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         protected $targets = array( 'desktop' );
  62
  63         // In-object cache for file dependencies
  64         protected $fileDeps = array();
  65         // In-object cache for message blob mtime
  66         protected $msgBlobMtime = array();
  67
  68         /* Methods */
  69
  70         /**
  71          * Get this module's name. This is set when the module is registered
  72          * with ResourceLoader::register()
  73          *
  74          * @return Mixed: Name (string) or null if no name was set
  75          */
  76         public function getName() {
  77                 return $this->name;
  78         }
  79
  80         /**
  81          * Set this module's name. This is called by ResourceLoader::register()
  82          * when registering the module. Other code should not call this.
  83          *
  84          * @param $name String: Name
  85          */
  86         public function setName( $name ) {
  87                 $this->name = $name;
  88         }
  89
  90         /**
  91          * Get this module's origin. This is set when the module is registered
  92          * with ResourceLoader::register()
  93          *
  94          * @return Int ResourceLoaderModule class constant, the subclass default
  95          *     if not set manually
  96          */
  97         public function getOrigin() {
  98                 return $this->origin;
  99         }
 100
 101         /**
 102          * Set this module's origin. This is called by ResourceLodaer::register()
 103          * when registering the module. Other code should not call this.
 104          *
 105          * @param $origin Int origin
 106          */
 107         public function setOrigin( $origin ) {
 108                 $this->origin = $origin;
 109         }
 110
 111         /**
 112          * @param $context ResourceLoaderContext
 113          * @return bool
 114          */
 115         public function getFlip( $context ) {
 116                 global $wgContLang;
 117
 118                 return $wgContLang->getDir() !== $context->getDirection();
 119         }
 120
 121         /**
 122          * Get all JS for this module for a given language and skin.
 123          * Includes all relevant JS except loader scripts.
 124          *
 125          * @param $context ResourceLoaderContext: Context object
 126          * @return String: JavaScript code
 127          */
 128         public function getScript( ResourceLoaderContext $context ) {
 129                 // Stub, override expected
 130                 return '';
 131         }
 132
 133         /**
 134          * Get the URL or URLs to load for this module's JS in debug mode.
 135          * The default behavior is to return a load.php?only=scripts URL for
 136          * the module, but file-based modules will want to override this to
 137          * load the files directly.
 138          *
 139          * This function is called only when 1) we're in debug mode, 2) there
 140          * is no only= parameter and 3) supportsURLLoading() returns true.
 141          * #2 is important to prevent an infinite loop, therefore this function
 142          * MUST return either an only= URL or a non-load.php URL.
 143          *
 144          * @param $context ResourceLoaderContext: Context object
 145          * @return Array of URLs
 146          */
 147         public function getScriptURLsForDebug( ResourceLoaderContext $context ) {
 148                 $url = ResourceLoader::makeLoaderURL(
 149                         array( $this->getName() ),
 150                         $context->getLanguage(),
 151                         $context->getSkin(),
 152                         $context->getUser(),
 153                         $context->getVersion(),
 154                         true, // debug
 155                         'scripts', // only
 156                         $context->getRequest()->getBool( 'printable' ),
 157                         $context->getRequest()->getBool( 'handheld' )
 158                 );
 159                 return array( $url );
 160         }
 161
 162         /**
 163          * Whether this module supports URL loading. If this function returns false,
 164          * getScript() will be used even in cases (debug mode, no only param) where
 165          * getScriptURLsForDebug() would normally be used instead.
 166          * @return bool
 167          */
 168         public function supportsURLLoading() {
 169                 return true;
 170         }
 171
 172         /**
 173          * Get all CSS for this module for a given skin.
 174          *
 175          * @param $context ResourceLoaderContext: Context object
 176          * @return Array: List of CSS strings or array of CSS strings keyed by media type.
 177          *  like array( 'screen' => '.foo { width: 0 }' );
 178          *  or array( 'screen' => array( '.foo { width: 0 }' ) );
 179          */
 180         public function getStyles( ResourceLoaderContext $context ) {
 181                 // Stub, override expected
 182                 return array();
 183         }
 184
 185         /**
 186          * Get the URL or URLs to load for this module's CSS in debug mode.
 187          * The default behavior is to return a load.php?only=styles URL for
 188          * the module, but file-based modules will want to override this to
 189          * load the files directly. See also getScriptURLsForDebug()
 190          *
 191          * @param $context ResourceLoaderContext: Context object
 192          * @return Array: array( mediaType => array( URL1, URL2, ... ), ... )
 193          */
 194         public function getStyleURLsForDebug( ResourceLoaderContext $context ) {
 195                 $url = ResourceLoader::makeLoaderURL(
 196                         array( $this->getName() ),
 197                         $context->getLanguage(),
 198                         $context->getSkin(),
 199                         $context->getUser(),
 200                         $context->getVersion(),
 201                         true, // debug
 202                         'styles', // only
 203                         $context->getRequest()->getBool( 'printable' ),
 204                         $context->getRequest()->getBool( 'handheld' )
 205                 );
 206                 return array( 'all' => array( $url ) );
 207         }
 208
 209         /**
 210          * Get the messages needed for this module.
 211          *
 212          * To get a JSON blob with messages, use MessageBlobStore::get()
 213          *
 214          * @return Array: List of message keys. Keys may occur more than once
 215          */
 216         public function getMessages() {
 217                 // Stub, override expected
 218                 return array();
 219         }
 220
 221         /**
 222          * Get the group this module is in.
 223          *
 224          * @return String: Group name
 225          */
 226         public function getGroup() {
 227                 // Stub, override expected
 228                 return null;
 229         }
 230
 231         /**
 232          * Get the origin of this module. Should only be overridden for foreign modules.
 233          *
 234          * @return String: Origin name, 'local' for local modules
 235          */
 236         public function getSource() {
 237                 // Stub, override expected
 238                 return 'local';
 239         }
 240
 241         /**
 242          * Where on the HTML page should this module's JS be loaded?
 243          *  - 'top': in the "<head>"
 244          *  - 'bottom': at the bottom of the "<body>"
 245          *
 246          * @return string
 247          */
 248         public function getPosition() {
 249                 return 'bottom';
 250         }
 251
 252         /**
 253          * Whether this module's JS expects to work without the client-side ResourceLoader module.
 254          * Returning true from this function will prevent mw.loader.state() call from being
 255          * appended to the bottom of the script.
 256          *
 257          * @return bool
 258          */
 259         public function isRaw() {
 260                 return false;
 261         }
 262
 263         /**
 264          * Get the loader JS for this module, if set.
 265          *
 266          * @return Mixed: JavaScript loader code as a string or boolean false if no custom loader set
 267          */
 268         public function getLoaderScript() {
 269                 // Stub, override expected
 270                 return false;
 271         }
 272
 273         /**
 274          * Get a list of modules this module depends on.
 275          *
 276          * Dependency information is taken into account when loading a module
 277          * on the client side. When adding a module on the server side,
 278          * dependency information is NOT taken into account and YOU are
 279          * responsible for adding dependent modules as well. If you don't do
 280          * this, the client side loader will send a second request back to the
 281          * server to fetch the missing modules, which kind of defeats the
 282          * purpose of the resource loader.
 283          *
 284          * To add dependencies dynamically on the client side, use a custom
 285          * loader script, see getLoaderScript()
 286          * @return Array: List of module names as strings
 287          */
 288         public function getDependencies() {
 289                 // Stub, override expected
 290                 return array();
 291         }
 292
 293         /**
 294          * Get target(s) for the module, eg ['desktop'] or ['desktop', 'mobile']
 295          *
 296          * @return array of strings
 297          */
 298         public function getTargets() {
 299                 return $this->targets;
 300         }
 301
 302         /**
 303          * Get the files this module depends on indirectly for a given skin.
 304          * Currently these are only image files referenced by the module's CSS.
 305          *
 306          * @param $skin String: Skin name
 307          * @return Array: List of files
 308          */
 309         public function getFileDependencies( $skin ) {
 310                 // Try in-object cache first
 311                 if ( isset( $this->fileDeps[$skin] ) ) {
 312                         return $this->fileDeps[$skin];
 313                 }
 314
 315                 $dbr = wfGetDB( DB_SLAVE );
 316                 $deps = $dbr->selectField( 'module_deps', 'md_deps', array(
 317                                 'md_module' => $this->getName(),
 318                                 'md_skin' => $skin,
 319                         ), __METHOD__
 320                 );
 321                 if ( !is_null( $deps ) ) {
 322                         $this->fileDeps[$skin] = (array) FormatJson::decode( $deps, true );
 323                 } else {
 324                         $this->fileDeps[$skin] = array();
 325                 }
 326                 return $this->fileDeps[$skin];
 327         }
 328
 329         /**
 330          * Set preloaded file dependency information. Used so we can load this
 331          * information for all modules at once.
 332          * @param $skin String: Skin name
 333          * @param $deps Array: Array of file names
 334          */
 335         public function setFileDependencies( $skin, $deps ) {
 336                 $this->fileDeps[$skin] = $deps;
 337         }
 338
 339         /**
 340          * Get the last modification timestamp of the message blob for this
 341          * module in a given language.
 342          * @param $lang String: Language code
 343          * @return Integer: UNIX timestamp, or 0 if the module doesn't have messages
 344          */
 345         public function getMsgBlobMtime( $lang ) {
 346                 if ( !isset( $this->msgBlobMtime[$lang] ) ) {
 347                         if ( !count( $this->getMessages() ) ) {
 348                                 return 0;
 349                         }
 350
 351                         $dbr = wfGetDB( DB_SLAVE );
 352                         $msgBlobMtime = $dbr->selectField( 'msg_resource', 'mr_timestamp', array(
 353                                         'mr_resource' => $this->getName(),
 354                                         'mr_lang' => $lang
 355                                 ), __METHOD__
 356                         );
 357                         // If no blob was found, but the module does have messages, that means we need
 358                         // to regenerate it. Return NOW
 359                         if ( $msgBlobMtime === false ) {
 360                                 $msgBlobMtime = wfTimestampNow();
 361                         }
 362                         $this->msgBlobMtime[$lang] = wfTimestamp( TS_UNIX, $msgBlobMtime );
 363                 }
 364                 return $this->msgBlobMtime[$lang];
 365         }
 366
 367         /**
 368          * Set a preloaded message blob last modification timestamp. Used so we
 369          * can load this information for all modules at once.
 370          * @param $lang String: Language code
 371          * @param $mtime Integer: UNIX timestamp or 0 if there is no such blob
 372          */
 373         public function setMsgBlobMtime( $lang, $mtime ) {
 374                 $this->msgBlobMtime[$lang] = $mtime;
 375         }
 376
 377         /* Abstract Methods */
 378
 379         /**
 380          * Get this module's last modification timestamp for a given
 381          * combination of language, skin and debug mode flag. This is typically
 382          * the highest of each of the relevant components' modification
 383          * timestamps. Whenever anything happens that changes the module's
 384          * contents for these parameters, the mtime should increase.
 385          *
 386          * NOTE: The mtime of the module's messages is NOT automatically included.
 387          * If you want this to happen, you'll need to call getMsgBlobMtime()
 388          * yourself and take its result into consideration.
 389          *
 390          * @param $context ResourceLoaderContext: Context object
 391          * @return Integer: UNIX timestamp
 392          */
 393         public function getModifiedTime( ResourceLoaderContext $context ) {
 394                 // 0 would mean now
 395                 return 1;
 396         }
 397
 398         /**
 399          * Check whether this module is known to be empty. If a child class
 400          * has an easy and cheap way to determine that this module is
 401          * definitely going to be empty, it should override this method to
 402          * return true in that case. Callers may optimize the request for this
 403          * module away if this function returns true.
 404          * @param $context ResourceLoaderContext: Context object
 405          * @return Boolean
 406          */
 407         public function isKnownEmpty( ResourceLoaderContext $context ) {
 408                 return false;
 409         }
 410
 411
 412         /** @var JSParser lazy-initialized; use self::javaScriptParser() */
 413         private static $jsParser;
 414         private static $parseCacheVersion = 1;
 415
 416         /**
 417          * Validate a given script file; if valid returns the original source.
 418          * If invalid, returns replacement JS source that throws an exception.
 419          *
 420          * @param string $fileName
 421          * @param string $contents
 422          * @return string JS with the original, or a replacement error
 423          */
 424         protected function validateScriptFile( $fileName, $contents ) {
 425                 global $wgResourceLoaderValidateJS;
 426                 if ( $wgResourceLoaderValidateJS ) {
 427                         // Try for cache hit
 428                         // Use CACHE_ANYTHING since filtering is very slow compared to DB queries
 429                         $key = wfMemcKey( 'resourceloader', 'jsparse', self::$parseCacheVersion, md5( $contents ) );
 430                         $cache = wfGetCache( CACHE_ANYTHING );
 431                         $cacheEntry = $cache->get( $key );
 432                         if ( is_string( $cacheEntry ) ) {
 433                                 return $cacheEntry;
 434                         }
 435
 436                         $parser = self::javaScriptParser();
 437                         try {
 438                                 $parser->parse( $contents, $fileName, 1 );
 439                                 $result = $contents;
 440                         } catch ( Exception $e ) {
 441                                 // We'll save this to cache to avoid having to validate broken JS over and over...
 442                                 $err = $e->getMessage();
 443                                 $result = "throw new Error(" . Xml::encodeJsVar( "JavaScript parse error: $err" ) . ");";
 444                         }
 445
 446                         $cache->set( $key, $result );
 447                         return $result;
 448                 } else {
 449                         return $contents;
 450                 }
 451         }
 452
 453         /**
 454          * @return JSParser
 455          */
 456         protected static function javaScriptParser() {
 457                 if ( !self::$jsParser ) {
 458                         self::$jsParser = new JSParser();
 459                 }
 460                 return self::$jsParser;
 461         }
 462
 463         /**
 464          * Safe version of filemtime(), which doesn't throw a PHP warning if the file doesn't exist
 465          * but returns 1 instead.
 466          * @param $filename string File name
 467          * @return int UNIX timestamp, or 1 if the file doesn't exist
 468          */
 469         protected static function safeFilemtime( $filename ) {
 470                 if ( file_exists( $filename ) ) {
 471                         return filemtime( $filename );
 472                 } else {
 473                         // We only ever map this function on an array if we're gonna call max() after,
 474                         // so return our standard minimum timestamps here. This is 1, not 0, because
 475                         // wfTimestamp(0) == NOW
 476                         return 1;
 477                 }
 478         }
 479 }