includes/resourceloader/ResourceLoaderModule.php

   1 <?php
   2 /**
   3  * Abstraction for resource loader modules.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @author Trevor Parscal
  22  * @author Roan Kattouw
  23  */
  24
  25 /**
  26  * Abstraction for resource loader modules, with name registration and maxage functionality.
  27  */
  28 abstract class ResourceLoaderModule {
  29
  30         # Type of resource
  31         const TYPE_SCRIPTS = 'scripts';
  32         const TYPE_STYLES = 'styles';
  33         const TYPE_MESSAGES = 'messages';
  34         const TYPE_COMBINED = 'combined';
  35
  36         # sitewide core module like a skin file or jQuery component
  37         const ORIGIN_CORE_SITEWIDE = 1;
  38
  39         # per-user module generated by the software
  40         const ORIGIN_CORE_INDIVIDUAL = 2;
  41
  42         # sitewide module generated from user-editable files, like MediaWiki:Common.js, or
  43         # modules accessible to multiple users, such as those generated by the Gadgets extension.
  44         const ORIGIN_USER_SITEWIDE = 3;
  45
  46         # per-user module generated from user-editable files, like User:Me/vector.js
  47         const ORIGIN_USER_INDIVIDUAL = 4;
  48
  49         # an access constant; make sure this is kept as the largest number in this group
  50         const ORIGIN_ALL = 10;
  51
  52         # script and style modules form a hierarchy of trustworthiness, with core modules like
  53         # skins and jQuery as most trustworthy, and user scripts as least trustworthy.  We can
  54         # limit the types of scripts and styles we allow to load on, say, sensitive special
  55         # pages like Special:UserLogin and Special:Preferences
  56         protected $origin = self::ORIGIN_CORE_SITEWIDE;
  57
  58         /* Protected Members */
  59
  60         protected $name = null;
  61
  62         // In-object cache for file dependencies
  63         protected $fileDeps = array();
  64         // In-object cache for message blob mtime
  65         protected $msgBlobMtime = array();
  66
  67         /* Methods */
  68
  69         /**
  70          * Get this module's name. This is set when the module is registered
  71          * with ResourceLoader::register()
  72          *
  73          * @return Mixed: Name (string) or null if no name was set
  74          */
  75         public function getName() {
  76                 return $this->name;
  77         }
  78
  79         /**
  80          * Set this module's name. This is called by ResourceLodaer::register()
  81          * when registering the module. Other code should not call this.
  82          *
  83          * @param $name String: Name
  84          */
  85         public function setName( $name ) {
  86                 $this->name = $name;
  87         }
  88
  89         /**
  90          * Get this module's origin. This is set when the module is registered
  91          * with ResourceLoader::register()
  92          *
  93          * @return Int ResourceLoaderModule class constant, the subclass default
  94          *     if not set manuall
  95          */
  96         public function getOrigin() {
  97                 return $this->origin;
  98         }
  99
 100         /**
 101          * Set this module's origin. This is called by ResourceLodaer::register()
 102          * when registering the module. Other code should not call this.
 103          *
 104          * @param $origin Int origin
 105          */
 106         public function setOrigin( $origin ) {
 107                 $this->origin = $origin;
 108         }
 109
 110         /**
 111          * @param $context ResourceLoaderContext
 112          * @return bool
 113          */
 114         public function getFlip( $context ) {
 115                 global $wgContLang;
 116
 117                 return $wgContLang->getDir() !== $context->getDirection();
 118         }
 119
 120         /**
 121          * Get all JS for this module for a given language and skin.
 122          * Includes all relevant JS except loader scripts.
 123          *
 124          * @param $context ResourceLoaderContext: Context object
 125          * @return String: JavaScript code
 126          */
 127         public function getScript( ResourceLoaderContext $context ) {
 128                 // Stub, override expected
 129                 return '';
 130         }
 131
 132         /**
 133          * Get the URL or URLs to load for this module's JS in debug mode.
 134          * The default behavior is to return a load.php?only=scripts URL for
 135          * the module, but file-based modules will want to override this to
 136          * load the files directly.
 137          *
 138          * This function is called only when 1) we're in debug mode, 2) there
 139          * is no only= parameter and 3) supportsURLLoading() returns true.
 140          * #2 is important to prevent an infinite loop, therefore this function
 141          * MUST return either an only= URL or a non-load.php URL.
 142          *
 143          * @param $context ResourceLoaderContext: Context object
 144          * @return Array of URLs
 145          */
 146         public function getScriptURLsForDebug( ResourceLoaderContext $context ) {
 147                 $url = ResourceLoader::makeLoaderURL(
 148                         array( $this->getName() ),
 149                         $context->getLanguage(),
 150                         $context->getSkin(),
 151                         $context->getUser(),
 152                         $context->getVersion(),
 153                         true, // debug
 154                         'scripts', // only
 155                         $context->getRequest()->getBool( 'printable' ),
 156                         $context->getRequest()->getBool( 'handheld' )
 157                 );
 158                 return array( $url );
 159         }
 160
 161         /**
 162          * Whether this module supports URL loading. If this function returns false,
 163          * getScript() will be used even in cases (debug mode, no only param) where
 164          * getScriptURLsForDebug() would normally be used instead.
 165          * @return bool
 166          */
 167         public function supportsURLLoading() {
 168                 return true;
 169         }
 170
 171         /**
 172          * Get all CSS for this module for a given skin.
 173          *
 174          * @param $context ResourceLoaderContext: Context object
 175          * @return Array: List of CSS strings keyed by media type
 176          */
 177         public function getStyles( ResourceLoaderContext $context ) {
 178                 // Stub, override expected
 179                 return array();
 180         }
 181
 182         /**
 183          * Get the URL or URLs to load for this module's CSS in debug mode.
 184          * The default behavior is to return a load.php?only=styles URL for
 185          * the module, but file-based modules will want to override this to
 186          * load the files directly. See also getScriptURLsForDebug()
 187          *
 188          * @param $context ResourceLoaderContext: Context object
 189          * @return Array: array( mediaType => array( URL1, URL2, ... ), ... )
 190          */
 191         public function getStyleURLsForDebug( ResourceLoaderContext $context ) {
 192                 $url = ResourceLoader::makeLoaderURL(
 193                         array( $this->getName() ),
 194                         $context->getLanguage(),
 195                         $context->getSkin(),
 196                         $context->getUser(),
 197                         $context->getVersion(),
 198                         true, // debug
 199                         'styles', // only
 200                         $context->getRequest()->getBool( 'printable' ),
 201                         $context->getRequest()->getBool( 'handheld' )
 202                 );
 203                 return array( 'all' => array( $url ) );
 204         }
 205
 206         /**
 207          * Get the messages needed for this module.
 208          *
 209          * To get a JSON blob with messages, use MessageBlobStore::get()
 210          *
 211          * @return Array: List of message keys. Keys may occur more than once
 212          */
 213         public function getMessages() {
 214                 // Stub, override expected
 215                 return array();
 216         }
 217
 218         /**
 219          * Get the group this module is in.
 220          *
 221          * @return String: Group name
 222          */
 223         public function getGroup() {
 224                 // Stub, override expected
 225                 return null;
 226         }
 227
 228         /**
 229          * Get the origin of this module. Should only be overridden for foreign modules.
 230          *
 231          * @return String: Origin name, 'local' for local modules
 232          */
 233         public function getSource() {
 234                 // Stub, override expected
 235                 return 'local';
 236         }
 237
 238         /**
 239          * Where on the HTML page should this module's JS be loaded?
 240          * 'top': in the <head>
 241          * 'bottom': at the bottom of the <body>
 242          *
 243          * @return string
 244          */
 245         public function getPosition() {
 246                 return 'bottom';
 247         }
 248
 249         /**
 250          * Whether this module's JS expects to work without the client-side ResourceLoader module.
 251          * Returning true from this function will prevent mw.loader.state() call from being
 252          * appended to the bottom of the script.
 253          *
 254          * @return bool
 255          */
 256         public function isRaw() {
 257                 return false;
 258         }
 259
 260         /**
 261          * Get the loader JS for this module, if set.
 262          *
 263          * @return Mixed: JavaScript loader code as a string or boolean false if no custom loader set
 264          */
 265         public function getLoaderScript() {
 266                 // Stub, override expected
 267                 return false;
 268         }
 269
 270         /**
 271          * Get a list of modules this module depends on.
 272          *
 273          * Dependency information is taken into account when loading a module
 274          * on the client side. When adding a module on the server side,
 275          * dependency information is NOT taken into account and YOU are
 276          * responsible for adding dependent modules as well. If you don't do
 277          * this, the client side loader will send a second request back to the
 278          * server to fetch the missing modules, which kind of defeats the
 279          * purpose of the resource loader.
 280          *
 281          * To add dependencies dynamically on the client side, use a custom
 282          * loader script, see getLoaderScript()
 283          * @return Array: List of module names as strings
 284          */
 285         public function getDependencies() {
 286                 // Stub, override expected
 287                 return array();
 288         }
 289
 290         /**
 291          * Get the files this module depends on indirectly for a given skin.
 292          * Currently these are only image files referenced by the module's CSS.
 293          *
 294          * @param $skin String: Skin name
 295          * @return Array: List of files
 296          */
 297         public function getFileDependencies( $skin ) {
 298                 // Try in-object cache first
 299                 if ( isset( $this->fileDeps[$skin] ) ) {
 300                         return $this->fileDeps[$skin];
 301                 }
 302
 303                 $dbr = wfGetDB( DB_SLAVE );
 304                 $deps = $dbr->selectField( 'module_deps', 'md_deps', array(
 305                                 'md_module' => $this->getName(),
 306                                 'md_skin' => $skin,
 307                         ), __METHOD__
 308                 );
 309                 if ( !is_null( $deps ) ) {
 310                         $this->fileDeps[$skin] = (array) FormatJson::decode( $deps, true );
 311                 } else {
 312                         $this->fileDeps[$skin] = array();
 313                 }
 314                 return $this->fileDeps[$skin];
 315         }
 316
 317         /**
 318          * Set preloaded file dependency information. Used so we can load this
 319          * information for all modules at once.
 320          * @param $skin String: Skin name
 321          * @param $deps Array: Array of file names
 322          */
 323         public function setFileDependencies( $skin, $deps ) {
 324                 $this->fileDeps[$skin] = $deps;
 325         }
 326
 327         /**
 328          * Get the last modification timestamp of the message blob for this
 329          * module in a given language.
 330          * @param $lang String: Language code
 331          * @return Integer: UNIX timestamp, or 0 if the module doesn't have messages
 332          */
 333         public function getMsgBlobMtime( $lang ) {
 334                 if ( !isset( $this->msgBlobMtime[$lang] ) ) {
 335                         if ( !count( $this->getMessages() ) )
 336                                 return 0;
 337
 338                         $dbr = wfGetDB( DB_SLAVE );
 339                         $msgBlobMtime = $dbr->selectField( 'msg_resource', 'mr_timestamp', array(
 340                                         'mr_resource' => $this->getName(),
 341                                         'mr_lang' => $lang
 342                                 ), __METHOD__
 343                         );
 344                         // If no blob was found, but the module does have messages, that means we need
 345                         // to regenerate it. Return NOW
 346                         if ( $msgBlobMtime === false ) {
 347                                 $msgBlobMtime = wfTimestampNow();
 348                         }
 349                         $this->msgBlobMtime[$lang] = wfTimestamp( TS_UNIX, $msgBlobMtime );
 350                 }
 351                 return $this->msgBlobMtime[$lang];
 352         }
 353
 354         /**
 355          * Set a preloaded message blob last modification timestamp. Used so we
 356          * can load this information for all modules at once.
 357          * @param $lang String: Language code
 358          * @param $mtime Integer: UNIX timestamp or 0 if there is no such blob
 359          */
 360         public function setMsgBlobMtime( $lang, $mtime ) {
 361                 $this->msgBlobMtime[$lang] = $mtime;
 362         }
 363
 364         /* Abstract Methods */
 365
 366         /**
 367          * Get this module's last modification timestamp for a given
 368          * combination of language, skin and debug mode flag. This is typically
 369          * the highest of each of the relevant components' modification
 370          * timestamps. Whenever anything happens that changes the module's
 371          * contents for these parameters, the mtime should increase.
 372          *
 373          * NOTE: The mtime of the module's messages is NOT automatically included.
 374          * If you want this to happen, you'll need to call getMsgBlobMtime()
 375          * yourself and take its result into consideration.
 376          *
 377          * @param $context ResourceLoaderContext: Context object
 378          * @return Integer: UNIX timestamp
 379          */
 380         public function getModifiedTime( ResourceLoaderContext $context ) {
 381                 // 0 would mean now
 382                 return 1;
 383         }
 384
 385         /**
 386          * Check whether this module is known to be empty. If a child class
 387          * has an easy and cheap way to determine that this module is
 388          * definitely going to be empty, it should override this method to
 389          * return true in that case. Callers may optimize the request for this
 390          * module away if this function returns true.
 391          * @param $context ResourceLoaderContext: Context object
 392          * @return Boolean
 393          */
 394         public function isKnownEmpty( ResourceLoaderContext $context ) {
 395                 return false;
 396         }
 397
 398
 399         /** @var JSParser lazy-initialized; use self::javaScriptParser() */
 400         private static $jsParser;
 401         private static $parseCacheVersion = 1;
 402
 403         /**
 404          * Validate a given script file; if valid returns the original source.
 405          * If invalid, returns replacement JS source that throws an exception.
 406          *
 407          * @param string $fileName
 408          * @param string $contents
 409          * @return string JS with the original, or a replacement error
 410          */
 411         protected function validateScriptFile( $fileName, $contents ) {
 412                 global $wgResourceLoaderValidateJS;
 413                 if ( $wgResourceLoaderValidateJS ) {
 414                         // Try for cache hit
 415                         // Use CACHE_ANYTHING since filtering is very slow compared to DB queries
 416                         $key = wfMemcKey( 'resourceloader', 'jsparse', self::$parseCacheVersion, md5( $contents ) );
 417                         $cache = wfGetCache( CACHE_ANYTHING );
 418                         $cacheEntry = $cache->get( $key );
 419                         if ( is_string( $cacheEntry ) ) {
 420                                 return $cacheEntry;
 421                         }
 422
 423                         $parser = self::javaScriptParser();
 424                         try {
 425                                 $parser->parse( $contents, $fileName, 1 );
 426                                 $result = $contents;
 427                         } catch (Exception $e) {
 428                                 // We'll save this to cache to avoid having to validate broken JS over and over...
 429                                 $err = $e->getMessage();
 430                                 $result = "throw new Error(" . Xml::encodeJsVar("JavaScript parse error: $err") . ");";
 431                         }
 432
 433                         $cache->set( $key, $result );
 434                         return $result;
 435                 } else {
 436                         return $contents;
 437                 }
 438         }
 439
 440         /**
 441          * @return JSParser
 442          */
 443         protected static function javaScriptParser() {
 444                 if ( !self::$jsParser ) {
 445                         self::$jsParser = new JSParser();
 446                 }
 447                 return self::$jsParser;
 448         }
 449
 450 }