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.
   8  *
   9  * Examples:
  10  * Fetching a message text for interface message
  11  *    $button = Xml::button( wfMessage( 'submit' )->text() );
  12  * </pre>
  13  * Messages can have parameters:
  14  *    wfMessage( 'welcome-to' )->params( $wgSitename )->text();
  15  *        {{GRAMMAR}} and friends work correctly
  16  *    wfMessage( 'are-friends', $user, $friend );
  17  *    wfMessage( 'bad-message' )->rawParams( '<script>...</script>' )->escaped();
  18  * </pre>
  19  * Sometimes the message text ends up in the database, so content language is needed.
  20  *    wfMessage( 'file-log', $user, $filename )->inContentLanguage()->text()
  21  * </pre>
  22  * Checking if message exists:
  23  *    wfMessage( 'mysterious-message' )->exists()
  24  * </pre>
  25  * If you want to use a different language:
  26  *    wfMessage( 'email-header' )->inLanguage( $user->getOption( 'language' ) )->plain()
  27  *        Note that you cannot parse the text except in the content or interface
  28  *        languages
  29  * </pre>
  30  *
  31  *
  32  * Comparison with old wfMsg* functions:
  33  *
  34  * Use full parsing.
  35  *     wfMsgExt( 'key', array( 'parseinline' ), 'apple' );
  36  *     === wfMessage( 'key', 'apple' )->parse();
  37  * </pre>
  38  * Parseinline is used because it is more useful when pre-building html.
  39  * In normal use it is better to use OutputPage::(add|wrap)WikiMsg.
  40  *
  41  * Places where html cannot be used. {{-transformation is done.
  42  *     wfMsgExt( 'key', array( 'parsemag' ), 'apple', 'pear' );
  43  *     === wfMessage( 'key', 'apple', 'pear' )->text();
  44  * </pre>
  45  *
  46  * Shortcut for escaping the message too, similar to wfMsgHTML, but
  47  * parameters are not replaced after escaping by default.
  48  * $escaped = wfMessage( 'key' )->rawParams( 'apple' )->escaped();
  49  * </pre>
  50  *
  51  * TODO:
  52  * - test, can we have tests?
  53  * - sort out the details marked with fixme
  54  *
  55  * @since 1.17
  56  * @author Niklas Laxström
  57  */
  58 class Message {
  59         /**
  60          * In which language to get this message. True, which is the default,
  61          * means the current interface language, false content language.
  62          */
  63         protected $interface = true;
  64
  65         /**
  66          * In which language to get this message. Overrides the $interface
  67          * variable.
  68          */
  69         protected $language = null;
  70
  71         /**
  72          * The message key.
  73          */
  74         protected $key;
  75
  76         /**
  77          * List of parameters which will be substituted into the message.
  78          */
  79         protected $parameters = array();
  80
  81         /**
  82          * Format for the message.
  83          * Supported formats are:
  84          * * text (transform)
  85          * * escaped (transform+htmlspecialchars)
  86          * * block-parse
  87          * * parse (default)
  88          * * plain
  89          */
  90         protected $format = 'parse';
  91
  92         /**
  93          * Whether database can be used.
  94          */
  95         protected $useDatabase = true;
  96
  97         /**
  98          * Constructor.
  99          * @param $key: message key, or array of message keys to try and use the first non-empty message for
 100          * @param $params Array message parameters
 101          * @return Message: $this
 102          */
 103         public function __construct( $key, $params = array() ) {
 104                 global $wgLang;
 105                 $this->key = $key;
 106                 $this->parameters = array_values( $params );
 107                 $this->language = $wgLang;
 108         }
 109
 110         /**
 111          * Factory function that is just wrapper for the real constructor. It is
 112          * intented to be used instead of the real constructor, because it allows
 113          * chaining method calls, while new objects don't.
 114          * @param $key String: message key
 115          * @param Varargs: parameters as Strings
 116          * @return Message: $this
 117          */
 118         public static function newFromKey( $key /*...*/ ) {
 119                 $params = func_get_args();
 120                 array_shift( $params );
 121                 return new self( $key, $params );
 122         }
 123
 124         /**
 125          * Factory function accepting multiple message keys and returning a message instance
 126          * for the first message which is non-empty. If all messages are empty then an
 127          * instance of the first message key is returned.
 128          * @param Varargs: message keys
 129          * @return Message: $this
 130          */
 131         public static function newFallbackSequence( /*...*/ ) {
 132                 $keys = func_get_args();
 133                 if ( func_num_args() == 1 ) {
 134                         if ( is_array($keys[0]) ) {
 135                                 // Allow an array to be passed as the first argument instead
 136                                 $keys = array_values($keys[0]);
 137                         } else {
 138                                 // Optimize a single string to not need special fallback handling
 139                                 $keys = $keys[0];
 140                         }
 141                 }
 142                 return new self( $keys );
 143         }
 144
 145         /**
 146          * Adds parameters to the parameter list of this message.
 147          * @param Varargs: parameters as Strings
 148          * @return Message: $this
 149          */
 150         public function params( /*...*/ ) {
 151                 $args_values = array_values( func_get_args() );
 152                 $this->parameters = array_merge( $this->parameters, $args_values );
 153                 return $this;
 154         }
 155
 156         /**
 157          * Add parameters that are substituted after parsing or escaping.
 158          * In other words the parsing process cannot access the contents
 159          * of this type of parameter, and you need to make sure it is
 160          * sanitized beforehand.  The parser will see "$n", instead.
 161          * @param Varargs: raw parameters as Strings
 162          * @return Message: $this
 163          */
 164         public function rawParams( /*...*/ ) {
 165                 $params = func_get_args();
 166                 foreach( $params as $param ) {
 167                         $this->parameters[] = self::rawParam( $param );
 168                 }
 169                 return $this;
 170         }
 171
 172         /**
 173          * Request the message in any language that is supported.
 174          * As a side effect interface message status is unconditionally
 175          * turned off.
 176          * @param $lang Mixed: language code or Language object.
 177          * @return Message: $this
 178          */
 179         public function inLanguage( $lang ) {
 180                 if( $lang instanceof Language ){
 181                         $this->language = $lang;
 182                 } elseif ( is_string( $lang ) ) {
 183                         if( $this->language->getCode() != $lang ) {
 184                                 $this->language = Language::factory( $lang );
 185                         }
 186                 } else {
 187                         $type = gettype( $lang );
 188                         throw new MWException( __METHOD__ . " must be "
 189                                 . "passed a String or Language object; $type given"
 190                         );
 191                 }
 192                 $this->interface = false;
 193                 return $this;
 194         }
 195
 196         /**
 197          * Request the message in the wiki's content language.
 198          * @return Message: $this
 199          */
 200         public function inContentLanguage() {
 201                 global $wgContLang;
 202                 $this->interface = false;
 203                 $this->language = $wgContLang;
 204                 return $this;
 205         }
 206
 207         /**
 208          * Enable or disable database use.
 209          * @param $value Boolean
 210          * @return Message: $this
 211          */
 212         public function useDatabase( $value ) {
 213                 $this->useDatabase = (bool) $value;
 214                 return $this;
 215         }
 216
 217         /**
 218          * Returns the message parsed from wikitext to HTML.
 219          * TODO: in PHP >= 5.2.0, we can make this a magic method,
 220          * and then we can do, eg:
 221          *     $foo = Message::get($key);
 222          *     $string = "<abbr>$foo</abbr>";
 223          * But we shouldn't implement that while MediaWiki still supports
 224          * PHP < 5.2; or people will start using it...
 225          * @return String: HTML
 226          */
 227         public function toString() {
 228                 $string = $this->getMessageText();
 229
 230                 # Replace parameters before text parsing
 231                 $string = $this->replaceParameters( $string, 'before' );
 232
 233                 # Maybe transform using the full parser
 234                 if( $this->format === 'parse' ) {
 235                         $string = $this->parseText( $string );
 236                         $m = array();
 237                         if( preg_match( '/^<p>(.*)\n?<\/p>\n?$/sU', $string, $m ) ) {
 238                                 $string = $m[1];
 239                         }
 240                 } elseif( $this->format === 'block-parse' ){
 241                         $string = $this->parseText( $string );
 242                 } elseif( $this->format === 'text' ){
 243                         $string = $this->transformText( $string );
 244                 } elseif( $this->format === 'escaped' ){
 245                         # FIXME: Sanitizer method here?
 246                         $string = $this->transformText( $string );
 247                         $string = htmlspecialchars( $string );
 248                 }
 249
 250                 # Raw parameter replacement
 251                 $string = $this->replaceParameters( $string, 'after' );
 252
 253                 return $string;
 254         }
 255
 256         /**
 257          * Fully parse the text from wikitext to HTML
 258          * @return String parsed HTML
 259          */
 260         public function parse() {
 261                 $this->format = 'parse';
 262                 return $this->toString();
 263         }
 264
 265         /**
 266          * Returns the message text. {{-transformation is done.
 267          * @return String: Unescaped message text.
 268          */
 269         public function text() {
 270                 $this->format = 'text';
 271                 return $this->toString();
 272         }
 273
 274         /**
 275          * Returns the message text as-is, only parameters are subsituted.
 276          * @return String: Unescaped untransformed message text.
 277          */
 278         public function plain() {
 279                 $this->format = 'plain';
 280                 return $this->toString();
 281         }
 282
 283         /**
 284          * Returns the parsed message text which is always surrounded by a block element.
 285          * @return String: HTML
 286          */
 287         public function parseAsBlock() {
 288                 $this->format = 'block-parse';
 289                 return $this->toString();
 290         }
 291
 292         /**
 293          * Returns the message text. {{-transformation is done and the result
 294          * is escaped excluding any raw parameters.
 295          * @return String: Escaped message text.
 296          */
 297         public function escaped() {
 298                 $this->format = 'escaped';
 299                 return $this->toString();
 300         }
 301
 302         /**
 303          * Check whether a message key has been defined currently.
 304          * @return Bool: true if it is and false if not.
 305          */
 306         public function exists() {
 307                 return $this->fetchMessage() !== false;
 308         }
 309
 310         /**
 311          * Check whether a message does not exist, or is an empty string
 312          * @return Bool: true if is is and false if not
 313          */
 314         public function isBlank() {
 315                 $message = $this->fetchMessage();
 316                 return $message === false || $message === '';
 317         }
 318
 319         /**
 320          * Check whether a message does not exist, is an empty string, or is "-"
 321          * @return Bool: true if is is and false if not
 322          */
 323         public function isDisabled() {
 324                 $message = $this->fetchMessage();
 325                 return $message === false || $message === '' || $message === '-';
 326         }
 327
 328         public static function rawParam( $value ) {
 329                 return array( 'raw' => $value );
 330         }
 331
 332         /**
 333          * Substitutes any paramaters into the message text.
 334          * @param $message String, the message text
 335          * @param $type String: either before or after
 336          * @return String
 337          */
 338         protected function replaceParameters( $message, $type = 'before' ) {
 339                 $replacementKeys = array();
 340                 foreach( $this->parameters as $n => $param ) {
 341                         if ( $type === 'before' && !is_array( $param ) ) {
 342                                 $replacementKeys['$' . ($n + 1)] = $param;
 343                         } elseif ( $type === 'after' && isset( $param['raw'] ) ) {
 344                                 $replacementKeys['$' . ($n + 1)] = $param['raw'];
 345                         }
 346                 }
 347                 $message = strtr( $message, $replacementKeys );
 348                 return $message;
 349         }
 350
 351         /**
 352          * Wrapper for what ever method we use to parse wikitext.
 353          * @param $string String: Wikitext message contents
 354          * @return Wikitext parsed into HTML
 355          */
 356         protected function parseText( $string ) {
 357                 global $wgOut;
 358                 return $wgOut->parse( $string, /*linestart*/true, $this->interface, $this->language );
 359         }
 360
 361         /**
 362          * Wrapper for what ever method we use to {{-transform wikitext.
 363          * @param $string String: Wikitext message contents
 364          * @return Wikitext with {{-constructs replaced with their values.
 365          */
 366         protected function transformText( $string ) {
 367                 global $wgMessageCache;
 368                 return $wgMessageCache->transform( $string, $this->interface, $this->language );
 369         }
 370
 371         /**
 372          * Returns the textual value for the message.
 373          * @return Message contents or placeholder
 374          */
 375         protected function getMessageText() {
 376                 $message = $this->fetchMessage();
 377                 if ( $message === false ) {
 378                         return '&lt;' . htmlspecialchars( is_array($this->key) ? $this->key[0] : $this->key ) . '&gt;';
 379                 } else {
 380                         return $message;
 381                 }
 382         }
 383
 384         /**
 385          * Wrapper for what ever method we use to get message contents
 386          */
 387         protected function fetchMessage() {
 388                 if ( !isset( $this->message ) ) {
 389                         global $wgMessageCache;
 390                         if ( is_array($this->key) ) {
 391                                 foreach ( $this->key as $key ) {
 392                                         $message = $wgMessageCache->get( $key, $this->useDatabase, $this->language );
 393                                         if ( $message !== false && $message !== '' ) {
 394                                                 break;
 395                                         }
 396                                 }
 397                                 $this->message = $message;
 398                         } else {
 399                                 $this->message = $wgMessageCache->get( $this->key, $this->useDatabase, $this->language );
 400                         }
 401                 }
 402                 return $this->message;
 403         }
 404
 405 }