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