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          * @var string
 207          */
 208         protected $message;
 209
 210         /**
 211          * Constructor.
 212          * @param $key: message key, or array of message keys to try and use the first non-empty message for
 213          * @param $params Array message parameters
 214          * @return Message: $this
 215          */
 216         public function __construct( $key, $params = array() ) {
 217                 global $wgLang;
 218                 $this->key = $key;
 219                 $this->parameters = array_values( $params );
 220                 $this->language = $wgLang;
 221         }
 222
 223         /**
 224          * Factory function that is just wrapper for the real constructor. It is
 225          * intented to be used instead of the real constructor, because it allows
 226          * chaining method calls, while new objects don't.
 227          * @param $key String: message key
 228          * @param Varargs: parameters as Strings
 229          * @return Message: $this
 230          */
 231         public static function newFromKey( $key /*...*/ ) {
 232                 $params = func_get_args();
 233                 array_shift( $params );
 234                 return new self( $key, $params );
 235         }
 236
 237         /**
 238          * Factory function accepting multiple message keys and returning a message instance
 239          * for the first message which is non-empty. If all messages are empty then an
 240          * instance of the first message key is returned.
 241          * @param Varargs: message keys (or first arg as an array of all the message keys)
 242          * @return Message: $this
 243          */
 244         public static function newFallbackSequence( /*...*/ ) {
 245                 $keys = func_get_args();
 246                 if ( func_num_args() == 1 ) {
 247                         if ( is_array($keys[0]) ) {
 248                                 // Allow an array to be passed as the first argument instead
 249                                 $keys = array_values($keys[0]);
 250                         } else {
 251                                 // Optimize a single string to not need special fallback handling
 252                                 $keys = $keys[0];
 253                         }
 254                 }
 255                 return new self( $keys );
 256         }
 257
 258         /**
 259          * Adds parameters to the parameter list of this message.
 260          * @param Varargs: parameters as Strings, or a single argument that is an array of Strings
 261          * @return Message: $this
 262          */
 263         public function params( /*...*/ ) {
 264                 $args = func_get_args();
 265                 if ( isset( $args[0] ) && is_array( $args[0] ) ) {
 266                         $args = $args[0];
 267                 }
 268                 $args_values = array_values( $args );
 269                 $this->parameters = array_merge( $this->parameters, $args_values );
 270                 return $this;
 271         }
 272
 273         /**
 274          * Add parameters that are substituted after parsing or escaping.
 275          * In other words the parsing process cannot access the contents
 276          * of this type of parameter, and you need to make sure it is
 277          * sanitized beforehand.  The parser will see "$n", instead.
 278          * @param Varargs: raw parameters as Strings (or single argument that is an array of raw parameters)
 279          * @return Message: $this
 280          */
 281         public function rawParams( /*...*/ ) {
 282                 $params = func_get_args();
 283                 if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 284                         $params = $params[0];
 285                 }
 286                 foreach( $params as $param ) {
 287                         $this->parameters[] = self::rawParam( $param );
 288                 }
 289                 return $this;
 290         }
 291
 292         /**
 293          * Add parameters that are numeric and will be passed through
 294          * Language::formatNum before substitution
 295          * @param Varargs: numeric parameters (or single argument that is array of numeric parameters)
 296          * @return Message: $this
 297          */
 298         public function numParams( /*...*/ ) {
 299                 $params = func_get_args();
 300                 if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 301                         $params = $params[0];
 302                 }
 303                 foreach( $params as $param ) {
 304                         $this->parameters[] = self::numParam( $param );
 305                 }
 306                 return $this;
 307         }
 308
 309         /**
 310          * Set the language and the title from a context object
 311          *
 312          * @param $context IContextSource
 313          * @return Message: $this
 314          */
 315         public function setContext( IContextSource $context ) {
 316                 $this->inLanguage( $context->getLanguage() );
 317                 $this->title( $context->getTitle() );
 318                 $this->interface = true;
 319
 320                 return $this;
 321         }
 322
 323         /**
 324          * Request the message in any language that is supported.
 325          * As a side effect interface message status is unconditionally
 326          * turned off.
 327          * @since 1.17
 328          * @param $lang Mixed: language code or Language object.
 329          * @return Message: $this
 330          */
 331         public function inLanguage( $lang ) {
 332                 if ( $lang instanceof Language || $lang instanceof StubUserLang ) {
 333                         $this->language = $lang;
 334                 } elseif ( is_string( $lang ) ) {
 335                         if( $this->language->getCode() != $lang ) {
 336                                 $this->language = Language::factory( $lang );
 337                         }
 338                 } else {
 339                         $type = gettype( $lang );
 340                         throw new MWException( __METHOD__ . " must be "
 341                                 . "passed a String or Language object; $type given"
 342                         );
 343                 }
 344                 $this->interface = false;
 345                 return $this;
 346         }
 347
 348         /**
 349          * Request the message in the wiki's content language,
 350          * unless it is disabled for this message.
 351          * @since 1.17
 352          * @see $wgForceUIMsgAsContentMsg
 353          * @return Message: $this
 354          */
 355         public function inContentLanguage() {
 356                 global $wgForceUIMsgAsContentMsg;
 357                 if ( in_array( $this->key, (array)$wgForceUIMsgAsContentMsg ) ) {
 358                         return $this;
 359                 }
 360
 361                 global $wgContLang;
 362                 $this->interface = false;
 363                 $this->language = $wgContLang;
 364                 return $this;
 365         }
 366
 367         /**
 368          * Allows manipulating the interface message flag directly.
 369          * Can be used to restore the flag after setting a language.
 370          * @param $value bool
 371          * @return Message: $this
 372          * @since 1.20
 373          */
 374         public function setInterfaceMessageFlag( $value ) {
 375                 $this->interface = (bool) $value;
 376                 return $this;
 377         }
 378
 379         /**
 380          * Enable or disable database use.
 381          * @param $value Boolean
 382          * @return Message: $this
 383          */
 384         public function useDatabase( $value ) {
 385                 $this->useDatabase = (bool) $value;
 386                 return $this;
 387         }
 388
 389         /**
 390          * Set the Title object to use as context when transforming the message
 391          *
 392          * @param $title Title object
 393          * @return Message: $this
 394          */
 395         public function title( $title ) {
 396                 $this->title = $title;
 397                 return $this;
 398         }
 399
 400         /**
 401          * Returns the message parsed from wikitext to HTML.
 402          * @return String: HTML
 403          */
 404         public function toString() {
 405                 $string = $this->fetchMessage();
 406
 407                 if ( $string === false ) {
 408                         $key =  htmlspecialchars( is_array( $this->key ) ? $this->key[0] : $this->key );
 409                         if ( $this->format === 'plain' ) {
 410                                 return '<' . $key . '>';
 411                         }
 412                         return '&lt;' . $key . '&gt;';
 413                 }
 414
 415                 # Replace parameters before text parsing
 416                 $string = $this->replaceParameters( $string, 'before' );
 417
 418                 # Maybe transform using the full parser
 419                 if( $this->format === 'parse' ) {
 420                         $string = $this->parseText( $string );
 421                         $m = array();
 422                         if( preg_match( '/^<p>(.*)\n?<\/p>\n?$/sU', $string, $m ) ) {
 423                                 $string = $m[1];
 424                         }
 425                 } elseif( $this->format === 'block-parse' ){
 426                         $string = $this->parseText( $string );
 427                 } elseif( $this->format === 'text' ){
 428                         $string = $this->transformText( $string );
 429                 } elseif( $this->format === 'escaped' ){
 430                         $string = $this->transformText( $string );
 431                         $string = htmlspecialchars( $string, ENT_QUOTES, 'UTF-8', false );
 432                 }
 433
 434                 # Raw parameter replacement
 435                 $string = $this->replaceParameters( $string, 'after' );
 436
 437                 return $string;
 438         }
 439
 440         /**
 441          * Magic method implementation of the above (for PHP >= 5.2.0), so we can do, eg:
 442          *     $foo = Message::get($key);
 443          *     $string = "<abbr>$foo</abbr>";
 444          * @return String
 445          */
 446         public function __toString() {
 447                 return $this->toString();
 448         }
 449
 450         /**
 451          * Fully parse the text from wikitext to HTML
 452          * @return String parsed HTML
 453          */
 454         public function parse() {
 455                 $this->format = 'parse';
 456                 return $this->toString();
 457         }
 458
 459         /**
 460          * Returns the message text. {{-transformation is done.
 461          * @return String: Unescaped message text.
 462          */
 463         public function text() {
 464                 $this->format = 'text';
 465                 return $this->toString();
 466         }
 467
 468         /**
 469          * Returns the message text as-is, only parameters are subsituted.
 470          * @return String: Unescaped untransformed message text.
 471          */
 472         public function plain() {
 473                 $this->format = 'plain';
 474                 return $this->toString();
 475         }
 476
 477         /**
 478          * Returns the parsed message text which is always surrounded by a block element.
 479          * @return String: HTML
 480          */
 481         public function parseAsBlock() {
 482                 $this->format = 'block-parse';
 483                 return $this->toString();
 484         }
 485
 486         /**
 487          * Returns the message text. {{-transformation is done and the result
 488          * is escaped excluding any raw parameters.
 489          * @return String: Escaped message text.
 490          */
 491         public function escaped() {
 492                 $this->format = 'escaped';
 493                 return $this->toString();
 494         }
 495
 496         /**
 497          * Check whether a message key has been defined currently.
 498          * @return Bool: true if it is and false if not.
 499          */
 500         public function exists() {
 501                 return $this->fetchMessage() !== false;
 502         }
 503
 504         /**
 505          * Check whether a message does not exist, or is an empty string
 506          * @return Bool: true if is is and false if not
 507          * @todo FIXME: Merge with isDisabled()?
 508          */
 509         public function isBlank() {
 510                 $message = $this->fetchMessage();
 511                 return $message === false || $message === '';
 512         }
 513
 514         /**
 515          * Check whether a message does not exist, is an empty string, or is "-"
 516          * @return Bool: true if is is and false if not
 517          */
 518         public function isDisabled() {
 519                 $message = $this->fetchMessage();
 520                 return $message === false || $message === '' || $message === '-';
 521         }
 522
 523         /**
 524          * @param $value
 525          * @return array
 526          */
 527         public static function rawParam( $value ) {
 528                 return array( 'raw' => $value );
 529         }
 530
 531         /**
 532          * @param $value
 533          * @return array
 534          */
 535         public static function numParam( $value ) {
 536                 return array( 'num' => $value );
 537         }
 538
 539         /**
 540          * Substitutes any paramaters into the message text.
 541          * @param $message String: the message text
 542          * @param $type String: either before or after
 543          * @return String
 544          */
 545         protected function replaceParameters( $message, $type = 'before' ) {
 546                 $replacementKeys = array();
 547                 foreach( $this->parameters as $n => $param ) {
 548                         list( $paramType, $value ) = $this->extractParam( $param );
 549                         if ( $type === $paramType ) {
 550                                 $replacementKeys['$' . ($n + 1)] = $value;
 551                         }
 552                 }
 553                 $message = strtr( $message, $replacementKeys );
 554                 return $message;
 555         }
 556
 557         /**
 558          * Extracts the parameter type and preprocessed the value if needed.
 559          * @param $param String|Array: Parameter as defined in this class.
 560          * @return Tuple(type, value)
 561          * @throws MWException
 562          */
 563         protected function extractParam( $param ) {
 564                 if ( is_array( $param ) && isset( $param['raw'] ) ) {
 565                         return array( 'after', $param['raw'] );
 566                 } elseif ( is_array( $param ) && isset( $param['num'] ) ) {
 567                         // Replace number params always in before step for now.
 568                         // No support for combined raw and num params
 569                         return array( 'before', $this->language->formatNum( $param['num'] ) );
 570                 } elseif ( !is_array( $param ) ) {
 571                         return array( 'before', $param );
 572                 } else {
 573                         throw new MWException( "Invalid message parameter" );
 574                 }
 575         }
 576
 577         /**
 578          * Wrapper for what ever method we use to parse wikitext.
 579          * @param $string String: Wikitext message contents
 580          * @return string Wikitext parsed into HTML
 581          */
 582         protected function parseText( $string ) {
 583                 return MessageCache::singleton()->parse( $string, $this->title, /*linestart*/true, $this->interface, $this->language )->getText();
 584         }
 585
 586         /**
 587          * Wrapper for what ever method we use to {{-transform wikitext.
 588          * @param $string String: Wikitext message contents
 589          * @return string Wikitext with {{-constructs replaced with their values.
 590          */
 591         protected function transformText( $string ) {
 592                 return MessageCache::singleton()->transform( $string, $this->interface, $this->language, $this->title );
 593         }
 594
 595         /**
 596          * Wrapper for what ever method we use to get message contents
 597          *
 598          * @return string
 599          */
 600         protected function fetchMessage() {
 601                 if ( !isset( $this->message ) ) {
 602                         $cache = MessageCache::singleton();
 603                         if ( is_array( $this->key ) ) {
 604                                 if ( !count( $this->key ) ) {
 605                                         throw new MWException( "Given empty message key array." );
 606                                 }
 607                                 foreach ( $this->key as $key ) {
 608                                         $message = $cache->get( $key, $this->useDatabase, $this->language );
 609                                         if ( $message !== false && $message !== '' ) {
 610                                                 break;
 611                                         }
 612                                 }
 613                                 $this->message = $message;
 614                         } else {
 615                                 $this->message = $cache->get( $this->key, $this->useDatabase, $this->language );
 616                         }
 617                 }
 618                 return $this->message;
 619         }
 620
 621 }