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 string $name 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 ResourceLoader::register()
 103          * when registering the module. Other code should not call this.
 104          *
 105          * @param int $origin origin
 106          */
 107         public function setOrigin( $origin ) {
 108                 $this->origin = $origin;
 109         }
 110
 111         /**
 112          * @param ResourceLoaderContext $context
 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 ResourceLoaderContext $context
 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 ResourceLoaderContext $context
 145          * @return array: 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 ResourceLoaderContext $context
 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 ResourceLoaderContext $context
 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.
 278          *
 279          * To add dependencies dynamically on the client side, use a custom
 280          * loader script, see getLoaderScript()
 281          * @return array: List of module names as strings
 282          */
 283         public function getDependencies() {
 284                 // Stub, override expected
 285                 return array();
 286         }
 287
 288         /**
 289          * Get target(s) for the module, eg ['desktop'] or ['desktop', 'mobile']
 290          *
 291          * @return array: Array of strings
 292          */
 293         public function getTargets() {
 294                 return $this->targets;
 295         }
 296
 297         /**
 298          * Get the files this module depends on indirectly for a given skin.
 299          * Currently these are only image files referenced by the module's CSS.
 300          *
 301          * @param string $skin Skin name
 302          * @return array: List of files
 303          */
 304         public function getFileDependencies( $skin ) {
 305                 // Try in-object cache first
 306                 if ( isset( $this->fileDeps[$skin] ) ) {
 307                         return $this->fileDeps[$skin];
 308                 }
 309
 310                 $dbr = wfGetDB( DB_SLAVE );
 311                 $deps = $dbr->selectField( 'module_deps', 'md_deps', array(
 312                                 'md_module' => $this->getName(),
 313                                 'md_skin' => $skin,
 314                         ), __METHOD__
 315                 );
 316                 if ( !is_null( $deps ) ) {
 317                         $this->fileDeps[$skin] = (array)FormatJson::decode( $deps, true );
 318                 } else {
 319                         $this->fileDeps[$skin] = array();
 320                 }
 321                 return $this->fileDeps[$skin];
 322         }
 323
 324         /**
 325          * Set preloaded file dependency information. Used so we can load this
 326          * information for all modules at once.
 327          * @param string $skin Skin name
 328          * @param array $deps Array of file names
 329          */
 330         public function setFileDependencies( $skin, $deps ) {
 331                 $this->fileDeps[$skin] = $deps;
 332         }
 333
 334         /**
 335          * Get the last modification timestamp of the message blob for this
 336          * module in a given language.
 337          * @param string $lang Language code
 338          * @return int: UNIX timestamp, or 0 if the module doesn't have messages
 339          */
 340         public function getMsgBlobMtime( $lang ) {
 341                 if ( !isset( $this->msgBlobMtime[$lang] ) ) {
 342                         if ( !count( $this->getMessages() ) ) {
 343                                 return 0;
 344                         }
 345
 346                         $dbr = wfGetDB( DB_SLAVE );
 347                         $msgBlobMtime = $dbr->selectField( 'msg_resource', 'mr_timestamp', array(
 348                                         'mr_resource' => $this->getName(),
 349                                         'mr_lang' => $lang
 350                                 ), __METHOD__
 351                         );
 352                         // If no blob was found, but the module does have messages, that means we need
 353                         // to regenerate it. Return NOW
 354                         if ( $msgBlobMtime === false ) {
 355                                 $msgBlobMtime = wfTimestampNow();
 356                         }
 357                         $this->msgBlobMtime[$lang] = wfTimestamp( TS_UNIX, $msgBlobMtime );
 358                 }
 359                 return $this->msgBlobMtime[$lang];
 360         }
 361
 362         /**
 363          * Set a preloaded message blob last modification timestamp. Used so we
 364          * can load this information for all modules at once.
 365          * @param string $lang Language code
 366          * @param $mtime Integer: UNIX timestamp or 0 if there is no such blob
 367          */
 368         public function setMsgBlobMtime( $lang, $mtime ) {
 369                 $this->msgBlobMtime[$lang] = $mtime;
 370         }
 371
 372         /* Abstract Methods */
 373
 374         /**
 375          * Get this module's last modification timestamp for a given
 376          * combination of language, skin and debug mode flag. This is typically
 377          * the highest of each of the relevant components' modification
 378          * timestamps. Whenever anything happens that changes the module's
 379          * contents for these parameters, the mtime should increase.
 380          *
 381          * NOTE: The mtime of the module's messages is NOT automatically included.
 382          * If you want this to happen, you'll need to call getMsgBlobMtime()
 383          * yourself and take its result into consideration.
 384          *
 385          * @param ResourceLoaderContext $context
 386          * @return int: UNIX timestamp
 387          */
 388         public function getModifiedTime( ResourceLoaderContext $context ) {
 389                 // 0 would mean now
 390                 return 1;
 391         }
 392
 393         /**
 394          * Check whether this module is known to be empty. If a child class
 395          * has an easy and cheap way to determine that this module is
 396          * definitely going to be empty, it should override this method to
 397          * return true in that case. Callers may optimize the request for this
 398          * module away if this function returns true.
 399          * @param ResourceLoaderContext $context
 400          * @return bool
 401          */
 402         public function isKnownEmpty( ResourceLoaderContext $context ) {
 403                 return false;
 404         }
 405
 406         /** @var JSParser lazy-initialized; use self::javaScriptParser() */
 407         private static $jsParser;
 408         private static $parseCacheVersion = 1;
 409
 410         /** @var array Global LESS variables */
 411         private static $lessVars;
 412
 413         /**
 414          * Validate a given script file; if valid returns the original source.
 415          * If invalid, returns replacement JS source that throws an exception.
 416          *
 417          * @param string $fileName
 418          * @param string $contents
 419          * @return string: JS with the original, or a replacement error
 420          */
 421         protected function validateScriptFile( $fileName, $contents ) {
 422                 global $wgResourceLoaderValidateJS;
 423                 if ( $wgResourceLoaderValidateJS ) {
 424                         // Try for cache hit
 425                         // Use CACHE_ANYTHING since filtering is very slow compared to DB queries
 426                         $key = wfMemcKey( 'resourceloader', 'jsparse', self::$parseCacheVersion, md5( $contents ) );
 427                         $cache = wfGetCache( CACHE_ANYTHING );
 428                         $cacheEntry = $cache->get( $key );
 429                         if ( is_string( $cacheEntry ) ) {
 430                                 return $cacheEntry;
 431                         }
 432
 433                         $parser = self::javaScriptParser();
 434                         try {
 435                                 $parser->parse( $contents, $fileName, 1 );
 436                                 $result = $contents;
 437                         } catch ( Exception $e ) {
 438                                 // We'll save this to cache to avoid having to validate broken JS over and over...
 439                                 $err = $e->getMessage();
 440                                 $result = "throw new Error(" . Xml::encodeJsVar( "JavaScript parse error: $err" ) . ");";
 441                         }
 442
 443                         $cache->set( $key, $result );
 444                         return $result;
 445                 } else {
 446                         return $contents;
 447                 }
 448         }
 449
 450         /**
 451          * @return JSParser
 452          */
 453         protected static function javaScriptParser() {
 454                 if ( !self::$jsParser ) {
 455                         self::$jsParser = new JSParser();
 456                 }
 457                 return self::$jsParser;
 458         }
 459
 460         /**
 461          * @return lessc
 462          */
 463         protected static function lessCompiler() {
 464                 global $wgResourceLoaderLESSFunctions, $wgResourceLoaderLESSImportPaths;
 465
 466                 $less = new lessc();
 467                 $less->setPreserveComments( true );
 468                 $less->setVariables( self::getLESSVars() );
 469                 $less->setImportDir( $wgResourceLoaderLESSImportPaths );
 470                 foreach ( $wgResourceLoaderLESSFunctions as $name => $func ) {
 471                         $less->registerFunction( $name, $func );
 472                 }
 473                 // To ensure embedded resources are refreshed when their source files
 474                 // change, track the names and modification times of any files that
 475                 // were embedded as data URIs in the generated CSS source.
 476                 $less->embeddedFiles = array();
 477                 return $less;
 478         }
 479
 480         /**
 481          * Get global LESS variables.
 482          *
 483          * @return array: Map of variable names to string CSS values.
 484          */
 485         protected static function getLESSVars() {
 486                 global $wgResourceLoaderLESSVars;
 487
 488                 if ( self::$lessVars === null ) {
 489                         self::$lessVars = $wgResourceLoaderLESSVars;
 490                         // Sort by key to ensure consistent hashing for cache lookups.
 491                         ksort( self::$lessVars );
 492                 }
 493                 return self::$lessVars;
 494         }
 495
 496         /**
 497          * Safe version of filemtime(), which doesn't throw a PHP warning if the file doesn't exist
 498          * but returns 1 instead.
 499          * @param string $filename File name
 500          * @return int UNIX timestamp, or 1 if the file doesn't exist
 501          */
 502         protected static function safeFilemtime( $filename ) {
 503                 if ( file_exists( $filename ) ) {
 504                         return filemtime( $filename );
 505                 } else {
 506                         // We only ever map this function on an array if we're gonna call max() after,
 507                         // so return our standard minimum timestamps here. This is 1, not 0, because
 508                         // wfTimestamp(0) == NOW
 509                         return 1;
 510                 }
 511         }
 512 }