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 String: message key
 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          * Adds parameters to the parameter list of this message.
 126          * @param Varargs: parameters as Strings
 127          * @return Message: $this
 128          */
 129         public function params( /*...*/ ) {
 130                 $this->parameters = array_merge( $this->parameters, array_values( func_get_args() ) );
 131                 return $this;
 132         }
 133
 134         /**
 135          * Add parameters that are substituted after parsing or escaping.
 136          * In other words the parsing process cannot access the contents
 137          * of this type of parameter, and you need to make sure it is
 138          * sanitized beforehand.  The parser will see "$n", instead.
 139          * @param Varargs: raw parameters as Strings
 140          * @return Message: $this
 141          */
 142         public function rawParams( /*...*/ ) {
 143                 $params = func_get_args();
 144                 foreach( $params as $param ) {
 145                         $this->parameters[] = self::rawParam( $param );
 146                 }
 147                 return $this;
 148         }
 149
 150         /**
 151          * Request the message in any language that is supported.
 152          * As a side effect interface message status is unconditionally
 153          * turned off.
 154          * @param $lang Mixed: language code or Language object.
 155          * @return Message: $this
 156          */
 157         public function inLanguage( $lang ) {
 158                 if( $lang instanceof Language ){
 159                         $this->language = $lang;
 160                 } elseif ( is_string( $lang ) ) {
 161                         if( $this->language->getCode() != $lang ) {
 162                                 $this->language = Language::factory( $lang );
 163                         }
 164                 } else {
 165                         $type = gettype( $lang );
 166                         throw new MWException( __METHOD__ . " must be "
 167                                 . "passed a String or Language object; $type given"
 168                         );
 169                 }
 170                 $this->interface = false;
 171                 return $this;
 172         }
 173
 174         /**
 175          * Request the message in the wiki's content language.
 176          * @return Message: $this
 177          */
 178         public function inContentLanguage() {
 179                 global $wgContLang;
 180                 $this->interface = false;
 181                 $this->language = $wgContLang;
 182                 return $this;
 183         }
 184
 185         /**
 186          * Enable or disable database use.
 187          * @param $value Boolean
 188          * @return Message: $this
 189          */
 190         public function useDatabase( $value ) {
 191                 $this->useDatabase = (bool) $value;
 192                 return $this;
 193         }
 194
 195         /**
 196          * Returns the message parsed from wikitext to HTML.
 197          * TODO: in PHP >= 5.2.0, we can make this a magic method,
 198          * and then we can do, eg:
 199          *     $foo = Message::get($key);
 200          *     $string = "<abbr>$foo</abbr>";
 201          * But we shouldn't implement that while MediaWiki still supports
 202          * PHP < 5.2; or people will start using it...
 203          * @return String: HTML
 204          */
 205         public function toString() {
 206                 $string = $this->getMessageText();
 207
 208                 # Replace parameters before text parsing
 209                 $string = $this->replaceParameters( $string, 'before' );
 210
 211                 # Maybe transform using the full parser
 212                 if( $this->format === 'parse' ) {
 213                         $string = $this->parseText( $string );
 214                         $m = array();
 215                         if( preg_match( '/^<p>(.*)\n?<\/p>\n?$/sU', $string, $m ) ) {
 216                                 $string = $m[1];
 217                         }
 218                 } elseif( $this->format === 'block-parse' ){
 219                         $string = $this->parseText( $string );
 220                 } elseif( $this->format === 'text' ){
 221                         $string = $this->transformText( $string );
 222                 } elseif( $this->format === 'escaped' ){
 223                         # FIXME: Sanitizer method here?
 224                         $string = $this->transformText( $string );
 225                         $string = htmlspecialchars( $string );
 226                 }
 227
 228                 # Raw parameter replacement
 229                 $string = $this->replaceParameters( $string, 'after' );
 230
 231                 return $string;
 232         }
 233
 234         /**
 235          * Fully parse the text from wikitext to HTML
 236          * @return String parsed HTML
 237          */
 238         public function parse() {
 239                 $this->format = 'parse';
 240                 return $this->toString();
 241         }
 242
 243         /**
 244          * Returns the message text. {{-transformation is done.
 245          * @return String: Unescaped message text.
 246          */
 247         public function text() {
 248                 $this->format = 'text';
 249                 return $this->toString();
 250         }
 251
 252         /**
 253          * Returns the message text as-is, only parameters are subsituted.
 254          * @return String: Unescaped untransformed message text.
 255          */
 256         public function plain() {
 257                 $this->format = 'plain';
 258                 return $this->toString();
 259         }
 260
 261         /**
 262          * Returns the parsed message text which is always surrounded by a block element.
 263          * @return String: HTML
 264          */
 265         public function parseAsBlock() {
 266                 $this->format = 'block-parse';
 267                 return $this->toString();
 268         }
 269
 270         /**
 271          * Returns the message text. {{-transformation is done and the result
 272          * is escaped excluding any raw parameters.
 273          * @return String: Escaped message text.
 274          */
 275         public function escaped() {
 276                 $this->format = 'escaped';
 277                 return $this->toString();
 278         }
 279
 280         /**
 281          * Check whether a message key has been defined currently.
 282          * @return Bool: true if it is and false if not.
 283          */
 284         public function exists() {
 285                 return $this->fetchMessage() !== false;
 286         }
 287
 288         public static function rawParam( $value ) {
 289                 return array( 'raw' => $value );
 290         }
 291
 292         /**
 293          * Substitutes any paramaters into the message text.
 294          * @param $message String, the message text
 295          * @param $type String: either before or after
 296          * @return String
 297          */
 298         protected function replaceParameters( $message, $type = 'before' ) {
 299                 $replacementKeys = array();
 300                 foreach( $this->parameters as $n => $param ) {
 301                         if ( $type === 'before' && !is_array( $param ) ) {
 302                                 $replacementKeys['$' . ($n + 1)] = $param;
 303                         } elseif ( $type === 'after' && isset( $param['raw'] ) ) {
 304                                 $replacementKeys['$' . ($n + 1)] = $param['raw'];
 305                         }
 306                 }
 307                 $message = strtr( $message, $replacementKeys );
 308                 return $message;
 309         }
 310
 311         /**
 312          * Wrapper for what ever method we use to parse wikitext.
 313          * @param $string String: Wikitext message contents
 314          * @return Wikitext parsed into HTML
 315          */
 316         protected function parseText( $string ) {
 317                 global $wgOut, $wgLang, $wgContLang;
 318                 if ( $this->language !== $wgLang && $this->language !== $wgContLang ) {
 319                         # FIXME: remove this limitation
 320                         throw new MWException( 'Can only parse in interface or content language' );
 321                 }
 322                 return $wgOut->parse( $string, /*linestart*/true, $this->interface );
 323         }
 324
 325         /**
 326          * Wrapper for what ever method we use to {{-transform wikitext.
 327          * @param $string String: Wikitext message contents
 328          * @return Wikitext with {{-constructs replaced with their values.
 329          */
 330         protected function transformText( $string ) {
 331                 global $wgMessageCache;
 332                 return $wgMessageCache->transform( $string, $this->interface, $this->language );
 333         }
 334
 335         /**
 336          * Returns the textual value for the message.
 337          * @return Message contents or placeholder
 338          */
 339         protected function getMessageText() {
 340                 $message = $this->fetchMessage();
 341                 if ( $message === false ) {
 342                         return '&lt;' . htmlspecialchars( $this->key ) . '&gt;';
 343                 } else {
 344                         return $message;
 345                 }
 346         }
 347
 348         /**
 349          * Wrapper for what ever method we use to get message contents
 350          */
 351         protected function fetchMessage() {
 352                 if ( !isset( $this->message ) ) {
 353                         global $wgMessageCache;
 354                         $this->message = $wgMessageCache->get( $this->key, $this->useDatabase, $this->language );
 355                 }
 356                 return $this->message;
 357         }
 358
 359 }