] List of keys to try when fetching the message.
 208          */
 209         protected $keysToTry;
 210
 211         /**
 212          * @var array List of parameters which will be substituted into the message.
 213          */
 214         protected $parameters = [];
 215
 216         /**
 217          * @var string
 218          * @deprecated
 219          */
 220         protected $format = 'parse';
 221
 222         /**
 223          * @var bool Whether database can be used.
 224          */
 225         protected $useDatabase = true;
 226
 227         /**
 228          * @var Title Title object to use as context.
 229          */
 230         protected $title = null;
 231
 232         /**
 233          * @var Content Content object representing the message.
 234          */
 235         protected $content = null;
 236
 237         /**
 238          * @var string
 239          */
 240         protected $message;
 241
 242         /**
 243          * @since 1.17
 244          * @param string|string[]|MessageSpecifier $key Message key, or array of
 245          * message keys to try and use the first non-empty message for, or a
 246          * MessageSpecifier to copy from.
 247          * @param array $params Message parameters.
 248          * @param Language|null $language [optional] Language to use (defaults to current user language).
 249          * @throws InvalidArgumentException
 250          */
 251         public function __construct( $key, $params = [], Language $language = null ) {
 252                 if ( $key instanceof MessageSpecifier ) {
 253                         if ( $params ) {
 254                                 throw new InvalidArgumentException(
 255                                         '$params must be empty if $key is a MessageSpecifier'
 256                                 );
 257                         }
 258                         $params = $key->getParams();
 259                         $key = $key->getKey();
 260                 }
 261
 262                 if ( !is_string( $key ) && !is_array( $key ) ) {
 263                         throw new InvalidArgumentException( '$key must be a string or an array' );
 264                 }
 265
 266                 $this->keysToTry = (array)$key;
 267
 268                 if ( empty( $this->keysToTry ) ) {
 269                         throw new InvalidArgumentException( '$key must not be an empty list' );
 270                 }
 271
 272                 $this->key = reset( $this->keysToTry );
 273
 274                 $this->parameters = array_values( $params );
 275                 // User language is only resolved in getLanguage(). This helps preserve the
 276                 // semantic intent of "user language" across serialize() and unserialize().
 277                 $this->language = $language ?: false;
 278         }
 279
 280         /**
 281          * @see Serializable::serialize()
 282          * @since 1.26
 283          * @return string
 284          */
 285         public function serialize() {
 286                 return serialize( [
 287                         'interface' => $this->interface,
 288                         'language' => $this->language ? $this->language->getCode() : false,
 289                         'key' => $this->key,
 290                         'keysToTry' => $this->keysToTry,
 291                         'parameters' => $this->parameters,
 292                         'format' => $this->format,
 293                         'useDatabase' => $this->useDatabase,
 294                         'titlestr' => $this->title ? $this->title->getFullText() : null,
 295                 ] );
 296         }
 297
 298         /**
 299          * @see Serializable::unserialize()
 300          * @since 1.26
 301          * @param string $serialized
 302          */
 303         public function unserialize( $serialized ) {
 304                 $data = unserialize( $serialized );
 305                 if ( !is_array( $data ) ) {
 306                         throw new InvalidArgumentException( __METHOD__ . ': Invalid serialized data' );
 307                 }
 308
 309                 $this->interface = $data['interface'];
 310                 $this->key = $data['key'];
 311                 $this->keysToTry = $data['keysToTry'];
 312                 $this->parameters = $data['parameters'];
 313                 $this->format = $data['format'];
 314                 $this->useDatabase = $data['useDatabase'];
 315                 $this->language = $data['language'] ? Language::factory( $data['language'] ) : false;
 316
 317                 if ( isset( $data['titlestr'] ) ) {
 318                         $this->title = Title::newFromText( $data['titlestr'] );
 319                 } elseif ( isset( $data['title'] ) && $data['title'] instanceof Title ) {
 320                         // Old serializations from before December 2018
 321                         $this->title = $data['title'];
 322                 } else {
 323                         $this->title = null; // Explicit for sanity
 324                 }
 325         }
 326
 327         /**
 328          * @since 1.24
 329          *
 330          * @return bool True if this is a multi-key message, that is, if the key provided to the
 331          * constructor was a fallback list of keys to try.
 332          */
 333         public function isMultiKey() {
 334                 return count( $this->keysToTry ) > 1;
 335         }
 336
 337         /**
 338          * @since 1.24
 339          *
 340          * @return string[] The list of keys to try when fetching the message text,
 341          * in order of preference.
 342          */
 343         public function getKeysToTry() {
 344                 return $this->keysToTry;
 345         }
 346
 347         /**
 348          * Returns the message key.
 349          *
 350          * If a list of multiple possible keys was supplied to the constructor, this method may
 351          * return any of these keys. After the message has been fetched, this method will return
 352          * the key that was actually used to fetch the message.
 353          *
 354          * @since 1.21
 355          *
 356          * @return string
 357          */
 358         public function getKey() {
 359                 return $this->key;
 360         }
 361
 362         /**
 363          * Returns the message parameters.
 364          *
 365          * @since 1.21
 366          *
 367          * @return array
 368          */
 369         public function getParams() {
 370                 return $this->parameters;
 371         }
 372
 373         /**
 374          * Returns the message format.
 375          *
 376          * @since 1.21
 377          *
 378          * @return string
 379          * @deprecated since 1.29 formatting is not stateful
 380          */
 381         public function getFormat() {
 382                 wfDeprecated( __METHOD__, '1.29' );
 383                 return $this->format;
 384         }
 385
 386         /**
 387          * Returns the Language of the Message.
 388          *
 389          * @since 1.23
 390          *
 391          * @return Language
 392          */
 393         public function getLanguage() {
 394                 // Defaults to false which means current user language
 395                 return $this->language ?: RequestContext::getMain()->getLanguage();
 396         }
 397
 398         /**
 399          * Factory function that is just wrapper for the real constructor. It is
 400          * intended to be used instead of the real constructor, because it allows
 401          * chaining method calls, while new objects don't.
 402          *
 403          * @since 1.17
 404          *
 405          * @param string|string[]|MessageSpecifier $key
 406          * @param mixed ...$params Parameters as strings.
 407          *
 408          * @return Message
 409          */
 410         public static function newFromKey( $key, ...$params ) {
 411                 return new self( $key, $params );
 412         }
 413
 414         /**
 415          * Transform a MessageSpecifier or a primitive value used interchangeably with
 416          * specifiers (a message key string, or a key + params array) into a proper Message.
 417          *
 418          * Also accepts a MessageSpecifier inside an array: that's not considered a valid format
 419          * but is an easy error to make due to how StatusValue stores messages internally.
 420          * Further array elements are ignored in that case.
 421          *
 422          * @param string|array|MessageSpecifier $value
 423          * @return Message
 424          * @throws InvalidArgumentException
 425          * @since 1.27
 426          */
 427         public static function newFromSpecifier( $value ) {
 428                 $params = [];
 429                 if ( is_array( $value ) ) {
 430                         $params = $value;
 431                         $value = array_shift( $params );
 432                 }
 433
 434                 if ( $value instanceof Message ) { // Message, RawMessage, ApiMessage, etc
 435                         $message = clone $value;
 436                 } elseif ( $value instanceof MessageSpecifier ) {
 437                         $message = new Message( $value );
 438                 } elseif ( is_string( $value ) ) {
 439                         $message = new Message( $value, $params );
 440                 } else {
 441                         throw new InvalidArgumentException( __METHOD__ . ': invalid argument type '
 442                                 . gettype( $value ) );
 443                 }
 444
 445                 return $message;
 446         }
 447
 448         /**
 449          * Factory function accepting multiple message keys and returning a message instance
 450          * for the first message which is non-empty. If all messages are empty then an
 451          * instance of the first message key is returned.
 452          *
 453          * @since 1.18
 454          *
 455          * @param string|string[] ...$keys Message keys, or first argument as an array of all the
 456          * message keys.
 457          *
 458          * @return Message
 459          */
 460         public static function newFallbackSequence( ...$keys ) {
 461                 if ( func_num_args() == 1 ) {
 462                         if ( is_array( $keys[0] ) ) {
 463                                 // Allow an array to be passed as the first argument instead
 464                                 $keys = array_values( $keys[0] );
 465                         } else {
 466                                 // Optimize a single string to not need special fallback handling
 467                                 $keys = $keys[0];
 468                         }
 469                 }
 470                 return new self( $keys );
 471         }
 472
 473         /**
 474          * Get a title object for a mediawiki message, where it can be found in the mediawiki namespace.
 475          * The title will be for the current language, if the message key is in
 476          * $wgForceUIMsgAsContentMsg it will be append with the language code (except content
 477          * language), because Message::inContentLanguage will also return in user language.
 478          *
 479          * @see $wgForceUIMsgAsContentMsg
 480          * @return Title
 481          * @since 1.26
 482          */
 483         public function getTitle() {
 484                 global $wgForceUIMsgAsContentMsg;
 485
 486                 $contLang = MediaWikiServices::getInstance()->getContentLanguage();
 487                 $lang = $this->getLanguage();
 488                 $title = $this->key;
 489                 if (
 490                         !$lang->equals( $contLang )
 491                         && in_array( $this->key, (array)$wgForceUIMsgAsContentMsg )
 492                 ) {
 493                         $title .= '/' . $lang->getCode();
 494                 }
 495
 496                 return Title::makeTitle(
 497                         NS_MEDIAWIKI, $contLang->ucfirst( strtr( $title, ' ', '_' ) ) );
 498         }
 499
 500         /**
 501          * Adds parameters to the parameter list of this message.
 502          *
 503          * @since 1.17
 504          *
 505          * @param mixed ...$args Parameters as strings or arrays from
 506          *  Message::numParam() and the like, or a single array of parameters.
 507          *
 508          * @return Message $this
 509          */
 510         public function params( ...$args ) {
 511                 // If $args has only one entry and it's an array, then it's either a
 512                 // non-varargs call or it happens to be a call with just a single
 513                 // "special" parameter. Since the "special" parameters don't have any
 514                 // numeric keys, we'll test that to differentiate the cases.
 515                 if ( count( $args ) === 1 && isset( $args[0] ) && is_array( $args[0] ) ) {
 516                         if ( $args[0] === [] ) {
 517                                 $args = [];
 518                         } else {
 519                                 foreach ( $args[0] as $key => $value ) {
 520                                         if ( is_int( $key ) ) {
 521                                                 $args = $args[0];
 522                                                 break;
 523                                         }
 524                                 }
 525                         }
 526                 }
 527
 528                 $this->parameters = array_merge( $this->parameters, array_values( $args ) );
 529                 return $this;
 530         }
 531
 532         /**
 533          * Add parameters that are substituted after parsing or escaping.
 534          * In other words the parsing process cannot access the contents
 535          * of this type of parameter, and you need to make sure it is
 536          * sanitized beforehand.  The parser will see "$n", instead.
 537          *
 538          * @since 1.17
 539          *
 540          * @param mixed ...$params Raw parameters as strings, or a single argument that is
 541          * an array of raw parameters.
 542          *
 543          * @return Message $this
 544          */
 545         public function rawParams( ...$params ) {
 546                 if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 547                         $params = $params[0];
 548                 }
 549                 foreach ( $params as $param ) {
 550                         $this->parameters[] = self::rawParam( $param );
 551                 }
 552                 return $this;
 553         }
 554
 555         /**
 556          * Add parameters that are numeric and will be passed through
 557          * Language::formatNum before substitution
 558          *
 559          * @since 1.18
 560          *
 561          * @param mixed ...$params Numeric parameters, or a single argument that is
 562          * an array of numeric parameters.
 563          *
 564          * @return Message $this
 565          */
 566         public function numParams( ...$params ) {
 567                 if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 568                         $params = $params[0];
 569                 }
 570                 foreach ( $params as $param ) {
 571                         $this->parameters[] = self::numParam( $param );
 572                 }
 573                 return $this;
 574         }
 575
 576         /**
 577          * Add parameters that are durations of time and will be passed through
 578          * Language::formatDuration before substitution
 579          *
 580          * @since 1.22
 581          *
 582          * @param int|int[] ...$params Duration parameters, or a single argument that is
 583          * an array of duration parameters.
 584          *
 585          * @return Message $this
 586          */
 587         public function durationParams( ...$params ) {
 588                 if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 589                         $params = $params[0];
 590                 }
 591                 foreach ( $params as $param ) {
 592                         $this->parameters[] = self::durationParam( $param );
 593                 }
 594                 return $this;
 595         }
 596
 597         /**
 598          * Add parameters that are expiration times and will be passed through
 599          * Language::formatExpiry before substitution
 600          *
 601          * @since 1.22
 602          *
 603          * @param string|string[] ...$params Expiry parameters, or a single argument that is
 604          * an array of expiry parameters.
 605          *
 606          * @return Message $this
 607          */
 608         public function expiryParams( ...$params ) {
 609                 if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 610                         $params = $params[0];
 611                 }
 612                 foreach ( $params as $param ) {
 613                         $this->parameters[] = self::expiryParam( $param );
 614                 }
 615                 return $this;
 616         }
 617
 618         /**
 619          * Add parameters that are time periods and will be passed through
 620          * Language::formatTimePeriod before substitution
 621          *
 622          * @since 1.22
 623          *
 624          * @param int|int[] ...$params Time period parameters, or a single argument that is
 625          * an array of time period parameters.
 626          *
 627          * @return Message $this
 628          */
 629         public function timeperiodParams( ...$params ) {
 630                 if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 631                         $params = $params[0];
 632                 }
 633                 foreach ( $params as $param ) {
 634                         $this->parameters[] = self::timeperiodParam( $param );
 635                 }
 636                 return $this;
 637         }
 638
 639         /**
 640          * Add parameters that are file sizes and will be passed through
 641          * Language::formatSize before substitution
 642          *
 643          * @since 1.22
 644          *
 645          * @param int|int[] ...$params Size parameters, or a single argument that is
 646          * an array of size parameters.
 647          *
 648          * @return Message $this
 649          */
 650         public function sizeParams( ...$params ) {
 651                 if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 652                         $params = $params[0];
 653                 }
 654                 foreach ( $params as $param ) {
 655                         $this->parameters[] = self::sizeParam( $param );
 656                 }
 657                 return $this;
 658         }
 659
 660         /**
 661          * Add parameters that are bitrates and will be passed through
 662          * Language::formatBitrate before substitution
 663          *
 664          * @since 1.22
 665          *
 666          * @param int|int[] ...$params Bit rate parameters, or a single argument that is
 667          * an array of bit rate parameters.
 668          *
 669          * @return Message $this
 670          */
 671         public function bitrateParams( ...$params ) {
 672                 if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 673                         $params = $params[0];
 674                 }
 675                 foreach ( $params as $param ) {
 676                         $this->parameters[] = self::bitrateParam( $param );
 677                 }
 678                 return $this;
 679         }
 680
 681         /**
 682          * Add parameters that are plaintext and will be passed through without
 683          * the content being evaluated.  Plaintext parameters are not valid as
 684          * arguments to parser functions. This differs from self::rawParams in
 685          * that the Message class handles escaping to match the output format.
 686          *
 687          * @since 1.25
 688          *
 689          * @param string|string[] ...$params plaintext parameters, or a single argument that is
 690          * an array of plaintext parameters.
 691          *
 692          * @return Message $this
 693          */
 694         public function plaintextParams( ...$params ) {
 695                 if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 696                         $params = $params[0];
 697                 }
 698                 foreach ( $params as $param ) {
 699                         $this->parameters[] = self::plaintextParam( $param );
 700                 }
 701                 return $this;
 702         }
 703
 704         /**
 705          * Set the language and the title from a context object
 706          *
 707          * @since 1.19
 708          *
 709          * @param IContextSource $context
 710          *
 711          * @return Message $this
 712          */
 713         public function setContext( IContextSource $context ) {
 714                 $this->inLanguage( $context->getLanguage() );
 715                 $this->title( $context->getTitle() );
 716                 $this->interface = true;
 717
 718                 return $this;
 719         }
 720
 721         /**
 722          * Request the message in any language that is supported.
 723          *
 724          * As a side effect interface message status is unconditionally
 725          * turned off.
 726          *
 727          * @since 1.17
 728          * @param Language|string $lang Language code or Language object.
 729          * @return Message $this
 730          * @throws MWException
 731          */
 732         public function inLanguage( $lang ) {
 733                 $previousLanguage = $this->language;
 734
 735                 if ( $lang instanceof Language ) {
 736                         $this->language = $lang;
 737                 } elseif ( is_string( $lang ) ) {
 738                         if ( !$this->language instanceof Language || $this->language->getCode() != $lang ) {
 739                                 $this->language = Language::factory( $lang );
 740                         }
 741                 } elseif ( $lang instanceof StubUserLang ) {
 742                         $this->language = false;
 743                 } else {
 744                         $type = gettype( $lang );
 745                         throw new MWException( __METHOD__ . " must be "
 746                                 . "passed a String or Language object; $type given"
 747                         );
 748                 }
 749
 750                 if ( $this->language !== $previousLanguage ) {
 751                         // The language has changed. Clear the message cache.
 752                         $this->message = null;
 753                 }
 754                 $this->interface = false;
 755                 return $this;
 756         }
 757
 758         /**
 759          * Request the message in the wiki's content language,
 760          * unless it is disabled for this message.
 761          *
 762          * @since 1.17
 763          * @see $wgForceUIMsgAsContentMsg
 764          *
 765          * @return Message $this
 766          */
 767         public function inContentLanguage() {
 768                 global $wgForceUIMsgAsContentMsg;
 769                 if ( in_array( $this->key, (array)$wgForceUIMsgAsContentMsg ) ) {
 770                         return $this;
 771                 }
 772
 773                 $this->inLanguage( MediaWikiServices::getInstance()->getContentLanguage() );
 774                 return $this;
 775         }
 776
 777         /**
 778          * Allows manipulating the interface message flag directly.
 779          * Can be used to restore the flag after setting a language.
 780          *
 781          * @since 1.20
 782          *
 783          * @param bool $interface
 784          *
 785          * @return Message $this
 786          */
 787         public function setInterfaceMessageFlag( $interface ) {
 788                 $this->interface = (bool)$interface;
 789                 return $this;
 790         }
 791
 792         /**
 793          * Enable or disable database use.
 794          *
 795          * @since 1.17
 796          *
 797          * @param bool $useDatabase
 798          *
 799          * @return Message $this
 800          */
 801         public function useDatabase( $useDatabase ) {
 802                 $this->useDatabase = (bool)$useDatabase;
 803                 $this->message = null;
 804                 return $this;
 805         }
 806
 807         /**
 808          * Set the Title object to use as context when transforming the message
 809          *
 810          * @since 1.18
 811          *
 812          * @param Title $title
 813          *
 814          * @return Message $this
 815          */
 816         public function title( $title ) {
 817                 $this->title = $title;
 818                 return $this;
 819         }
 820
 821         /**
 822          * Returns the message as a Content object.
 823          *
 824          * @return Content
 825          */
 826         public function content() {
 827                 if ( !$this->content ) {
 828                         $this->content = new MessageContent( $this );
 829                 }
 830
 831                 return $this->content;
 832         }
 833
 834         /**
 835          * Returns the message parsed from wikitext to HTML.
 836          *
 837          * @since 1.17
 838          *
 839          * @param string|null $format One of the FORMAT_* constants. Null means use whatever was used
 840          *   the last time (this is for B/C and should be avoided).
 841          *
 842          * @return string HTML
 843          * @suppress SecurityCheck-DoubleEscaped phan false positive
 844          */
 845         public function toString( $format = null ) {
 846                 if ( $format === null ) {
 847                         $ex = new LogicException( __METHOD__ . ' using implicit format: ' . $this->format );
 848                         LoggerFactory::getInstance( 'message-format' )->warning(
 849                                 $ex->getMessage(), [ 'exception' => $ex, 'format' => $this->format, 'key' => $this->key ] );
 850                         $format = $this->format;
 851                 }
 852                 $string = $this->fetchMessage();
 853
 854                 if ( $string === false ) {
 855                         // Err on the side of safety, ensure that the output
 856                         // is always html safe in the event the message key is
 857                         // missing, since in that case its highly likely the
 858                         // message key is user-controlled.
 859                         // '⧼' is used instead of '<' to side-step any
 860                         // double-escaping issues.
 861                         // (Keep synchronised with mw.Message#toString in JS.)
 862                         return '⧼' . htmlspecialchars( $this->key ) . '⧽';
 863                 }
 864
 865                 # Replace $* with a list of parameters for &uselang=qqx.
 866                 if ( strpos( $string, '$*' ) !== false ) {
 867                         $paramlist = '';
 868                         if ( $this->parameters !== [] ) {
 869                                 $paramlist = ': $' . implode( ', $', range( 1, count( $this->parameters ) ) );
 870                         }
 871                         $string = str_replace( '$*', $paramlist, $string );
 872                 }
 873
 874                 # Replace parameters before text parsing
 875                 $string = $this->replaceParameters( $string, 'before', $format );
 876
 877                 # Maybe transform using the full parser
 878                 if ( $format === self::FORMAT_PARSE ) {
 879                         $string = $this->parseText( $string );
 880                         $string = Parser::stripOuterParagraph( $string );
 881                 } elseif ( $format === self::FORMAT_BLOCK_PARSE ) {
 882                         $string = $this->parseText( $string );
 883                 } elseif ( $format === self::FORMAT_TEXT ) {
 884                         $string = $this->transformText( $string );
 885                 } elseif ( $format === self::FORMAT_ESCAPED ) {
 886                         $string = $this->transformText( $string );
 887                         $string = htmlspecialchars( $string, ENT_QUOTES, 'UTF-8', false );
 888                 }
 889
 890                 # Raw parameter replacement
 891                 $string = $this->replaceParameters( $string, 'after', $format );
 892
 893                 return $string;
 894         }
 895
 896         /**
 897          * Magic method implementation of the above (for PHP >= 5.2.0), so we can do, eg:
 898          *     $foo = new Message( $key );
 899          *     $string = "<abbr>$foo</abbr>";
 900          *
 901          * @since 1.18
 902          *
 903          * @return string
 904          */
 905         public function __toString() {
 906                 // PHP doesn't allow __toString to throw exceptions and will
 907                 // trigger a fatal error if it does. So, catch any exceptions.
 908
 909                 try {
 910                         return $this->toString( self::FORMAT_PARSE );
 911                 } catch ( Exception $ex ) {
 912                         try {
 913                                 trigger_error( "Exception caught in " . __METHOD__ . " (message " . $this->key . "): "
 914                                         . $ex, E_USER_WARNING );
 915                         } catch ( Exception $ex ) {
 916                                 // Doh! Cause a fatal error after all?
 917                         }
 918
 919                         return '⧼' . htmlspecialchars( $this->key ) . '⧽';
 920                 }
 921         }
 922
 923         /**
 924          * Fully parse the text from wikitext to HTML.
 925          *
 926          * @since 1.17
 927          *
 928          * @return string Parsed HTML.
 929          */
 930         public function parse() {
 931                 $this->format = self::FORMAT_PARSE;
 932                 return $this->toString( self::FORMAT_PARSE );
 933         }
 934
 935         /**
 936          * Returns the message text. {{-transformation is done.
 937          *
 938          * @since 1.17
 939          *
 940          * @return string Unescaped message text.
 941          */
 942         public function text() {
 943                 $this->format = self::FORMAT_TEXT;
 944                 return $this->toString( self::FORMAT_TEXT );
 945         }
 946
 947         /**
 948          * Returns the message text as-is, only parameters are substituted.
 949          *
 950          * @since 1.17
 951          *
 952          * @return string Unescaped untransformed message text.
 953          */
 954         public function plain() {
 955                 $this->format = self::FORMAT_PLAIN;
 956                 return $this->toString( self::FORMAT_PLAIN );
 957         }
 958
 959         /**
 960          * Returns the parsed message text which is always surrounded by a block element.
 961          *
 962          * @since 1.17
 963          *
 964          * @return string HTML
 965          */
 966         public function parseAsBlock() {
 967                 $this->format = self::FORMAT_BLOCK_PARSE;
 968                 return $this->toString( self::FORMAT_BLOCK_PARSE );
 969         }
 970
 971         /**
 972          * Returns the message text. {{-transformation is done and the result
 973          * is escaped excluding any raw parameters.
 974          *
 975          * @since 1.17
 976          *
 977          * @return string Escaped message text.
 978          */
 979         public function escaped() {
 980                 $this->format = self::FORMAT_ESCAPED;
 981                 return $this->toString( self::FORMAT_ESCAPED );
 982         }
 983
 984         /**
 985          * Check whether a message key has been defined currently.
 986          *
 987          * @since 1.17
 988          *
 989          * @return bool
 990          */
 991         public function exists() {
 992                 return $this->fetchMessage() !== false;
 993         }
 994
 995         /**
 996          * Check whether a message does not exist, or is an empty string
 997          *
 998          * @since 1.18
 999          * @todo FIXME: Merge with isDisabled()?
1000          *
1001          * @return bool
1002          */
1003         public function isBlank() {
1004                 $message = $this->fetchMessage();
1005                 return $message === false || $message === '';
1006         }
1007
1008         /**
1009          * Check whether a message does not exist, is an empty string, or is "-".
1010          *
1011          * @since 1.18
1012          *
1013          * @return bool
1014          */
1015         public function isDisabled() {
1016                 $message = $this->fetchMessage();
1017                 return $message === false || $message === '' || $message === '-';
1018         }
1019
1020         /**
1021          * @since 1.17
1022          *
1023          * @param mixed $raw
1024          *
1025          * @return array Array with a single "raw" key.
1026          */
1027         public static function rawParam( $raw ) {
1028                 return [ 'raw' => $raw ];
1029         }
1030
1031         /**
1032          * @since 1.18
1033          *
1034          * @param mixed $num
1035          *
1036          * @return array Array with a single "num" key.
1037          */
1038         public static function numParam( $num ) {
1039                 return [ 'num' => $num ];
1040         }
1041
1042         /**
1043          * @since 1.22
1044          *
1045          * @param int $duration
1046          *
1047          * @return int[] Array with a single "duration" key.
1048          */
1049         public static function durationParam( $duration ) {
1050                 return [ 'duration' => $duration ];
1051         }
1052
1053         /**
1054          * @since 1.22
1055          *
1056          * @param string $expiry
1057          *
1058          * @return string[] Array with a single "expiry" key.
1059          */
1060         public static function expiryParam( $expiry ) {
1061                 return [ 'expiry' => $expiry ];
1062         }
1063
1064         /**
1065          * @since 1.22
1066          *
1067          * @param int $period
1068          *
1069          * @return int[] Array with a single "period" key.
1070          */
1071         public static function timeperiodParam( $period ) {
1072                 return [ 'period' => $period ];
1073         }
1074
1075         /**
1076          * @since 1.22
1077          *
1078          * @param int $size
1079          *
1080          * @return int[] Array with a single "size" key.
1081          */
1082         public static function sizeParam( $size ) {
1083                 return [ 'size' => $size ];
1084         }
1085
1086         /**
1087          * @since 1.22
1088          *
1089          * @param int $bitrate
1090          *
1091          * @return int[] Array with a single "bitrate" key.
1092          */
1093         public static function bitrateParam( $bitrate ) {
1094                 return [ 'bitrate' => $bitrate ];
1095         }
1096
1097         /**
1098          * @since 1.25
1099          *
1100          * @param string $plaintext
1101          *
1102          * @return string[] Array with a single "plaintext" key.
1103          */
1104         public static function plaintextParam( $plaintext ) {
1105                 return [ 'plaintext' => $plaintext ];
1106         }
1107
1108         /**
1109          * @since 1.29
1110          *
1111          * @param array $list
1112          * @param string $type 'comma', 'semicolon', 'pipe', 'text'
1113          * @return array Array with "list" and "type" keys.
1114          */
1115         public static function listParam( array $list, $type = 'text' ) {
1116                 if ( !isset( self::$listTypeMap[$type] ) ) {
1117                         throw new InvalidArgumentException(
1118                                 "Invalid type '$type'. Known types are: " . implode( ', ', array_keys( self::$listTypeMap ) )
1119                         );
1120                 }
1121                 return [ 'list' => $list, 'type' => $type ];
1122         }
1123
1124         /**
1125          * Substitutes any parameters into the message text.
1126          *
1127          * @since 1.17
1128          *
1129          * @param string $message The message text.
1130          * @param string $type Either "before" or "after".
1131          * @param string $format One of the FORMAT_* constants.
1132          *
1133          * @return string
1134          */
1135         protected function replaceParameters( $message, $type, $format ) {
1136                 // A temporary marker for $1 parameters that is only valid
1137                 // in non-attribute contexts. However if the entire message is escaped
1138                 // then we don't want to use it because it will be mangled in all contexts
1139                 // and its unnessary as ->escaped() messages aren't html.
1140                 $marker = $format === self::FORMAT_ESCAPED ? '$' : '$\'"';
1141                 $replacementKeys = [];
1142                 foreach ( $this->parameters as $n => $param ) {
1143                         list( $paramType, $value ) = $this->extractParam( $param, $format );
1144                         if ( $type === 'before' ) {
1145                                 if ( $paramType === 'before' ) {
1146                                         $replacementKeys['$' . ( $n + 1 )] = $value;
1147                                 } else /* $paramType === 'after' */ {
1148                                         // To protect against XSS from replacing parameters
1149                                         // inside html attributes, we convert $1 to $'"1.
1150                                         // In the event that one of the parameters ends up
1151                                         // in an attribute, either the ' or the " will be
1152                                         // escaped, breaking the replacement and avoiding XSS.
1153                                         $replacementKeys['$' . ( $n + 1 )] = $marker . ( $n + 1 );
1154                                 }
1155                         } elseif ( $paramType === 'after' ) {
1156                                 $replacementKeys[$marker . ( $n + 1 )] = $value;
1157                         }
1158                 }
1159                 return strtr( $message, $replacementKeys );
1160         }
1161
1162         /**
1163          * Extracts the parameter type and preprocessed the value if needed.
1164          *
1165          * @since 1.18
1166          *
1167          * @param mixed $param Parameter as defined in this class.
1168          * @param string $format One of the FORMAT_* constants.
1169          *
1170          * @return array Array with the parameter type (either "before" or "after") and the value.
1171          */
1172         protected function extractParam( $param, $format ) {
1173                 if ( is_array( $param ) ) {
1174                         if ( isset( $param['raw'] ) ) {
1175                                 return [ 'after', $param['raw'] ];
1176                         } elseif ( isset( $param['num'] ) ) {
1177                                 // Replace number params always in before step for now.
1178                                 // No support for combined raw and num params
1179                                 return [ 'before', $this->getLanguage()->formatNum( $param['num'] ) ];
1180                         } elseif ( isset( $param['duration'] ) ) {
1181                                 return [ 'before', $this->getLanguage()->formatDuration( $param['duration'] ) ];
1182                         } elseif ( isset( $param['expiry'] ) ) {
1183                                 return [ 'before', $this->getLanguage()->formatExpiry( $param['expiry'] ) ];
1184                         } elseif ( isset( $param['period'] ) ) {
1185                                 return [ 'before', $this->getLanguage()->formatTimePeriod( $param['period'] ) ];
1186                         } elseif ( isset( $param['size'] ) ) {
1187                                 return [ 'before', $this->getLanguage()->formatSize( $param['size'] ) ];
1188                         } elseif ( isset( $param['bitrate'] ) ) {
1189                                 return [ 'before', $this->getLanguage()->formatBitrate( $param['bitrate'] ) ];
1190                         } elseif ( isset( $param['plaintext'] ) ) {
1191                                 return [ 'after', $this->formatPlaintext( $param['plaintext'], $format ) ];
1192                         } elseif ( isset( $param['list'] ) ) {
1193                                 return $this->formatListParam( $param['list'], $param['type'], $format );
1194                         } else {
1195                                 if ( !is_scalar( $param ) ) {
1196                                         $param = serialize( $param );
1197                                 }
1198                                 LoggerFactory::getInstance( 'Bug58676' )->warning(
1199                                         'Invalid parameter for message "{msgkey}": {param}',
1200                                         [
1201                                                 'exception' => new Exception,
1202                                                 'msgkey' => $this->getKey(),
1203                                                 'param' => htmlspecialchars( $param ),
1204                                         ]
1205                                 );
1206
1207                                 return [ 'before', '[INVALID]' ];
1208                         }
1209                 } elseif ( $param instanceof Message ) {
1210                         // Match language, flags, etc. to the current message.
1211                         $msg = clone $param;
1212                         if ( $msg->language !== $this->language || $msg->useDatabase !== $this->useDatabase ) {
1213                                 // Cache depends on these parameters
1214                                 $msg->message = null;
1215                         }
1216                         $msg->interface = $this->interface;
1217                         $msg->language = $this->language;
1218                         $msg->useDatabase = $this->useDatabase;
1219                         $msg->title = $this->title;
1220
1221                         // DWIM
1222                         if ( $format === 'block-parse' ) {
1223                                 $format = 'parse';
1224                         }
1225                         $msg->format = $format;
1226
1227                         // Message objects should not be before parameters because
1228                         // then they'll get double escaped. If the message needs to be
1229                         // escaped, it'll happen right here when we call toString().
1230                         return [ 'after', $msg->toString( $format ) ];
1231                 } else {
1232                         return [ 'before', $param ];
1233                 }
1234         }
1235
1236         /**
1237          * Wrapper for what ever method we use to parse wikitext.
1238          *
1239          * @since 1.17
1240          *
1241          * @param string $string Wikitext message contents.
1242          *
1243          * @return string Wikitext parsed into HTML.
1244          */
1245         protected function parseText( $string ) {
1246                 $out = MessageCache::singleton()->parse(
1247                         $string,
1248                         $this->title,
1249                         /*linestart*/true,
1250                         $this->interface,
1251                         $this->getLanguage()
1252                 );
1253
1254                 return $out instanceof ParserOutput
1255                         ? $out->getText( [
1256                                 'enableSectionEditLinks' => false,
1257                                 // Wrapping messages in an extra <div> is probably not expected. If
1258                                 // they're outside the content area they probably shouldn't be
1259                                 // targeted by CSS that's targeting the parser output, and if
1260                                 // they're inside they already are from the outer div.
1261                                 'unwrap' => true,
1262                         ] )
1263                         : $out;
1264         }
1265
1266         /**
1267          * Wrapper for what ever method we use to {{-transform wikitext.
1268          *
1269          * @since 1.17
1270          *
1271          * @param string $string Wikitext message contents.
1272          *
1273          * @return string Wikitext with {{-constructs replaced with their values.
1274          */
1275         protected function transformText( $string ) {
1276                 return MessageCache::singleton()->transform(
1277                         $string,
1278                         $this->interface,
1279                         $this->getLanguage(),
1280                         $this->title
1281                 );
1282         }
1283
1284         /**
1285          * Wrapper for what ever method we use to get message contents.
1286          *
1287          * @since 1.17
1288          *
1289          * @return string
1290          * @throws MWException If message key array is empty.
1291          */
1292         protected function fetchMessage() {
1293                 if ( $this->message === null ) {
1294                         $cache = MessageCache::singleton();
1295
1296                         foreach ( $this->keysToTry as $key ) {
1297                                 $message = $cache->get( $key, $this->useDatabase, $this->getLanguage() );
1298                                 if ( $message !== false && $message !== '' ) {
1299                                         break;
1300                                 }
1301                         }
1302
1303                         // NOTE: The constructor makes sure keysToTry isn't empty,
1304                         //       so we know that $key and $message are initialized.
1305                         $this->key = $key;
1306                         $this->message = $message;
1307                 }
1308                 return $this->message;
1309         }
1310
1311         /**
1312          * Formats a message parameter wrapped with 'plaintext'. Ensures that
1313          * the entire string is displayed unchanged when displayed in the output
1314          * format.
1315          *
1316          * @since 1.25
1317          *
1318          * @param string $plaintext String to ensure plaintext output of
1319          * @param string $format One of the FORMAT_* constants.
1320          *
1321          * @return string Input plaintext encoded for output to $format
1322          */
1323         protected function formatPlaintext( $plaintext, $format ) {
1324                 switch ( $format ) {
1325                         case self::FORMAT_TEXT:
1326                         case self::FORMAT_PLAIN:
1327                                 return $plaintext;
1328
1329                         case self::FORMAT_PARSE:
1330                         case self::FORMAT_BLOCK_PARSE:
1331                         case self::FORMAT_ESCAPED:
1332                         default:
1333                                 return htmlspecialchars( $plaintext, ENT_QUOTES );
1334                 }
1335         }
1336
1337         /**
1338          * Formats a list of parameters as a concatenated string.
1339          * @since 1.29
1340          * @param array $params
1341          * @param string $listType
1342          * @param string $format One of the FORMAT_* constants.
1343          * @return array Array with the parameter type (either "before" or "after") and the value.
1344          */
1345         protected function formatListParam( array $params, $listType, $format ) {
1346                 if ( !isset( self::$listTypeMap[$listType] ) ) {
1347                         $warning = 'Invalid list type for message "' . $this->getKey() . '": '
1348                                 . htmlspecialchars( $listType )
1349                                 . ' (params are ' . htmlspecialchars( serialize( $params ) ) . ')';
1350                         trigger_error( $warning, E_USER_WARNING );
1351                         $e = new Exception;
1352                         wfDebugLog( 'Bug58676', $warning . "\n" . $e->getTraceAsString() );
1353                         return [ 'before', '[INVALID]' ];
1354                 }
1355                 $func = self::$listTypeMap[$listType];
1356
1357                 // Handle an empty list sensibly
1358                 if ( !$params ) {
1359                         return [ 'before', $this->getLanguage()->$func( [] ) ];
1360                 }
1361
1362                 // First, determine what kinds of list items we have
1363                 $types = [];
1364                 $vars = [];
1365                 $list = [];
1366                 foreach ( $params as $n => $p ) {
1367                         list( $type, $value ) = $this->extractParam( $p, $format );
1368                         $types[$type] = true;
1369                         $list[] = $value;
1370                         $vars[] = '$' . ( $n + 1 );
1371                 }
1372
1373                 // Easy case: all are 'before' or 'after', so just join the
1374                 // values and use the same type.
1375                 if ( count( $types ) === 1 ) {
1376                         return [ key( $types ), $this->getLanguage()->$func( $list ) ];
1377                 }
1378
1379                 // Hard case: We need to process each value per its type, then
1380                 // return the concatenated values as 'after'. We handle this by turning
1381                 // the list into a RawMessage and processing that as a parameter.
1382                 $vars = $this->getLanguage()->$func( $vars );
1383                 return $this->extractParam( new RawMessage( $vars, $params ), $format );
1384         }
1385 }