includes/resourceloader/ResourceLoaderModule.php

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