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 user 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 setting.
 171          *
 172          * @var Language|bool Explicit language object, or false for user language
 173          */
 174         protected $language = false;
 175
 176         /**
 177          * @var string The message key. If $keysToTry has more than one element,
 178          * this may change to one of the keys to try when fetching the message text.
 179          */
 180         protected $key;
 181
 182         /**
 183          * @var string[] List of keys to try when fetching the message.
 184          */
 185         protected $keysToTry;
 186
 187         /**
 188          * @var array List of parameters which will be substituted into the message.
 189          */
 190         protected $parameters = [];
 191
 192         /**
 193          * Format for the message.
 194          * Supported formats are:
 195          * * text (transform)
 196          * * escaped (transform+htmlspecialchars)
 197          * * block-parse
 198          * * parse (default)
 199          * * plain
 200          *
 201          * @var string
 202          */
 203         protected $format = 'parse';
 204
 205         /**
 206          * @var bool Whether database can be used.
 207          */
 208         protected $useDatabase = true;
 209
 210         /**
 211          * @var Title Title object to use as context.
 212          */
 213         protected $title = null;
 214
 215         /**
 216          * @var Content Content object representing the message.
 217          */
 218         protected $content = null;
 219
 220         /**
 221          * @var string
 222          */
 223         protected $message;
 224
 225         /**
 226          * @since 1.17
 227          * @param string|string[]|MessageSpecifier $key Message key, or array of
 228          * message keys to try and use the first non-empty message for, or a
 229          * MessageSpecifier to copy from.
 230          * @param array $params Message parameters.
 231          * @param Language $language [optional] Language to use (defaults to current user language).
 232          * @throws InvalidArgumentException
 233          */
 234         public function __construct( $key, $params = [], Language $language = null ) {
 235                 if ( $key instanceof MessageSpecifier ) {
 236                         if ( $params ) {
 237                                 throw new InvalidArgumentException(
 238                                         '$params must be empty if $key is a MessageSpecifier'
 239                                 );
 240                         }
 241                         $params = $key->getParams();
 242                         $key = $key->getKey();
 243                 }
 244
 245                 if ( !is_string( $key ) && !is_array( $key ) ) {
 246                         throw new InvalidArgumentException( '$key must be a string or an array' );
 247                 }
 248
 249                 $this->keysToTry = (array)$key;
 250
 251                 if ( empty( $this->keysToTry ) ) {
 252                         throw new InvalidArgumentException( '$key must not be an empty list' );
 253                 }
 254
 255                 $this->key = reset( $this->keysToTry );
 256
 257                 $this->parameters = array_values( $params );
 258                 // User language is only resolved in getLanguage(). This helps preserve the
 259                 // semantic intent of "user language" across serialize() and unserialize().
 260                 $this->language = $language ?: false;
 261         }
 262
 263         /**
 264          * @see Serializable::serialize()
 265          * @since 1.26
 266          * @return string
 267          */
 268         public function serialize() {
 269                 return serialize( [
 270                         'interface' => $this->interface,
 271                         'language' => $this->language ? $this->language->getCode() : false,
 272                         'key' => $this->key,
 273                         'keysToTry' => $this->keysToTry,
 274                         'parameters' => $this->parameters,
 275                         'format' => $this->format,
 276                         'useDatabase' => $this->useDatabase,
 277                         'title' => $this->title,
 278                 ] );
 279         }
 280
 281         /**
 282          * @see Serializable::unserialize()
 283          * @since 1.26
 284          * @param string $serialized
 285          */
 286         public function unserialize( $serialized ) {
 287                 $data = unserialize( $serialized );
 288                 $this->interface = $data['interface'];
 289                 $this->key = $data['key'];
 290                 $this->keysToTry = $data['keysToTry'];
 291                 $this->parameters = $data['parameters'];
 292                 $this->format = $data['format'];
 293                 $this->useDatabase = $data['useDatabase'];
 294                 $this->language = $data['language'] ? Language::factory( $data['language'] ) : false;
 295                 $this->title = $data['title'];
 296         }
 297
 298         /**
 299          * @since 1.24
 300          *
 301          * @return bool True if this is a multi-key message, that is, if the key provided to the
 302          * constructor was a fallback list of keys to try.
 303          */
 304         public function isMultiKey() {
 305                 return count( $this->keysToTry ) > 1;
 306         }
 307
 308         /**
 309          * @since 1.24
 310          *
 311          * @return string[] The list of keys to try when fetching the message text,
 312          * in order of preference.
 313          */
 314         public function getKeysToTry() {
 315                 return $this->keysToTry;
 316         }
 317
 318         /**
 319          * Returns the message key.
 320          *
 321          * If a list of multiple possible keys was supplied to the constructor, this method may
 322          * return any of these keys. After the message has been fetched, this method will return
 323          * the key that was actually used to fetch the message.
 324          *
 325          * @since 1.21
 326          *
 327          * @return string
 328          */
 329         public function getKey() {
 330                 return $this->key;
 331         }
 332
 333         /**
 334          * Returns the message parameters.
 335          *
 336          * @since 1.21
 337          *
 338          * @return array
 339          */
 340         public function getParams() {
 341                 return $this->parameters;
 342         }
 343
 344         /**
 345          * Returns the message format.
 346          *
 347          * @since 1.21
 348          *
 349          * @return string
 350          */
 351         public function getFormat() {
 352                 return $this->format;
 353         }
 354
 355         /**
 356          * Returns the Language of the Message.
 357          *
 358          * @since 1.23
 359          *
 360          * @return Language
 361          */
 362         public function getLanguage() {
 363                 // Defaults to false which means current user language
 364                 return $this->language ?: RequestContext::getMain()->getLanguage();
 365         }
 366
 367         /**
 368          * Factory function that is just wrapper for the real constructor. It is
 369          * intended to be used instead of the real constructor, because it allows
 370          * chaining method calls, while new objects don't.
 371          *
 372          * @since 1.17
 373          *
 374          * @param string|string[]|MessageSpecifier $key
 375          * @param mixed $param,... Parameters as strings.
 376          *
 377          * @return Message
 378          */
 379         public static function newFromKey( $key /*...*/ ) {
 380                 $params = func_get_args();
 381                 array_shift( $params );
 382                 return new self( $key, $params );
 383         }
 384
 385         /**
 386          * Transform a MessageSpecifier or a primitive value used interchangeably with
 387          * specifiers (a message key string, or a key + params array) into a proper Message
 388          * @param string|array|MessageSpecifier $value
 389          * @return Message
 390          * @throws InvalidArgumentException
 391          */
 392         public static function newFromSpecifier( $value ) {
 393                 if ( $value instanceof RawMessage ) {
 394                         $message = new RawMessage( $value->getKey(), $value->getParams() );
 395                 } elseif ( $value instanceof MessageSpecifier ) {
 396                         $message = new Message( $value );
 397                 } elseif ( is_array( $value ) ) {
 398                         $key = array_shift( $value );
 399                         $message = new Message( $key, $value );
 400                 } elseif ( is_string( $value ) ) {
 401                         $message = new Message( $value );
 402                 } else {
 403                         throw new InvalidArgumentException( __METHOD__ . ': invalid argument type '
 404                                 . gettype( $value ) );
 405                 }
 406
 407                 return $message;
 408         }
 409
 410         /**
 411          * Factory function accepting multiple message keys and returning a message instance
 412          * for the first message which is non-empty. If all messages are empty then an
 413          * instance of the first message key is returned.
 414          *
 415          * @since 1.18
 416          *
 417          * @param string|string[] $keys,... Message keys, or first argument as an array of all the
 418          * message keys.
 419          *
 420          * @return Message
 421          */
 422         public static function newFallbackSequence( /*...*/ ) {
 423                 $keys = func_get_args();
 424                 if ( func_num_args() == 1 ) {
 425                         if ( is_array( $keys[0] ) ) {
 426                                 // Allow an array to be passed as the first argument instead
 427                                 $keys = array_values( $keys[0] );
 428                         } else {
 429                                 // Optimize a single string to not need special fallback handling
 430                                 $keys = $keys[0];
 431                         }
 432                 }
 433                 return new self( $keys );
 434         }
 435
 436         /**
 437          * Get a title object for a mediawiki message, where it can be found in the mediawiki namespace.
 438          * The title will be for the current language, if the message key is in
 439          * $wgForceUIMsgAsContentMsg it will be append with the language code (except content
 440          * language), because Message::inContentLanguage will also return in user language.
 441          *
 442          * @see $wgForceUIMsgAsContentMsg
 443          * @return Title
 444          * @since 1.26
 445          */
 446         public function getTitle() {
 447                 global $wgContLang, $wgForceUIMsgAsContentMsg;
 448
 449                 $code = $this->getLanguage()->getCode();
 450                 $title = $this->key;
 451                 if (
 452                         $wgContLang->getCode() !== $code
 453                         && in_array( $this->key, (array)$wgForceUIMsgAsContentMsg )
 454                 ) {
 455                         $title .= '/' . $code;
 456                 }
 457
 458                 return Title::makeTitle( NS_MEDIAWIKI, $wgContLang->ucfirst( strtr( $title, ' ', '_' ) ) );
 459         }
 460
 461         /**
 462          * Adds parameters to the parameter list of this message.
 463          *
 464          * @since 1.17
 465          *
 466          * @param mixed ... Parameters as strings, or a single argument that is
 467          * an array of strings.
 468          *
 469          * @return Message $this
 470          */
 471         public function params( /*...*/ ) {
 472                 $args = func_get_args();
 473                 if ( isset( $args[0] ) && is_array( $args[0] ) ) {
 474                         $args = $args[0];
 475                 }
 476                 $args_values = array_values( $args );
 477                 $this->parameters = array_merge( $this->parameters, $args_values );
 478                 return $this;
 479         }
 480
 481         /**
 482          * Add parameters that are substituted after parsing or escaping.
 483          * In other words the parsing process cannot access the contents
 484          * of this type of parameter, and you need to make sure it is
 485          * sanitized beforehand.  The parser will see "$n", instead.
 486          *
 487          * @since 1.17
 488          *
 489          * @param mixed $params,... Raw parameters as strings, or a single argument that is
 490          * an array of raw parameters.
 491          *
 492          * @return Message $this
 493          */
 494         public function rawParams( /*...*/ ) {
 495                 $params = func_get_args();
 496                 if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 497                         $params = $params[0];
 498                 }
 499                 foreach ( $params as $param ) {
 500                         $this->parameters[] = self::rawParam( $param );
 501                 }
 502                 return $this;
 503         }
 504
 505         /**
 506          * Add parameters that are numeric and will be passed through
 507          * Language::formatNum before substitution
 508          *
 509          * @since 1.18
 510          *
 511          * @param mixed $param,... Numeric parameters, or a single argument that is
 512          * an array of numeric parameters.
 513          *
 514          * @return Message $this
 515          */
 516         public function numParams( /*...*/ ) {
 517                 $params = func_get_args();
 518                 if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 519                         $params = $params[0];
 520                 }
 521                 foreach ( $params as $param ) {
 522                         $this->parameters[] = self::numParam( $param );
 523                 }
 524                 return $this;
 525         }
 526
 527         /**
 528          * Add parameters that are durations of time and will be passed through
 529          * Language::formatDuration before substitution
 530          *
 531          * @since 1.22
 532          *
 533          * @param int|int[] $param,... Duration parameters, or a single argument that is
 534          * an array of duration parameters.
 535          *
 536          * @return Message $this
 537          */
 538         public function durationParams( /*...*/ ) {
 539                 $params = func_get_args();
 540                 if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 541                         $params = $params[0];
 542                 }
 543                 foreach ( $params as $param ) {
 544                         $this->parameters[] = self::durationParam( $param );
 545                 }
 546                 return $this;
 547         }
 548
 549         /**
 550          * Add parameters that are expiration times and will be passed through
 551          * Language::formatExpiry before substitution
 552          *
 553          * @since 1.22
 554          *
 555          * @param string|string[] $param,... Expiry parameters, or a single argument that is
 556          * an array of expiry parameters.
 557          *
 558          * @return Message $this
 559          */
 560         public function expiryParams( /*...*/ ) {
 561                 $params = func_get_args();
 562                 if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 563                         $params = $params[0];
 564                 }
 565                 foreach ( $params as $param ) {
 566                         $this->parameters[] = self::expiryParam( $param );
 567                 }
 568                 return $this;
 569         }
 570
 571         /**
 572          * Add parameters that are time periods and will be passed through
 573          * Language::formatTimePeriod before substitution
 574          *
 575          * @since 1.22
 576          *
 577          * @param int|int[] $param,... Time period parameters, or a single argument that is
 578          * an array of time period parameters.
 579          *
 580          * @return Message $this
 581          */
 582         public function timeperiodParams( /*...*/ ) {
 583                 $params = func_get_args();
 584                 if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 585                         $params = $params[0];
 586                 }
 587                 foreach ( $params as $param ) {
 588                         $this->parameters[] = self::timeperiodParam( $param );
 589                 }
 590                 return $this;
 591         }
 592
 593         /**
 594          * Add parameters that are file sizes and will be passed through
 595          * Language::formatSize before substitution
 596          *
 597          * @since 1.22
 598          *
 599          * @param int|int[] $param,... Size parameters, or a single argument that is
 600          * an array of size parameters.
 601          *
 602          * @return Message $this
 603          */
 604         public function sizeParams( /*...*/ ) {
 605                 $params = func_get_args();
 606                 if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 607                         $params = $params[0];
 608                 }
 609                 foreach ( $params as $param ) {
 610                         $this->parameters[] = self::sizeParam( $param );
 611                 }
 612                 return $this;
 613         }
 614
 615         /**
 616          * Add parameters that are bitrates and will be passed through
 617          * Language::formatBitrate before substitution
 618          *
 619          * @since 1.22
 620          *
 621          * @param int|int[] $param,... Bit rate parameters, or a single argument that is
 622          * an array of bit rate parameters.
 623          *
 624          * @return Message $this
 625          */
 626         public function bitrateParams( /*...*/ ) {
 627                 $params = func_get_args();
 628                 if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 629                         $params = $params[0];
 630                 }
 631                 foreach ( $params as $param ) {
 632                         $this->parameters[] = self::bitrateParam( $param );
 633                 }
 634                 return $this;
 635         }
 636
 637         /**
 638          * Add parameters that are plaintext and will be passed through without
 639          * the content being evaluated.  Plaintext parameters are not valid as
 640          * arguments to parser functions. This differs from self::rawParams in
 641          * that the Message class handles escaping to match the output format.
 642          *
 643          * @since 1.25
 644          *
 645          * @param string|string[] $param,... plaintext parameters, or a single argument that is
 646          * an array of plaintext parameters.
 647          *
 648          * @return Message $this
 649          */
 650         public function plaintextParams( /*...*/ ) {
 651                 $params = func_get_args();
 652                 if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 653                         $params = $params[0];
 654                 }
 655                 foreach ( $params as $param ) {
 656                         $this->parameters[] = self::plaintextParam( $param );
 657                 }
 658                 return $this;
 659         }
 660
 661         /**
 662          * Set the language and the title from a context object
 663          *
 664          * @since 1.19
 665          *
 666          * @param IContextSource $context
 667          *
 668          * @return Message $this
 669          */
 670         public function setContext( IContextSource $context ) {
 671                 $this->inLanguage( $context->getLanguage() );
 672                 $this->title( $context->getTitle() );
 673                 $this->interface = true;
 674
 675                 return $this;
 676         }
 677
 678         /**
 679          * Request the message in any language that is supported.
 680          *
 681          * As a side effect interface message status is unconditionally
 682          * turned off.
 683          *
 684          * @since 1.17
 685          * @param Language|string $lang Language code or Language object.
 686          * @return Message $this
 687          * @throws MWException
 688          */
 689         public function inLanguage( $lang ) {
 690                 if ( $lang instanceof Language ) {
 691                         $this->language = $lang;
 692                 } elseif ( is_string( $lang ) ) {
 693                         if ( !$this->language instanceof Language || $this->language->getCode() != $lang ) {
 694                                 $this->language = Language::factory( $lang );
 695                         }
 696                 } elseif ( $lang instanceof StubUserLang ) {
 697                         $this->language = false;
 698                 } else {
 699                         $type = gettype( $lang );
 700                         throw new MWException( __METHOD__ . " must be "
 701                                 . "passed a String or Language object; $type given"
 702                         );
 703                 }
 704                 $this->message = null;
 705                 $this->interface = false;
 706                 return $this;
 707         }
 708
 709         /**
 710          * Request the message in the wiki's content language,
 711          * unless it is disabled for this message.
 712          *
 713          * @since 1.17
 714          * @see $wgForceUIMsgAsContentMsg
 715          *
 716          * @return Message $this
 717          */
 718         public function inContentLanguage() {
 719                 global $wgForceUIMsgAsContentMsg;
 720                 if ( in_array( $this->key, (array)$wgForceUIMsgAsContentMsg ) ) {
 721                         return $this;
 722                 }
 723
 724                 global $wgContLang;
 725                 $this->inLanguage( $wgContLang );
 726                 return $this;
 727         }
 728
 729         /**
 730          * Allows manipulating the interface message flag directly.
 731          * Can be used to restore the flag after setting a language.
 732          *
 733          * @since 1.20
 734          *
 735          * @param bool $interface
 736          *
 737          * @return Message $this
 738          */
 739         public function setInterfaceMessageFlag( $interface ) {
 740                 $this->interface = (bool)$interface;
 741                 return $this;
 742         }
 743
 744         /**
 745          * Enable or disable database use.
 746          *
 747          * @since 1.17
 748          *
 749          * @param bool $useDatabase
 750          *
 751          * @return Message $this
 752          */
 753         public function useDatabase( $useDatabase ) {
 754                 $this->useDatabase = (bool)$useDatabase;
 755                 return $this;
 756         }
 757
 758         /**
 759          * Set the Title object to use as context when transforming the message
 760          *
 761          * @since 1.18
 762          *
 763          * @param Title $title
 764          *
 765          * @return Message $this
 766          */
 767         public function title( $title ) {
 768                 $this->title = $title;
 769                 return $this;
 770         }
 771
 772         /**
 773          * Returns the message as a Content object.
 774          *
 775          * @return Content
 776          */
 777         public function content() {
 778                 if ( !$this->content ) {
 779                         $this->content = new MessageContent( $this );
 780                 }
 781
 782                 return $this->content;
 783         }
 784
 785         /**
 786          * Returns the message parsed from wikitext to HTML.
 787          *
 788          * @since 1.17
 789          *
 790          * @return string HTML
 791          */
 792         public function toString() {
 793                 $string = $this->fetchMessage();
 794
 795                 if ( $string === false ) {
 796                         if ( $this->format === 'plain' || $this->format === 'text' ) {
 797                                 return '<' . $this->key . '>';
 798                         }
 799                         return '&lt;' . htmlspecialchars( $this->key ) . '&gt;';
 800                 }
 801
 802                 # Replace $* with a list of parameters for &uselang=qqx.
 803                 if ( strpos( $string, '$*' ) !== false ) {
 804                         $paramlist = '';
 805                         if ( $this->parameters !== [] ) {
 806                                 $paramlist = ': $' . implode( ', $', range( 1, count( $this->parameters ) ) );
 807                         }
 808                         $string = str_replace( '$*', $paramlist, $string );
 809                 }
 810
 811                 # Replace parameters before text parsing
 812                 $string = $this->replaceParameters( $string, 'before' );
 813
 814                 # Maybe transform using the full parser
 815                 if ( $this->format === 'parse' ) {
 816                         $string = $this->parseText( $string );
 817                         $string = Parser::stripOuterParagraph( $string );
 818                 } elseif ( $this->format === 'block-parse' ) {
 819                         $string = $this->parseText( $string );
 820                 } elseif ( $this->format === 'text' ) {
 821                         $string = $this->transformText( $string );
 822                 } elseif ( $this->format === 'escaped' ) {
 823                         $string = $this->transformText( $string );
 824                         $string = htmlspecialchars( $string, ENT_QUOTES, 'UTF-8', false );
 825                 }
 826
 827                 # Raw parameter replacement
 828                 $string = $this->replaceParameters( $string, 'after' );
 829
 830                 return $string;
 831         }
 832
 833         /**
 834          * Magic method implementation of the above (for PHP >= 5.2.0), so we can do, eg:
 835          *     $foo = new Message( $key );
 836          *     $string = "<abbr>$foo</abbr>";
 837          *
 838          * @since 1.18
 839          *
 840          * @return string
 841          */
 842         public function __toString() {
 843                 // PHP doesn't allow __toString to throw exceptions and will
 844                 // trigger a fatal error if it does. So, catch any exceptions.
 845
 846                 try {
 847                         return $this->toString();
 848                 } catch ( Exception $ex ) {
 849                         try {
 850                                 trigger_error( "Exception caught in " . __METHOD__ . " (message " . $this->key . "): "
 851                                         . $ex, E_USER_WARNING );
 852                         } catch ( Exception $ex ) {
 853                                 // Doh! Cause a fatal error after all?
 854                         }
 855
 856                         if ( $this->format === 'plain' || $this->format === 'text' ) {
 857                                 return '<' . $this->key . '>';
 858                         }
 859                         return '&lt;' . htmlspecialchars( $this->key ) . '&gt;';
 860                 }
 861         }
 862
 863         /**
 864          * Fully parse the text from wikitext to HTML.
 865          *
 866          * @since 1.17
 867          *
 868          * @return string Parsed HTML.
 869          */
 870         public function parse() {
 871                 $this->format = 'parse';
 872                 return $this->toString();
 873         }
 874
 875         /**
 876          * Returns the message text. {{-transformation is done.
 877          *
 878          * @since 1.17
 879          *
 880          * @return string Unescaped message text.
 881          */
 882         public function text() {
 883                 $this->format = 'text';
 884                 return $this->toString();
 885         }
 886
 887         /**
 888          * Returns the message text as-is, only parameters are substituted.
 889          *
 890          * @since 1.17
 891          *
 892          * @return string Unescaped untransformed message text.
 893          */
 894         public function plain() {
 895                 $this->format = 'plain';
 896                 return $this->toString();
 897         }
 898
 899         /**
 900          * Returns the parsed message text which is always surrounded by a block element.
 901          *
 902          * @since 1.17
 903          *
 904          * @return string HTML
 905          */
 906         public function parseAsBlock() {
 907                 $this->format = 'block-parse';
 908                 return $this->toString();
 909         }
 910
 911         /**
 912          * Returns the message text. {{-transformation is done and the result
 913          * is escaped excluding any raw parameters.
 914          *
 915          * @since 1.17
 916          *
 917          * @return string Escaped message text.
 918          */
 919         public function escaped() {
 920                 $this->format = 'escaped';
 921                 return $this->toString();
 922         }
 923
 924         /**
 925          * Check whether a message key has been defined currently.
 926          *
 927          * @since 1.17
 928          *
 929          * @return bool
 930          */
 931         public function exists() {
 932                 return $this->fetchMessage() !== false;
 933         }
 934
 935         /**
 936          * Check whether a message does not exist, or is an empty string
 937          *
 938          * @since 1.18
 939          * @todo FIXME: Merge with isDisabled()?
 940          *
 941          * @return bool
 942          */
 943         public function isBlank() {
 944                 $message = $this->fetchMessage();
 945                 return $message === false || $message === '';
 946         }
 947
 948         /**
 949          * Check whether a message does not exist, is an empty string, or is "-".
 950          *
 951          * @since 1.18
 952          *
 953          * @return bool
 954          */
 955         public function isDisabled() {
 956                 $message = $this->fetchMessage();
 957                 return $message === false || $message === '' || $message === '-';
 958         }
 959
 960         /**
 961          * @since 1.17
 962          *
 963          * @param mixed $raw
 964          *
 965          * @return array Array with a single "raw" key.
 966          */
 967         public static function rawParam( $raw ) {
 968                 return [ 'raw' => $raw ];
 969         }
 970
 971         /**
 972          * @since 1.18
 973          *
 974          * @param mixed $num
 975          *
 976          * @return array Array with a single "num" key.
 977          */
 978         public static function numParam( $num ) {
 979                 return [ 'num' => $num ];
 980         }
 981
 982         /**
 983          * @since 1.22
 984          *
 985          * @param int $duration
 986          *
 987          * @return int[] Array with a single "duration" key.
 988          */
 989         public static function durationParam( $duration ) {
 990                 return [ 'duration' => $duration ];
 991         }
 992
 993         /**
 994          * @since 1.22
 995          *
 996          * @param string $expiry
 997          *
 998          * @return string[] Array with a single "expiry" key.
 999          */
1000         public static function expiryParam( $expiry ) {
1001                 return [ 'expiry' => $expiry ];
1002         }
1003
1004         /**
1005          * @since 1.22
1006          *
1007          * @param number $period
1008          *
1009          * @return number[] Array with a single "period" key.
1010          */
1011         public static function timeperiodParam( $period ) {
1012                 return [ 'period' => $period ];
1013         }
1014
1015         /**
1016          * @since 1.22
1017          *
1018          * @param int $size
1019          *
1020          * @return int[] Array with a single "size" key.
1021          */
1022         public static function sizeParam( $size ) {
1023                 return [ 'size' => $size ];
1024         }
1025
1026         /**
1027          * @since 1.22
1028          *
1029          * @param int $bitrate
1030          *
1031          * @return int[] Array with a single "bitrate" key.
1032          */
1033         public static function bitrateParam( $bitrate ) {
1034                 return [ 'bitrate' => $bitrate ];
1035         }
1036
1037         /**
1038          * @since 1.25
1039          *
1040          * @param string $plaintext
1041          *
1042          * @return string[] Array with a single "plaintext" key.
1043          */
1044         public static function plaintextParam( $plaintext ) {
1045                 return [ 'plaintext' => $plaintext ];
1046         }
1047
1048         /**
1049          * Substitutes any parameters into the message text.
1050          *
1051          * @since 1.17
1052          *
1053          * @param string $message The message text.
1054          * @param string $type Either "before" or "after".
1055          *
1056          * @return string
1057          */
1058         protected function replaceParameters( $message, $type = 'before' ) {
1059                 $replacementKeys = [];
1060                 foreach ( $this->parameters as $n => $param ) {
1061                         list( $paramType, $value ) = $this->extractParam( $param );
1062                         if ( $type === $paramType ) {
1063                                 $replacementKeys['$' . ( $n + 1 )] = $value;
1064                         }
1065                 }
1066                 $message = strtr( $message, $replacementKeys );
1067                 return $message;
1068         }
1069
1070         /**
1071          * Extracts the parameter type and preprocessed the value if needed.
1072          *
1073          * @since 1.18
1074          *
1075          * @param mixed $param Parameter as defined in this class.
1076          *
1077          * @return array Array with the parameter type (either "before" or "after") and the value.
1078          */
1079         protected function extractParam( $param ) {
1080                 if ( is_array( $param ) ) {
1081                         if ( isset( $param['raw'] ) ) {
1082                                 return [ 'after', $param['raw'] ];
1083                         } elseif ( isset( $param['num'] ) ) {
1084                                 // Replace number params always in before step for now.
1085                                 // No support for combined raw and num params
1086                                 return [ 'before', $this->getLanguage()->formatNum( $param['num'] ) ];
1087                         } elseif ( isset( $param['duration'] ) ) {
1088                                 return [ 'before', $this->getLanguage()->formatDuration( $param['duration'] ) ];
1089                         } elseif ( isset( $param['expiry'] ) ) {
1090                                 return [ 'before', $this->getLanguage()->formatExpiry( $param['expiry'] ) ];
1091                         } elseif ( isset( $param['period'] ) ) {
1092                                 return [ 'before', $this->getLanguage()->formatTimePeriod( $param['period'] ) ];
1093                         } elseif ( isset( $param['size'] ) ) {
1094                                 return [ 'before', $this->getLanguage()->formatSize( $param['size'] ) ];
1095                         } elseif ( isset( $param['bitrate'] ) ) {
1096                                 return [ 'before', $this->getLanguage()->formatBitrate( $param['bitrate'] ) ];
1097                         } elseif ( isset( $param['plaintext'] ) ) {
1098                                 return [ 'after', $this->formatPlaintext( $param['plaintext'] ) ];
1099                         } else {
1100                                 $warning = 'Invalid parameter for message "' . $this->getKey() . '": ' .
1101                                         htmlspecialchars( serialize( $param ) );
1102                                 trigger_error( $warning, E_USER_WARNING );
1103                                 $e = new Exception;
1104                                 wfDebugLog( 'Bug58676', $warning . "\n" . $e->getTraceAsString() );
1105
1106                                 return [ 'before', '[INVALID]' ];
1107                         }
1108                 } elseif ( $param instanceof Message ) {
1109                         // Message objects should not be before parameters because
1110                         // then they'll get double escaped. If the message needs to be
1111                         // escaped, it'll happen right here when we call toString().
1112                         return [ 'after', $param->toString() ];
1113                 } else {
1114                         return [ 'before', $param ];
1115                 }
1116         }
1117
1118         /**
1119          * Wrapper for what ever method we use to parse wikitext.
1120          *
1121          * @since 1.17
1122          *
1123          * @param string $string Wikitext message contents.
1124          *
1125          * @return string Wikitext parsed into HTML.
1126          */
1127         protected function parseText( $string ) {
1128                 $out = MessageCache::singleton()->parse(
1129                         $string,
1130                         $this->title,
1131                         /*linestart*/true,
1132                         $this->interface,
1133                         $this->getLanguage()
1134                 );
1135
1136                 return $out instanceof ParserOutput ? $out->getText() : $out;
1137         }
1138
1139         /**
1140          * Wrapper for what ever method we use to {{-transform wikitext.
1141          *
1142          * @since 1.17
1143          *
1144          * @param string $string Wikitext message contents.
1145          *
1146          * @return string Wikitext with {{-constructs replaced with their values.
1147          */
1148         protected function transformText( $string ) {
1149                 return MessageCache::singleton()->transform(
1150                         $string,
1151                         $this->interface,
1152                         $this->getLanguage(),
1153                         $this->title
1154                 );
1155         }
1156
1157         /**
1158          * Wrapper for what ever method we use to get message contents.
1159          *
1160          * @since 1.17
1161          *
1162          * @return string
1163          * @throws MWException If message key array is empty.
1164          */
1165         protected function fetchMessage() {
1166                 if ( $this->message === null ) {
1167                         $cache = MessageCache::singleton();
1168
1169                         foreach ( $this->keysToTry as $key ) {
1170                                 $message = $cache->get( $key, $this->useDatabase, $this->getLanguage() );
1171                                 if ( $message !== false && $message !== '' ) {
1172                                         break;
1173                                 }
1174                         }
1175
1176                         // NOTE: The constructor makes sure keysToTry isn't empty,
1177                         //       so we know that $key and $message are initialized.
1178                         $this->key = $key;
1179                         $this->message = $message;
1180                 }
1181                 return $this->message;
1182         }
1183
1184         /**
1185          * Formats a message parameter wrapped with 'plaintext'. Ensures that
1186          * the entire string is displayed unchanged when displayed in the output
1187          * format.
1188          *
1189          * @since 1.25
1190          *
1191          * @param string $plaintext String to ensure plaintext output of
1192          *
1193          * @return string Input plaintext encoded for output to $this->format
1194          */
1195         protected function formatPlaintext( $plaintext ) {
1196                 switch ( $this->format ) {
1197                 case 'text':
1198                 case 'plain':
1199                         return $plaintext;
1200
1201                 case 'parse':
1202                 case 'block-parse':
1203                 case 'escaped':
1204                 default:
1205                         return htmlspecialchars( $plaintext, ENT_QUOTES );
1206
1207                 }
1208         }
1209 }
1210
1211 /**
1212  * Variant of the Message class.
1213  *
1214  * Rather than treating the message key as a lookup
1215  * value (which is passed to the MessageCache and
1216  * translated as necessary), a RawMessage key is
1217  * treated as the actual message.
1218  *
1219  * All other functionality (parsing, escaping, etc.)
1220  * is preserved.
1221  *
1222  * @since 1.21
1223  */
1224 class RawMessage extends Message {
1225
1226         /**
1227          * Call the parent constructor, then store the key as
1228          * the message.
1229          *
1230          * @see Message::__construct
1231          *
1232          * @param string $text Message to use.
1233          * @param array $params Parameters for the message.
1234          *
1235          * @throws InvalidArgumentException
1236          */
1237         public function __construct( $text, $params = [] ) {
1238                 if ( !is_string( $text ) ) {
1239                         throw new InvalidArgumentException( '$text must be a string' );
1240                 }
1241
1242                 parent::__construct( $text, $params );
1243
1244                 // The key is the message.
1245                 $this->message = $text;
1246         }
1247
1248         /**
1249          * Fetch the message (in this case, the key).
1250          *
1251          * @return string
1252          */
1253         public function fetchMessage() {
1254                 // Just in case the message is unset somewhere.
1255                 if ( $this->message === null ) {
1256                         $this->message = $this->key;
1257                 }
1258
1259                 return $this->message;
1260         }
1261
1262 }