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' )->params( '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' )->params( '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                 return new self( $key, array_shift( func_get_args() ) );
 120         }
 121
 122         /**
 123          * Adds parameters to the parameter list of this message.
 124          * @param Varargs: parameters as Strings
 125          * @return Message: $this
 126          */
 127         public function params( /*...*/ ) {
 128                 $this->parameters = array_merge( $this->parameters, array_values( func_get_args() ) );
 129                 return $this;
 130         }
 131
 132         /**
 133          * Add parameters that are substituted after parsing or escaping.
 134          * In other words the parsing process cannot access the contents
 135          * of this type of parameter, and you need to make sure it is
 136          * sanitized beforehand.  The parser will see "$n", instead.
 137          * @param Varargs: raw parameters as Strings
 138          * @return Message: $this
 139          */
 140         public function rawParams( /*...*/ ) {
 141                 $params = func_get_args();
 142                 foreach( $params as $param ) {
 143                         $this->parameters[] = self::rawParam( $param );
 144                 }
 145                 return $this;
 146         }
 147
 148         /**
 149          * Request the message in any language that is supported.
 150          * As a side effect interface message status is unconditionally
 151          * turned off.
 152          * @param $lang Mixed: language code or Language object.
 153          * @return Message: $this
 154          */
 155         public function inLanguage( $lang ) {
 156                 if( $lang instanceof Language ){
 157                         $this->language = $lang;
 158                 } elseif ( is_string( $lang ) ) {
 159                         $this->language = Language::factory( $lang );
 160                 } else {
 161                         $type = gettype( $lang );
 162                         throw new MWException( __METHOD__ . " must be "
 163                                 . "passed a String or Language object; $type given"
 164                         );
 165                 }
 166                 $this->interface = false;
 167                 return $this;
 168         }
 169
 170         /**
 171          * Request the message in the wiki's content language.
 172          * @return Message: $this
 173          */
 174         public function inContentLanguage() {
 175                 $this->interface = false;
 176                 $this->language = null;
 177                 return $this;
 178         }
 179
 180         /**
 181          * Enable or disable database use.
 182          * @param $value Boolean
 183          * @return Message: $this
 184          */
 185         public function useDatabase( $value ) {
 186                 $this->useDatabase = (bool) $value;
 187                 return $this;
 188         }
 189
 190         /**
 191          * Returns the message parsed from wikitext to HTML.
 192          * TODO: in PHP >= 5.2.0, we can make this a magic method,
 193          * and then we can do, eg:
 194          *     $foo = Message::get($key);
 195          *     $string = "<abbr>$foo</abbr>";
 196          * But we shouldn't implement that while MediaWiki still supports
 197          * PHP < 5.2; or people will start using it...
 198          * @return String: HTML
 199          */
 200         public function toString() {
 201                 $string = $this->getMessageText();
 202
 203                 # Replace parameters before text parsing
 204                 $string = $this->replaceParameters( $string, 'before' );
 205
 206                 # Maybe transform using the full parser
 207                 if( $this->format === 'parse' ) {
 208                         $string = $this->parseText( $string );
 209                         $m = array();
 210                         if( preg_match( '/^<p>(.*)\n?<\/p>\n?$/sU', $string, $m ) ) {
 211                                 $string = $m[1];
 212                         }
 213                 } elseif( $this->format === 'block-parse' ){
 214                         $string = $this->parseText( $string );
 215                 } elseif( $this->format === 'text' ){
 216                         $string = $this->transformText( $string );
 217                 } elseif( $this->format === 'escaped' ){
 218                         # FIXME: Sanitizer method here?
 219                         $string = $this->transformText( $string );
 220                         $string = htmlspecialchars( $string );
 221                 }
 222
 223                 # Raw parameter replacement
 224                 $string = $this->replaceParameters( $string, 'after' );
 225
 226                 return $string;
 227         }
 228
 229         /**
 230          * Fully parse the text from wikitext to HTML
 231          * @return String parsed HTML
 232          */
 233         public function parse() {
 234                 $this->format = 'parse';
 235                 return $this->toString();
 236         }
 237
 238         /**
 239          * Returns the message text. {{-transformation is done.
 240          * @return String: Unescaped message text.
 241          */
 242         public function text() {
 243                 $this->format = 'text';
 244                 return $this->toString();
 245         }
 246
 247         /**
 248          * Returns the message text as-is, only parameters are subsituted.
 249          * @return String: Unescaped untransformed message text.
 250          */
 251         public function plain() {
 252                 $this->format = 'plain';
 253                 return $this->toString();
 254         }
 255
 256         /**
 257          * Returns the parsed message text which is always surrounded by a block element.
 258          * @return String: HTML
 259          */
 260         public function parseAsBlock() {
 261                 $this->format = 'block-parse';
 262                 return $this->toString();
 263         }
 264
 265         /**
 266          * Returns the message text. {{-transformation is done and the result
 267          * is excaped excluding any raw parameters.
 268          * @return String: Escaped message text.
 269          */
 270         public function escaped() {
 271                 $this->format = 'escaped';
 272                 return $this->toString();
 273         }
 274
 275         /**
 276          * Check whether a message key has been defined currently.
 277          * @return Bool: true if it is and false if not.
 278          */
 279         public function exists() {
 280                 return $this->fetchMessage() !== false;
 281         }
 282
 283         public static function rawParam( $value ) {
 284                 return array( 'raw' => $value );
 285         }
 286
 287         /**
 288          * Substitutes any paramaters into the message text.
 289          * @param $message String, the message text
 290          * @param $type String: either before or after
 291          * @return String
 292          */
 293         protected function replaceParameters( $message, $type = 'before' ) {
 294                 $replacementKeys = array();
 295                 foreach( $this->parameters as $n => $param ) {
 296                         if ( $type === 'before' && !is_array( $param ) ) {
 297                                 $replacementKeys['$' . ($n + 1)] = $param;
 298                         } elseif ( $type === 'after' && isset( $param['raw'] ) ) {
 299                                 $replacementKeys['$' . ($n + 1)] = $param['raw'];
 300                         }
 301                 }
 302                 $message = strtr( $message, $replacementKeys );
 303                 return $message;
 304         }
 305
 306         /**
 307          * Wrapper for what ever method we use to parse wikitext.
 308          * @param $string String: Wikitext message contents
 309          * @return Wikitext parsed into HTML
 310          */
 311         protected function parseText( $string ) {
 312                 global $wgOut;
 313                 if ( $this->language !== null ) {
 314                         # FIXME: remove this limitation
 315                         throw new MWException( 'Can only parse in interface or content language' );
 316                 }
 317                 return $wgOut->parse( $string, /*linestart*/true, $this->interface );
 318         }
 319
 320         /**
 321          * Wrapper for what ever method we use to {{-transform wikitext.
 322          * @param $string String: Wikitext message contents
 323          * @return Wikitext with {{-constructs replaced with their values.
 324          */
 325         protected function transformText( $string ) {
 326                 global $wgMessageCache;
 327                 return $wgMessageCache->transform( $string, $this->interface, $this->language );
 328         }
 329
 330         /**
 331          * Returns the textual value for the message.
 332          * @return Message contents or placeholder
 333          */
 334         protected function getMessageText() {
 335                 $message = $this->fetchMessage();
 336                 if ( $message === false ) {
 337                         return '&lt;' . htmlspecialchars( $this->key ) . '&gt;';
 338                 } else {
 339                         return $message;
 340                 }
 341         }
 342
 343         /**
 344          * Wrapper for what ever method we use to get message contents
 345          */
 346         protected function fetchMessage() {
 347                 if ( !isset( $this->message ) ) {
 348                         global $wgMessageCache;
 349                         $this->message = $wgMessageCache->get( $this->key, $this->useDatabase, $this->language );
 350                 }
 351                 return $this->message;
 352         }
 353
 354 }