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/New_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          * @param $key: message key, or array of message keys to try and use the first non-empty message for
 218          * @param $params Array message parameters
 219          * @return Message: $this
 220          */
 221         public function __construct( $key, $params = array() ) {
 222                 global $wgLang;
 223                 $this->key = $key;
 224                 $this->parameters = array_values( $params );
 225                 $this->language = $wgLang;
 226         }
 227
 228         /**
 229          * Factory function that is just wrapper for the real constructor. It is
 230          * intented to be used instead of the real constructor, because it allows
 231          * chaining method calls, while new objects don't.
 232          * @param $key String: message key
 233          * @param Varargs: parameters as Strings
 234          * @return Message: $this
 235          */
 236         public static function newFromKey( $key /*...*/ ) {
 237                 $params = func_get_args();
 238                 array_shift( $params );
 239                 return new self( $key, $params );
 240         }
 241
 242         /**
 243          * Factory function accepting multiple message keys and returning a message instance
 244          * for the first message which is non-empty. If all messages are empty then an
 245          * instance of the first message key is returned.
 246          * @param Varargs: message keys (or first arg as an array of all the message keys)
 247          * @return Message: $this
 248          */
 249         public static function newFallbackSequence( /*...*/ ) {
 250                 $keys = func_get_args();
 251                 if ( func_num_args() == 1 ) {
 252                         if ( is_array($keys[0]) ) {
 253                                 // Allow an array to be passed as the first argument instead
 254                                 $keys = array_values($keys[0]);
 255                         } else {
 256                                 // Optimize a single string to not need special fallback handling
 257                                 $keys = $keys[0];
 258                         }
 259                 }
 260                 return new self( $keys );
 261         }
 262
 263         /**
 264          * Adds parameters to the parameter list of this message.
 265          * @param Varargs: parameters as Strings, or a single argument that is an array of Strings
 266          * @return Message: $this
 267          */
 268         public function params( /*...*/ ) {
 269                 $args = func_get_args();
 270                 if ( isset( $args[0] ) && is_array( $args[0] ) ) {
 271                         $args = $args[0];
 272                 }
 273                 $args_values = array_values( $args );
 274                 $this->parameters = array_merge( $this->parameters, $args_values );
 275                 return $this;
 276         }
 277
 278         /**
 279          * Add parameters that are substituted after parsing or escaping.
 280          * In other words the parsing process cannot access the contents
 281          * of this type of parameter, and you need to make sure it is
 282          * sanitized beforehand.  The parser will see "$n", instead.
 283          * @param Varargs: raw parameters as Strings (or single argument that is an array of raw parameters)
 284          * @return Message: $this
 285          */
 286         public function rawParams( /*...*/ ) {
 287                 $params = func_get_args();
 288                 if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 289                         $params = $params[0];
 290                 }
 291                 foreach( $params as $param ) {
 292                         $this->parameters[] = self::rawParam( $param );
 293                 }
 294                 return $this;
 295         }
 296
 297         /**
 298          * Add parameters that are numeric and will be passed through
 299          * Language::formatNum before substitution
 300          * @param Varargs: numeric parameters (or single argument that is array of numeric parameters)
 301          * @return Message: $this
 302          */
 303         public function numParams( /*...*/ ) {
 304                 $params = func_get_args();
 305                 if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 306                         $params = $params[0];
 307                 }
 308                 foreach( $params as $param ) {
 309                         $this->parameters[] = self::numParam( $param );
 310                 }
 311                 return $this;
 312         }
 313
 314         /**
 315          * Set the language and the title from a context object
 316          *
 317          * @param $context IContextSource
 318          * @return Message: $this
 319          */
 320         public function setContext( IContextSource $context ) {
 321                 $this->inLanguage( $context->getLanguage() );
 322                 $this->title( $context->getTitle() );
 323                 $this->interface = true;
 324
 325                 return $this;
 326         }
 327
 328         /**
 329          * Request the message in any language that is supported.
 330          * As a side effect interface message status is unconditionally
 331          * turned off.
 332          * @param $lang Mixed: language code or Language object.
 333          * @return Message: $this
 334          */
 335         public function inLanguage( $lang ) {
 336                 if ( $lang instanceof Language || $lang instanceof StubUserLang ) {
 337                         $this->language = $lang;
 338                 } elseif ( is_string( $lang ) ) {
 339                         if( $this->language->getCode() != $lang ) {
 340                                 $this->language = Language::factory( $lang );
 341                         }
 342                 } else {
 343                         $type = gettype( $lang );
 344                         throw new MWException( __METHOD__ . " must be "
 345                                 . "passed a String or Language object; $type given"
 346                         );
 347                 }
 348                 $this->interface = false;
 349                 return $this;
 350         }
 351
 352         /**
 353          * Request the message in the wiki's content language,
 354          * unless it is disabled for this message.
 355          * @see $wgForceUIMsgAsContentMsg
 356          * @return Message: $this
 357          */
 358         public function inContentLanguage() {
 359                 global $wgForceUIMsgAsContentMsg;
 360                 if ( in_array( $this->key, (array)$wgForceUIMsgAsContentMsg ) ) {
 361                         return $this;
 362                 }
 363
 364                 global $wgContLang;
 365                 $this->interface = false;
 366                 $this->language = $wgContLang;
 367                 return $this;
 368         }
 369
 370         /**
 371          * Allows manipulating the interface message flag directly.
 372          * Can be used to restore the flag after setting a language.
 373          * @param $value bool
 374          * @return Message: $this
 375          * @since 1.20
 376          */
 377         public function setInterfaceMessageFlag( $value ) {
 378                 $this->interface = (bool) $value;
 379                 return $this;
 380         }
 381
 382         /**
 383          * Enable or disable database use.
 384          * @param $value Boolean
 385          * @return Message: $this
 386          */
 387         public function useDatabase( $value ) {
 388                 $this->useDatabase = (bool) $value;
 389                 return $this;
 390         }
 391
 392         /**
 393          * Set the Title object to use as context when transforming the message
 394          *
 395          * @param $title Title object
 396          * @return Message: $this
 397          */
 398         public function title( $title ) {
 399                 $this->title = $title;
 400                 return $this;
 401         }
 402
 403         /**
 404          * Returns the message as a Content object.
 405          * @return Content
 406          */
 407         public function content() {
 408                 if ( !$this->content ) {
 409                         $this->content = new MessageContent( $this->key );
 410                 }
 411
 412                 return $this->content;
 413         }
 414
 415         /**
 416          * Returns the message parsed from wikitext to HTML.
 417          * @return String: HTML
 418          */
 419         public function toString() {
 420                 $string = $this->fetchMessage();
 421
 422                 if ( $string === false ) {
 423                         $key =  htmlspecialchars( is_array( $this->key ) ? $this->key[0] : $this->key );
 424                         if ( $this->format === 'plain' ) {
 425                                 return '<' . $key . '>';
 426                         }
 427                         return '&lt;' . $key . '&gt;';
 428                 }
 429
 430                 # Replace parameters before text parsing
 431                 $string = $this->replaceParameters( $string, 'before' );
 432
 433                 # Maybe transform using the full parser
 434                 if( $this->format === 'parse' ) {
 435                         $string = $this->parseText( $string );
 436                         $m = array();
 437                         if( preg_match( '/^<p>(.*)\n?<\/p>\n?$/sU', $string, $m ) ) {
 438                                 $string = $m[1];
 439                         }
 440                 } elseif( $this->format === 'block-parse' ){
 441                         $string = $this->parseText( $string );
 442                 } elseif( $this->format === 'text' ){
 443                         $string = $this->transformText( $string );
 444                 } elseif( $this->format === 'escaped' ){
 445                         $string = $this->transformText( $string );
 446                         $string = htmlspecialchars( $string, ENT_QUOTES, 'UTF-8', false );
 447                 }
 448
 449                 # Raw parameter replacement
 450                 $string = $this->replaceParameters( $string, 'after' );
 451
 452                 return $string;
 453         }
 454
 455         /**
 456          * Magic method implementation of the above (for PHP >= 5.2.0), so we can do, eg:
 457          *     $foo = Message::get($key);
 458          *     $string = "<abbr>$foo</abbr>";
 459          * @return String
 460          */
 461         public function __toString() {
 462                 return $this->toString();
 463         }
 464
 465         /**
 466          * Fully parse the text from wikitext to HTML
 467          * @return String parsed HTML
 468          */
 469         public function parse() {
 470                 $this->format = 'parse';
 471                 return $this->toString();
 472         }
 473
 474         /**
 475          * Returns the message text. {{-transformation is done.
 476          * @return String: Unescaped message text.
 477          */
 478         public function text() {
 479                 $this->format = 'text';
 480                 return $this->toString();
 481         }
 482
 483         /**
 484          * Returns the message text as-is, only parameters are subsituted.
 485          * @return String: Unescaped untransformed message text.
 486          */
 487         public function plain() {
 488                 $this->format = 'plain';
 489                 return $this->toString();
 490         }
 491
 492         /**
 493          * Returns the parsed message text which is always surrounded by a block element.
 494          * @return String: HTML
 495          */
 496         public function parseAsBlock() {
 497                 $this->format = 'block-parse';
 498                 return $this->toString();
 499         }
 500
 501         /**
 502          * Returns the message text. {{-transformation is done and the result
 503          * is escaped excluding any raw parameters.
 504          * @return String: Escaped message text.
 505          */
 506         public function escaped() {
 507                 $this->format = 'escaped';
 508                 return $this->toString();
 509         }
 510
 511         /**
 512          * Check whether a message key has been defined currently.
 513          * @return Bool: true if it is and false if not.
 514          */
 515         public function exists() {
 516                 return $this->fetchMessage() !== false;
 517         }
 518
 519         /**
 520          * Check whether a message does not exist, or is an empty string
 521          * @return Bool: true if is is and false if not
 522          * @todo FIXME: Merge with isDisabled()?
 523          */
 524         public function isBlank() {
 525                 $message = $this->fetchMessage();
 526                 return $message === false || $message === '';
 527         }
 528
 529         /**
 530          * Check whether a message does not exist, is an empty string, or is "-"
 531          * @return Bool: true if is is and false if not
 532          */
 533         public function isDisabled() {
 534                 $message = $this->fetchMessage();
 535                 return $message === false || $message === '' || $message === '-';
 536         }
 537
 538         /**
 539          * @param $value
 540          * @return array
 541          */
 542         public static function rawParam( $value ) {
 543                 return array( 'raw' => $value );
 544         }
 545
 546         /**
 547          * @param $value
 548          * @return array
 549          */
 550         public static function numParam( $value ) {
 551                 return array( 'num' => $value );
 552         }
 553
 554         /**
 555          * Substitutes any paramaters into the message text.
 556          * @param $message String: the message text
 557          * @param $type String: either before or after
 558          * @return String
 559          */
 560         protected function replaceParameters( $message, $type = 'before' ) {
 561                 $replacementKeys = array();
 562                 foreach( $this->parameters as $n => $param ) {
 563                         list( $paramType, $value ) = $this->extractParam( $param );
 564                         if ( $type === $paramType ) {
 565                                 $replacementKeys['$' . ($n + 1)] = $value;
 566                         }
 567                 }
 568                 $message = strtr( $message, $replacementKeys );
 569                 return $message;
 570         }
 571
 572         /**
 573          * Extracts the parameter type and preprocessed the value if needed.
 574          * @param $param String|Array: Parameter as defined in this class.
 575          * @return Tuple(type, value)
 576          * @throws MWException
 577          */
 578         protected function extractParam( $param ) {
 579                 if ( is_array( $param ) && isset( $param['raw'] ) ) {
 580                         return array( 'after', $param['raw'] );
 581                 } elseif ( is_array( $param ) && isset( $param['num'] ) ) {
 582                         // Replace number params always in before step for now.
 583                         // No support for combined raw and num params
 584                         return array( 'before', $this->language->formatNum( $param['num'] ) );
 585                 } elseif ( !is_array( $param ) ) {
 586                         return array( 'before', $param );
 587                 } else {
 588                         throw new MWException( "Invalid message parameter" );
 589                 }
 590         }
 591
 592         /**
 593          * Wrapper for what ever method we use to parse wikitext.
 594          * @param $string String: Wikitext message contents
 595          * @return string Wikitext parsed into HTML
 596          */
 597         protected function parseText( $string ) {
 598                 return MessageCache::singleton()->parse( $string, $this->title, /*linestart*/true, $this->interface, $this->language )->getText();
 599         }
 600
 601         /**
 602          * Wrapper for what ever method we use to {{-transform wikitext.
 603          * @param $string String: Wikitext message contents
 604          * @return string Wikitext with {{-constructs replaced with their values.
 605          */
 606         protected function transformText( $string ) {
 607                 return MessageCache::singleton()->transform( $string, $this->interface, $this->language, $this->title );
 608         }
 609
 610         /**
 611          * Wrapper for what ever method we use to get message contents
 612          *
 613          * @return string
 614          */
 615         protected function fetchMessage() {
 616                 if ( !isset( $this->message ) ) {
 617                         $cache = MessageCache::singleton();
 618                         if ( is_array( $this->key ) ) {
 619                                 if ( !count( $this->key ) ) {
 620                                         throw new MWException( "Given empty message key array." );
 621                                 }
 622                                 foreach ( $this->key as $key ) {
 623                                         $message = $cache->get( $key, $this->useDatabase, $this->language );
 624                                         if ( $message !== false && $message !== '' ) {
 625                                                 break;
 626                                         }
 627                                 }
 628                                 $this->message = $message;
 629                         } else {
 630                                 $this->message = $cache->get( $this->key, $this->useDatabase, $this->language );
 631                         }
 632                 }
 633                 return $this->message;
 634         }
 635
 636 }