includes/Message.php

   1 <?php
   2 /**
   3  * OBS!!! *EXPERIMENTAL* This class is still under discussion.
   4  *
   5  * This class provides methods for fetching interface messages and
   6  * processing them into variety of formats that are needed in MediaWiki.
   7  *
   8  * It is intented to replace the old wfMsg* functions that over time grew
   9  * unusable.
  10  *
  11  * Examples:
  12  * Fetching a message text for interface message
  13  *    $button = Xml::button( Message::key( 'submit' )->text() );
  14  * </pre>
  15  * Messages can have parameters:
  16  *    Message::key( 'welcome-to' )->params( $wgSitename )->text();
  17  *        {{GRAMMAR}} and friends work correctly
  18  *    Message::key( 'are-friends', $user, $friend );
  19  *    Message::key( 'bad-message' )->rawParams( '<script>...</script>' )->escaped();
  20  * </pre>
  21  * Sometimes the message text ends up in the database, so content language is needed.
  22  *    Message::key( 'file-log' )->params( $user, $filename )->inContentLanguage()->text()
  23  * </pre>
  24  * Checking if message exists:
  25  *    Message::key( 'mysterious-message' )->exists()
  26  * </pre>
  27  * If you want to use a different language:
  28  *    Message::key( 'email-header' )->inLanguage( $user->getOption( 'language' ) )->plain()
  29  *        Note that you cannot parse the text except in the content or interface
  30  *        languages
  31  * </pre>
  32  *
  33  *
  34  * Comparison with old wfMsg* functions:
  35  *
  36  * Use full parsing.
  37  *     wfMsgExt( 'key', array( 'parseinline' ), 'apple' );
  38  *     === Message::key( 'key', 'apple' )->parse();
  39  * </pre>
  40  * Parseinline is used because it is more useful when pre-building html.
  41  * In normal use it is better to use OutputPage::(add|wrap)WikiMsg.
  42  *
  43  * Places where html cannot be used. {{-transformation is done.
  44  *     wfMsgExt( 'key', array( 'parsemag' ), 'apple', 'pear' );
  45  *     === Message::key( 'key', 'apple', 'pear' )->text();
  46  * </pre>
  47  *
  48  * Shortcut for escaping the message too, similar to wfMsgHTML, but
  49  * parameters are not replaced after escaping by default.
  50  * $escaped = Message::key( 'key' )->rawParams( 'apple' )->escaped();
  51  * </pre>
  52  *
  53  * TODO:
  54  * - test, can we have tests?
  55  * - sort out the details marked with fixme
  56  * - should we have _m() or similar global wrapper?
  57  *
  58  * @since 1.17
  59  */
  60 class Message {
  61         /**
  62          * In which language to get this message. True, which is the default,
  63          * means the current interface language, false content language.
  64          */
  65         protected $interface = true;
  66
  67         /**
  68          * In which language to get this message. Overrides the $interface
  69          * variable.
  70          */
  71         protected $language = null;
  72
  73         /**
  74          * The message key.
  75          */
  76         protected $key;
  77
  78         /**
  79          * List of parameters which will be substituted into the message.
  80          */
  81         protected $parameters = array();
  82
  83         /**
  84          * Format for the message.
  85          * Supported formats are:
  86          * * text (transform)
  87          * * escaped (transform+htmlspecialchars)
  88          * * block-parse
  89          * * parse (default)
  90          * * plain
  91          */
  92         protected $format = 'parse';
  93
  94         /**
  95          * Whether database can be used.
  96          */
  97         protected $useDatabase = true;
  98
  99         /**
 100          * Constructor.
 101          * @param $key String: message key
 102          * @param $params Array message parameters
 103          * @return Message: $this
 104          */
 105         public function __construct( $key, $params = array() ) {
 106                 $this->key = $key;
 107                 $this->parameters = array_values( $params );
 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 key( $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                         $this->language = Language::factory( $lang );
 162                 } else {
 163                         $type = gettype( $lang );
 164                         throw new MWException( __METHOD__ . " must be "
 165                                 . "passed a String or Language object; $type given"
 166                         );
 167                 }
 168                 $this->interface = false;
 169                 return $this;
 170         }
 171
 172         /**
 173          * Request the message in the wiki's content language.
 174          * @return Message: $this
 175          */
 176         public function inContentLanguage() {
 177                 $this->interface = false;
 178                 $this->language = null;
 179                 return $this;
 180         }
 181
 182         /**
 183          * Enable or disable database use.
 184          * @param $value Boolean
 185          * @return Message: $this
 186          */
 187         public function useDatabase( $value ) {
 188                 $this->useDatabase = (bool) $value;
 189                 return $this;
 190         }
 191
 192         /**
 193          * Returns the message parsed from wikitext to HTML.
 194          * TODO: in PHP >= 5.2.0, we can make this a magic method,
 195          * and then we can do, eg:
 196          *     $foo = Message::get($key);
 197          *     $string = "<abbr>$foo</abbr>";
 198          * But we shouldn't implement that while MediaWiki still supports
 199          * PHP < 5.2; or people will start using it...
 200          * @return String: HTML
 201          */
 202         public function toString() {
 203                 $string = $this->getMessageText();
 204
 205                 # Replace parameters before text parsing
 206                 $string = $this->replaceParameters( $string, 'before' );
 207
 208                 # Maybe transform using the full parser
 209                 if( $this->format === 'parse' ) {
 210                         $string = $this->parseText( $string );
 211                         $m = array();
 212                         if( preg_match( '/^<p>(.*)\n?<\/p>\n?$/sU', $string, $m ) ) {
 213                                 $string = $m[1];
 214                         }
 215                 } elseif( $this->format === 'block-parse' ){
 216                         $string = $this->parseText( $string );
 217                 } elseif( $this->format === 'text' ){
 218                         $string = $this->transformText( $string );
 219                 } elseif( $this->format === 'escaped' ){
 220                         # FIXME: Sanitizer method here?
 221                         $string = $this->transformText( $string );
 222                         $string = htmlspecialchars( $string );
 223                 }
 224
 225                 # Raw parameter replacement
 226                 $string = $this->replaceParameters( $string, 'after' );
 227
 228                 return $string;
 229         }
 230
 231         /**
 232          * Fully parse the text from wikitext to HTML
 233          * @return String parsed HTML
 234          */
 235         public function parse() {
 236                 $this->format = 'parse';
 237                 return $this->toString();
 238         }
 239
 240         /**
 241          * Returns the message text. {{-transformation is done.
 242          * @return String: Unescaped message text.
 243          */
 244         public function text() {
 245                 $this->format = 'text';
 246                 return $this->toString();
 247         }
 248
 249         /**
 250          * Returns the message text as-is, only parameters are subsituted.
 251          * @return String: Unescaped untransformed message text.
 252          */
 253         public function plain() {
 254                 $this->format = 'plain';
 255                 return $this->toString();
 256         }
 257
 258         /**
 259          * Returns the parsed message text which is always surrounded by a block element.
 260          * @return String: HTML
 261          */
 262         public function parseAsBlock() {
 263                 $this->format = 'block-parse';
 264                 return $this->toString();
 265         }
 266
 267         /**
 268          * Returns the message text. {{-transformation is done and the result
 269          * is excaped excluding any raw parameters.
 270          * @return String: Escaped message text.
 271          */
 272         public function escaped() {
 273                 $this->format = 'escaped';
 274                 return $this->toString();
 275         }
 276
 277         /**
 278          * Check whether a message key has been defined currently.
 279          * @return Bool: true if it is and false if not.
 280          */
 281         public function exists() {
 282                 return $this->fetchMessage() !== false;
 283         }
 284
 285         public static function rawParam( $value ) {
 286                 return array( 'raw' => $value );
 287         }
 288
 289         /**
 290          * Substitutes any paramaters into the message text.
 291          * @param $message String, the message text
 292          * @param $type String: either before or after
 293          * @return String
 294          */
 295         protected function replaceParameters( $message, $type = 'before' ) {
 296                 $replacementKeys = array();
 297                 foreach( $this->parameters as $n => $param ) {
 298                         if ( $type === 'before' && !is_array( $param ) ) {
 299                                 $replacementKeys['$' . ($n + 1)] = $param;
 300                         } elseif ( $type === 'after' && isset( $param['raw'] ) ) {
 301                                 $replacementKeys['$' . ($n + 1)] = $param['raw'];
 302                         }
 303                 }
 304                 $message = strtr( $message, $replacementKeys );
 305                 return $message;
 306         }
 307
 308         /**
 309          * Wrapper for what ever method we use to parse wikitext.
 310          * @param $string String: Wikitext message contents
 311          * @return Wikitext parsed into HTML
 312          */
 313         protected function parseText( $string ) {
 314                 global $wgOut;
 315                 if ( $this->language !== null ) {
 316                         # FIXME: remove this limitation
 317                         throw new MWException( 'Can only parse in interface or content language' );
 318                 }
 319                 return $wgOut->parse( $string, /*linestart*/true, $this->interface );
 320         }
 321
 322         /**
 323          * Wrapper for what ever method we use to {{-transform wikitext.
 324          * @param $string String: Wikitext message contents
 325          * @return Wikitext with {{-constructs replaced with their values.
 326          */
 327         protected function transformText( $string ) {
 328                 global $wgMessageCache;
 329                 return $wgMessageCache->transform( $string, $this->interface, $this->language );
 330         }
 331
 332         /**
 333          * Returns the textual value for the message.
 334          * @return Message contents or placeholder
 335          */
 336         protected function getMessageText() {
 337                 $message = $this->fetchMessage();
 338                 if ( $message === false ) {
 339                         return '&lt;' . htmlspecialchars( $this->key ) . '&gt;';
 340                 } else {
 341                         return $message;
 342                 }
 343         }
 344
 345         /**
 346          * Wrapper for what ever method we use to get message contents
 347          */
 348         protected function fetchMessage() {
 349                 if ( !isset( $this->message ) ) {
 350                         global $wgMessageCache;
 351                         $this->message = $wgMessageCache->get( $this->key, $this->useDatabase, $this->language );
 352                 }
 353                 return $this->message;
 354         }
 355
 356 }