includes/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 use MediaWiki\MediaWikiServices;
  24
  25 /**
  26  * The Message class provides methods which fulfil two basic services:
  27  *  - fetching interface messages
  28  *  - processing messages into a variety of formats
  29  *
  30  * First implemented with MediaWiki 1.17, the Message class is intended to
  31  * replace the old wfMsg* functions that over time grew unusable.
  32  * @see https://www.mediawiki.org/wiki/Manual:Messages_API for equivalences
  33  * between old and new functions.
  34  *
  35  * You should use the wfMessage() global function which acts as a wrapper for
  36  * the Message class. The wrapper let you pass parameters as arguments.
  37  *
  38  * The most basic usage cases would be:
  39  *
  40  * @code
  41  *     // Initialize a Message object using the 'some_key' message key
  42  *     $message = wfMessage( 'some_key' );
  43  *
  44  *     // Using two parameters those values are strings 'value1' and 'value2':
  45  *     $message = wfMessage( 'some_key',
  46  *          'value1', 'value2'
  47  *     );
  48  * @endcode
  49  *
  50  * @section message_global_fn Global function wrapper:
  51  *
  52  * Since wfMessage() returns a Message instance, you can chain its call with
  53  * a method. Some of them return a Message instance too so you can chain them.
  54  * You will find below several examples of wfMessage() usage.
  55  *
  56  * Fetching a message text for interface message:
  57  *
  58  * @code
  59  *    $button = Xml::button(
  60  *         wfMessage( 'submit' )->text()
  61  *    );
  62  * @endcode
  63  *
  64  * A Message instance can be passed parameters after it has been constructed,
  65  * use the params() method to do so:
  66  *
  67  * @code
  68  *     wfMessage( 'welcome-to' )
  69  *         ->params( $wgSitename )
  70  *         ->text();
  71  * @endcode
  72  *
  73  * {{GRAMMAR}} and friends work correctly:
  74  *
  75  * @code
  76  *    wfMessage( 'are-friends',
  77  *        $user, $friend
  78  *    );
  79  *    wfMessage( 'bad-message' )
  80  *         ->rawParams( '<script>...</script>' )
  81  *         ->escaped();
  82  * @endcode
  83  *
  84  * @section message_language Changing language:
  85  *
  86  * Messages can be requested in a different language or in whatever current
  87  * content language is being used. The methods are:
  88  *     - Message->inContentLanguage()
  89  *     - Message->inLanguage()
  90  *
  91  * Sometimes the message text ends up in the database, so content language is
  92  * needed:
  93  *
  94  * @code
  95  *    wfMessage( 'file-log',
  96  *        $user, $filename
  97  *    )->inContentLanguage()->text();
  98  * @endcode
  99  *
 100  * Checking whether a message exists:
 101  *
 102  * @code
 103  *    wfMessage( 'mysterious-message' )->exists()
 104  *    // returns a boolean whether the 'mysterious-message' key exist.
 105  * @endcode
 106  *
 107  * If you want to use a different language:
 108  *
 109  * @code
 110  *    $userLanguage = $user->getOption( 'language' );
 111  *    wfMessage( 'email-header' )
 112  *         ->inLanguage( $userLanguage )
 113  *         ->plain();
 114  * @endcode
 115  *
 116  * @note You can parse the text only in the content or interface languages
 117  *
 118  * @section message_compare_old Comparison with old wfMsg* functions:
 119  *
 120  * Use full parsing:
 121  *
 122  * @code
 123  *     // old style:
 124  *     wfMsgExt( 'key', [ 'parseinline' ], 'apple' );
 125  *     // new style:
 126  *     wfMessage( 'key', 'apple' )->parse();
 127  * @endcode
 128  *
 129  * Parseinline is used because it is more useful when pre-building HTML.
 130  * In normal use it is better to use OutputPage::(add|wrap)WikiMsg.
 131  *
 132  * Places where HTML cannot be used. {{-transformation is done.
 133  * @code
 134  *     // old style:
 135  *     wfMsgExt( 'key', [ 'parsemag' ], 'apple', 'pear' );
 136  *     // new style:
 137  *     wfMessage( 'key', 'apple', 'pear' )->text();
 138  * @endcode
 139  *
 140  * Shortcut for escaping the message too, similar to wfMsgHTML(), but
 141  * parameters are not replaced after escaping by default.
 142  * @code
 143  *     $escaped = wfMessage( 'key' )
 144  *          ->rawParams( 'apple' )
 145  *          ->escaped();
 146  * @endcode
 147  *
 148  * @section message_appendix Appendix:
 149  *
 150  * @todo
 151  * - test, can we have tests?
 152  * - this documentation needs to be extended
 153  *
 154  * @see https://www.mediawiki.org/wiki/WfMessage()
 155  * @see https://www.mediawiki.org/wiki/New_messages_API
 156  * @see https://www.mediawiki.org/wiki/Localisation
 157  *
 158  * @since 1.17
 159  */
 160 class Message implements MessageSpecifier, Serializable {
 161         /** Use message text as-is */
 162         const FORMAT_PLAIN = 'plain';
 163         /** Use normal wikitext -> HTML parsing (the result will be wrapped in a block-level HTML tag) */
 164         const FORMAT_BLOCK_PARSE = 'block-parse';
 165         /** Use normal wikitext -> HTML parsing but strip the block-level wrapper */
 166         const FORMAT_PARSE = 'parse';
 167         /** Transform {{..}} constructs but don't transform to HTML */
 168         const FORMAT_TEXT = 'text';
 169         /** Transform {{..}} constructs, HTML-escape the result */
 170         const FORMAT_ESCAPED = 'escaped';
 171
 172         /**
 173          * Mapping from Message::listParam() types to Language methods.
 174          * @var array
 175          */
 176         protected static $listTypeMap = [
 177                 'comma' => 'commaList',
 178                 'semicolon' => 'semicolonList',
 179                 'pipe' => 'pipeList',
 180                 'text' => 'listToText',
 181         ];
 182
 183         /**
 184          * In which language to get this message. True, which is the default,
 185          * means the current user language, false content language.
 186          *
 187          * @var bool
 188          */
 189         protected $interface = true;
 190
 191         /**
 192          * In which language to get this message. Overrides the $interface setting.
 193          *
 194          * @var Language|bool Explicit language object, or false for user language
 195          */
 196         protected $language = false;
 197
 198         /**
 199          * @var string The message key. If $keysToTry has more than one element,
 200          * this may change to one of the keys to try when fetching the message text.
 201          */
 202         protected $key;
 203
 204         /**
 205          * @var string[] List of keys to try when fetching the message.
 206          */
 207         protected $keysToTry;
 208
 209         /**
 210          * @var array List of parameters which will be substituted into the message.
 211          */
 212         protected $parameters = [];
 213
 214         /**
 215          * @var string
 216          * @deprecated
 217          */
 218         protected $format = 'parse';
 219
 220         /**
 221          * @var bool Whether database can be used.
 222          */
 223         protected $useDatabase = true;
 224
 225         /**
 226          * @var Title Title object to use as context.
 227          */
 228         protected $title = null;
 229
 230         /**
 231          * @var Content Content object representing the message.
 232          */
 233         protected $content = null;
 234
 235         /**
 236          * @var string
 237          */
 238         protected $message;
 239
 240         /**
 241          * @since 1.17
 242          * @param string|string[]|MessageSpecifier $key Message key, or array of
 243          * message keys to try and use the first non-empty message for, or a
 244          * MessageSpecifier to copy from.
 245          * @param array $params Message parameters.
 246          * @param Language|null $language [optional] Language to use (defaults to current user language).
 247          * @throws InvalidArgumentException
 248          */
 249         public function __construct( $key, $params = [], Language $language = null ) {
 250                 if ( $key instanceof MessageSpecifier ) {
 251                         if ( $params ) {
 252                                 throw new InvalidArgumentException(
 253                                         '$params must be empty if $key is a MessageSpecifier'
 254                                 );
 255                         }
 256                         $params = $key->getParams();
 257                         $key = $key->getKey();
 258                 }
 259
 260                 if ( !is_string( $key ) && !is_array( $key ) ) {
 261                         throw new InvalidArgumentException( '$key must be a string or an array' );
 262                 }
 263
 264                 $this->keysToTry = (array)$key;
 265
 266                 if ( empty( $this->keysToTry ) ) {
 267                         throw new InvalidArgumentException( '$key must not be an empty list' );
 268                 }
 269
 270                 $this->key = reset( $this->keysToTry );
 271
 272                 $this->parameters = array_values( $params );
 273                 // User language is only resolved in getLanguage(). This helps preserve the
 274                 // semantic intent of "user language" across serialize() and unserialize().
 275                 $this->language = $language ?: false;
 276         }
 277
 278         /**
 279          * @see Serializable::serialize()
 280          * @since 1.26
 281          * @return string
 282          */
 283         public function serialize() {
 284                 return serialize( [
 285                         'interface' => $this->interface,
 286                         'language' => $this->language ? $this->language->getCode() : false,
 287                         'key' => $this->key,
 288                         'keysToTry' => $this->keysToTry,
 289                         'parameters' => $this->parameters,
 290                         'format' => $this->format,
 291                         'useDatabase' => $this->useDatabase,
 292                         'title' => $this->title,
 293                         'titlestr' => $this->title ? $this->title->getFullText() : null,
 294                 ] );
 295         }
 296
 297         /**
 298          * @see Serializable::unserialize()
 299          * @since 1.26
 300          * @param string $serialized
 301          */
 302         public function unserialize( $serialized ) {
 303                 $data = unserialize( $serialized );
 304                 $this->interface = $data['interface'];
 305                 $this->key = $data['key'];
 306                 $this->keysToTry = $data['keysToTry'];
 307                 $this->parameters = $data['parameters'];
 308                 $this->format = $data['format'];
 309                 $this->useDatabase = $data['useDatabase'];
 310                 $this->language = $data['language'] ? Language::factory( $data['language'] ) : false;
 311
 312                 if ( isset( $data['titlestr'] ) ) {
 313                         $this->title = Title::newFromText( $data['titlestr'] );
 314                 } elseif ( isset( $data['title'] ) && $data['title'] instanceof Title ) {
 315                         // Old serializations from before December 2018
 316                         $this->title = $data['title'];
 317                 } else {
 318                         $this->title = null; // Explicit for sanity
 319                 }
 320         }
 321
 322         /**
 323          * @since 1.24
 324          *
 325          * @return bool True if this is a multi-key message, that is, if the key provided to the
 326          * constructor was a fallback list of keys to try.
 327          */
 328         public function isMultiKey() {
 329                 return count( $this->keysToTry ) > 1;
 330         }
 331
 332         /**
 333          * @since 1.24
 334          *
 335          * @return string[] The list of keys to try when fetching the message text,
 336          * in order of preference.
 337          */
 338         public function getKeysToTry() {
 339                 return $this->keysToTry;
 340         }
 341
 342         /**
 343          * Returns the message key.
 344          *
 345          * If a list of multiple possible keys was supplied to the constructor, this method may
 346          * return any of these keys. After the message has been fetched, this method will return
 347          * the key that was actually used to fetch the message.
 348          *
 349          * @since 1.21
 350          *
 351          * @return string
 352          */
 353         public function getKey() {
 354                 return $this->key;
 355         }
 356
 357         /**
 358          * Returns the message parameters.
 359          *
 360          * @since 1.21
 361          *
 362          * @return array
 363          */
 364         public function getParams() {
 365                 return $this->parameters;
 366         }
 367
 368         /**
 369          * Returns the message format.
 370          *
 371          * @since 1.21
 372          *
 373          * @return string
 374          * @deprecated since 1.29 formatting is not stateful
 375          */
 376         public function getFormat() {
 377                 wfDeprecated( __METHOD__, '1.29' );
 378                 return $this->format;
 379         }
 380
 381         /**
 382          * Returns the Language of the Message.
 383          *
 384          * @since 1.23
 385          *
 386          * @return Language
 387          */
 388         public function getLanguage() {
 389                 // Defaults to false which means current user language
 390                 return $this->language ?: RequestContext::getMain()->getLanguage();
 391         }
 392
 393         /**
 394          * Factory function that is just wrapper for the real constructor. It is
 395          * intended to be used instead of the real constructor, because it allows
 396          * chaining method calls, while new objects don't.
 397          *
 398          * @since 1.17
 399          *
 400          * @param string|string[]|MessageSpecifier $key
 401          * @param mixed $param,... Parameters as strings.
 402          *
 403          * @return Message
 404          */
 405         public static function newFromKey( $key /*...*/ ) {
 406                 $params = func_get_args();
 407                 array_shift( $params );
 408                 return new self( $key, $params );
 409         }
 410
 411         /**
 412          * Transform a MessageSpecifier or a primitive value used interchangeably with
 413          * specifiers (a message key string, or a key + params array) into a proper Message.
 414          *
 415          * Also accepts a MessageSpecifier inside an array: that's not considered a valid format
 416          * but is an easy error to make due to how StatusValue stores messages internally.
 417          * Further array elements are ignored in that case.
 418          *
 419          * @param string|array|MessageSpecifier $value
 420          * @return Message
 421          * @throws InvalidArgumentException
 422          * @since 1.27
 423          */
 424         public static function newFromSpecifier( $value ) {
 425                 $params = [];
 426                 if ( is_array( $value ) ) {
 427                         $params = $value;
 428                         $value = array_shift( $params );
 429                 }
 430
 431                 if ( $value instanceof Message ) { // Message, RawMessage, ApiMessage, etc
 432                         $message = clone $value;
 433                 } elseif ( $value instanceof MessageSpecifier ) {
 434                         $message = new Message( $value );
 435                 } elseif ( is_string( $value ) ) {
 436                         $message = new Message( $value, $params );
 437                 } else {
 438                         throw new InvalidArgumentException( __METHOD__ . ': invalid argument type '
 439                                 . gettype( $value ) );
 440                 }
 441
 442                 return $message;
 443         }
 444
 445         /**
 446          * Factory function accepting multiple message keys and returning a message instance
 447          * for the first message which is non-empty. If all messages are empty then an
 448          * instance of the first message key is returned.
 449          *
 450          * @since 1.18
 451          *
 452          * @param string|string[] $keys,... Message keys, or first argument as an array of all the
 453          * message keys.
 454          *
 455          * @return Message
 456          */
 457         public static function newFallbackSequence( /*...*/ ) {
 458                 $keys = func_get_args();
 459                 if ( func_num_args() == 1 ) {
 460                         if ( is_array( $keys[0] ) ) {
 461                                 // Allow an array to be passed as the first argument instead
 462                                 $keys = array_values( $keys[0] );
 463                         } else {
 464                                 // Optimize a single string to not need special fallback handling
 465                                 $keys = $keys[0];
 466                         }
 467                 }
 468                 return new self( $keys );
 469         }
 470
 471         /**
 472          * Get a title object for a mediawiki message, where it can be found in the mediawiki namespace.
 473          * The title will be for the current language, if the message key is in
 474          * $wgForceUIMsgAsContentMsg it will be append with the language code (except content
 475          * language), because Message::inContentLanguage will also return in user language.
 476          *
 477          * @see $wgForceUIMsgAsContentMsg
 478          * @return Title
 479          * @since 1.26
 480          */
 481         public function getTitle() {
 482                 global $wgForceUIMsgAsContentMsg;
 483
 484                 $contLang = MediaWikiServices::getInstance()->getContentLanguage();
 485                 $lang = $this->getLanguage();
 486                 $title = $this->key;
 487                 if (
 488                         !$lang->equals( $contLang )
 489                         && in_array( $this->key, (array)$wgForceUIMsgAsContentMsg )
 490                 ) {
 491                         $title .= '/' . $lang->getCode();
 492                 }
 493
 494                 return Title::makeTitle(
 495                         NS_MEDIAWIKI, $contLang->ucfirst( strtr( $title, ' ', '_' ) ) );
 496         }
 497
 498         /**
 499          * Adds parameters to the parameter list of this message.
 500          *
 501          * @since 1.17
 502          *
 503          * @param mixed $args,... Parameters as strings or arrays from
 504          *  Message::numParam() and the like, or a single array of parameters.
 505          *
 506          * @return Message $this
 507          */
 508         public function params( /*...*/ ) {
 509                 $args = func_get_args();
 510
 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( /*...*/ ) {
 546                 $params = func_get_args();
 547                 if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 548                         $params = $params[0];
 549                 }
 550                 foreach ( $params as $param ) {
 551                         $this->parameters[] = self::rawParam( $param );
 552                 }
 553                 return $this;
 554         }
 555
 556         /**
 557          * Add parameters that are numeric and will be passed through
 558          * Language::formatNum before substitution
 559          *
 560          * @since 1.18
 561          *
 562          * @param mixed $param,... Numeric parameters, or a single argument that is
 563          * an array of numeric parameters.
 564          *
 565          * @return Message $this
 566          */
 567         public function numParams( /*...*/ ) {
 568                 $params = func_get_args();
 569                 if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 570                         $params = $params[0];
 571                 }
 572                 foreach ( $params as $param ) {
 573                         $this->parameters[] = self::numParam( $param );
 574                 }
 575                 return $this;
 576         }
 577
 578         /**
 579          * Add parameters that are durations of time and will be passed through
 580          * Language::formatDuration before substitution
 581          *
 582          * @since 1.22
 583          *
 584          * @param int|int[] $param,... Duration parameters, or a single argument that is
 585          * an array of duration parameters.
 586          *
 587          * @return Message $this
 588          */
 589         public function durationParams( /*...*/ ) {
 590                 $params = func_get_args();
 591                 if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 592                         $params = $params[0];
 593                 }
 594                 foreach ( $params as $param ) {
 595                         $this->parameters[] = self::durationParam( $param );
 596                 }
 597                 return $this;
 598         }
 599
 600         /**
 601          * Add parameters that are expiration times and will be passed through
 602          * Language::formatExpiry before substitution
 603          *
 604          * @since 1.22
 605          *
 606          * @param string|string[] $param,... Expiry parameters, or a single argument that is
 607          * an array of expiry parameters.
 608          *
 609          * @return Message $this
 610          */
 611         public function expiryParams( /*...*/ ) {
 612                 $params = func_get_args();
 613                 if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 614                         $params = $params[0];
 615                 }
 616                 foreach ( $params as $param ) {
 617                         $this->parameters[] = self::expiryParam( $param );
 618                 }
 619                 return $this;
 620         }
 621
 622         /**
 623          * Add parameters that are time periods and will be passed through
 624          * Language::formatTimePeriod before substitution
 625          *
 626          * @since 1.22
 627          *
 628          * @param int|int[] $param,... Time period parameters, or a single argument that is
 629          * an array of time period parameters.
 630          *
 631          * @return Message $this
 632          */
 633         public function timeperiodParams( /*...*/ ) {
 634                 $params = func_get_args();
 635                 if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 636                         $params = $params[0];
 637                 }
 638                 foreach ( $params as $param ) {
 639                         $this->parameters[] = self::timeperiodParam( $param );
 640                 }
 641                 return $this;
 642         }
 643
 644         /**
 645          * Add parameters that are file sizes and will be passed through
 646          * Language::formatSize before substitution
 647          *
 648          * @since 1.22
 649          *
 650          * @param int|int[] $param,... Size parameters, or a single argument that is
 651          * an array of size parameters.
 652          *
 653          * @return Message $this
 654          */
 655         public function sizeParams( /*...*/ ) {
 656                 $params = func_get_args();
 657                 if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 658                         $params = $params[0];
 659                 }
 660                 foreach ( $params as $param ) {
 661                         $this->parameters[] = self::sizeParam( $param );
 662                 }
 663                 return $this;
 664         }
 665
 666         /**
 667          * Add parameters that are bitrates and will be passed through
 668          * Language::formatBitrate before substitution
 669          *
 670          * @since 1.22
 671          *
 672          * @param int|int[] $param,... Bit rate parameters, or a single argument that is
 673          * an array of bit rate parameters.
 674          *
 675          * @return Message $this
 676          */
 677         public function bitrateParams( /*...*/ ) {
 678                 $params = func_get_args();
 679                 if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 680                         $params = $params[0];
 681                 }
 682                 foreach ( $params as $param ) {
 683                         $this->parameters[] = self::bitrateParam( $param );
 684                 }
 685                 return $this;
 686         }
 687
 688         /**
 689          * Add parameters that are plaintext and will be passed through without
 690          * the content being evaluated.  Plaintext parameters are not valid as
 691          * arguments to parser functions. This differs from self::rawParams in
 692          * that the Message class handles escaping to match the output format.
 693          *
 694          * @since 1.25
 695          *
 696          * @param string|string[] $param,... plaintext parameters, or a single argument that is
 697          * an array of plaintext parameters.
 698          *
 699          * @return Message $this
 700          */
 701         public function plaintextParams( /*...*/ ) {
 702                 $params = func_get_args();
 703                 if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 704                         $params = $params[0];
 705                 }
 706                 foreach ( $params as $param ) {
 707                         $this->parameters[] = self::plaintextParam( $param );
 708                 }
 709                 return $this;
 710         }
 711
 712         /**
 713          * Set the language and the title from a context object
 714          *
 715          * @since 1.19
 716          *
 717          * @param IContextSource $context
 718          *
 719          * @return Message $this
 720          */
 721         public function setContext( IContextSource $context ) {
 722                 $this->inLanguage( $context->getLanguage() );
 723                 $this->title( $context->getTitle() );
 724                 $this->interface = true;
 725
 726                 return $this;
 727         }
 728
 729         /**
 730          * Request the message in any language that is supported.
 731          *
 732          * As a side effect interface message status is unconditionally
 733          * turned off.
 734          *
 735          * @since 1.17
 736          * @param Language|string $lang Language code or Language object.
 737          * @return Message $this
 738          * @throws MWException
 739          */
 740         public function inLanguage( $lang ) {
 741                 $previousLanguage = $this->language;
 742
 743                 if ( $lang instanceof Language ) {
 744                         $this->language = $lang;
 745                 } elseif ( is_string( $lang ) ) {
 746                         if ( !$this->language instanceof Language || $this->language->getCode() != $lang ) {
 747                                 $this->language = Language::factory( $lang );
 748                         }
 749                 } elseif ( $lang instanceof StubUserLang ) {
 750                         $this->language = false;
 751                 } else {
 752                         $type = gettype( $lang );
 753                         throw new MWException( __METHOD__ . " must be "
 754                                 . "passed a String or Language object; $type given"
 755                         );
 756                 }
 757
 758                 if ( $this->language !== $previousLanguage ) {
 759                         // The language has changed. Clear the message cache.
 760                         $this->message = null;
 761                 }
 762                 $this->interface = false;
 763                 return $this;
 764         }
 765
 766         /**
 767          * Request the message in the wiki's content language,
 768          * unless it is disabled for this message.
 769          *
 770          * @since 1.17
 771          * @see $wgForceUIMsgAsContentMsg
 772          *
 773          * @return Message $this
 774          */
 775         public function inContentLanguage() {
 776                 global $wgForceUIMsgAsContentMsg;
 777                 if ( in_array( $this->key, (array)$wgForceUIMsgAsContentMsg ) ) {
 778                         return $this;
 779                 }
 780
 781                 $this->inLanguage( MediaWikiServices::getInstance()->getContentLanguage() );
 782                 return $this;
 783         }
 784
 785         /**
 786          * Allows manipulating the interface message flag directly.
 787          * Can be used to restore the flag after setting a language.
 788          *
 789          * @since 1.20
 790          *
 791          * @param bool $interface
 792          *
 793          * @return Message $this
 794          */
 795         public function setInterfaceMessageFlag( $interface ) {
 796                 $this->interface = (bool)$interface;
 797                 return $this;
 798         }
 799
 800         /**
 801          * Enable or disable database use.
 802          *
 803          * @since 1.17
 804          *
 805          * @param bool $useDatabase
 806          *
 807          * @return Message $this
 808          */
 809         public function useDatabase( $useDatabase ) {
 810                 $this->useDatabase = (bool)$useDatabase;
 811                 $this->message = null;
 812                 return $this;
 813         }
 814
 815         /**
 816          * Set the Title object to use as context when transforming the message
 817          *
 818          * @since 1.18
 819          *
 820          * @param Title $title
 821          *
 822          * @return Message $this
 823          */
 824         public function title( $title ) {
 825                 $this->title = $title;
 826                 return $this;
 827         }
 828
 829         /**
 830          * Returns the message as a Content object.
 831          *
 832          * @return Content
 833          */
 834         public function content() {
 835                 if ( !$this->content ) {
 836                         $this->content = new MessageContent( $this );
 837                 }
 838
 839                 return $this->content;
 840         }
 841
 842         /**
 843          * Returns the message parsed from wikitext to HTML.
 844          *
 845          * @since 1.17
 846          *
 847          * @param string|null $format One of the FORMAT_* constants. Null means use whatever was used
 848          *   the last time (this is for B/C and should be avoided).
 849          *
 850          * @return string HTML
 851          * @suppress SecurityCheck-DoubleEscaped phan false positive
 852          */
 853         public function toString( $format = null ) {
 854                 if ( $format === null ) {
 855                         $ex = new LogicException( __METHOD__ . ' using implicit format: ' . $this->format );
 856                         \MediaWiki\Logger\LoggerFactory::getInstance( 'message-format' )->warning(
 857                                 $ex->getMessage(), [ 'exception' => $ex, 'format' => $this->format, 'key' => $this->key ] );
 858                         $format = $this->format;
 859                 }
 860                 $string = $this->fetchMessage();
 861
 862                 if ( $string === false ) {
 863                         // Err on the side of safety, ensure that the output
 864                         // is always html safe in the event the message key is
 865                         // missing, since in that case its highly likely the
 866                         // message key is user-controlled.
 867                         // '⧼' is used instead of '<' to side-step any
 868                         // double-escaping issues.
 869                         // (Keep synchronised with mw.Message#toString in JS.)
 870                         return '⧼' . htmlspecialchars( $this->key ) . '⧽';
 871                 }
 872
 873                 # Replace $* with a list of parameters for &uselang=qqx.
 874                 if ( strpos( $string, '$*' ) !== false ) {
 875                         $paramlist = '';
 876                         if ( $this->parameters !== [] ) {
 877                                 $paramlist = ': $' . implode( ', $', range( 1, count( $this->parameters ) ) );
 878                         }
 879                         $string = str_replace( '$*', $paramlist, $string );
 880                 }
 881
 882                 # Replace parameters before text parsing
 883                 $string = $this->replaceParameters( $string, 'before', $format );
 884
 885                 # Maybe transform using the full parser
 886                 if ( $format === self::FORMAT_PARSE ) {
 887                         $string = $this->parseText( $string );
 888                         $string = Parser::stripOuterParagraph( $string );
 889                 } elseif ( $format === self::FORMAT_BLOCK_PARSE ) {
 890                         $string = $this->parseText( $string );
 891                 } elseif ( $format === self::FORMAT_TEXT ) {
 892                         $string = $this->transformText( $string );
 893                 } elseif ( $format === self::FORMAT_ESCAPED ) {
 894                         $string = $this->transformText( $string );
 895                         $string = htmlspecialchars( $string, ENT_QUOTES, 'UTF-8', false );
 896                 }
 897
 898                 # Raw parameter replacement
 899                 $string = $this->replaceParameters( $string, 'after', $format );
 900
 901                 return $string;
 902         }
 903
 904         /**
 905          * Magic method implementation of the above (for PHP >= 5.2.0), so we can do, eg:
 906          *     $foo = new Message( $key );
 907          *     $string = "<abbr>$foo</abbr>";
 908          *
 909          * @since 1.18
 910          *
 911          * @return string
 912          */
 913         public function __toString() {
 914                 // PHP doesn't allow __toString to throw exceptions and will
 915                 // trigger a fatal error if it does. So, catch any exceptions.
 916
 917                 try {
 918                         return $this->toString( self::FORMAT_PARSE );
 919                 } catch ( Exception $ex ) {
 920                         try {
 921                                 trigger_error( "Exception caught in " . __METHOD__ . " (message " . $this->key . "): "
 922                                         . $ex, E_USER_WARNING );
 923                         } catch ( Exception $ex ) {
 924                                 // Doh! Cause a fatal error after all?
 925                         }
 926
 927                         return '⧼' . htmlspecialchars( $this->key ) . '⧽';
 928                 }
 929         }
 930
 931         /**
 932          * Fully parse the text from wikitext to HTML.
 933          *
 934          * @since 1.17
 935          *
 936          * @return string Parsed HTML.
 937          */
 938         public function parse() {
 939                 $this->format = self::FORMAT_PARSE;
 940                 return $this->toString( self::FORMAT_PARSE );
 941         }
 942
 943         /**
 944          * Returns the message text. {{-transformation is done.
 945          *
 946          * @since 1.17
 947          *
 948          * @return string Unescaped message text.
 949          */
 950         public function text() {
 951                 $this->format = self::FORMAT_TEXT;
 952                 return $this->toString( self::FORMAT_TEXT );
 953         }
 954
 955         /**
 956          * Returns the message text as-is, only parameters are substituted.
 957          *
 958          * @since 1.17
 959          *
 960          * @return string Unescaped untransformed message text.
 961          */
 962         public function plain() {
 963                 $this->format = self::FORMAT_PLAIN;
 964                 return $this->toString( self::FORMAT_PLAIN );
 965         }
 966
 967         /**
 968          * Returns the parsed message text which is always surrounded by a block element.
 969          *
 970          * @since 1.17
 971          *
 972          * @return string HTML
 973          */
 974         public function parseAsBlock() {
 975                 $this->format = self::FORMAT_BLOCK_PARSE;
 976                 return $this->toString( self::FORMAT_BLOCK_PARSE );
 977         }
 978
 979         /**
 980          * Returns the message text. {{-transformation is done and the result
 981          * is escaped excluding any raw parameters.
 982          *
 983          * @since 1.17
 984          *
 985          * @return string Escaped message text.
 986          */
 987         public function escaped() {
 988                 $this->format = self::FORMAT_ESCAPED;
 989                 return $this->toString( self::FORMAT_ESCAPED );
 990         }
 991
 992         /**
 993          * Check whether a message key has been defined currently.
 994          *
 995          * @since 1.17
 996          *
 997          * @return bool
 998          */
 999         public function exists() {
1000                 return $this->fetchMessage() !== false;
1001         }
1002
1003         /**
1004          * Check whether a message does not exist, or is an empty string
1005          *
1006          * @since 1.18
1007          * @todo FIXME: Merge with isDisabled()?
1008          *
1009          * @return bool
1010          */
1011         public function isBlank() {
1012                 $message = $this->fetchMessage();
1013                 return $message === false || $message === '';
1014         }
1015
1016         /**
1017          * Check whether a message does not exist, is an empty string, or is "-".
1018          *
1019          * @since 1.18
1020          *
1021          * @return bool
1022          */
1023         public function isDisabled() {
1024                 $message = $this->fetchMessage();
1025                 return $message === false || $message === '' || $message === '-';
1026         }
1027
1028         /**
1029          * @since 1.17
1030          *
1031          * @param mixed $raw
1032          *
1033          * @return array Array with a single "raw" key.
1034          */
1035         public static function rawParam( $raw ) {
1036                 return [ 'raw' => $raw ];
1037         }
1038
1039         /**
1040          * @since 1.18
1041          *
1042          * @param mixed $num
1043          *
1044          * @return array Array with a single "num" key.
1045          */
1046         public static function numParam( $num ) {
1047                 return [ 'num' => $num ];
1048         }
1049
1050         /**
1051          * @since 1.22
1052          *
1053          * @param int $duration
1054          *
1055          * @return int[] Array with a single "duration" key.
1056          */
1057         public static function durationParam( $duration ) {
1058                 return [ 'duration' => $duration ];
1059         }
1060
1061         /**
1062          * @since 1.22
1063          *
1064          * @param string $expiry
1065          *
1066          * @return string[] Array with a single "expiry" key.
1067          */
1068         public static function expiryParam( $expiry ) {
1069                 return [ 'expiry' => $expiry ];
1070         }
1071
1072         /**
1073          * @since 1.22
1074          *
1075          * @param int $period
1076          *
1077          * @return int[] Array with a single "period" key.
1078          */
1079         public static function timeperiodParam( $period ) {
1080                 return [ 'period' => $period ];
1081         }
1082
1083         /**
1084          * @since 1.22
1085          *
1086          * @param int $size
1087          *
1088          * @return int[] Array with a single "size" key.
1089          */
1090         public static function sizeParam( $size ) {
1091                 return [ 'size' => $size ];
1092         }
1093
1094         /**
1095          * @since 1.22
1096          *
1097          * @param int $bitrate
1098          *
1099          * @return int[] Array with a single "bitrate" key.
1100          */
1101         public static function bitrateParam( $bitrate ) {
1102                 return [ 'bitrate' => $bitrate ];
1103         }
1104
1105         /**
1106          * @since 1.25
1107          *
1108          * @param string $plaintext
1109          *
1110          * @return string[] Array with a single "plaintext" key.
1111          */
1112         public static function plaintextParam( $plaintext ) {
1113                 return [ 'plaintext' => $plaintext ];
1114         }
1115
1116         /**
1117          * @since 1.29
1118          *
1119          * @param array $list
1120          * @param string $type 'comma', 'semicolon', 'pipe', 'text'
1121          * @return array Array with "list" and "type" keys.
1122          */
1123         public static function listParam( array $list, $type = 'text' ) {
1124                 if ( !isset( self::$listTypeMap[$type] ) ) {
1125                         throw new InvalidArgumentException(
1126                                 "Invalid type '$type'. Known types are: " . implode( ', ', array_keys( self::$listTypeMap ) )
1127                         );
1128                 }
1129                 return [ 'list' => $list, 'type' => $type ];
1130         }
1131
1132         /**
1133          * Substitutes any parameters into the message text.
1134          *
1135          * @since 1.17
1136          *
1137          * @param string $message The message text.
1138          * @param string $type Either "before" or "after".
1139          * @param string $format One of the FORMAT_* constants.
1140          *
1141          * @return string
1142          */
1143         protected function replaceParameters( $message, $type, $format ) {
1144                 // A temporary marker for $1 parameters that is only valid
1145                 // in non-attribute contexts. However if the entire message is escaped
1146                 // then we don't want to use it because it will be mangled in all contexts
1147                 // and its unnessary as ->escaped() messages aren't html.
1148                 $marker = $format === self::FORMAT_ESCAPED ? '$' : '$\'"';
1149                 $replacementKeys = [];
1150                 foreach ( $this->parameters as $n => $param ) {
1151                         list( $paramType, $value ) = $this->extractParam( $param, $format );
1152                         if ( $type === 'before' ) {
1153                                 if ( $paramType === 'before' ) {
1154                                         $replacementKeys['$' . ( $n + 1 )] = $value;
1155                                 } else /* $paramType === 'after' */ {
1156                                         // To protect against XSS from replacing parameters
1157                                         // inside html attributes, we convert $1 to $'"1.
1158                                         // In the event that one of the parameters ends up
1159                                         // in an attribute, either the ' or the " will be
1160                                         // escaped, breaking the replacement and avoiding XSS.
1161                                         $replacementKeys['$' . ( $n + 1 )] = $marker . ( $n + 1 );
1162                                 }
1163                         } else {
1164                                 if ( $paramType === 'after' ) {
1165                                         $replacementKeys[$marker . ( $n + 1 )] = $value;
1166                                 }
1167                         }
1168                 }
1169                 $message = strtr( $message, $replacementKeys );
1170                 return $message;
1171         }
1172
1173         /**
1174          * Extracts the parameter type and preprocessed the value if needed.
1175          *
1176          * @since 1.18
1177          *
1178          * @param mixed $param Parameter as defined in this class.
1179          * @param string $format One of the FORMAT_* constants.
1180          *
1181          * @return array Array with the parameter type (either "before" or "after") and the value.
1182          */
1183         protected function extractParam( $param, $format ) {
1184                 if ( is_array( $param ) ) {
1185                         if ( isset( $param['raw'] ) ) {
1186                                 return [ 'after', $param['raw'] ];
1187                         } elseif ( isset( $param['num'] ) ) {
1188                                 // Replace number params always in before step for now.
1189                                 // No support for combined raw and num params
1190                                 return [ 'before', $this->getLanguage()->formatNum( $param['num'] ) ];
1191                         } elseif ( isset( $param['duration'] ) ) {
1192                                 return [ 'before', $this->getLanguage()->formatDuration( $param['duration'] ) ];
1193                         } elseif ( isset( $param['expiry'] ) ) {
1194                                 return [ 'before', $this->getLanguage()->formatExpiry( $param['expiry'] ) ];
1195                         } elseif ( isset( $param['period'] ) ) {
1196                                 return [ 'before', $this->getLanguage()->formatTimePeriod( $param['period'] ) ];
1197                         } elseif ( isset( $param['size'] ) ) {
1198                                 return [ 'before', $this->getLanguage()->formatSize( $param['size'] ) ];
1199                         } elseif ( isset( $param['bitrate'] ) ) {
1200                                 return [ 'before', $this->getLanguage()->formatBitrate( $param['bitrate'] ) ];
1201                         } elseif ( isset( $param['plaintext'] ) ) {
1202                                 return [ 'after', $this->formatPlaintext( $param['plaintext'], $format ) ];
1203                         } elseif ( isset( $param['list'] ) ) {
1204                                 return $this->formatListParam( $param['list'], $param['type'], $format );
1205                         } else {
1206                                 if ( !is_scalar( $param ) ) {
1207                                         $param = serialize( $param );
1208                                 }
1209                                 \MediaWiki\Logger\LoggerFactory::getInstance( 'Bug58676' )->warning(
1210                                         'Invalid parameter for message "{msgkey}": {param}',
1211                                         [
1212                                                 'exception' => new Exception,
1213                                                 'msgkey' => $this->getKey(),
1214                                                 'param' => htmlspecialchars( $param ),
1215                                         ]
1216                                 );
1217
1218                                 return [ 'before', '[INVALID]' ];
1219                         }
1220                 } elseif ( $param instanceof Message ) {
1221                         // Match language, flags, etc. to the current message.
1222                         $msg = clone $param;
1223                         if ( $msg->language !== $this->language || $msg->useDatabase !== $this->useDatabase ) {
1224                                 // Cache depends on these parameters
1225                                 $msg->message = null;
1226                         }
1227                         $msg->interface = $this->interface;
1228                         $msg->language = $this->language;
1229                         $msg->useDatabase = $this->useDatabase;
1230                         $msg->title = $this->title;
1231
1232                         // DWIM
1233                         if ( $format === 'block-parse' ) {
1234                                 $format = 'parse';
1235                         }
1236                         $msg->format = $format;
1237
1238                         // Message objects should not be before parameters because
1239                         // then they'll get double escaped. If the message needs to be
1240                         // escaped, it'll happen right here when we call toString().
1241                         return [ 'after', $msg->toString( $format ) ];
1242                 } else {
1243                         return [ 'before', $param ];
1244                 }
1245         }
1246
1247         /**
1248          * Wrapper for what ever method we use to parse wikitext.
1249          *
1250          * @since 1.17
1251          *
1252          * @param string $string Wikitext message contents.
1253          *
1254          * @return string Wikitext parsed into HTML.
1255          */
1256         protected function parseText( $string ) {
1257                 $out = MessageCache::singleton()->parse(
1258                         $string,
1259                         $this->title,
1260                         /*linestart*/true,
1261                         $this->interface,
1262                         $this->getLanguage()
1263                 );
1264
1265                 return $out instanceof ParserOutput
1266                         ? $out->getText( [
1267                                 'enableSectionEditLinks' => false,
1268                                 // Wrapping messages in an extra <div> is probably not expected. If
1269                                 // they're outside the content area they probably shouldn't be
1270                                 // targeted by CSS that's targeting the parser output, and if
1271                                 // they're inside they already are from the outer div.
1272                                 'unwrap' => true,
1273                         ] )
1274                         : $out;
1275         }
1276
1277         /**
1278          * Wrapper for what ever method we use to {{-transform wikitext.
1279          *
1280          * @since 1.17
1281          *
1282          * @param string $string Wikitext message contents.
1283          *
1284          * @return string Wikitext with {{-constructs replaced with their values.
1285          */
1286         protected function transformText( $string ) {
1287                 return MessageCache::singleton()->transform(
1288                         $string,
1289                         $this->interface,
1290                         $this->getLanguage(),
1291                         $this->title
1292                 );
1293         }
1294
1295         /**
1296          * Wrapper for what ever method we use to get message contents.
1297          *
1298          * @since 1.17
1299          *
1300          * @return string
1301          * @throws MWException If message key array is empty.
1302          */
1303         protected function fetchMessage() {
1304                 if ( $this->message === null ) {
1305                         $cache = MessageCache::singleton();
1306
1307                         foreach ( $this->keysToTry as $key ) {
1308                                 $message = $cache->get( $key, $this->useDatabase, $this->getLanguage() );
1309                                 if ( $message !== false && $message !== '' ) {
1310                                         break;
1311                                 }
1312                         }
1313
1314                         // NOTE: The constructor makes sure keysToTry isn't empty,
1315                         //       so we know that $key and $message are initialized.
1316                         $this->key = $key;
1317                         $this->message = $message;
1318                 }
1319                 return $this->message;
1320         }
1321
1322         /**
1323          * Formats a message parameter wrapped with 'plaintext'. Ensures that
1324          * the entire string is displayed unchanged when displayed in the output
1325          * format.
1326          *
1327          * @since 1.25
1328          *
1329          * @param string $plaintext String to ensure plaintext output of
1330          * @param string $format One of the FORMAT_* constants.
1331          *
1332          * @return string Input plaintext encoded for output to $format
1333          */
1334         protected function formatPlaintext( $plaintext, $format ) {
1335                 switch ( $format ) {
1336                         case self::FORMAT_TEXT:
1337                         case self::FORMAT_PLAIN:
1338                                 return $plaintext;
1339
1340                         case self::FORMAT_PARSE:
1341                         case self::FORMAT_BLOCK_PARSE:
1342                         case self::FORMAT_ESCAPED:
1343                         default:
1344                                 return htmlspecialchars( $plaintext, ENT_QUOTES );
1345                 }
1346         }
1347
1348         /**
1349          * Formats a list of parameters as a concatenated string.
1350          * @since 1.29
1351          * @param array $params
1352          * @param string $listType
1353          * @param string $format One of the FORMAT_* constants.
1354          * @return array Array with the parameter type (either "before" or "after") and the value.
1355          */
1356         protected function formatListParam( array $params, $listType, $format ) {
1357                 if ( !isset( self::$listTypeMap[$listType] ) ) {
1358                         $warning = 'Invalid list type for message "' . $this->getKey() . '": '
1359                                 . htmlspecialchars( $listType )
1360                                 . ' (params are ' . htmlspecialchars( serialize( $params ) ) . ')';
1361                         trigger_error( $warning, E_USER_WARNING );
1362                         $e = new Exception;
1363                         wfDebugLog( 'Bug58676', $warning . "\n" . $e->getTraceAsString() );
1364                         return [ 'before', '[INVALID]' ];
1365                 }
1366                 $func = self::$listTypeMap[$listType];
1367
1368                 // Handle an empty list sensibly
1369                 if ( !$params ) {
1370                         return [ 'before', $this->getLanguage()->$func( [] ) ];
1371                 }
1372
1373                 // First, determine what kinds of list items we have
1374                 $types = [];
1375                 $vars = [];
1376                 $list = [];
1377                 foreach ( $params as $n => $p ) {
1378                         list( $type, $value ) = $this->extractParam( $p, $format );
1379                         $types[$type] = true;
1380                         $list[] = $value;
1381                         $vars[] = '$' . ( $n + 1 );
1382                 }
1383
1384                 // Easy case: all are 'before' or 'after', so just join the
1385                 // values and use the same type.
1386                 if ( count( $types ) === 1 ) {
1387                         return [ key( $types ), $this->getLanguage()->$func( $list ) ];
1388                 }
1389
1390                 // Hard case: We need to process each value per its type, then
1391                 // return the concatenated values as 'after'. We handle this by turning
1392                 // the list into a RawMessage and processing that as a parameter.
1393                 $vars = $this->getLanguage()->$func( $vars );
1394                 return $this->extractParam( new RawMessage( $vars, $params ), $format );
1395         }
1396 }