includes/Message.php

   1 <?php
   2 /**
   3  * The Message class provides methods which fullfil two basic services:
   4  *  - fetching interface messages
   5  *  - processing messages into a variety of formats
   6  *
   7  * First implemented with MediaWiki 1.17, the Message class is intented to
   8  * replace the old wfMsg* functions that over time grew unusable.
   9  * @see https://www.mediawiki.org/wiki/New_messages_API for equivalences
  10  * between old and new functions.
  11  *
  12  * You should use the wfMessage() global function which acts as a wrapper for
  13  * the Message class. The wrapper let you pass parameters as arguments.
  14  *
  15  * The most basic usage cases would be:
  16  *
  17  * @code
  18  *     // Initialize a Message object using the 'some_key' message key
  19  *     $message = wfMessage( 'some_key' );
  20  *
  21  *     // Using two parameters those values are strings 'value1' and 'value2':
  22  *     $message = wfMessage( 'some_key',
  23  *          'value1', 'value2'
  24  *     );
  25  * @endcode
  26  *
  27  * @section message_global_fn Global function wrapper:
  28  *
  29  * Since wfMessage() returns a Message instance, you can chain its call with
  30  * a method. Some of them return a Message instance too so you can chain them.
  31  * You will find below several examples of wfMessage() usage.
  32  *
  33  * Fetching a message text for interface message:
  34  *
  35  * @code
  36  *    $button = Xml::button(
  37  *         wfMessage( 'submit' )->text()
  38  *    );
  39  * @endcode
  40  *
  41  * A Message instance can be passed parameters after it has been constructed,
  42  * use the params() method to do so:
  43  *
  44  * @code
  45  *     wfMessage( 'welcome-to' )
  46  *         ->params( $wgSitename )
  47  *         ->text();
  48  * @endcode
  49  *
  50  * {{GRAMMAR}} and friends work correctly:
  51  *
  52  * @code
  53  *    wfMessage( 'are-friends',
  54  *        $user, $friend
  55  *    );
  56  *    wfMessage( 'bad-message' )
  57  *         ->rawParams( '<script>...</script>' )
  58  *         ->escaped();
  59  * @endcode
  60  *
  61  * @section message_language Changing language:
  62  *
  63  * Messages can be requested in a different language or in whatever current
  64  * content language is being used. The methods are:
  65  *     - Message->inContentLanguage()
  66  *     - Message->inLanguage()
  67  *
  68  * Sometimes the message text ends up in the database, so content language is
  69  * needed:
  70  *
  71  * @code
  72  *    wfMessage( 'file-log',
  73  *        $user, $filename
  74  *    )->inContentLanguage()->text();
  75  * @endcode
  76  *
  77  * Checking whether a message exists:
  78  *
  79  * @code
  80  *    wfMessage( 'mysterious-message' )->exists()
  81  *    // returns a boolean whether the 'mysterious-message' key exist.
  82  * @endcode
  83  *
  84  * If you want to use a different language:
  85  *
  86  * @code
  87  *    $userLanguage = $user->getOption( 'language' );
  88  *    wfMessage( 'email-header' )
  89  *         ->inLanguage( $userLanguage )
  90  *         ->plain();
  91  * @endcode
  92  *
  93  * @note You can parse the text only in the content or interface languages
  94  *
  95  * @section message_compare_old Comparison with old wfMsg* functions:
  96  *
  97  * Use full parsing:
  98  *
  99  * @code
 100  *     // old style:
 101  *     wfMsgExt( 'key', array( 'parseinline' ), 'apple' );
 102  *     // new style:
 103  *     wfMessage( 'key', 'apple' )->parse();
 104  * @endcode
 105  *
 106  * Parseinline is used because it is more useful when pre-building HTML.
 107  * In normal use it is better to use OutputPage::(add|wrap)WikiMsg.
 108  *
 109  * Places where HTML cannot be used. {{-transformation is done.
 110  * @code
 111  *     // old style:
 112  *     wfMsgExt( 'key', array( 'parsemag' ), 'apple', 'pear' );
 113  *     // new style:
 114  *     wfMessage( 'key', 'apple', 'pear' )->text();
 115  * @endcode
 116  *
 117  * Shortcut for escaping the message too, similar to wfMsgHTML(), but
 118  * parameters are not replaced after escaping by default.
 119  * @code
 120  *     $escaped = wfMessage( 'key' )
 121  *          ->rawParams( 'apple' )
 122  *          ->escaped();
 123  * @endcode
 124  *
 125  * @section message_appendix Appendix:
 126  *
 127  * @todo
 128  * - test, can we have tests?
 129  * - this documentation needs to be extended
 130  *
 131  * @see https://www.mediawiki.org/wiki/WfMessage()
 132  * @see https://www.mediawiki.org/wiki/New_messages_API
 133  * @see https://www.mediawiki.org/wiki/Localisation
 134  *
 135  * @since 1.17
 136  * @author Niklas Laxström
 137  */
 138 class Message {
 139         /**
 140          * In which language to get this message. True, which is the default,
 141          * means the current interface language, false content language.
 142          */
 143         protected $interface = true;
 144
 145         /**
 146          * In which language to get this message. Overrides the $interface
 147          * variable.
 148          *
 149          * @var Language
 150          */
 151         protected $language = null;
 152
 153         /**
 154          * The message key.
 155          */
 156         protected $key;
 157
 158         /**
 159          * List of parameters which will be substituted into the message.
 160          */
 161         protected $parameters = array();
 162
 163         /**
 164          * Format for the message.
 165          * Supported formats are:
 166          * * text (transform)
 167          * * escaped (transform+htmlspecialchars)
 168          * * block-parse
 169          * * parse (default)
 170          * * plain
 171          */
 172         protected $format = 'parse';
 173
 174         /**
 175          * Whether database can be used.
 176          */
 177         protected $useDatabase = true;
 178
 179         /**
 180          * Title object to use as context
 181          */
 182         protected $title = null;
 183
 184         /**
 185          * @var string
 186          */
 187         protected $message;
 188
 189         /**
 190          * Constructor.
 191          * @param $key: message key, or array of message keys to try and use the first non-empty message for
 192          * @param $params Array message parameters
 193          * @return Message: $this
 194          */
 195         public function __construct( $key, $params = array() ) {
 196                 global $wgLang;
 197                 $this->key = $key;
 198                 $this->parameters = array_values( $params );
 199                 $this->language = $wgLang;
 200         }
 201
 202         /**
 203          * Factory function that is just wrapper for the real constructor. It is
 204          * intented to be used instead of the real constructor, because it allows
 205          * chaining method calls, while new objects don't.
 206          * @param $key String: message key
 207          * @param Varargs: parameters as Strings
 208          * @return Message: $this
 209          */
 210         public static function newFromKey( $key /*...*/ ) {
 211                 $params = func_get_args();
 212                 array_shift( $params );
 213                 return new self( $key, $params );
 214         }
 215
 216         /**
 217          * Factory function accepting multiple message keys and returning a message instance
 218          * for the first message which is non-empty. If all messages are empty then an
 219          * instance of the first message key is returned.
 220          * @param Varargs: message keys (or first arg as an array of all the message keys)
 221          * @return Message: $this
 222          */
 223         public static function newFallbackSequence( /*...*/ ) {
 224                 $keys = func_get_args();
 225                 if ( func_num_args() == 1 ) {
 226                         if ( is_array($keys[0]) ) {
 227                                 // Allow an array to be passed as the first argument instead
 228                                 $keys = array_values($keys[0]);
 229                         } else {
 230                                 // Optimize a single string to not need special fallback handling
 231                                 $keys = $keys[0];
 232                         }
 233                 }
 234                 return new self( $keys );
 235         }
 236
 237         /**
 238          * Adds parameters to the parameter list of this message.
 239          * @param Varargs: parameters as Strings, or a single argument that is an array of Strings
 240          * @return Message: $this
 241          */
 242         public function params( /*...*/ ) {
 243                 $args = func_get_args();
 244                 if ( isset( $args[0] ) && is_array( $args[0] ) ) {
 245                         $args = $args[0];
 246                 }
 247                 $args_values = array_values( $args );
 248                 $this->parameters = array_merge( $this->parameters, $args_values );
 249                 return $this;
 250         }
 251
 252         /**
 253          * Add parameters that are substituted after parsing or escaping.
 254          * In other words the parsing process cannot access the contents
 255          * of this type of parameter, and you need to make sure it is
 256          * sanitized beforehand.  The parser will see "$n", instead.
 257          * @param Varargs: raw parameters as Strings (or single argument that is an array of raw parameters)
 258          * @return Message: $this
 259          */
 260         public function rawParams( /*...*/ ) {
 261                 $params = func_get_args();
 262                 if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 263                         $params = $params[0];
 264                 }
 265                 foreach( $params as $param ) {
 266                         $this->parameters[] = self::rawParam( $param );
 267                 }
 268                 return $this;
 269         }
 270
 271         /**
 272          * Add parameters that are numeric and will be passed through
 273          * Language::formatNum before substitution
 274          * @param Varargs: numeric parameters (or single argument that is array of numeric parameters)
 275          * @return Message: $this
 276          */
 277         public function numParams( /*...*/ ) {
 278                 $params = func_get_args();
 279                 if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 280                         $params = $params[0];
 281                 }
 282                 foreach( $params as $param ) {
 283                         $this->parameters[] = self::numParam( $param );
 284                 }
 285                 return $this;
 286         }
 287
 288         /**
 289          * Set the language and the title from a context object
 290          *
 291          * @param $context IContextSource
 292          * @return Message: $this
 293          */
 294         public function setContext( IContextSource $context ) {
 295                 $this->inLanguage( $context->getLanguage() );
 296                 $this->title( $context->getTitle() );
 297
 298                 return $this;
 299         }
 300
 301         /**
 302          * Request the message in any language that is supported.
 303          * As a side effect interface message status is unconditionally
 304          * turned off.
 305          * @param $lang Mixed: language code or Language object.
 306          * @return Message: $this
 307          */
 308         public function inLanguage( $lang ) {
 309                 if ( $lang instanceof Language || $lang instanceof StubUserLang ) {
 310                         $this->language = $lang;
 311                 } elseif ( is_string( $lang ) ) {
 312                         if( $this->language->getCode() != $lang ) {
 313                                 $this->language = Language::factory( $lang );
 314                         }
 315                 } else {
 316                         $type = gettype( $lang );
 317                         throw new MWException( __METHOD__ . " must be "
 318                                 . "passed a String or Language object; $type given"
 319                         );
 320                 }
 321                 $this->interface = false;
 322                 return $this;
 323         }
 324
 325         /**
 326          * Request the message in the wiki's content language,
 327          * unless it is disabled for this message.
 328          * @see $wgForceUIMsgAsContentMsg
 329          * @return Message: $this
 330          */
 331         public function inContentLanguage() {
 332                 global $wgForceUIMsgAsContentMsg;
 333                 if ( in_array( $this->key, (array)$wgForceUIMsgAsContentMsg ) ) {
 334                         return $this;
 335                 }
 336
 337                 global $wgContLang;
 338                 $this->interface = false;
 339                 $this->language = $wgContLang;
 340                 return $this;
 341         }
 342
 343         /**
 344          * Allows manipulating the interface message flag directly.
 345          * Can be used to restore the flag after setting a language.
 346          * @param $value bool
 347          * @return Message: $this
 348          * @since 1.20
 349          */
 350         public function setInterfaceMessageFlag( $value ) {
 351                 $this->interface = (bool) $value;
 352                 return $this;
 353         }
 354
 355         /**
 356          * Enable or disable database use.
 357          * @param $value Boolean
 358          * @return Message: $this
 359          */
 360         public function useDatabase( $value ) {
 361                 $this->useDatabase = (bool) $value;
 362                 return $this;
 363         }
 364
 365         /**
 366          * Set the Title object to use as context when transforming the message
 367          *
 368          * @param $title Title object
 369          * @return Message: $this
 370          */
 371         public function title( $title ) {
 372                 $this->title = $title;
 373                 return $this;
 374         }
 375
 376         /**
 377          * Returns the message parsed from wikitext to HTML.
 378          * @return String: HTML
 379          */
 380         public function toString() {
 381                 $string = $this->getMessageText();
 382
 383                 # Replace parameters before text parsing
 384                 $string = $this->replaceParameters( $string, 'before' );
 385
 386                 # Maybe transform using the full parser
 387                 if( $this->format === 'parse' ) {
 388                         $string = $this->parseText( $string );
 389                         $m = array();
 390                         if( preg_match( '/^<p>(.*)\n?<\/p>\n?$/sU', $string, $m ) ) {
 391                                 $string = $m[1];
 392                         }
 393                 } elseif( $this->format === 'block-parse' ){
 394                         $string = $this->parseText( $string );
 395                 } elseif( $this->format === 'text' ){
 396                         $string = $this->transformText( $string );
 397                 } elseif( $this->format === 'escaped' ){
 398                         $string = $this->transformText( $string );
 399                         $string = htmlspecialchars( $string, ENT_QUOTES, 'UTF-8', false );
 400                 }
 401
 402                 # Raw parameter replacement
 403                 $string = $this->replaceParameters( $string, 'after' );
 404
 405                 return $string;
 406         }
 407
 408         /**
 409          * Magic method implementation of the above (for PHP >= 5.2.0), so we can do, eg:
 410          *     $foo = Message::get($key);
 411          *     $string = "<abbr>$foo</abbr>";
 412          * @return String
 413          */
 414         public function __toString() {
 415                 return $this->toString();
 416         }
 417
 418         /**
 419          * Fully parse the text from wikitext to HTML
 420          * @return String parsed HTML
 421          */
 422         public function parse() {
 423                 $this->format = 'parse';
 424                 return $this->toString();
 425         }
 426
 427         /**
 428          * Returns the message text. {{-transformation is done.
 429          * @return String: Unescaped message text.
 430          */
 431         public function text() {
 432                 $this->format = 'text';
 433                 return $this->toString();
 434         }
 435
 436         /**
 437          * Returns the message text as-is, only parameters are subsituted.
 438          * @return String: Unescaped untransformed message text.
 439          */
 440         public function plain() {
 441                 $this->format = 'plain';
 442                 return $this->toString();
 443         }
 444
 445         /**
 446          * Returns the parsed message text which is always surrounded by a block element.
 447          * @return String: HTML
 448          */
 449         public function parseAsBlock() {
 450                 $this->format = 'block-parse';
 451                 return $this->toString();
 452         }
 453
 454         /**
 455          * Returns the message text. {{-transformation is done and the result
 456          * is escaped excluding any raw parameters.
 457          * @return String: Escaped message text.
 458          */
 459         public function escaped() {
 460                 $this->format = 'escaped';
 461                 return $this->toString();
 462         }
 463
 464         /**
 465          * Check whether a message key has been defined currently.
 466          * @return Bool: true if it is and false if not.
 467          */
 468         public function exists() {
 469                 return $this->fetchMessage() !== false;
 470         }
 471
 472         /**
 473          * Check whether a message does not exist, or is an empty string
 474          * @return Bool: true if is is and false if not
 475          * @todo FIXME: Merge with isDisabled()?
 476          */
 477         public function isBlank() {
 478                 $message = $this->fetchMessage();
 479                 return $message === false || $message === '';
 480         }
 481
 482         /**
 483          * Check whether a message does not exist, is an empty string, or is "-"
 484          * @return Bool: true if is is and false if not
 485          */
 486         public function isDisabled() {
 487                 $message = $this->fetchMessage();
 488                 return $message === false || $message === '' || $message === '-';
 489         }
 490
 491         /**
 492          * @param $value
 493          * @return array
 494          */
 495         public static function rawParam( $value ) {
 496                 return array( 'raw' => $value );
 497         }
 498
 499         /**
 500          * @param $value
 501          * @return array
 502          */
 503         public static function numParam( $value ) {
 504                 return array( 'num' => $value );
 505         }
 506
 507         /**
 508          * Substitutes any paramaters into the message text.
 509          * @param $message String: the message text
 510          * @param $type String: either before or after
 511          * @return String
 512          */
 513         protected function replaceParameters( $message, $type = 'before' ) {
 514                 $replacementKeys = array();
 515                 foreach( $this->parameters as $n => $param ) {
 516                         list( $paramType, $value ) = $this->extractParam( $param );
 517                         if ( $type === $paramType ) {
 518                                 $replacementKeys['$' . ($n + 1)] = $value;
 519                         }
 520                 }
 521                 $message = strtr( $message, $replacementKeys );
 522                 return $message;
 523         }
 524
 525         /**
 526          * Extracts the parameter type and preprocessed the value if needed.
 527          * @param $param String|Array: Parameter as defined in this class.
 528          * @return Tuple(type, value)
 529          * @throws MWException
 530          */
 531         protected function extractParam( $param ) {
 532                 if ( is_array( $param ) && isset( $param['raw'] ) ) {
 533                         return array( 'after', $param['raw'] );
 534                 } elseif ( is_array( $param ) && isset( $param['num'] ) ) {
 535                         // Replace number params always in before step for now.
 536                         // No support for combined raw and num params
 537                         return array( 'before', $this->language->formatNum( $param['num'] ) );
 538                 } elseif ( !is_array( $param ) ) {
 539                         return array( 'before', $param );
 540                 } else {
 541                         throw new MWException( "Invalid message parameter" );
 542                 }
 543         }
 544
 545         /**
 546          * Wrapper for what ever method we use to parse wikitext.
 547          * @param $string String: Wikitext message contents
 548          * @return string Wikitext parsed into HTML
 549          */
 550         protected function parseText( $string ) {
 551                 return MessageCache::singleton()->parse( $string, $this->title, /*linestart*/true, $this->interface, $this->language )->getText();
 552         }
 553
 554         /**
 555          * Wrapper for what ever method we use to {{-transform wikitext.
 556          * @param $string String: Wikitext message contents
 557          * @return string Wikitext with {{-constructs replaced with their values.
 558          */
 559         protected function transformText( $string ) {
 560                 return MessageCache::singleton()->transform( $string, $this->interface, $this->language, $this->title );
 561         }
 562
 563         /**
 564          * Returns the textual value for the message.
 565          * @return Message contents or placeholder
 566          */
 567         protected function getMessageText() {
 568                 $message = $this->fetchMessage();
 569                 if ( $message === false ) {
 570                         return '&lt;' . htmlspecialchars( is_array($this->key) ? $this->key[0] : $this->key ) . '&gt;';
 571                 } else {
 572                         return $message;
 573                 }
 574         }
 575
 576         /**
 577          * Wrapper for what ever method we use to get message contents
 578          *
 579          * @return string
 580          */
 581         protected function fetchMessage() {
 582                 if ( !isset( $this->message ) ) {
 583                         $cache = MessageCache::singleton();
 584                         if ( is_array( $this->key ) ) {
 585                                 if ( !count( $this->key ) ) {
 586                                         throw new MWException( "Given empty message key array." );
 587                                 }
 588                                 foreach ( $this->key as $key ) {
 589                                         $message = $cache->get( $key, $this->useDatabase, $this->language );
 590                                         if ( $message !== false && $message !== '' ) {
 591                                                 break;
 592                                         }
 593                                 }
 594                                 $this->message = $message;
 595                         } else {
 596                                 $this->message = $cache->get( $this->key, $this->useDatabase, $this->language );
 597                         }
 598                 }
 599                 return $this->message;
 600         }
 601
 602 }