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                 $this->interface = true;
 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          * Allows manipulating the interface message flag directly.
 346          * Can be used to restore the flag after setting a language.
 347          * @param $value bool
 348          * @return Message: $this
 349          * @since 1.20
 350          */
 351         public function setInterfaceMessageFlag( $value ) {
 352                 $this->interface = (bool) $value;
 353                 return $this;
 354         }
 355
 356         /**
 357          * Enable or disable database use.
 358          * @param $value Boolean
 359          * @return Message: $this
 360          */
 361         public function useDatabase( $value ) {
 362                 $this->useDatabase = (bool) $value;
 363                 return $this;
 364         }
 365
 366         /**
 367          * Set the Title object to use as context when transforming the message
 368          *
 369          * @param $title Title object
 370          * @return Message: $this
 371          */
 372         public function title( $title ) {
 373                 $this->title = $title;
 374                 return $this;
 375         }
 376
 377         /**
 378          * Returns the message parsed from wikitext to HTML.
 379          * @return String: HTML
 380          */
 381         public function toString() {
 382                 $string = $this->getMessageText();
 383
 384                 # Replace parameters before text parsing
 385                 $string = $this->replaceParameters( $string, 'before' );
 386
 387                 # Maybe transform using the full parser
 388                 if( $this->format === 'parse' ) {
 389                         $string = $this->parseText( $string );
 390                         $m = array();
 391                         if( preg_match( '/^<p>(.*)\n?<\/p>\n?$/sU', $string, $m ) ) {
 392                                 $string = $m[1];
 393                         }
 394                 } elseif( $this->format === 'block-parse' ){
 395                         $string = $this->parseText( $string );
 396                 } elseif( $this->format === 'text' ){
 397                         $string = $this->transformText( $string );
 398                 } elseif( $this->format === 'escaped' ){
 399                         $string = $this->transformText( $string );
 400                         $string = htmlspecialchars( $string, ENT_QUOTES, 'UTF-8', false );
 401                 }
 402
 403                 # Raw parameter replacement
 404                 $string = $this->replaceParameters( $string, 'after' );
 405
 406                 return $string;
 407         }
 408
 409         /**
 410          * Magic method implementation of the above (for PHP >= 5.2.0), so we can do, eg:
 411          *     $foo = Message::get($key);
 412          *     $string = "<abbr>$foo</abbr>";
 413          * @return String
 414          */
 415         public function __toString() {
 416                 return $this->toString();
 417         }
 418
 419         /**
 420          * Fully parse the text from wikitext to HTML
 421          * @return String parsed HTML
 422          */
 423         public function parse() {
 424                 $this->format = 'parse';
 425                 return $this->toString();
 426         }
 427
 428         /**
 429          * Returns the message text. {{-transformation is done.
 430          * @return String: Unescaped message text.
 431          */
 432         public function text() {
 433                 $this->format = 'text';
 434                 return $this->toString();
 435         }
 436
 437         /**
 438          * Returns the message text as-is, only parameters are subsituted.
 439          * @return String: Unescaped untransformed message text.
 440          */
 441         public function plain() {
 442                 $this->format = 'plain';
 443                 return $this->toString();
 444         }
 445
 446         /**
 447          * Returns the parsed message text which is always surrounded by a block element.
 448          * @return String: HTML
 449          */
 450         public function parseAsBlock() {
 451                 $this->format = 'block-parse';
 452                 return $this->toString();
 453         }
 454
 455         /**
 456          * Returns the message text. {{-transformation is done and the result
 457          * is escaped excluding any raw parameters.
 458          * @return String: Escaped message text.
 459          */
 460         public function escaped() {
 461                 $this->format = 'escaped';
 462                 return $this->toString();
 463         }
 464
 465         /**
 466          * Check whether a message key has been defined currently.
 467          * @return Bool: true if it is and false if not.
 468          */
 469         public function exists() {
 470                 return $this->fetchMessage() !== false;
 471         }
 472
 473         /**
 474          * Check whether a message does not exist, or is an empty string
 475          * @return Bool: true if is is and false if not
 476          * @todo FIXME: Merge with isDisabled()?
 477          */
 478         public function isBlank() {
 479                 $message = $this->fetchMessage();
 480                 return $message === false || $message === '';
 481         }
 482
 483         /**
 484          * Check whether a message does not exist, is an empty string, or is "-"
 485          * @return Bool: true if is is and false if not
 486          */
 487         public function isDisabled() {
 488                 $message = $this->fetchMessage();
 489                 return $message === false || $message === '' || $message === '-';
 490         }
 491
 492         /**
 493          * @param $value
 494          * @return array
 495          */
 496         public static function rawParam( $value ) {
 497                 return array( 'raw' => $value );
 498         }
 499
 500         /**
 501          * @param $value
 502          * @return array
 503          */
 504         public static function numParam( $value ) {
 505                 return array( 'num' => $value );
 506         }
 507
 508         /**
 509          * Substitutes any paramaters into the message text.
 510          * @param $message String: the message text
 511          * @param $type String: either before or after
 512          * @return String
 513          */
 514         protected function replaceParameters( $message, $type = 'before' ) {
 515                 $replacementKeys = array();
 516                 foreach( $this->parameters as $n => $param ) {
 517                         list( $paramType, $value ) = $this->extractParam( $param );
 518                         if ( $type === $paramType ) {
 519                                 $replacementKeys['$' . ($n + 1)] = $value;
 520                         }
 521                 }
 522                 $message = strtr( $message, $replacementKeys );
 523                 return $message;
 524         }
 525
 526         /**
 527          * Extracts the parameter type and preprocessed the value if needed.
 528          * @param $param String|Array: Parameter as defined in this class.
 529          * @return Tuple(type, value)
 530          * @throws MWException
 531          */
 532         protected function extractParam( $param ) {
 533                 if ( is_array( $param ) && isset( $param['raw'] ) ) {
 534                         return array( 'after', $param['raw'] );
 535                 } elseif ( is_array( $param ) && isset( $param['num'] ) ) {
 536                         // Replace number params always in before step for now.
 537                         // No support for combined raw and num params
 538                         return array( 'before', $this->language->formatNum( $param['num'] ) );
 539                 } elseif ( !is_array( $param ) ) {
 540                         return array( 'before', $param );
 541                 } else {
 542                         throw new MWException( "Invalid message parameter" );
 543                 }
 544         }
 545
 546         /**
 547          * Wrapper for what ever method we use to parse wikitext.
 548          * @param $string String: Wikitext message contents
 549          * @return string Wikitext parsed into HTML
 550          */
 551         protected function parseText( $string ) {
 552                 return MessageCache::singleton()->parse( $string, $this->title, /*linestart*/true, $this->interface, $this->language )->getText();
 553         }
 554
 555         /**
 556          * Wrapper for what ever method we use to {{-transform wikitext.
 557          * @param $string String: Wikitext message contents
 558          * @return string Wikitext with {{-constructs replaced with their values.
 559          */
 560         protected function transformText( $string ) {
 561                 return MessageCache::singleton()->transform( $string, $this->interface, $this->language, $this->title );
 562         }
 563
 564         /**
 565          * Returns the textual value for the message.
 566          * @return Message contents or placeholder
 567          */
 568         protected function getMessageText() {
 569                 $message = $this->fetchMessage();
 570                 if ( $message === false ) {
 571                         return '&lt;' . htmlspecialchars( is_array($this->key) ? $this->key[0] : $this->key ) . '&gt;';
 572                 } else {
 573                         return $message;
 574                 }
 575         }
 576
 577         /**
 578          * Wrapper for what ever method we use to get message contents
 579          *
 580          * @return string
 581          */
 582         protected function fetchMessage() {
 583                 if ( !isset( $this->message ) ) {
 584                         $cache = MessageCache::singleton();
 585                         if ( is_array( $this->key ) ) {
 586                                 if ( !count( $this->key ) ) {
 587                                         throw new MWException( "Given empty message key array." );
 588                                 }
 589                                 foreach ( $this->key as $key ) {
 590                                         $message = $cache->get( $key, $this->useDatabase, $this->language );
 591                                         if ( $message !== false && $message !== '' ) {
 592                                                 break;
 593                                         }
 594                                 }
 595                                 $this->message = $message;
 596                         } else {
 597                                 $this->message = $cache->get( $this->key, $this->useDatabase, $this->language );
 598                         }
 599                 }
 600                 return $this->message;
 601         }
 602
 603 }