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 fullfil 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 intented 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          * In which language to get this message. True, which is the default,
 162          * means the current interface language, false content language.
 163          */
 164         protected $interface = true;
 165
 166         /**
 167          * In which language to get this message. Overrides the $interface
 168          * variable.
 169          *
 170          * @var Language
 171          */
 172         protected $language = null;
 173
 174         /**
 175          * The message key.
 176          */
 177         protected $key;
 178
 179         /**
 180          * List of parameters which will be substituted into the message.
 181          */
 182         protected $parameters = array();
 183
 184         /**
 185          * Format for the message.
 186          * Supported formats are:
 187          * * text (transform)
 188          * * escaped (transform+htmlspecialchars)
 189          * * block-parse
 190          * * parse (default)
 191          * * plain
 192          */
 193         protected $format = 'parse';
 194
 195         /**
 196          * Whether database can be used.
 197          */
 198         protected $useDatabase = true;
 199
 200         /**
 201          * Title object to use as context
 202          */
 203         protected $title = null;
 204
 205         /**
 206          * Content object representing the message
 207          */
 208         protected $content = null;
 209
 210         /**
 211          * @var string
 212          */
 213         protected $message;
 214
 215         /**
 216          * Constructor.
 217          * @since 1.17
 218          * @param $key: message key, or array of message keys to try and use the first non-empty message for
 219          * @param $params Array message parameters
 220          * @return Message: $this
 221          */
 222         public function __construct( $key, $params = array() ) {
 223                 global $wgLang;
 224                 $this->key = $key;
 225                 $this->parameters = array_values( $params );
 226                 $this->language = $wgLang;
 227         }
 228
 229         /**
 230          * Factory function that is just wrapper for the real constructor. It is
 231          * intented to be used instead of the real constructor, because it allows
 232          * chaining method calls, while new objects don't.
 233          * @since 1.17
 234          * @param $key String: message key
 235          * @param Varargs: parameters as Strings
 236          * @return Message: $this
 237          */
 238         public static function newFromKey( $key /*...*/ ) {
 239                 $params = func_get_args();
 240                 array_shift( $params );
 241                 return new self( $key, $params );
 242         }
 243
 244         /**
 245          * Factory function accepting multiple message keys and returning a message instance
 246          * for the first message which is non-empty. If all messages are empty then an
 247          * instance of the first message key is returned.
 248          * @since 1.18
 249          * @param Varargs: message keys (or first arg as an array of all the message keys)
 250          * @return Message: $this
 251          */
 252         public static function newFallbackSequence( /*...*/ ) {
 253                 $keys = func_get_args();
 254                 if ( func_num_args() == 1 ) {
 255                         if ( is_array($keys[0]) ) {
 256                                 // Allow an array to be passed as the first argument instead
 257                                 $keys = array_values($keys[0]);
 258                         } else {
 259                                 // Optimize a single string to not need special fallback handling
 260                                 $keys = $keys[0];
 261                         }
 262                 }
 263                 return new self( $keys );
 264         }
 265
 266         /**
 267          * Adds parameters to the parameter list of this message.
 268          * @since 1.17
 269          * @param Varargs: parameters as Strings, or a single argument that is an array of Strings
 270          * @return Message: $this
 271          */
 272         public function params( /*...*/ ) {
 273                 $args = func_get_args();
 274                 if ( isset( $args[0] ) && is_array( $args[0] ) ) {
 275                         $args = $args[0];
 276                 }
 277                 $args_values = array_values( $args );
 278                 $this->parameters = array_merge( $this->parameters, $args_values );
 279                 return $this;
 280         }
 281
 282         /**
 283          * Add parameters that are substituted after parsing or escaping.
 284          * In other words the parsing process cannot access the contents
 285          * of this type of parameter, and you need to make sure it is
 286          * sanitized beforehand.  The parser will see "$n", instead.
 287          * @since 1.17
 288          * @param Varargs: raw parameters as Strings (or single argument that is an array of raw parameters)
 289          * @return Message: $this
 290          */
 291         public function rawParams( /*...*/ ) {
 292                 $params = func_get_args();
 293                 if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 294                         $params = $params[0];
 295                 }
 296                 foreach( $params as $param ) {
 297                         $this->parameters[] = self::rawParam( $param );
 298                 }
 299                 return $this;
 300         }
 301
 302         /**
 303          * Add parameters that are numeric and will be passed through
 304          * Language::formatNum before substitution
 305          * @since 1.18
 306          * @param Varargs: numeric parameters (or single argument that is array of numeric parameters)
 307          * @return Message: $this
 308          */
 309         public function numParams( /*...*/ ) {
 310                 $params = func_get_args();
 311                 if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 312                         $params = $params[0];
 313                 }
 314                 foreach( $params as $param ) {
 315                         $this->parameters[] = self::numParam( $param );
 316                 }
 317                 return $this;
 318         }
 319
 320         /**
 321          * Set the language and the title from a context object
 322          * @since 1.19
 323          * @param $context IContextSource
 324          * @return Message: $this
 325          */
 326         public function setContext( IContextSource $context ) {
 327                 $this->inLanguage( $context->getLanguage() );
 328                 $this->title( $context->getTitle() );
 329                 $this->interface = true;
 330
 331                 return $this;
 332         }
 333
 334         /**
 335          * Request the message in any language that is supported.
 336          * As a side effect interface message status is unconditionally
 337          * turned off.
 338          * @since 1.17
 339          * @param $lang Mixed: language code or Language object.
 340          * @throws MWException
 341          * @return Message: $this
 342          */
 343         public function inLanguage( $lang ) {
 344                 if ( $lang instanceof Language || $lang instanceof StubUserLang ) {
 345                         $this->language = $lang;
 346                 } elseif ( is_string( $lang ) ) {
 347                         if( $this->language->getCode() != $lang ) {
 348                                 $this->language = Language::factory( $lang );
 349                         }
 350                 } else {
 351                         $type = gettype( $lang );
 352                         throw new MWException( __METHOD__ . " must be "
 353                                 . "passed a String or Language object; $type given"
 354                         );
 355                 }
 356                 $this->interface = false;
 357                 return $this;
 358         }
 359
 360         /**
 361          * Request the message in the wiki's content language,
 362          * unless it is disabled for this message.
 363          * @since 1.17
 364          * @see $wgForceUIMsgAsContentMsg
 365          * @return Message: $this
 366          */
 367         public function inContentLanguage() {
 368                 global $wgForceUIMsgAsContentMsg;
 369                 if ( in_array( $this->key, (array)$wgForceUIMsgAsContentMsg ) ) {
 370                         return $this;
 371                 }
 372
 373                 global $wgContLang;
 374                 $this->interface = false;
 375                 $this->language = $wgContLang;
 376                 return $this;
 377         }
 378
 379         /**
 380          * Allows manipulating the interface message flag directly.
 381          * Can be used to restore the flag after setting a language.
 382          * @param $value bool
 383          * @return Message: $this
 384          * @since 1.20
 385          */
 386         public function setInterfaceMessageFlag( $value ) {
 387                 $this->interface = (bool) $value;
 388                 return $this;
 389         }
 390
 391         /**
 392          * Enable or disable database use.
 393          * @since 1.17
 394          * @param $value Boolean
 395          * @return Message: $this
 396          */
 397         public function useDatabase( $value ) {
 398                 $this->useDatabase = (bool) $value;
 399                 return $this;
 400         }
 401
 402         /**
 403          * Set the Title object to use as context when transforming the message
 404          * @since 1.18
 405          * @param $title Title object
 406          * @return Message: $this
 407          */
 408         public function title( $title ) {
 409                 $this->title = $title;
 410                 return $this;
 411         }
 412
 413         /**
 414          * Returns the message as a Content object.
 415          * @return Content
 416          */
 417         public function content() {
 418                 if ( !$this->content ) {
 419                         $this->content = new MessageContent( $this->key );
 420                 }
 421
 422                 return $this->content;
 423         }
 424
 425         /**
 426          * Returns the message parsed from wikitext to HTML.
 427          * @since 1.17
 428          * @return String: HTML
 429          */
 430         public function toString() {
 431                 $string = $this->fetchMessage();
 432
 433                 if ( $string === false ) {
 434                         $key =  htmlspecialchars( is_array( $this->key ) ? $this->key[0] : $this->key );
 435                         if ( $this->format === 'plain' ) {
 436                                 return '<' . $key . '>';
 437                         }
 438                         return '&lt;' . $key . '&gt;';
 439                 }
 440
 441                 # Replace $* with a list of parameters for &uselang=qqx.
 442                 if ( strpos( $string, '$*' ) !== false ) {
 443                         $paramlist = '';
 444                         if ( $this->parameters !== array() ) {
 445                                 $paramlist = ': $' . implode( ', $', range( 1, count( $this->parameters ) ) );
 446                         }
 447                         $string = str_replace( '$*', $paramlist, $string );
 448                 }
 449
 450                 # Replace parameters before text parsing
 451                 $string = $this->replaceParameters( $string, 'before' );
 452
 453                 # Maybe transform using the full parser
 454                 if( $this->format === 'parse' ) {
 455                         $string = $this->parseText( $string );
 456                         $m = array();
 457                         if( preg_match( '/^<p>(.*)\n?<\/p>\n?$/sU', $string, $m ) ) {
 458                                 $string = $m[1];
 459                         }
 460                 } elseif( $this->format === 'block-parse' ) {
 461                         $string = $this->parseText( $string );
 462                 } elseif( $this->format === 'text' ) {
 463                         $string = $this->transformText( $string );
 464                 } elseif( $this->format === 'escaped' ) {
 465                         $string = $this->transformText( $string );
 466                         $string = htmlspecialchars( $string, ENT_QUOTES, 'UTF-8', false );
 467                 }
 468
 469                 # Raw parameter replacement
 470                 $string = $this->replaceParameters( $string, 'after' );
 471
 472                 return $string;
 473         }
 474
 475         /**
 476          * Magic method implementation of the above (for PHP >= 5.2.0), so we can do, eg:
 477          *     $foo = Message::get($key);
 478          *     $string = "<abbr>$foo</abbr>";
 479          * @since 1.18
 480          * @return String
 481          */
 482         public function __toString() {
 483                 // PHP doesn't allow __toString to throw exceptions and will
 484                 // trigger a fatal error if it does. So, catch any exceptions.
 485
 486                 try {
 487                         return $this->toString();
 488                 } catch ( Exception $ex ) {
 489                         try {
 490                                 trigger_error( "Exception caught in " . __METHOD__ . " (message " . $this->key . "): "
 491                                         . $ex, E_USER_WARNING );
 492                         } catch ( Exception $ex ) {
 493                                 // Doh! Cause a fatal error after all?
 494                         }
 495
 496                         if ( $this->format === 'plain' ) {
 497                                 return '<' . $this->key . '>';
 498                         }
 499                         return '&lt;' . $this->key . '&gt;';
 500                 }
 501         }
 502
 503         /**
 504          * Fully parse the text from wikitext to HTML
 505          * @since 1.17
 506          * @return String parsed HTML
 507          */
 508         public function parse() {
 509                 $this->format = 'parse';
 510                 return $this->toString();
 511         }
 512
 513         /**
 514          * Returns the message text. {{-transformation is done.
 515          * @since 1.17
 516          * @return String: Unescaped message text.
 517          */
 518         public function text() {
 519                 $this->format = 'text';
 520                 return $this->toString();
 521         }
 522
 523         /**
 524          * Returns the message text as-is, only parameters are subsituted.
 525          * @since 1.17
 526          * @return String: Unescaped untransformed message text.
 527          */
 528         public function plain() {
 529                 $this->format = 'plain';
 530                 return $this->toString();
 531         }
 532
 533         /**
 534          * Returns the parsed message text which is always surrounded by a block element.
 535          * @since 1.17
 536          * @return String: HTML
 537          */
 538         public function parseAsBlock() {
 539                 $this->format = 'block-parse';
 540                 return $this->toString();
 541         }
 542
 543         /**
 544          * Returns the message text. {{-transformation is done and the result
 545          * is escaped excluding any raw parameters.
 546          * @since 1.17
 547          * @return String: Escaped message text.
 548          */
 549         public function escaped() {
 550                 $this->format = 'escaped';
 551                 return $this->toString();
 552         }
 553
 554         /**
 555          * Check whether a message key has been defined currently.
 556          * @since 1.17
 557          * @return Bool: true if it is and false if not.
 558          */
 559         public function exists() {
 560                 return $this->fetchMessage() !== false;
 561         }
 562
 563         /**
 564          * Check whether a message does not exist, or is an empty string
 565          * @since 1.18
 566          * @return Bool: true if is is and false if not
 567          * @todo FIXME: Merge with isDisabled()?
 568          */
 569         public function isBlank() {
 570                 $message = $this->fetchMessage();
 571                 return $message === false || $message === '';
 572         }
 573
 574         /**
 575          * Check whether a message does not exist, is an empty string, or is "-"
 576          * @since 1.18
 577          * @return Bool: true if it is and false if not
 578          */
 579         public function isDisabled() {
 580                 $message = $this->fetchMessage();
 581                 return $message === false || $message === '' || $message === '-';
 582         }
 583
 584         /**
 585          * @since 1.17
 586          * @param $value
 587          * @return array
 588          */
 589         public static function rawParam( $value ) {
 590                 return array( 'raw' => $value );
 591         }
 592
 593         /**
 594          * @since 1.18
 595          * @param $value
 596          * @return array
 597          */
 598         public static function numParam( $value ) {
 599                 return array( 'num' => $value );
 600         }
 601
 602         /**
 603          * Substitutes any paramaters into the message text.
 604          * @since 1.17
 605          * @param $message String: the message text
 606          * @param $type String: either before or after
 607          * @return String
 608          */
 609         protected function replaceParameters( $message, $type = 'before' ) {
 610                 $replacementKeys = array();
 611                 foreach( $this->parameters as $n => $param ) {
 612                         list( $paramType, $value ) = $this->extractParam( $param );
 613                         if ( $type === $paramType ) {
 614                                 $replacementKeys['$' . ($n + 1)] = $value;
 615                         }
 616                 }
 617                 $message = strtr( $message, $replacementKeys );
 618                 return $message;
 619         }
 620
 621         /**
 622          * Extracts the parameter type and preprocessed the value if needed.
 623          * @since 1.18
 624          * @param $param String|Array: Parameter as defined in this class.
 625          * @return Tuple(type, value)
 626          */
 627         protected function extractParam( $param ) {
 628                 if ( is_array( $param ) && isset( $param['raw'] ) ) {
 629                         return array( 'after', $param['raw'] );
 630                 } elseif ( is_array( $param ) && isset( $param['num'] ) ) {
 631                         // Replace number params always in before step for now.
 632                         // No support for combined raw and num params
 633                         return array( 'before', $this->language->formatNum( $param['num'] ) );
 634                 } elseif ( !is_array( $param ) ) {
 635                         return array( 'before', $param );
 636                 } else {
 637                         trigger_error(
 638                                 "Invalid message parameter: " . htmlspecialchars( serialize( $param ) ),
 639                                 E_USER_WARNING
 640                         );
 641                         return array( 'before', '[INVALID]' );
 642                 }
 643         }
 644
 645         /**
 646          * Wrapper for what ever method we use to parse wikitext.
 647          * @since 1.17
 648          * @param $string String: Wikitext message contents
 649          * @return string Wikitext parsed into HTML
 650          */
 651         protected function parseText( $string ) {
 652                 $out = MessageCache::singleton()->parse( $string, $this->title, /*linestart*/true, $this->interface, $this->language );
 653                 return is_object( $out ) ? $out->getText() : $out;
 654         }
 655
 656         /**
 657          * Wrapper for what ever method we use to {{-transform wikitext.
 658          * @since 1.17
 659          * @param $string String: Wikitext message contents
 660          * @return string Wikitext with {{-constructs replaced with their values.
 661          */
 662         protected function transformText( $string ) {
 663                 return MessageCache::singleton()->transform( $string, $this->interface, $this->language, $this->title );
 664         }
 665
 666         /**
 667          * Wrapper for what ever method we use to get message contents
 668          * @since 1.17
 669          * @throws MWException
 670          * @return string
 671          */
 672         protected function fetchMessage() {
 673                 if ( !isset( $this->message ) ) {
 674                         $cache = MessageCache::singleton();
 675                         if ( is_array( $this->key ) ) {
 676                                 if ( !count( $this->key ) ) {
 677                                         throw new MWException( "Given empty message key array." );
 678                                 }
 679                                 foreach ( $this->key as $key ) {
 680                                         $message = $cache->get( $key, $this->useDatabase, $this->language );
 681                                         if ( $message !== false && $message !== '' ) {
 682                                                 break;
 683                                         }
 684                                 }
 685                                 $this->message = $message;
 686                         } else {
 687                                 $this->message = $cache->get( $this->key, $this->useDatabase, $this->language );
 688                         }
 689                 }
 690                 return $this->message;
 691         }
 692
 693 }
 694
 695 /**
 696  * Variant of the Message class.
 697  *
 698  * Rather than treating the message key as a lookup
 699  * value (which is passed to the MessageCache and
 700  * translated as necessary), a RawMessage key is
 701  * treated as the actual message.
 702  *
 703  * All other functionality (parsing, escaping, etc.)
 704  * is preserved.
 705  *
 706  * @since 1.21
 707  */
 708 class RawMessage extends Message {
 709         /**
 710          * Call the parent constructor, then store the key as
 711          * the message.
 712          *
 713          * @param $key Message to use
 714          * @param $params Parameters for the message
 715          * @see Message::__construct
 716          */
 717         public function __construct( $key, $params = array() ) {
 718                 parent::__construct( $key, $params );
 719                 // The key is the message.
 720                 $this->message = $key;
 721         }
 722
 723         /**
 724          * Fetch the message (in this case, the key).
 725          *
 726          * @return string
 727          */
 728         public function fetchMessage() {
 729                 // Just in case the message is unset somewhere.
 730                 if( !isset( $this->message ) ) {
 731                         $this->message = $this->key;
 732                 }
 733                 return $this->message;
 734         }
 735 }