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 {
 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[] $key Message key or array of message keys to try and use the first
 230          * non-empty message for.
 231          * @param array $params Message parameters.
 232          * @param Language $language Optional language of the message, defaults to $wgLang.
 233          *
 234          * @throws InvalidArgumentException
 235          */
 236         public function __construct( $key, $params = array(), Language $language = null ) {
 237                 global $wgLang;
 238
 239                 if ( !is_string( $key ) && !is_array( $key ) ) {
 240                         throw new InvalidArgumentException( '$key must be a string or an array' );
 241                 }
 242
 243                 $this->keysToTry = (array)$key;
 244
 245                 if ( empty( $this->keysToTry ) ) {
 246                         throw new InvalidArgumentException( '$key must not be an empty list' );
 247                 }
 248
 249                 $this->key = reset( $this->keysToTry );
 250
 251                 $this->parameters = array_values( $params );
 252                 $this->language = $language ? $language : $wgLang;
 253         }
 254
 255         /**
 256          * @since 1.24
 257          *
 258          * @return bool True if this is a multi-key message, that is, if the key provided to the
 259          * constructor was a fallback list of keys to try.
 260          */
 261         public function isMultiKey() {
 262                 return count( $this->keysToTry ) > 1;
 263         }
 264
 265         /**
 266          * @since 1.24
 267          *
 268          * @return string[] The list of keys to try when fetching the message text,
 269          * in order of preference.
 270          */
 271         public function getKeysToTry() {
 272                 return $this->keysToTry;
 273         }
 274
 275         /**
 276          * Returns the message key.
 277          *
 278          * If a list of multiple possible keys was supplied to the constructor, this method may
 279          * return any of these keys. After the message ahs been fetched, this method will return
 280          * the key that was actually used to fetch the message.
 281          *
 282          * @since 1.21
 283          *
 284          * @return string
 285          */
 286         public function getKey() {
 287                 return $this->key;
 288         }
 289
 290         /**
 291          * Returns the message parameters.
 292          *
 293          * @since 1.21
 294          *
 295          * @return array
 296          */
 297         public function getParams() {
 298                 return $this->parameters;
 299         }
 300
 301         /**
 302          * Returns the message format.
 303          *
 304          * @since 1.21
 305          *
 306          * @return string
 307          */
 308         public function getFormat() {
 309                 return $this->format;
 310         }
 311
 312         /**
 313          * Returns the Language of the Message.
 314          *
 315          * @since 1.23
 316          *
 317          * @return Language
 318          */
 319         public function getLanguage() {
 320                 return $this->language;
 321         }
 322
 323         /**
 324          * Factory function that is just wrapper for the real constructor. It is
 325          * intended to be used instead of the real constructor, because it allows
 326          * chaining method calls, while new objects don't.
 327          *
 328          * @since 1.17
 329          *
 330          * @param string|string[] $key Message key or array of keys.
 331          * @param mixed $param,... Parameters as strings.
 332          *
 333          * @return Message
 334          */
 335         public static function newFromKey( $key /*...*/ ) {
 336                 $params = func_get_args();
 337                 array_shift( $params );
 338                 return new self( $key, $params );
 339         }
 340
 341         /**
 342          * Factory function accepting multiple message keys and returning a message instance
 343          * for the first message which is non-empty. If all messages are empty then an
 344          * instance of the first message key is returned.
 345          *
 346          * @since 1.18
 347          *
 348          * @param string|string[] $keys,... Message keys, or first argument as an array of all the
 349          * message keys.
 350          *
 351          * @return Message
 352          */
 353         public static function newFallbackSequence( /*...*/ ) {
 354                 $keys = func_get_args();
 355                 if ( func_num_args() == 1 ) {
 356                         if ( is_array( $keys[0] ) ) {
 357                                 // Allow an array to be passed as the first argument instead
 358                                 $keys = array_values( $keys[0] );
 359                         } else {
 360                                 // Optimize a single string to not need special fallback handling
 361                                 $keys = $keys[0];
 362                         }
 363                 }
 364                 return new self( $keys );
 365         }
 366
 367         /**
 368          * Adds parameters to the parameter list of this message.
 369          *
 370          * @since 1.17
 371          *
 372          * @param mixed $params,... Parameters as strings, or a single argument that is
 373          * an array of strings.
 374          *
 375          * @return Message $this
 376          */
 377         public function params( /*...*/ ) {
 378                 $args = func_get_args();
 379                 if ( isset( $args[0] ) && is_array( $args[0] ) ) {
 380                         $args = $args[0];
 381                 }
 382                 $args_values = array_values( $args );
 383                 $this->parameters = array_merge( $this->parameters, $args_values );
 384                 return $this;
 385         }
 386
 387         /**
 388          * Add parameters that are substituted after parsing or escaping.
 389          * In other words the parsing process cannot access the contents
 390          * of this type of parameter, and you need to make sure it is
 391          * sanitized beforehand.  The parser will see "$n", instead.
 392          *
 393          * @since 1.17
 394          *
 395          * @param mixed $params,... Raw parameters as strings, or a single argument that is
 396          * an array of raw parameters.
 397          *
 398          * @return Message $this
 399          */
 400         public function rawParams( /*...*/ ) {
 401                 $params = func_get_args();
 402                 if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 403                         $params = $params[0];
 404                 }
 405                 foreach ( $params as $param ) {
 406                         $this->parameters[] = self::rawParam( $param );
 407                 }
 408                 return $this;
 409         }
 410
 411         /**
 412          * Add parameters that are numeric and will be passed through
 413          * Language::formatNum before substitution
 414          *
 415          * @since 1.18
 416          *
 417          * @param mixed $param,... Numeric parameters, or a single argument that is
 418          * an array of numeric parameters.
 419          *
 420          * @return Message $this
 421          */
 422         public function numParams( /*...*/ ) {
 423                 $params = func_get_args();
 424                 if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 425                         $params = $params[0];
 426                 }
 427                 foreach ( $params as $param ) {
 428                         $this->parameters[] = self::numParam( $param );
 429                 }
 430                 return $this;
 431         }
 432
 433         /**
 434          * Add parameters that are durations of time and will be passed through
 435          * Language::formatDuration before substitution
 436          *
 437          * @since 1.22
 438          *
 439          * @param int|int[] $param,... Duration parameters, or a single argument that is
 440          * an array of duration parameters.
 441          *
 442          * @return Message $this
 443          */
 444         public function durationParams( /*...*/ ) {
 445                 $params = func_get_args();
 446                 if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 447                         $params = $params[0];
 448                 }
 449                 foreach ( $params as $param ) {
 450                         $this->parameters[] = self::durationParam( $param );
 451                 }
 452                 return $this;
 453         }
 454
 455         /**
 456          * Add parameters that are expiration times and will be passed through
 457          * Language::formatExpiry before substitution
 458          *
 459          * @since 1.22
 460          *
 461          * @param string|string[] $param,... Expiry parameters, or a single argument that is
 462          * an array of expiry parameters.
 463          *
 464          * @return Message $this
 465          */
 466         public function expiryParams( /*...*/ ) {
 467                 $params = func_get_args();
 468                 if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 469                         $params = $params[0];
 470                 }
 471                 foreach ( $params as $param ) {
 472                         $this->parameters[] = self::expiryParam( $param );
 473                 }
 474                 return $this;
 475         }
 476
 477         /**
 478          * Add parameters that are time periods and will be passed through
 479          * Language::formatTimePeriod before substitution
 480          *
 481          * @since 1.22
 482          *
 483          * @param int|int[] $param,... Time period parameters, or a single argument that is
 484          * an array of time period parameters.
 485          *
 486          * @return Message $this
 487          */
 488         public function timeperiodParams( /*...*/ ) {
 489                 $params = func_get_args();
 490                 if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 491                         $params = $params[0];
 492                 }
 493                 foreach ( $params as $param ) {
 494                         $this->parameters[] = self::timeperiodParam( $param );
 495                 }
 496                 return $this;
 497         }
 498
 499         /**
 500          * Add parameters that are file sizes and will be passed through
 501          * Language::formatSize before substitution
 502          *
 503          * @since 1.22
 504          *
 505          * @param int|int[] $param,... Size parameters, or a single argument that is
 506          * an array of size parameters.
 507          *
 508          * @return Message $this
 509          */
 510         public function sizeParams( /*...*/ ) {
 511                 $params = func_get_args();
 512                 if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 513                         $params = $params[0];
 514                 }
 515                 foreach ( $params as $param ) {
 516                         $this->parameters[] = self::sizeParam( $param );
 517                 }
 518                 return $this;
 519         }
 520
 521         /**
 522          * Add parameters that are bitrates and will be passed through
 523          * Language::formatBitrate before substitution
 524          *
 525          * @since 1.22
 526          *
 527          * @param int|int[] $param,... Bit rate parameters, or a single argument that is
 528          * an array of bit rate parameters.
 529          *
 530          * @return Message $this
 531          */
 532         public function bitrateParams( /*...*/ ) {
 533                 $params = func_get_args();
 534                 if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 535                         $params = $params[0];
 536                 }
 537                 foreach ( $params as $param ) {
 538                         $this->parameters[] = self::bitrateParam( $param );
 539                 }
 540                 return $this;
 541         }
 542
 543         /**
 544          * Set the language and the title from a context object
 545          *
 546          * @since 1.19
 547          *
 548          * @param IContextSource $context
 549          *
 550          * @return Message $this
 551          */
 552         public function setContext( IContextSource $context ) {
 553                 $this->inLanguage( $context->getLanguage() );
 554                 $this->title( $context->getTitle() );
 555                 $this->interface = true;
 556
 557                 return $this;
 558         }
 559
 560         /**
 561          * Request the message in any language that is supported.
 562          * As a side effect interface message status is unconditionally
 563          * turned off.
 564          *
 565          * @since 1.17
 566          *
 567          * @param Language|string $lang Language code or Language object.
 568          *
 569          * @return Message $this
 570          * @throws MWException
 571          */
 572         public function inLanguage( $lang ) {
 573                 if ( $lang instanceof Language || $lang instanceof StubUserLang ) {
 574                         $this->language = $lang;
 575                 } elseif ( is_string( $lang ) ) {
 576                         if ( $this->language->getCode() != $lang ) {
 577                                 $this->language = Language::factory( $lang );
 578                         }
 579                 } else {
 580                         $type = gettype( $lang );
 581                         throw new MWException( __METHOD__ . " must be "
 582                                 . "passed a String or Language object; $type given"
 583                         );
 584                 }
 585                 $this->message = null;
 586                 $this->interface = false;
 587                 return $this;
 588         }
 589
 590         /**
 591          * Request the message in the wiki's content language,
 592          * unless it is disabled for this message.
 593          *
 594          * @since 1.17
 595          * @see $wgForceUIMsgAsContentMsg
 596          *
 597          * @return Message $this
 598          */
 599         public function inContentLanguage() {
 600                 global $wgForceUIMsgAsContentMsg;
 601                 if ( in_array( $this->key, (array)$wgForceUIMsgAsContentMsg ) ) {
 602                         return $this;
 603                 }
 604
 605                 global $wgContLang;
 606                 $this->inLanguage( $wgContLang );
 607                 return $this;
 608         }
 609
 610         /**
 611          * Allows manipulating the interface message flag directly.
 612          * Can be used to restore the flag after setting a language.
 613          *
 614          * @since 1.20
 615          *
 616          * @param bool $interface
 617          *
 618          * @return Message $this
 619          */
 620         public function setInterfaceMessageFlag( $interface ) {
 621                 $this->interface = (bool)$interface;
 622                 return $this;
 623         }
 624
 625         /**
 626          * Enable or disable database use.
 627          *
 628          * @since 1.17
 629          *
 630          * @param bool $useDatabase
 631          *
 632          * @return Message $this
 633          */
 634         public function useDatabase( $useDatabase ) {
 635                 $this->useDatabase = (bool)$useDatabase;
 636                 return $this;
 637         }
 638
 639         /**
 640          * Set the Title object to use as context when transforming the message
 641          *
 642          * @since 1.18
 643          *
 644          * @param Title $title
 645          *
 646          * @return Message $this
 647          */
 648         public function title( $title ) {
 649                 $this->title = $title;
 650                 return $this;
 651         }
 652
 653         /**
 654          * Returns the message as a Content object.
 655          *
 656          * @return Content
 657          */
 658         public function content() {
 659                 if ( !$this->content ) {
 660                         $this->content = new MessageContent( $this );
 661                 }
 662
 663                 return $this->content;
 664         }
 665
 666         /**
 667          * Returns the message parsed from wikitext to HTML.
 668          *
 669          * @since 1.17
 670          *
 671          * @return string HTML
 672          */
 673         public function toString() {
 674                 $string = $this->fetchMessage();
 675
 676                 if ( $string === false ) {
 677                         $key = htmlspecialchars( $this->key );
 678                         if ( $this->format === 'plain' ) {
 679                                 return '<' . $key . '>';
 680                         }
 681                         return '&lt;' . $key . '&gt;';
 682                 }
 683
 684                 # Replace $* with a list of parameters for &uselang=qqx.
 685                 if ( strpos( $string, '$*' ) !== false ) {
 686                         $paramlist = '';
 687                         if ( $this->parameters !== array() ) {
 688                                 $paramlist = ': $' . implode( ', $', range( 1, count( $this->parameters ) ) );
 689                         }
 690                         $string = str_replace( '$*', $paramlist, $string );
 691                 }
 692
 693                 # Replace parameters before text parsing
 694                 $string = $this->replaceParameters( $string, 'before' );
 695
 696                 # Maybe transform using the full parser
 697                 if ( $this->format === 'parse' ) {
 698                         $string = $this->parseText( $string );
 699                         $string = Parser::stripOuterParagraph( $string );
 700                 } elseif ( $this->format === 'block-parse' ) {
 701                         $string = $this->parseText( $string );
 702                 } elseif ( $this->format === 'text' ) {
 703                         $string = $this->transformText( $string );
 704                 } elseif ( $this->format === 'escaped' ) {
 705                         $string = $this->transformText( $string );
 706                         $string = htmlspecialchars( $string, ENT_QUOTES, 'UTF-8', false );
 707                 }
 708
 709                 # Raw parameter replacement
 710                 $string = $this->replaceParameters( $string, 'after' );
 711
 712                 return $string;
 713         }
 714
 715         /**
 716          * Magic method implementation of the above (for PHP >= 5.2.0), so we can do, eg:
 717          *     $foo = Message::get( $key );
 718          *     $string = "<abbr>$foo</abbr>";
 719          *
 720          * @since 1.18
 721          *
 722          * @return string
 723          */
 724         public function __toString() {
 725                 // PHP doesn't allow __toString to throw exceptions and will
 726                 // trigger a fatal error if it does. So, catch any exceptions.
 727
 728                 try {
 729                         return $this->toString();
 730                 } catch ( Exception $ex ) {
 731                         try {
 732                                 trigger_error( "Exception caught in " . __METHOD__ . " (message " . $this->key . "): "
 733                                         . $ex, E_USER_WARNING );
 734                         } catch ( Exception $ex ) {
 735                                 // Doh! Cause a fatal error after all?
 736                         }
 737
 738                         if ( $this->format === 'plain' ) {
 739                                 return '<' . $this->key . '>';
 740                         }
 741                         return '&lt;' . $this->key . '&gt;';
 742                 }
 743         }
 744
 745         /**
 746          * Fully parse the text from wikitext to HTML.
 747          *
 748          * @since 1.17
 749          *
 750          * @return string Parsed HTML.
 751          */
 752         public function parse() {
 753                 $this->format = 'parse';
 754                 return $this->toString();
 755         }
 756
 757         /**
 758          * Returns the message text. {{-transformation is done.
 759          *
 760          * @since 1.17
 761          *
 762          * @return string Unescaped message text.
 763          */
 764         public function text() {
 765                 $this->format = 'text';
 766                 return $this->toString();
 767         }
 768
 769         /**
 770          * Returns the message text as-is, only parameters are substituted.
 771          *
 772          * @since 1.17
 773          *
 774          * @return string Unescaped untransformed message text.
 775          */
 776         public function plain() {
 777                 $this->format = 'plain';
 778                 return $this->toString();
 779         }
 780
 781         /**
 782          * Returns the parsed message text which is always surrounded by a block element.
 783          *
 784          * @since 1.17
 785          *
 786          * @return string HTML
 787          */
 788         public function parseAsBlock() {
 789                 $this->format = 'block-parse';
 790                 return $this->toString();
 791         }
 792
 793         /**
 794          * Returns the message text. {{-transformation is done and the result
 795          * is escaped excluding any raw parameters.
 796          *
 797          * @since 1.17
 798          *
 799          * @return string Escaped message text.
 800          */
 801         public function escaped() {
 802                 $this->format = 'escaped';
 803                 return $this->toString();
 804         }
 805
 806         /**
 807          * Check whether a message key has been defined currently.
 808          *
 809          * @since 1.17
 810          *
 811          * @return bool
 812          */
 813         public function exists() {
 814                 return $this->fetchMessage() !== false;
 815         }
 816
 817         /**
 818          * Check whether a message does not exist, or is an empty string
 819          *
 820          * @since 1.18
 821          * @todo FIXME: Merge with isDisabled()?
 822          *
 823          * @return bool
 824          */
 825         public function isBlank() {
 826                 $message = $this->fetchMessage();
 827                 return $message === false || $message === '';
 828         }
 829
 830         /**
 831          * Check whether a message does not exist, is an empty string, or is "-".
 832          *
 833          * @since 1.18
 834          *
 835          * @return bool
 836          */
 837         public function isDisabled() {
 838                 $message = $this->fetchMessage();
 839                 return $message === false || $message === '' || $message === '-';
 840         }
 841
 842         /**
 843          * @since 1.17
 844          *
 845          * @param mixed $raw
 846          *
 847          * @return array Array with a single "raw" key.
 848          */
 849         public static function rawParam( $raw ) {
 850                 return array( 'raw' => $raw );
 851         }
 852
 853         /**
 854          * @since 1.18
 855          *
 856          * @param mixed $num
 857          *
 858          * @return array Array with a single "num" key.
 859          */
 860         public static function numParam( $num ) {
 861                 return array( 'num' => $num );
 862         }
 863
 864         /**
 865          * @since 1.22
 866          *
 867          * @param int $duration
 868          *
 869          * @return int[] Array with a single "duration" key.
 870          */
 871         public static function durationParam( $duration ) {
 872                 return array( 'duration' => $duration );
 873         }
 874
 875         /**
 876          * @since 1.22
 877          *
 878          * @param string $expiry
 879          *
 880          * @return string[] Array with a single "expiry" key.
 881          */
 882         public static function expiryParam( $expiry ) {
 883                 return array( 'expiry' => $expiry );
 884         }
 885
 886         /**
 887          * @since 1.22
 888          *
 889          * @param number $period
 890          *
 891          * @return number[] Array with a single "period" key.
 892          */
 893         public static function timeperiodParam( $period ) {
 894                 return array( 'period' => $period );
 895         }
 896
 897         /**
 898          * @since 1.22
 899          *
 900          * @param int $size
 901          *
 902          * @return int[] Array with a single "size" key.
 903          */
 904         public static function sizeParam( $size ) {
 905                 return array( 'size' => $size );
 906         }
 907
 908         /**
 909          * @since 1.22
 910          *
 911          * @param int $bitrate
 912          *
 913          * @return int[] Array with a single "bitrate" key.
 914          */
 915         public static function bitrateParam( $bitrate ) {
 916                 return array( 'bitrate' => $bitrate );
 917         }
 918
 919         /**
 920          * Substitutes any parameters into the message text.
 921          *
 922          * @since 1.17
 923          *
 924          * @param string $message The message text.
 925          * @param string $type Either "before" or "after".
 926          *
 927          * @return string
 928          */
 929         protected function replaceParameters( $message, $type = 'before' ) {
 930                 $replacementKeys = array();
 931                 foreach ( $this->parameters as $n => $param ) {
 932                         list( $paramType, $value ) = $this->extractParam( $param );
 933                         if ( $type === $paramType ) {
 934                                 $replacementKeys['$' . ( $n + 1 )] = $value;
 935                         }
 936                 }
 937                 $message = strtr( $message, $replacementKeys );
 938                 return $message;
 939         }
 940
 941         /**
 942          * Extracts the parameter type and preprocessed the value if needed.
 943          *
 944          * @since 1.18
 945          *
 946          * @param mixed $param Parameter as defined in this class.
 947          *
 948          * @return array Array with the parameter type (either "before" or "after") and the value.
 949          */
 950         protected function extractParam( $param ) {
 951                 if ( is_array( $param ) ) {
 952                         if ( isset( $param['raw'] ) ) {
 953                                 return array( 'after', $param['raw'] );
 954                         } elseif ( isset( $param['num'] ) ) {
 955                                 // Replace number params always in before step for now.
 956                                 // No support for combined raw and num params
 957                                 return array( 'before', $this->language->formatNum( $param['num'] ) );
 958                         } elseif ( isset( $param['duration'] ) ) {
 959                                 return array( 'before', $this->language->formatDuration( $param['duration'] ) );
 960                         } elseif ( isset( $param['expiry'] ) ) {
 961                                 return array( 'before', $this->language->formatExpiry( $param['expiry'] ) );
 962                         } elseif ( isset( $param['period'] ) ) {
 963                                 return array( 'before', $this->language->formatTimePeriod( $param['period'] ) );
 964                         } elseif ( isset( $param['size'] ) ) {
 965                                 return array( 'before', $this->language->formatSize( $param['size'] ) );
 966                         } elseif ( isset( $param['bitrate'] ) ) {
 967                                 return array( 'before', $this->language->formatBitrate( $param['bitrate'] ) );
 968                         } else {
 969                                 $warning = 'Invalid parameter for message "' . $this->getKey() . '": ' .
 970                                         htmlspecialchars( serialize( $param ) );
 971                                 trigger_error( $warning, E_USER_WARNING );
 972                                 $e = new Exception;
 973                                 wfDebugLog( 'Bug58676', $warning . "\n" . $e->getTraceAsString() );
 974
 975                                 return array( 'before', '[INVALID]' );
 976                         }
 977                 } elseif ( $param instanceof Message ) {
 978                         // Message objects should not be before parameters because
 979                         // then they'll get double escaped. If the message needs to be
 980                         // escaped, it'll happen right here when we call toString().
 981                         return array( 'after', $param->toString() );
 982                 } else {
 983                         return array( 'before', $param );
 984                 }
 985         }
 986
 987         /**
 988          * Wrapper for what ever method we use to parse wikitext.
 989          *
 990          * @since 1.17
 991          *
 992          * @param string $string Wikitext message contents.
 993          *
 994          * @return string Wikitext parsed into HTML.
 995          */
 996         protected function parseText( $string ) {
 997                 $out = MessageCache::singleton()->parse(
 998                         $string,
 999                         $this->title,
1000                         /*linestart*/true,
1001                         $this->interface,
1002                         $this->language
1003                 );
1004
1005                 return $out instanceof ParserOutput ? $out->getText() : $out;
1006         }
1007
1008         /**
1009          * Wrapper for what ever method we use to {{-transform wikitext.
1010          *
1011          * @since 1.17
1012          *
1013          * @param string $string Wikitext message contents.
1014          *
1015          * @return string Wikitext with {{-constructs replaced with their values.
1016          */
1017         protected function transformText( $string ) {
1018                 return MessageCache::singleton()->transform(
1019                         $string,
1020                         $this->interface,
1021                         $this->language,
1022                         $this->title
1023                 );
1024         }
1025
1026         /**
1027          * Wrapper for what ever method we use to get message contents.
1028          *
1029          * @since 1.17
1030          *
1031          * @return string
1032          * @throws MWException If message key array is empty.
1033          */
1034         protected function fetchMessage() {
1035                 if ( $this->message === null ) {
1036                         $cache = MessageCache::singleton();
1037
1038                         foreach ( $this->keysToTry as $key ) {
1039                                 $message = $cache->get( $key, $this->useDatabase, $this->language );
1040                                 if ( $message !== false && $message !== '' ) {
1041                                         break;
1042                                 }
1043                         }
1044
1045                         // NOTE: The constructor makes sure keysToTry isn't empty,
1046                         //       so we know that $key and $message are initialized.
1047                         $this->key = $key;
1048                         $this->message = $message;
1049                 }
1050                 return $this->message;
1051         }
1052
1053 }
1054
1055 /**
1056  * Variant of the Message class.
1057  *
1058  * Rather than treating the message key as a lookup
1059  * value (which is passed to the MessageCache and
1060  * translated as necessary), a RawMessage key is
1061  * treated as the actual message.
1062  *
1063  * All other functionality (parsing, escaping, etc.)
1064  * is preserved.
1065  *
1066  * @since 1.21
1067  */
1068 class RawMessage extends Message {
1069
1070         /**
1071          * Call the parent constructor, then store the key as
1072          * the message.
1073          *
1074          * @see Message::__construct
1075          *
1076          * @param string $text Message to use.
1077          * @param array $params Parameters for the message.
1078          *
1079          * @throws InvalidArgumentException
1080          */
1081         public function __construct( $text, $params = array() ) {
1082                 if ( !is_string( $text ) ) {
1083                         throw new InvalidArgumentException( '$text must be a string' );
1084                 }
1085
1086                 parent::__construct( $text, $params );
1087
1088                 // The key is the message.
1089                 $this->message = $text;
1090         }
1091
1092         /**
1093          * Fetch the message (in this case, the key).
1094          *
1095          * @return string
1096          */
1097         public function fetchMessage() {
1098                 // Just in case the message is unset somewhere.
1099                 if ( $this->message === null ) {
1100                         $this->message = $this->key;
1101                 }
1102
1103                 return $this->message;
1104         }
1105
1106 }