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