includes/Message.php

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