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 = array();
 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 = array(), 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( array(
 273                         'interface' => $this->interface,
 274                         'language' => $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                 $data = unserialize( $serialized );
 291                 $this->interface = $data['interface'];
 292                 $this->key = $data['key'];
 293                 $this->keysToTry = $data['keysToTry'];
 294                 $this->parameters = $data['parameters'];
 295                 $this->format = $data['format'];
 296                 $this->useDatabase = $data['useDatabase'];
 297                 $this->language = Language::factory( $data['language'] );
 298                 $this->title = $data['title'];
 299         }
 300
 301         /**
 302          * @since 1.24
 303          *
 304          * @return bool True if this is a multi-key message, that is, if the key provided to the
 305          * constructor was a fallback list of keys to try.
 306          */
 307         public function isMultiKey() {
 308                 return count( $this->keysToTry ) > 1;
 309         }
 310
 311         /**
 312          * @since 1.24
 313          *
 314          * @return string[] The list of keys to try when fetching the message text,
 315          * in order of preference.
 316          */
 317         public function getKeysToTry() {
 318                 return $this->keysToTry;
 319         }
 320
 321         /**
 322          * Returns the message key.
 323          *
 324          * If a list of multiple possible keys was supplied to the constructor, this method may
 325          * return any of these keys. After the message has been fetched, this method will return
 326          * the key that was actually used to fetch the message.
 327          *
 328          * @since 1.21
 329          *
 330          * @return string
 331          */
 332         public function getKey() {
 333                 return $this->key;
 334         }
 335
 336         /**
 337          * Returns the message parameters.
 338          *
 339          * @since 1.21
 340          *
 341          * @return array
 342          */
 343         public function getParams() {
 344                 return $this->parameters;
 345         }
 346
 347         /**
 348          * Returns the message format.
 349          *
 350          * @since 1.21
 351          *
 352          * @return string
 353          */
 354         public function getFormat() {
 355                 return $this->format;
 356         }
 357
 358         /**
 359          * Returns the Language of the Message.
 360          *
 361          * @since 1.23
 362          *
 363          * @return Language
 364          */
 365         public function getLanguage() {
 366                 return $this->language;
 367         }
 368
 369         /**
 370          * Factory function that is just wrapper for the real constructor. It is
 371          * intended to be used instead of the real constructor, because it allows
 372          * chaining method calls, while new objects don't.
 373          *
 374          * @since 1.17
 375          *
 376          * @param string|string[]|MessageSpecifier $key
 377          * @param mixed $param,... Parameters as strings.
 378          *
 379          * @return Message
 380          */
 381         public static function newFromKey( $key /*...*/ ) {
 382                 $params = func_get_args();
 383                 array_shift( $params );
 384                 return new self( $key, $params );
 385         }
 386
 387         /**
 388          * Factory function accepting multiple message keys and returning a message instance
 389          * for the first message which is non-empty. If all messages are empty then an
 390          * instance of the first message key is returned.
 391          *
 392          * @since 1.18
 393          *
 394          * @param string|string[] $keys,... Message keys, or first argument as an array of all the
 395          * message keys.
 396          *
 397          * @return Message
 398          */
 399         public static function newFallbackSequence( /*...*/ ) {
 400                 $keys = func_get_args();
 401                 if ( func_num_args() == 1 ) {
 402                         if ( is_array( $keys[0] ) ) {
 403                                 // Allow an array to be passed as the first argument instead
 404                                 $keys = array_values( $keys[0] );
 405                         } else {
 406                                 // Optimize a single string to not need special fallback handling
 407                                 $keys = $keys[0];
 408                         }
 409                 }
 410                 return new self( $keys );
 411         }
 412
 413         /**
 414          * Get a title object for a mediawiki message, where it can be found in the mediawiki namespace.
 415          * The title will be for the current language, if the message key is in
 416          * $wgForceUIMsgAsContentMsg it will be append with the language code (except content
 417          * language), because Message::inContentLanguage will also return in user language.
 418          *
 419          * @see $wgForceUIMsgAsContentMsg
 420          * @return Title
 421          * @since 1.26
 422          */
 423         public function getTitle() {
 424                 global $wgContLang, $wgForceUIMsgAsContentMsg;
 425
 426                 $code = $this->language->getCode();
 427                 $title = $this->key;
 428                 if (
 429                         $wgContLang->getCode() !== $code
 430                         && in_array( $this->key, (array)$wgForceUIMsgAsContentMsg )
 431                 ) {
 432                         $title .= '/' . $code;
 433                 }
 434
 435                 return Title::makeTitle( NS_MEDIAWIKI, $wgContLang->ucfirst( strtr( $title, ' ', '_' ) ) );
 436         }
 437
 438         /**
 439          * Adds parameters to the parameter list of this message.
 440          *
 441          * @since 1.17
 442          *
 443          * @param mixed $params,... Parameters as strings, or a single argument that is
 444          * an array of strings.
 445          *
 446          * @return Message $this
 447          */
 448         public function params( /*...*/ ) {
 449                 $args = func_get_args();
 450                 if ( isset( $args[0] ) && is_array( $args[0] ) ) {
 451                         $args = $args[0];
 452                 }
 453                 $args_values = array_values( $args );
 454                 $this->parameters = array_merge( $this->parameters, $args_values );
 455                 return $this;
 456         }
 457
 458         /**
 459          * Add parameters that are substituted after parsing or escaping.
 460          * In other words the parsing process cannot access the contents
 461          * of this type of parameter, and you need to make sure it is
 462          * sanitized beforehand.  The parser will see "$n", instead.
 463          *
 464          * @since 1.17
 465          *
 466          * @param mixed $params,... Raw parameters as strings, or a single argument that is
 467          * an array of raw parameters.
 468          *
 469          * @return Message $this
 470          */
 471         public function rawParams( /*...*/ ) {
 472                 $params = func_get_args();
 473                 if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 474                         $params = $params[0];
 475                 }
 476                 foreach ( $params as $param ) {
 477                         $this->parameters[] = self::rawParam( $param );
 478                 }
 479                 return $this;
 480         }
 481
 482         /**
 483          * Add parameters that are numeric and will be passed through
 484          * Language::formatNum before substitution
 485          *
 486          * @since 1.18
 487          *
 488          * @param mixed $param,... Numeric parameters, or a single argument that is
 489          * an array of numeric parameters.
 490          *
 491          * @return Message $this
 492          */
 493         public function numParams( /*...*/ ) {
 494                 $params = func_get_args();
 495                 if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 496                         $params = $params[0];
 497                 }
 498                 foreach ( $params as $param ) {
 499                         $this->parameters[] = self::numParam( $param );
 500                 }
 501                 return $this;
 502         }
 503
 504         /**
 505          * Add parameters that are durations of time and will be passed through
 506          * Language::formatDuration before substitution
 507          *
 508          * @since 1.22
 509          *
 510          * @param int|int[] $param,... Duration parameters, or a single argument that is
 511          * an array of duration parameters.
 512          *
 513          * @return Message $this
 514          */
 515         public function durationParams( /*...*/ ) {
 516                 $params = func_get_args();
 517                 if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 518                         $params = $params[0];
 519                 }
 520                 foreach ( $params as $param ) {
 521                         $this->parameters[] = self::durationParam( $param );
 522                 }
 523                 return $this;
 524         }
 525
 526         /**
 527          * Add parameters that are expiration times and will be passed through
 528          * Language::formatExpiry before substitution
 529          *
 530          * @since 1.22
 531          *
 532          * @param string|string[] $param,... Expiry parameters, or a single argument that is
 533          * an array of expiry parameters.
 534          *
 535          * @return Message $this
 536          */
 537         public function expiryParams( /*...*/ ) {
 538                 $params = func_get_args();
 539                 if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 540                         $params = $params[0];
 541                 }
 542                 foreach ( $params as $param ) {
 543                         $this->parameters[] = self::expiryParam( $param );
 544                 }
 545                 return $this;
 546         }
 547
 548         /**
 549          * Add parameters that are time periods and will be passed through
 550          * Language::formatTimePeriod before substitution
 551          *
 552          * @since 1.22
 553          *
 554          * @param int|int[] $param,... Time period parameters, or a single argument that is
 555          * an array of time period parameters.
 556          *
 557          * @return Message $this
 558          */
 559         public function timeperiodParams( /*...*/ ) {
 560                 $params = func_get_args();
 561                 if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 562                         $params = $params[0];
 563                 }
 564                 foreach ( $params as $param ) {
 565                         $this->parameters[] = self::timeperiodParam( $param );
 566                 }
 567                 return $this;
 568         }
 569
 570         /**
 571          * Add parameters that are file sizes and will be passed through
 572          * Language::formatSize before substitution
 573          *
 574          * @since 1.22
 575          *
 576          * @param int|int[] $param,... Size parameters, or a single argument that is
 577          * an array of size parameters.
 578          *
 579          * @return Message $this
 580          */
 581         public function sizeParams( /*...*/ ) {
 582                 $params = func_get_args();
 583                 if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 584                         $params = $params[0];
 585                 }
 586                 foreach ( $params as $param ) {
 587                         $this->parameters[] = self::sizeParam( $param );
 588                 }
 589                 return $this;
 590         }
 591
 592         /**
 593          * Add parameters that are bitrates and will be passed through
 594          * Language::formatBitrate before substitution
 595          *
 596          * @since 1.22
 597          *
 598          * @param int|int[] $param,... Bit rate parameters, or a single argument that is
 599          * an array of bit rate parameters.
 600          *
 601          * @return Message $this
 602          */
 603         public function bitrateParams( /*...*/ ) {
 604                 $params = func_get_args();
 605                 if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 606                         $params = $params[0];
 607                 }
 608                 foreach ( $params as $param ) {
 609                         $this->parameters[] = self::bitrateParam( $param );
 610                 }
 611                 return $this;
 612         }
 613
 614         /**
 615          * Add parameters that are plaintext and will be passed through without
 616          * the content being evaluated.  Plaintext parameters are not valid as
 617          * arguments to parser functions. This differs from self::rawParams in
 618          * that the Message class handles escaping to match the output format.
 619          *
 620          * @since 1.25
 621          *
 622          * @param string|string[] $param,... plaintext parameters, or a single argument that is
 623          * an array of plaintext parameters.
 624          *
 625          * @return Message $this
 626          */
 627         public function plaintextParams( /*...*/ ) {
 628                 $params = func_get_args();
 629                 if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 630                         $params = $params[0];
 631                 }
 632                 foreach ( $params as $param ) {
 633                         $this->parameters[] = self::plaintextParam( $param );
 634                 }
 635                 return $this;
 636         }
 637
 638         /**
 639          * Set the language and the title from a context object
 640          *
 641          * @since 1.19
 642          *
 643          * @param IContextSource $context
 644          *
 645          * @return Message $this
 646          */
 647         public function setContext( IContextSource $context ) {
 648                 $this->inLanguage( $context->getLanguage() );
 649                 $this->title( $context->getTitle() );
 650                 $this->interface = true;
 651
 652                 return $this;
 653         }
 654
 655         /**
 656          * Request the message in any language that is supported.
 657          * As a side effect interface message status is unconditionally
 658          * turned off.
 659          *
 660          * @since 1.17
 661          *
 662          * @param Language|string $lang Language code or Language object.
 663          *
 664          * @return Message $this
 665          * @throws MWException
 666          */
 667         public function inLanguage( $lang ) {
 668                 if ( $lang instanceof Language || $lang instanceof StubUserLang ) {
 669                         $this->language = $lang;
 670                 } elseif ( is_string( $lang ) ) {
 671                         if ( !$this->language instanceof Language || $this->language->getCode() != $lang ) {
 672                                 $this->language = Language::factory( $lang );
 673                         }
 674                 } else {
 675                         $type = gettype( $lang );
 676                         throw new MWException( __METHOD__ . " must be "
 677                                 . "passed a String or Language object; $type given"
 678                         );
 679                 }
 680                 $this->message = null;
 681                 $this->interface = false;
 682                 return $this;
 683         }
 684
 685         /**
 686          * Request the message in the wiki's content language,
 687          * unless it is disabled for this message.
 688          *
 689          * @since 1.17
 690          * @see $wgForceUIMsgAsContentMsg
 691          *
 692          * @return Message $this
 693          */
 694         public function inContentLanguage() {
 695                 global $wgForceUIMsgAsContentMsg;
 696                 if ( in_array( $this->key, (array)$wgForceUIMsgAsContentMsg ) ) {
 697                         return $this;
 698                 }
 699
 700                 global $wgContLang;
 701                 $this->inLanguage( $wgContLang );
 702                 return $this;
 703         }
 704
 705         /**
 706          * Allows manipulating the interface message flag directly.
 707          * Can be used to restore the flag after setting a language.
 708          *
 709          * @since 1.20
 710          *
 711          * @param bool $interface
 712          *
 713          * @return Message $this
 714          */
 715         public function setInterfaceMessageFlag( $interface ) {
 716                 $this->interface = (bool)$interface;
 717                 return $this;
 718         }
 719
 720         /**
 721          * Enable or disable database use.
 722          *
 723          * @since 1.17
 724          *
 725          * @param bool $useDatabase
 726          *
 727          * @return Message $this
 728          */
 729         public function useDatabase( $useDatabase ) {
 730                 $this->useDatabase = (bool)$useDatabase;
 731                 return $this;
 732         }
 733
 734         /**
 735          * Set the Title object to use as context when transforming the message
 736          *
 737          * @since 1.18
 738          *
 739          * @param Title $title
 740          *
 741          * @return Message $this
 742          */
 743         public function title( $title ) {
 744                 $this->title = $title;
 745                 return $this;
 746         }
 747
 748         /**
 749          * Returns the message as a Content object.
 750          *
 751          * @return Content
 752          */
 753         public function content() {
 754                 if ( !$this->content ) {
 755                         $this->content = new MessageContent( $this );
 756                 }
 757
 758                 return $this->content;
 759         }
 760
 761         /**
 762          * Returns the message parsed from wikitext to HTML.
 763          *
 764          * @since 1.17
 765          *
 766          * @return string HTML
 767          */
 768         public function toString() {
 769                 $string = $this->fetchMessage();
 770
 771                 if ( $string === false ) {
 772                         if ( $this->format === 'plain' || $this->format === 'text' ) {
 773                                 return '<' . $this->key . '>';
 774                         }
 775                         return '&lt;' . htmlspecialchars( $this->key ) . '&gt;';
 776                 }
 777
 778                 # Replace $* with a list of parameters for &uselang=qqx.
 779                 if ( strpos( $string, '$*' ) !== false ) {
 780                         $paramlist = '';
 781                         if ( $this->parameters !== array() ) {
 782                                 $paramlist = ': $' . implode( ', $', range( 1, count( $this->parameters ) ) );
 783                         }
 784                         $string = str_replace( '$*', $paramlist, $string );
 785                 }
 786
 787                 # Replace parameters before text parsing
 788                 $string = $this->replaceParameters( $string, 'before' );
 789
 790                 # Maybe transform using the full parser
 791                 if ( $this->format === 'parse' ) {
 792                         $string = $this->parseText( $string );
 793                         $string = Parser::stripOuterParagraph( $string );
 794                 } elseif ( $this->format === 'block-parse' ) {
 795                         $string = $this->parseText( $string );
 796                 } elseif ( $this->format === 'text' ) {
 797                         $string = $this->transformText( $string );
 798                 } elseif ( $this->format === 'escaped' ) {
 799                         $string = $this->transformText( $string );
 800                         $string = htmlspecialchars( $string, ENT_QUOTES, 'UTF-8', false );
 801                 }
 802
 803                 # Raw parameter replacement
 804                 $string = $this->replaceParameters( $string, 'after' );
 805
 806                 return $string;
 807         }
 808
 809         /**
 810          * Magic method implementation of the above (for PHP >= 5.2.0), so we can do, eg:
 811          *     $foo = Message::get( $key );
 812          *     $string = "<abbr>$foo</abbr>";
 813          *
 814          * @since 1.18
 815          *
 816          * @return string
 817          */
 818         public function __toString() {
 819                 // PHP doesn't allow __toString to throw exceptions and will
 820                 // trigger a fatal error if it does. So, catch any exceptions.
 821
 822                 try {
 823                         return $this->toString();
 824                 } catch ( Exception $ex ) {
 825                         try {
 826                                 trigger_error( "Exception caught in " . __METHOD__ . " (message " . $this->key . "): "
 827                                         . $ex, E_USER_WARNING );
 828                         } catch ( Exception $ex ) {
 829                                 // Doh! Cause a fatal error after all?
 830                         }
 831
 832                         if ( $this->format === 'plain' || $this->format === 'text' ) {
 833                                 return '<' . $this->key . '>';
 834                         }
 835                         return '&lt;' . htmlspecialchars( $this->key ) . '&gt;';
 836                 }
 837         }
 838
 839         /**
 840          * Fully parse the text from wikitext to HTML.
 841          *
 842          * @since 1.17
 843          *
 844          * @return string Parsed HTML.
 845          */
 846         public function parse() {
 847                 $this->format = 'parse';
 848                 return $this->toString();
 849         }
 850
 851         /**
 852          * Returns the message text. {{-transformation is done.
 853          *
 854          * @since 1.17
 855          *
 856          * @return string Unescaped message text.
 857          */
 858         public function text() {
 859                 $this->format = 'text';
 860                 return $this->toString();
 861         }
 862
 863         /**
 864          * Returns the message text as-is, only parameters are substituted.
 865          *
 866          * @since 1.17
 867          *
 868          * @return string Unescaped untransformed message text.
 869          */
 870         public function plain() {
 871                 $this->format = 'plain';
 872                 return $this->toString();
 873         }
 874
 875         /**
 876          * Returns the parsed message text which is always surrounded by a block element.
 877          *
 878          * @since 1.17
 879          *
 880          * @return string HTML
 881          */
 882         public function parseAsBlock() {
 883                 $this->format = 'block-parse';
 884                 return $this->toString();
 885         }
 886
 887         /**
 888          * Returns the message text. {{-transformation is done and the result
 889          * is escaped excluding any raw parameters.
 890          *
 891          * @since 1.17
 892          *
 893          * @return string Escaped message text.
 894          */
 895         public function escaped() {
 896                 $this->format = 'escaped';
 897                 return $this->toString();
 898         }
 899
 900         /**
 901          * Check whether a message key has been defined currently.
 902          *
 903          * @since 1.17
 904          *
 905          * @return bool
 906          */
 907         public function exists() {
 908                 return $this->fetchMessage() !== false;
 909         }
 910
 911         /**
 912          * Check whether a message does not exist, or is an empty string
 913          *
 914          * @since 1.18
 915          * @todo FIXME: Merge with isDisabled()?
 916          *
 917          * @return bool
 918          */
 919         public function isBlank() {
 920                 $message = $this->fetchMessage();
 921                 return $message === false || $message === '';
 922         }
 923
 924         /**
 925          * Check whether a message does not exist, is an empty string, or is "-".
 926          *
 927          * @since 1.18
 928          *
 929          * @return bool
 930          */
 931         public function isDisabled() {
 932                 $message = $this->fetchMessage();
 933                 return $message === false || $message === '' || $message === '-';
 934         }
 935
 936         /**
 937          * @since 1.17
 938          *
 939          * @param mixed $raw
 940          *
 941          * @return array Array with a single "raw" key.
 942          */
 943         public static function rawParam( $raw ) {
 944                 return array( 'raw' => $raw );
 945         }
 946
 947         /**
 948          * @since 1.18
 949          *
 950          * @param mixed $num
 951          *
 952          * @return array Array with a single "num" key.
 953          */
 954         public static function numParam( $num ) {
 955                 return array( 'num' => $num );
 956         }
 957
 958         /**
 959          * @since 1.22
 960          *
 961          * @param int $duration
 962          *
 963          * @return int[] Array with a single "duration" key.
 964          */
 965         public static function durationParam( $duration ) {
 966                 return array( 'duration' => $duration );
 967         }
 968
 969         /**
 970          * @since 1.22
 971          *
 972          * @param string $expiry
 973          *
 974          * @return string[] Array with a single "expiry" key.
 975          */
 976         public static function expiryParam( $expiry ) {
 977                 return array( 'expiry' => $expiry );
 978         }
 979
 980         /**
 981          * @since 1.22
 982          *
 983          * @param number $period
 984          *
 985          * @return number[] Array with a single "period" key.
 986          */
 987         public static function timeperiodParam( $period ) {
 988                 return array( 'period' => $period );
 989         }
 990
 991         /**
 992          * @since 1.22
 993          *
 994          * @param int $size
 995          *
 996          * @return int[] Array with a single "size" key.
 997          */
 998         public static function sizeParam( $size ) {
 999                 return array( 'size' => $size );
1000         }
1001
1002         /**
1003          * @since 1.22
1004          *
1005          * @param int $bitrate
1006          *
1007          * @return int[] Array with a single "bitrate" key.
1008          */
1009         public static function bitrateParam( $bitrate ) {
1010                 return array( 'bitrate' => $bitrate );
1011         }
1012
1013         /**
1014          * @since 1.25
1015          *
1016          * @param string $plaintext
1017          *
1018          * @return string[] Array with a single "plaintext" key.
1019          */
1020         public static function plaintextParam( $plaintext ) {
1021                 return array( 'plaintext' => $plaintext );
1022         }
1023
1024         /**
1025          * Substitutes any parameters into the message text.
1026          *
1027          * @since 1.17
1028          *
1029          * @param string $message The message text.
1030          * @param string $type Either "before" or "after".
1031          *
1032          * @return string
1033          */
1034         protected function replaceParameters( $message, $type = 'before' ) {
1035                 $replacementKeys = array();
1036                 foreach ( $this->parameters as $n => $param ) {
1037                         list( $paramType, $value ) = $this->extractParam( $param );
1038                         if ( $type === $paramType ) {
1039                                 $replacementKeys['$' . ( $n + 1 )] = $value;
1040                         }
1041                 }
1042                 $message = strtr( $message, $replacementKeys );
1043                 return $message;
1044         }
1045
1046         /**
1047          * Extracts the parameter type and preprocessed the value if needed.
1048          *
1049          * @since 1.18
1050          *
1051          * @param mixed $param Parameter as defined in this class.
1052          *
1053          * @return array Array with the parameter type (either "before" or "after") and the value.
1054          */
1055         protected function extractParam( $param ) {
1056                 if ( is_array( $param ) ) {
1057                         if ( isset( $param['raw'] ) ) {
1058                                 return array( 'after', $param['raw'] );
1059                         } elseif ( isset( $param['num'] ) ) {
1060                                 // Replace number params always in before step for now.
1061                                 // No support for combined raw and num params
1062                                 return array( 'before', $this->language->formatNum( $param['num'] ) );
1063                         } elseif ( isset( $param['duration'] ) ) {
1064                                 return array( 'before', $this->language->formatDuration( $param['duration'] ) );
1065                         } elseif ( isset( $param['expiry'] ) ) {
1066                                 return array( 'before', $this->language->formatExpiry( $param['expiry'] ) );
1067                         } elseif ( isset( $param['period'] ) ) {
1068                                 return array( 'before', $this->language->formatTimePeriod( $param['period'] ) );
1069                         } elseif ( isset( $param['size'] ) ) {
1070                                 return array( 'before', $this->language->formatSize( $param['size'] ) );
1071                         } elseif ( isset( $param['bitrate'] ) ) {
1072                                 return array( 'before', $this->language->formatBitrate( $param['bitrate'] ) );
1073                         } elseif ( isset( $param['plaintext'] ) ) {
1074                                 return array( 'after', $this->formatPlaintext( $param['plaintext'] ) );
1075                         } else {
1076                                 $warning = 'Invalid parameter for message "' . $this->getKey() . '": ' .
1077                                         htmlspecialchars( serialize( $param ) );
1078                                 trigger_error( $warning, E_USER_WARNING );
1079                                 $e = new Exception;
1080                                 wfDebugLog( 'Bug58676', $warning . "\n" . $e->getTraceAsString() );
1081
1082                                 return array( 'before', '[INVALID]' );
1083                         }
1084                 } elseif ( $param instanceof Message ) {
1085                         // Message objects should not be before parameters because
1086                         // then they'll get double escaped. If the message needs to be
1087                         // escaped, it'll happen right here when we call toString().
1088                         return array( 'after', $param->toString() );
1089                 } else {
1090                         return array( 'before', $param );
1091                 }
1092         }
1093
1094         /**
1095          * Wrapper for what ever method we use to parse wikitext.
1096          *
1097          * @since 1.17
1098          *
1099          * @param string $string Wikitext message contents.
1100          *
1101          * @return string Wikitext parsed into HTML.
1102          */
1103         protected function parseText( $string ) {
1104                 $out = MessageCache::singleton()->parse(
1105                         $string,
1106                         $this->title,
1107                         /*linestart*/true,
1108                         $this->interface,
1109                         $this->language
1110                 );
1111
1112                 return $out instanceof ParserOutput ? $out->getText() : $out;
1113         }
1114
1115         /**
1116          * Wrapper for what ever method we use to {{-transform wikitext.
1117          *
1118          * @since 1.17
1119          *
1120          * @param string $string Wikitext message contents.
1121          *
1122          * @return string Wikitext with {{-constructs replaced with their values.
1123          */
1124         protected function transformText( $string ) {
1125                 return MessageCache::singleton()->transform(
1126                         $string,
1127                         $this->interface,
1128                         $this->language,
1129                         $this->title
1130                 );
1131         }
1132
1133         /**
1134          * Wrapper for what ever method we use to get message contents.
1135          *
1136          * @since 1.17
1137          *
1138          * @return string
1139          * @throws MWException If message key array is empty.
1140          */
1141         protected function fetchMessage() {
1142                 if ( $this->message === null ) {
1143                         $cache = MessageCache::singleton();
1144
1145                         foreach ( $this->keysToTry as $key ) {
1146                                 $message = $cache->get( $key, $this->useDatabase, $this->language );
1147                                 if ( $message !== false && $message !== '' ) {
1148                                         break;
1149                                 }
1150                         }
1151
1152                         // NOTE: The constructor makes sure keysToTry isn't empty,
1153                         //       so we know that $key and $message are initialized.
1154                         $this->key = $key;
1155                         $this->message = $message;
1156                 }
1157                 return $this->message;
1158         }
1159
1160         /**
1161          * Formats a message parameter wrapped with 'plaintext'. Ensures that
1162          * the entire string is displayed unchanged when displayed in the output
1163          * format.
1164          *
1165          * @since 1.25
1166          *
1167          * @param string $plaintext String to ensure plaintext output of
1168          *
1169          * @return string Input plaintext encoded for output to $this->format
1170          */
1171         protected function formatPlaintext( $plaintext ) {
1172                 switch ( $this->format ) {
1173                 case 'text':
1174                 case 'plain':
1175                         return $plaintext;
1176
1177                 case 'parse':
1178                 case 'block-parse':
1179                 case 'escaped':
1180                 default:
1181                         return htmlspecialchars( $plaintext, ENT_QUOTES );
1182
1183                 }
1184         }
1185 }
1186
1187 /**
1188  * Variant of the Message class.
1189  *
1190  * Rather than treating the message key as a lookup
1191  * value (which is passed to the MessageCache and
1192  * translated as necessary), a RawMessage key is
1193  * treated as the actual message.
1194  *
1195  * All other functionality (parsing, escaping, etc.)
1196  * is preserved.
1197  *
1198  * @since 1.21
1199  */
1200 class RawMessage extends Message {
1201
1202         /**
1203          * Call the parent constructor, then store the key as
1204          * the message.
1205          *
1206          * @see Message::__construct
1207          *
1208          * @param string $text Message to use.
1209          * @param array $params Parameters for the message.
1210          *
1211          * @throws InvalidArgumentException
1212          */
1213         public function __construct( $text, $params = array() ) {
1214                 if ( !is_string( $text ) ) {
1215                         throw new InvalidArgumentException( '$text must be a string' );
1216                 }
1217
1218                 parent::__construct( $text, $params );
1219
1220                 // The key is the message.
1221                 $this->message = $text;
1222         }
1223
1224         /**
1225          * Fetch the message (in this case, the key).
1226          *
1227          * @return string
1228          */
1229         public function fetchMessage() {
1230                 // Just in case the message is unset somewhere.
1231                 if ( $this->message === null ) {
1232                         $this->message = $this->key;
1233                 }
1234
1235                 return $this->message;
1236         }
1237
1238 }