resources/mediawiki/mediawiki.js

   1 /*
   2  * Core MediaWiki JavaScript Library
   3  */
   4
   5 var mw = ( function ( $, undefined ) {
   6         'use strict';
   7
   8         /* Private Members */
   9
  10         var hasOwn = Object.prototype.hasOwnProperty,
  11                 slice = Array.prototype.slice;
  12
  13         /* Object constructors */
  14
  15         /**
  16          * Creates an object that can be read from or written to from prototype functions
  17          * that allow both single and multiple variables at once.
  18          * @class mw.Map
  19          *
  20          * @constructor
  21          * @param {boolean} global Whether to store the values in the global window
  22          *  object or a exclusively in the object property 'values'.
  23          */
  24         function Map( global ) {
  25                 this.values = global === true ? window : {};
  26                 return this;
  27         }
  28
  29         Map.prototype = {
  30                 /**
  31                  * Get the value of one or multiple a keys.
  32                  *
  33                  * If called with no arguments, all values will be returned.
  34                  *
  35                  * @param selection mixed String key or array of keys to get values for.
  36                  * @param fallback mixed Value to use in case key(s) do not exist (optional).
  37                  * @return mixed If selection was a string returns the value or null,
  38                  *  If selection was an array, returns an object of key/values (value is null if not found),
  39                  *  If selection was not passed or invalid, will return the 'values' object member (be careful as
  40                  *  objects are always passed by reference in JavaScript!).
  41                  * @return {string|Object|null} Values as a string or object, null if invalid/inexistant.
  42                  */
  43                 get: function ( selection, fallback ) {
  44                         var results, i;
  45                         // If we only do this in the `return` block, it'll fail for the
  46                         // call to get() from the mutli-selection block.
  47                         fallback = arguments.length > 1 ? fallback : null;
  48
  49                         if ( $.isArray( selection ) ) {
  50                                 selection = slice.call( selection );
  51                                 results = {};
  52                                 for ( i = 0; i < selection.length; i++ ) {
  53                                         results[selection[i]] = this.get( selection[i], fallback );
  54                                 }
  55                                 return results;
  56                         }
  57
  58                         if ( typeof selection === 'string' ) {
  59                                 if ( !hasOwn.call( this.values, selection ) ) {
  60                                         return fallback;
  61                                 }
  62                                 return this.values[selection];
  63                         }
  64
  65                         if ( selection === undefined ) {
  66                                 return this.values;
  67                         }
  68
  69                         // invalid selection key
  70                         return null;
  71                 },
  72
  73                 /**
  74                  * Sets one or multiple key/value pairs.
  75                  *
  76                  * @param selection {mixed} String key or array of keys to set values for.
  77                  * @param value {mixed} Value to set (optional, only in use when key is a string)
  78                  * @return {Boolean} This returns true on success, false on failure.
  79                  */
  80                 set: function ( selection, value ) {
  81                         var s;
  82
  83                         if ( $.isPlainObject( selection ) ) {
  84                                 for ( s in selection ) {
  85                                         this.values[s] = selection[s];
  86                                 }
  87                                 return true;
  88                         }
  89                         if ( typeof selection === 'string' && arguments.length > 1 ) {
  90                                 this.values[selection] = value;
  91                                 return true;
  92                         }
  93                         return false;
  94                 },
  95
  96                 /**
  97                  * Checks if one or multiple keys exist.
  98                  *
  99                  * @param selection {mixed} String key or array of keys to check
 100                  * @return {boolean} Existence of key(s)
 101                  */
 102                 exists: function ( selection ) {
 103                         var s;
 104
 105                         if ( $.isArray( selection ) ) {
 106                                 for ( s = 0; s < selection.length; s++ ) {
 107                                         if ( typeof selection[s] !== 'string' || !hasOwn.call( this.values, selection[s] ) ) {
 108                                                 return false;
 109                                         }
 110                                 }
 111                                 return true;
 112                         }
 113                         return typeof selection === 'string' && hasOwn.call( this.values, selection );
 114                 }
 115         };
 116
 117         /**
 118          * Object constructor for messages,
 119          * similar to the Message class in MediaWiki PHP.
 120          * @class mw.Message
 121          *
 122          * @constructor
 123          * @param {mw.Map} map Message storage
 124          * @param {string} key
 125          * @param {Array} [parameters]
 126          */
 127         function Message( map, key, parameters ) {
 128                 this.format = 'text';
 129                 this.map = map;
 130                 this.key = key;
 131                 this.parameters = parameters === undefined ? [] : slice.call( parameters );
 132                 return this;
 133         }
 134
 135         Message.prototype = {
 136                 /**
 137                  * Simple message parser, does $N replacement, HTML-escaping (only for
 138                  * 'escaped' format), and nothing else.
 139                  *
 140                  * This may be overridden to provide a more complex message parser.
 141                  *
 142                  * The primary override is in mediawiki.jqueryMsg.
 143                  *
 144                  * This function will not be called for nonexistent messages.
 145                  */
 146                 parser: function () {
 147                         var parameters = this.parameters;
 148                         return this.map.get( this.key ).replace( /\$(\d+)/g, function ( str, match ) {
 149                                 var index = parseInt( match, 10 ) - 1;
 150                                 return parameters[index] !== undefined ? parameters[index] : '$' + match;
 151                         } );
 152                 },
 153
 154                 /**
 155                  * Appends (does not replace) parameters for replacement to the .parameters property.
 156                  *
 157                  * @param {Array} parameters
 158                  * @chainable
 159                  */
 160                 params: function ( parameters ) {
 161                         var i;
 162                         for ( i = 0; i < parameters.length; i += 1 ) {
 163                                 this.parameters.push( parameters[i] );
 164                         }
 165                         return this;
 166                 },
 167
 168                 /**
 169                  * Converts message object to it's string form based on the state of format.
 170                  *
 171                  * @return {string} Message as a string in the current form or `<key>` if key does not exist.
 172                  */
 173                 toString: function () {
 174                         var text;
 175
 176                         if ( !this.exists() ) {
 177                                 // Use <key> as text if key does not exist
 178                                 if ( this.format === 'escaped' || this.format === 'parse' ) {
 179                                         // format 'escaped' and 'parse' need to have the brackets and key html escaped
 180                                         return mw.html.escape( '<' + this.key + '>' );
 181                                 }
 182                                 return '<' + this.key + '>';
 183                         }
 184
 185                         if ( this.format === 'plain' || this.format === 'text' || this.format === 'parse' ) {
 186                                 text = this.parser();
 187                         }
 188
 189                         if ( this.format === 'escaped' ) {
 190                                 text = this.parser();
 191                                 text = mw.html.escape( text );
 192                         }
 193
 194                         return text;
 195                 },
 196
 197                 /**
 198                  * Changes format to 'parse' and converts message to string
 199                  *
 200                  * If jqueryMsg is loaded, this parses the message text from wikitext
 201                  * (where supported) to HTML
 202                  *
 203                  * Otherwise, it is equivalent to plain.
 204                  *
 205                  * @return {string} String form of parsed message
 206                  */
 207                 parse: function () {
 208                         this.format = 'parse';
 209                         return this.toString();
 210                 },
 211
 212                 /**
 213                  * Changes format to 'plain' and converts message to string
 214                  *
 215                  * This substitutes parameters, but otherwise does not change the
 216                  * message text.
 217                  *
 218                  * @return {string} String form of plain message
 219                  */
 220                 plain: function () {
 221                         this.format = 'plain';
 222                         return this.toString();
 223                 },
 224
 225                 /**
 226                  * Changes format to 'text' and converts message to string
 227                  *
 228                  * If jqueryMsg is loaded, {{-transformation is done where supported
 229                  * (such as {{plural:}}, {{gender:}}, {{int:}}).
 230                  *
 231                  * Otherwise, it is equivalent to plain.
 232                  */
 233                 text: function () {
 234                         this.format = 'text';
 235                         return this.toString();
 236                 },
 237
 238                 /**
 239                  * Changes the format to 'escaped' and converts message to string
 240                  *
 241                  * This is equivalent to using the 'text' format (see text method), then
 242                  * HTML-escaping the output.
 243                  *
 244                  * @return {string} String form of html escaped message
 245                  */
 246                 escaped: function () {
 247                         this.format = 'escaped';
 248                         return this.toString();
 249                 },
 250
 251                 /**
 252                  * Checks if message exists
 253                  *
 254                  * @see mw.Map#exists
 255                  * @return {boolean}
 256                  */
 257                 exists: function () {
 258                         return this.map.exists( this.key );
 259                 }
 260         };
 261
 262         /**
 263          * @class mw
 264          * @alternateClassName mediaWiki
 265          * @singleton
 266          */
 267         return {
 268                 /* Public Members */
 269
 270                 /**
 271                  * Dummy function which in debug mode can be replaced with a function that
 272                  * emulates console.log in console-less environments.
 273                  */
 274                 log: function () { },
 275
 276                 // Make the Map constructor publicly available.
 277                 Map: Map,
 278
 279                 // Make the Message constructor publicly available.
 280                 Message: Message,
 281
 282                 /**
 283                  * List of configuration values
 284                  *
 285                  * Dummy placeholder. Initiated in startUp module as a new instance of mw.Map().
 286                  * If `$wgLegacyJavaScriptGlobals` is true, this Map will have its values
 287                  * in the global window object.
 288                  * @property
 289                  */
 290                 config: null,
 291
 292                 /**
 293                  * Empty object that plugins can be installed in.
 294                  * @property
 295                  */
 296                 libs: {},
 297
 298                 /* Extension points */
 299
 300                 /**
 301                  * @property
 302                  */
 303                 legacy: {},
 304
 305                 /**
 306                  * Localization system
 307                  * @property {mw.Map}
 308                  */
 309                 messages: new Map(),
 310
 311                 /* Public Methods */
 312
 313                 /**
 314                  * Gets a message object, similar to wfMessage().
 315                  *
 316                  * @param {string} key Key of message to get
 317                  * @param {Mixed...} parameters Parameters for the $N replacements in messages.
 318                  * @return {mw.Message}
 319                  */
 320                 message: function ( key ) {
 321                         // Variadic arguments
 322                         var parameters = slice.call( arguments, 1 );
 323                         return new Message( mw.messages, key, parameters );
 324                 },
 325
 326                 /**
 327                  * Gets a message string, similar to wfMessage()
 328                  *
 329                  * @see mw.Message#toString
 330                  * @param {string} key Key of message to get
 331                  * @param {Mixed...} parameters Parameters for the $N replacements in messages.
 332                  * @return {string}
 333                  */
 334                 msg: function ( /* key, parameters... */ ) {
 335                         return mw.message.apply( mw.message, arguments ).toString();
 336                 },
 337
 338                 /**
 339                  * Client-side module loader which integrates with the MediaWiki ResourceLoader
 340                  * @class mw.loader
 341                  * @singleton
 342                  */
 343                 loader: ( function () {
 344
 345                         /* Private Members */
 346
 347                         /**
 348                          * Mapping of registered modules
 349                          *
 350                          * The jquery module is pre-registered, because it must have already
 351                          * been provided for this object to have been built, and in debug mode
 352                          * jquery would have been provided through a unique loader request,
 353                          * making it impossible to hold back registration of jquery until after
 354                          * mediawiki.
 355                          *
 356                          * For exact details on support for script, style and messages, look at
 357                          * mw.loader.implement.
 358                          *
 359                          * Format:
 360                          *     {
 361                          *         'moduleName': {
 362                          *             'version': ############## (unix timestamp),
 363                          *             'dependencies': ['required.foo', 'bar.also', ...], (or) function () {}
 364                          *             'group': 'somegroup', (or) null,
 365                          *             'source': 'local', 'someforeignwiki', (or) null
 366                          *             'state': 'registered', 'loading', 'loaded', 'ready', 'error' or 'missing'
 367                          *             'script': ...,
 368                          *             'style': ...,
 369                          *             'messages': { 'key': 'value' },
 370                          *         }
 371                          *     }
 372                          *
 373                          * @property
 374                          * @private
 375                          */
 376                         var registry = {},
 377                                 //
 378                                 // Mapping of sources, keyed by source-id, values are objects.
 379                                 // Format:
 380                                 //      {
 381                                 //              'sourceId': {
 382                                 //                      'loadScript': 'http://foo.bar/w/load.php'
 383                                 //              }
 384                                 //      }
 385                                 //
 386                                 sources = {},
 387                                 // List of modules which will be loaded as when ready
 388                                 batch = [],
 389                                 // List of modules to be loaded
 390                                 queue = [],
 391                                 // List of callback functions waiting for modules to be ready to be called
 392                                 jobs = [],
 393                                 // Selector cache for the marker element. Use getMarker() to get/use the marker!
 394                                 $marker = null;
 395
 396                         /* Private methods */
 397
 398                         function getMarker() {
 399                                 // Cached ?
 400                                 if ( $marker ) {
 401                                         return $marker;
 402                                 }
 403
 404                                 $marker = $( 'meta[name="ResourceLoaderDynamicStyles"]' );
 405                                 if ( $marker.length ) {
 406                                         return $marker;
 407                                 }
 408                                 mw.log( 'getMarker> No <meta name="ResourceLoaderDynamicStyles"> found, inserting dynamically.' );
 409                                 $marker = $( '<meta>' ).attr( 'name', 'ResourceLoaderDynamicStyles' ).appendTo( 'head' );
 410
 411                                 return $marker;
 412                         }
 413
 414                         /**
 415                          * Create a new style tag and add it to the DOM.
 416                          *
 417                          * @private
 418                          * @param {string} text CSS text
 419                          * @param {Mixed} [nextnode] An Element or jQuery object for an element where
 420                          * the style tag should be inserted before. Otherwise appended to the `<head>`.
 421                          * @return {HTMLElement} Node reference to the created `<style>` tag.
 422                          */
 423                         function addStyleTag( text, nextnode ) {
 424                                 var s = document.createElement( 'style' );
 425                                 // Insert into document before setting cssText (bug 33305)
 426                                 if ( nextnode ) {
 427                                         // Must be inserted with native insertBefore, not $.fn.before.
 428                                         // When using jQuery to insert it, like $nextnode.before( s ),
 429                                         // then IE6 will throw "Access is denied" when trying to append
 430                                         // to .cssText later. Some kind of weird security measure.
 431                                         // http://stackoverflow.com/q/12586482/319266
 432                                         // Works: jsfiddle.net/zJzMy/1
 433                                         // Fails: jsfiddle.net/uJTQz
 434                                         // Works again: http://jsfiddle.net/Azr4w/ (diff: the next 3 lines)
 435                                         if ( nextnode.jquery ) {
 436                                                 nextnode = nextnode.get( 0 );
 437                                         }
 438                                         nextnode.parentNode.insertBefore( s, nextnode );
 439                                 } else {
 440                                         document.getElementsByTagName( 'head' )[0].appendChild( s );
 441                                 }
 442                                 if ( s.styleSheet ) {
 443                                         // IE
 444                                         s.styleSheet.cssText = text;
 445                                 } else {
 446                                         // Other browsers.
 447                                         // (Safari sometimes borks on non-string values,
 448                                         // play safe by casting to a string, just in case.)
 449                                         s.appendChild( document.createTextNode( String( text ) ) );
 450                                 }
 451                                 return s;
 452                         }
 453
 454                         /**
 455                          * Checks if certain cssText is safe to append to
 456                          * a stylesheet.
 457                          *
 458                          * Right now it only makes sure that cssText containing `@import`
 459                          * rules will end up in a new stylesheet (as those only work when
 460                          * placed at the start of a stylesheet; bug 35562).
 461                          * This could later be extended to take care of other bugs, such as
 462                          * the IE cssRules limit - not the same as the IE styleSheets limit).
 463                          * @private
 464                          * @param {jQuery} $style
 465                          * @param {string} cssText
 466                          * @return {boolean}
 467                          */
 468                         function canExpandStylesheetWith( $style, cssText ) {
 469                                 return cssText.indexOf( '@import' ) === -1;
 470                         }
 471
 472                         function addEmbeddedCSS( cssText ) {
 473                                 var $style, styleEl;
 474                                 $style = getMarker().prev();
 475                                 // Re-use `<style>` tags if possible, this to try to stay
 476                                 // under the IE stylesheet limit (bug 31676).
 477                                 // Also verify that the the element before Marker actually is one
 478                                 // that came from ResourceLoader, and not a style tag that some
 479                                 // other script inserted before our marker, or, more importantly,
 480                                 // it may not be a style tag at all (could be `<meta>` or `<script>`).
 481                                 if (
 482                                         $style.data( 'ResourceLoaderDynamicStyleTag' ) === true &&
 483                                         canExpandStylesheetWith( $style, cssText )
 484                                 ) {
 485                                         // There's already a dynamic <style> tag present and
 486                                         // canExpandStylesheetWith() gave a green light to append more to it.
 487                                         styleEl = $style.get( 0 );
 488                                         if ( styleEl.styleSheet ) {
 489                                                 try {
 490                                                         styleEl.styleSheet.cssText += cssText; // IE
 491                                                 } catch ( e ) {
 492                                                         log( 'addEmbeddedCSS fail\ne.message: ' + e.message, e );
 493                                                 }
 494                                         } else {
 495                                                 styleEl.appendChild( document.createTextNode( String( cssText ) ) );
 496                                         }
 497                                 } else {
 498                                         $( addStyleTag( cssText, getMarker() ) )
 499                                                 .data( 'ResourceLoaderDynamicStyleTag', true );
 500                                 }
 501                         }
 502
 503                         /**
 504                          * Generates an ISO8601 "basic" string from a UNIX timestamp
 505                          * @private
 506                          */
 507                         function formatVersionNumber( timestamp ) {
 508                                 var     d = new Date();
 509                                 function pad( a, b, c ) {
 510                                         return [a < 10 ? '0' + a : a, b < 10 ? '0' + b : b, c < 10 ? '0' + c : c].join( '' );
 511                                 }
 512                                 d.setTime( timestamp * 1000 );
 513                                 return [
 514                                         pad( d.getUTCFullYear(), d.getUTCMonth() + 1, d.getUTCDate() ), 'T',
 515                                         pad( d.getUTCHours(), d.getUTCMinutes(), d.getUTCSeconds() ), 'Z'
 516                                 ].join( '' );
 517                         }
 518
 519                         /**
 520                          * Resolves dependencies and detects circular references.
 521                          *
 522                          * @private
 523                          * @param {string} module Name of the top-level module whose dependencies shall be
 524                          *   resolved and sorted.
 525                          * @param {Array} resolved Returns a topological sort of the given module and its
 526                          *   dependencies, such that later modules depend on earlier modules. The array
 527                          *   contains the module names. If the array contains already some module names,
 528                          *   this function appends its result to the pre-existing array.
 529                          * @param {Object} [unresolved] Hash used to track the current dependency
 530                          *   chain; used to report loops in the dependency graph.
 531                          * @throws {Error} If any unregistered module or a dependency loop is encountered
 532                          */
 533                         function sortDependencies( module, resolved, unresolved ) {
 534                                 var n, deps, len;
 535
 536                                 if ( registry[module] === undefined ) {
 537                                         throw new Error( 'Unknown dependency: ' + module );
 538                                 }
 539                                 // Resolves dynamic loader function and replaces it with its own results
 540                                 if ( $.isFunction( registry[module].dependencies ) ) {
 541                                         registry[module].dependencies = registry[module].dependencies();
 542                                         // Ensures the module's dependencies are always in an array
 543                                         if ( typeof registry[module].dependencies !== 'object' ) {
 544                                                 registry[module].dependencies = [registry[module].dependencies];
 545                                         }
 546                                 }
 547                                 if ( $.inArray( module, resolved ) !== -1 ) {
 548                                         // Module already resolved; nothing to do.
 549                                         return;
 550                                 }
 551                                 // unresolved is optional, supply it if not passed in
 552                                 if ( !unresolved ) {
 553                                         unresolved = {};
 554                                 }
 555                                 // Tracks down dependencies
 556                                 deps = registry[module].dependencies;
 557                                 len = deps.length;
 558                                 for ( n = 0; n < len; n += 1 ) {
 559                                         if ( $.inArray( deps[n], resolved ) === -1 ) {
 560                                                 if ( unresolved[deps[n]] ) {
 561                                                         throw new Error(
 562                                                                 'Circular reference detected: ' + module +
 563                                                                 ' -> ' + deps[n]
 564                                                         );
 565                                                 }
 566
 567                                                 // Add to unresolved
 568                                                 unresolved[module] = true;
 569                                                 sortDependencies( deps[n], resolved, unresolved );
 570                                                 delete unresolved[module];
 571                                         }
 572                                 }
 573                                 resolved[resolved.length] = module;
 574                         }
 575
 576                         /**
 577                          * Gets a list of module names that a module depends on in their proper dependency
 578                          * order.
 579                          *
 580                          * @private
 581                          * @param {string} module Module name or array of string module names
 582                          * @return {Array} list of dependencies, including 'module'.
 583                          * @throws {Error} If circular reference is detected
 584                          */
 585                         function resolve( module ) {
 586                                 var m, resolved;
 587
 588                                 // Allow calling with an array of module names
 589                                 if ( $.isArray( module ) ) {
 590                                         resolved = [];
 591                                         for ( m = 0; m < module.length; m += 1 ) {
 592                                                 sortDependencies( module[m], resolved );
 593                                         }
 594                                         return resolved;
 595                                 }
 596
 597                                 if ( typeof module === 'string' ) {
 598                                         resolved = [];
 599                                         sortDependencies( module, resolved );
 600                                         return resolved;
 601                                 }
 602
 603                                 throw new Error( 'Invalid module argument: ' + module );
 604                         }
 605
 606                         /**
 607                          * Narrows a list of module names down to those matching a specific
 608                          * state (see comment on top of this scope for a list of valid states).
 609                          * One can also filter for 'unregistered', which will return the
 610                          * modules names that don't have a registry entry.
 611                          *
 612                          * @private
 613                          * @param {string|string[]} states Module states to filter by
 614                          * @param {Array} modules List of module names to filter (optional, by default the entire
 615                          * registry is used)
 616                          * @return {Array} List of filtered module names
 617                          */
 618                         function filter( states, modules ) {
 619                                 var list, module, s, m;
 620
 621                                 // Allow states to be given as a string
 622                                 if ( typeof states === 'string' ) {
 623                                         states = [states];
 624                                 }
 625                                 // If called without a list of modules, build and use a list of all modules
 626                                 list = [];
 627                                 if ( modules === undefined ) {
 628                                         modules = [];
 629                                         for ( module in registry ) {
 630                                                 modules[modules.length] = module;
 631                                         }
 632                                 }
 633                                 // Build a list of modules which are in one of the specified states
 634                                 for ( s = 0; s < states.length; s += 1 ) {
 635                                         for ( m = 0; m < modules.length; m += 1 ) {
 636                                                 if ( registry[modules[m]] === undefined ) {
 637                                                         // Module does not exist
 638                                                         if ( states[s] === 'unregistered' ) {
 639                                                                 // OK, undefined
 640                                                                 list[list.length] = modules[m];
 641                                                         }
 642                                                 } else {
 643                                                         // Module exists, check state
 644                                                         if ( registry[modules[m]].state === states[s] ) {
 645                                                                 // OK, correct state
 646                                                                 list[list.length] = modules[m];
 647                                                         }
 648                                                 }
 649                                         }
 650                                 }
 651                                 return list;
 652                         }
 653
 654                         /**
 655                          * Determine whether all dependencies are in state 'ready', which means we may
 656                          * execute the module or job now.
 657                          *
 658                          * @private
 659                          * @param {Array} dependencies Dependencies (module names) to be checked.
 660                          * @return {boolean} True if all dependencies are in state 'ready', false otherwise
 661                          */
 662                         function allReady( dependencies ) {
 663                                 return filter( 'ready', dependencies ).length === dependencies.length;
 664                         }
 665
 666                         /**
 667                          * Log a message to window.console, if possible. Useful to force logging of some
 668                          * errors that are otherwise hard to detect (I.e., this logs also in production mode).
 669                          * Gets console references in each invocation, so that delayed debugging tools work
 670                          * fine. No need for optimization here, which would only result in losing logs.
 671                          *
 672                          * @private
 673                          * @param {string} msg text for the log entry.
 674                          * @param {Error} [e]
 675                          */
 676                         function log( msg, e ) {
 677                                 var console = window.console;
 678                                 if ( console && console.log ) {
 679                                         console.log( msg );
 680                                         // If we have an exception object, log it through .error() to trigger
 681                                         // proper stacktraces in browsers that support it. There are no (known)
 682                                         // browsers that don't support .error(), that do support .log() and
 683                                         // have useful exception handling through .log().
 684                                         if ( e && console.error ) {
 685                                                 console.error( e );
 686                                         }
 687                                 }
 688                         }
 689
 690                         /**
 691                          * A module has entered state 'ready', 'error', or 'missing'. Automatically update pending jobs
 692                          * and modules that depend upon this module. if the given module failed, propagate the 'error'
 693                          * state up the dependency tree; otherwise, execute all jobs/modules that now have all their
 694                          * dependencies satisfied. On jobs depending on a failed module, run the error callback, if any.
 695                          *
 696                          * @private
 697                          * @param {string} module Name of module that entered one of the states 'ready', 'error', or 'missing'.
 698                          */
 699                         function handlePending( module ) {
 700                                 var j, job, hasErrors, m, stateChange;
 701
 702                                 // Modules.
 703                                 if ( $.inArray( registry[module].state, ['error', 'missing'] ) !== -1 ) {
 704                                         // If the current module failed, mark all dependent modules also as failed.
 705                                         // Iterate until steady-state to propagate the error state upwards in the
 706                                         // dependency tree.
 707                                         do {
 708                                                 stateChange = false;
 709                                                 for ( m in registry ) {
 710                                                         if ( $.inArray( registry[m].state, ['error', 'missing'] ) === -1 ) {
 711                                                                 if ( filter( ['error', 'missing'], registry[m].dependencies ).length > 0 ) {
 712                                                                         registry[m].state = 'error';
 713                                                                         stateChange = true;
 714                                                                 }
 715                                                         }
 716                                                 }
 717                                         } while ( stateChange );
 718                                 }
 719
 720                                 // Execute all jobs whose dependencies are either all satisfied or contain at least one failed module.
 721                                 for ( j = 0; j < jobs.length; j += 1 ) {
 722                                         hasErrors = filter( ['error', 'missing'], jobs[j].dependencies ).length > 0;
 723                                         if ( hasErrors || allReady( jobs[j].dependencies ) ) {
 724                                                 // All dependencies satisfied, or some have errors
 725                                                 job = jobs[j];
 726                                                 jobs.splice( j, 1 );
 727                                                 j -= 1;
 728                                                 try {
 729                                                         if ( hasErrors ) {
 730                                                                 throw new Error( 'Module ' + module + ' failed.');
 731                                                         } else {
 732                                                                 if ( $.isFunction( job.ready ) ) {
 733                                                                         job.ready();
 734                                                                 }
 735                                                         }
 736                                                 } catch ( e ) {
 737                                                         if ( $.isFunction( job.error ) ) {
 738                                                                 try {
 739                                                                         job.error( e, [module] );
 740                                                                 } catch ( ex ) {
 741                                                                         // A user-defined operation raised an exception. Swallow to protect
 742                                                                         // our state machine!
 743                                                                         log( 'Exception thrown by job.error()', ex );
 744                                                                 }
 745                                                         }
 746                                                 }
 747                                         }
 748                                 }
 749
 750                                 if ( registry[module].state === 'ready' ) {
 751                                         // The current module became 'ready'. Recursively execute all dependent modules that are loaded
 752                                         // and now have all dependencies satisfied.
 753                                         for ( m in registry ) {
 754                                                 if ( registry[m].state === 'loaded' && allReady( registry[m].dependencies ) ) {
 755                                                         execute( m );
 756                                                 }
 757                                         }
 758                                 }
 759                         }
 760
 761                         /**
 762                          * Adds a script tag to the DOM, either using document.write or low-level DOM manipulation,
 763                          * depending on whether document-ready has occurred yet and whether we are in async mode.
 764                          *
 765                          * @private
 766                          * @param {string} src URL to script, will be used as the src attribute in the script tag
 767                          * @param {Function} [callback] Callback which will be run when the script is done
 768                          */
 769                         function addScript( src, callback, async ) {
 770                                 /*jshint evil:true */
 771                                 var script, head,
 772                                         done = false;
 773
 774                                 // Using isReady directly instead of storing it locally from
 775                                 // a $.fn.ready callback (bug 31895).
 776                                 if ( $.isReady || async ) {
 777                                         // Can't use jQuery.getScript because that only uses <script> for cross-domain,
 778                                         // it uses XHR and eval for same-domain scripts, which we don't want because it
 779                                         // messes up line numbers.
 780                                         // The below is based on jQuery ([jquery@1.8.2]/src/ajax/script.js)
 781
 782                                         // IE-safe way of getting the <head>. document.head isn't supported
 783                                         // in old IE, and doesn't work when in the <head>.
 784                                         head = document.getElementsByTagName( 'head' )[0] || document.body;
 785
 786                                         script = document.createElement( 'script' );
 787                                         script.async = true;
 788                                         script.src = src;
 789                                         if ( $.isFunction( callback ) ) {
 790                                                 script.onload = script.onreadystatechange = function () {
 791                                                         if (
 792                                                                 !done
 793                                                                 && (
 794                                                                         !script.readyState
 795                                                                         || /loaded|complete/.test( script.readyState )
 796                                                                 )
 797                                                         ) {
 798                                                                 done = true;
 799
 800                                                                 // Handle memory leak in IE
 801                                                                 script.onload = script.onreadystatechange = null;
 802
 803                                                                 // Remove the script
 804                                                                 if ( script.parentNode ) {
 805                                                                         script.parentNode.removeChild( script );
 806                                                                 }
 807
 808                                                                 // Dereference the script
 809                                                                 script = undefined;
 810
 811                                                                 callback();
 812                                                         }
 813                                                 };
 814                                         }
 815
 816                                         if ( window.opera ) {
 817                                                 // Appending to the <head> blocks rendering completely in Opera,
 818                                                 // so append to the <body> after document ready. This means the
 819                                                 // scripts only start loading after the document has been rendered,
 820                                                 // but so be it. Opera users don't deserve faster web pages if their
 821                                                 // browser makes it impossible.
 822                                                 $( function () {
 823                                                         document.body.appendChild( script );
 824                                                 } );
 825                                         } else {
 826                                                 head.appendChild( script );
 827                                         }
 828                                 } else {
 829                                         document.write( mw.html.element( 'script', { 'src': src }, '' ) );
 830                                         if ( $.isFunction( callback ) ) {
 831                                                 // Document.write is synchronous, so this is called when it's done
 832                                                 // FIXME: that's a lie. doc.write isn't actually synchronous
 833                                                 callback();
 834                                         }
 835                                 }
 836                         }
 837
 838                         /**
 839                          * Executes a loaded module, making it ready to use
 840                          *
 841                          * @private
 842                          * @param {string} module Module name to execute
 843                          */
 844                         function execute( module ) {
 845                                 var key, value, media, i, urls, script, markModuleReady, nestedAddScript;
 846
 847                                 if ( registry[module] === undefined ) {
 848                                         throw new Error( 'Module has not been registered yet: ' + module );
 849                                 } else if ( registry[module].state === 'registered' ) {
 850                                         throw new Error( 'Module has not been requested from the server yet: ' + module );
 851                                 } else if ( registry[module].state === 'loading' ) {
 852                                         throw new Error( 'Module has not completed loading yet: ' + module );
 853                                 } else if ( registry[module].state === 'ready' ) {
 854                                         throw new Error( 'Module has already been loaded: ' + module );
 855                                 }
 856
 857                                 /**
 858                                  * Define loop-function here for efficiency
 859                                  * and to avoid re-using badly scoped variables.
 860                                  * @ignore
 861                                  */
 862                                 function addLink( media, url ) {
 863                                         var el = document.createElement( 'link' );
 864                                         getMarker().before( el ); // IE: Insert in dom before setting href
 865                                         el.rel = 'stylesheet';
 866                                         if ( media && media !== 'all' ) {
 867                                                 el.media = media;
 868                                         }
 869                                         el.href = url;
 870                                 }
 871
 872                                 // Process styles (see also mw.loader.implement)
 873                                 // * back-compat: { <media>: css }
 874                                 // * back-compat: { <media>: [url, ..] }
 875                                 // * { "css": [css, ..] }
 876                                 // * { "url": { <media>: [url, ..] } }
 877                                 if ( $.isPlainObject( registry[module].style ) ) {
 878                                         for ( key in registry[module].style ) {
 879                                                 value = registry[module].style[key];
 880                                                 media = undefined;
 881
 882                                                 if ( key !== 'url' && key !== 'css' ) {
 883                                                         // Backwards compatibility, key is a media-type
 884                                                         if ( typeof value === 'string' ) {
 885                                                                 // back-compat: { <media>: css }
 886                                                                 // Ignore 'media' because it isn't supported (nor was it used).
 887                                                                 // Strings are pre-wrapped in "@media". The media-type was just ""
 888                                                                 // (because it had to be set to something).
 889                                                                 // This is one of the reasons why this format is no longer used.
 890                                                                 addEmbeddedCSS( value );
 891                                                         } else {
 892                                                                 // back-compat: { <media>: [url, ..] }
 893                                                                 media = key;
 894                                                                 key = 'bc-url';
 895                                                         }
 896                                                 }
 897
 898                                                 // Array of css strings in key 'css',
 899                                                 // or back-compat array of urls from media-type
 900                                                 if ( $.isArray( value ) ) {
 901                                                         for ( i = 0; i < value.length; i += 1 ) {
 902                                                                 if ( key === 'bc-url' ) {
 903                                                                         // back-compat: { <media>: [url, ..] }
 904                                                                         addLink( media, value[i] );
 905                                                                 } else if ( key === 'css' ) {
 906                                                                         // { "css": [css, ..] }
 907                                                                         addEmbeddedCSS( value[i] );
 908                                                                 }
 909                                                         }
 910                                                 // Not an array, but a regular object
 911                                                 // Array of urls inside media-type key
 912                                                 } else if ( typeof value === 'object' ) {
 913                                                         // { "url": { <media>: [url, ..] } }
 914                                                         for ( media in value ) {
 915                                                                 urls = value[media];
 916                                                                 for ( i = 0; i < urls.length; i += 1 ) {
 917                                                                         addLink( media, urls[i] );
 918                                                                 }
 919                                                         }
 920                                                 }
 921                                         }
 922                                 }
 923
 924                                 // Add localizations to message system
 925                                 if ( $.isPlainObject( registry[module].messages ) ) {
 926                                         mw.messages.set( registry[module].messages );
 927                                 }
 928
 929                                 // Execute script
 930                                 try {
 931                                         script = registry[module].script;
 932                                         markModuleReady = function () {
 933                                                 registry[module].state = 'ready';
 934                                                 handlePending( module );
 935                                         };
 936                                         nestedAddScript = function ( arr, callback, async, i ) {
 937                                                 // Recursively call addScript() in its own callback
 938                                                 // for each element of arr.
 939                                                 if ( i >= arr.length ) {
 940                                                         // We're at the end of the array
 941                                                         callback();
 942                                                         return;
 943                                                 }
 944
 945                                                 addScript( arr[i], function () {
 946                                                         nestedAddScript( arr, callback, async, i + 1 );
 947                                                 }, async );
 948                                         };
 949
 950                                         if ( $.isArray( script ) ) {
 951                                                 registry[module].state = 'loading';
 952                                                 nestedAddScript( script, markModuleReady, registry[module].async, 0 );
 953                                         } else if ( $.isFunction( script ) ) {
 954                                                 registry[module].state = 'ready';
 955                                                 script( $ );
 956                                                 handlePending( module );
 957                                         }
 958                                 } catch ( e ) {
 959                                         // This needs to NOT use mw.log because these errors are common in production mode
 960                                         // and not in debug mode, such as when a symbol that should be global isn't exported
 961                                         log( 'Exception thrown by ' + module + ': ' + e.message, e );
 962                                         registry[module].state = 'error';
 963                                         handlePending( module );
 964                                 }
 965                         }
 966
 967                         /**
 968                          * Adds a dependencies to the queue with optional callbacks to be run
 969                          * when the dependencies are ready or fail
 970                          *
 971                          * @private
 972                          * @param {string|string[]} dependencies Module name or array of string module names
 973                          * @param {Function} ready Callback to execute when all dependencies are ready
 974                          * @param {Function} error Callback to execute when any dependency fails
 975                          * @param {boolean} [async] If true, load modules asynchronously even if
 976                          *  document ready has not yet occurred.
 977                          */
 978                         function request( dependencies, ready, error, async ) {
 979                                 var n;
 980
 981                                 // Allow calling by single module name
 982                                 if ( typeof dependencies === 'string' ) {
 983                                         dependencies = [dependencies];
 984                                 }
 985
 986                                 // Add ready and error callbacks if they were given
 987                                 if ( ready !== undefined || error !== undefined ) {
 988                                         jobs[jobs.length] = {
 989                                                 'dependencies': filter(
 990                                                         ['registered', 'loading', 'loaded'],
 991                                                         dependencies
 992                                                 ),
 993                                                 'ready': ready,
 994                                                 'error': error
 995                                         };
 996                                 }
 997
 998                                 // Queue up any dependencies that are registered
 999                                 dependencies = filter( ['registered'], dependencies );
1000                                 for ( n = 0; n < dependencies.length; n += 1 ) {
1001                                         if ( $.inArray( dependencies[n], queue ) === -1 ) {
1002                                                 queue[queue.length] = dependencies[n];
1003                                                 if ( async ) {
1004                                                         // Mark this module as async in the registry
1005                                                         registry[dependencies[n]].async = true;
1006                                                 }
1007                                         }
1008                                 }
1009
1010                                 // Work the queue
1011                                 mw.loader.work();
1012                         }
1013
1014                         function sortQuery(o) {
1015                                 var sorted = {}, key, a = [];
1016                                 for ( key in o ) {
1017                                         if ( hasOwn.call( o, key ) ) {
1018                                                 a.push( key );
1019                                         }
1020                                 }
1021                                 a.sort();
1022                                 for ( key = 0; key < a.length; key += 1 ) {
1023                                         sorted[a[key]] = o[a[key]];
1024                                 }
1025                                 return sorted;
1026                         }
1027
1028                         /**
1029                          * Converts a module map of the form { foo: [ 'bar', 'baz' ], bar: [ 'baz, 'quux' ] }
1030                          * to a query string of the form foo.bar,baz|bar.baz,quux
1031                          * @private
1032                          */
1033                         function buildModulesString( moduleMap ) {
1034                                 var arr = [], p, prefix;
1035                                 for ( prefix in moduleMap ) {
1036                                         p = prefix === '' ? '' : prefix + '.';
1037                                         arr.push( p + moduleMap[prefix].join( ',' ) );
1038                                 }
1039                                 return arr.join( '|' );
1040                         }
1041
1042                         /**
1043                          * Asynchronously append a script tag to the end of the body
1044                          * that invokes load.php
1045                          * @private
1046                          * @param {Object} moduleMap Module map, see #buildModulesString
1047                          * @param {Object} currReqBase Object with other parameters (other than 'modules') to use in the request
1048                          * @param {string} sourceLoadScript URL of load.php
1049                          * @param {boolean} async If true, use an asynchrounous request even if document ready has not yet occurred
1050                          */
1051                         function doRequest( moduleMap, currReqBase, sourceLoadScript, async ) {
1052                                 var request = $.extend(
1053                                         { modules: buildModulesString( moduleMap ) },
1054                                         currReqBase
1055                                 );
1056                                 request = sortQuery( request );
1057                                 // Asynchronously append a script tag to the end of the body
1058                                 // Append &* to avoid triggering the IE6 extension check
1059                                 addScript( sourceLoadScript + '?' + $.param( request ) + '&*', null, async );
1060                         }
1061
1062                         /* Public Methods */
1063                         return {
1064                                 addStyleTag: addStyleTag,
1065
1066                                 /**
1067                                  * Requests dependencies from server, loading and executing when things when ready.
1068                                  */
1069                                 work: function () {
1070                                         var     reqBase, splits, maxQueryLength, q, b, bSource, bGroup, bSourceGroup,
1071                                                 source, group, g, i, modules, maxVersion, sourceLoadScript,
1072                                                 currReqBase, currReqBaseLength, moduleMap, l,
1073                                                 lastDotIndex, prefix, suffix, bytesAdded, async;
1074
1075                                         // Build a list of request parameters common to all requests.
1076                                         reqBase = {
1077                                                 skin: mw.config.get( 'skin' ),
1078                                                 lang: mw.config.get( 'wgUserLanguage' ),
1079                                                 debug: mw.config.get( 'debug' )
1080                                         };
1081                                         // Split module batch by source and by group.
1082                                         splits = {};
1083                                         maxQueryLength = mw.config.get( 'wgResourceLoaderMaxQueryLength', -1 );
1084
1085                                         // Appends a list of modules from the queue to the batch
1086                                         for ( q = 0; q < queue.length; q += 1 ) {
1087                                                 // Only request modules which are registered
1088                                                 if ( registry[queue[q]] !== undefined && registry[queue[q]].state === 'registered' ) {
1089                                                         // Prevent duplicate entries
1090                                                         if ( $.inArray( queue[q], batch ) === -1 ) {
1091                                                                 batch[batch.length] = queue[q];
1092                                                                 // Mark registered modules as loading
1093                                                                 registry[queue[q]].state = 'loading';
1094                                                         }
1095                                                 }
1096                                         }
1097                                         // Early exit if there's nothing to load...
1098                                         if ( !batch.length ) {
1099                                                 return;
1100                                         }
1101
1102                                         // The queue has been processed into the batch, clear up the queue.
1103                                         queue = [];
1104
1105                                         // Always order modules alphabetically to help reduce cache
1106                                         // misses for otherwise identical content.
1107                                         batch.sort();
1108
1109                                         // Split batch by source and by group.
1110                                         for ( b = 0; b < batch.length; b += 1 ) {
1111                                                 bSource = registry[batch[b]].source;
1112                                                 bGroup = registry[batch[b]].group;
1113                                                 if ( splits[bSource] === undefined ) {
1114                                                         splits[bSource] = {};
1115                                                 }
1116                                                 if ( splits[bSource][bGroup] === undefined ) {
1117                                                         splits[bSource][bGroup] = [];
1118                                                 }
1119                                                 bSourceGroup = splits[bSource][bGroup];
1120                                                 bSourceGroup[bSourceGroup.length] = batch[b];
1121                                         }
1122
1123                                         // Clear the batch - this MUST happen before we append any
1124                                         // script elements to the body or it's possible that a script
1125                                         // will be locally cached, instantly load, and work the batch
1126                                         // again, all before we've cleared it causing each request to
1127                                         // include modules which are already loaded.
1128                                         batch = [];
1129
1130                                         for ( source in splits ) {
1131
1132                                                 sourceLoadScript = sources[source].loadScript;
1133
1134                                                 for ( group in splits[source] ) {
1135
1136                                                         // Cache access to currently selected list of
1137                                                         // modules for this group from this source.
1138                                                         modules = splits[source][group];
1139
1140                                                         // Calculate the highest timestamp
1141                                                         maxVersion = 0;
1142                                                         for ( g = 0; g < modules.length; g += 1 ) {
1143                                                                 if ( registry[modules[g]].version > maxVersion ) {
1144                                                                         maxVersion = registry[modules[g]].version;
1145                                                                 }
1146                                                         }
1147
1148                                                         currReqBase = $.extend( { version: formatVersionNumber( maxVersion ) }, reqBase );
1149                                                         // For user modules append a user name to the request.
1150                                                         if ( group === 'user' && mw.config.get( 'wgUserName' ) !== null ) {
1151                                                                 currReqBase.user = mw.config.get( 'wgUserName' );
1152                                                         }
1153                                                         currReqBaseLength = $.param( currReqBase ).length;
1154                                                         async = true;
1155                                                         // We may need to split up the request to honor the query string length limit,
1156                                                         // so build it piece by piece.
1157                                                         l = currReqBaseLength + 9; // '&modules='.length == 9
1158
1159                                                         moduleMap = {}; // { prefix: [ suffixes ] }
1160
1161                                                         for ( i = 0; i < modules.length; i += 1 ) {
1162                                                                 // Determine how many bytes this module would add to the query string
1163                                                                 lastDotIndex = modules[i].lastIndexOf( '.' );
1164                                                                 // Note that these substr() calls work even if lastDotIndex == -1
1165                                                                 prefix = modules[i].substr( 0, lastDotIndex );
1166                                                                 suffix = modules[i].substr( lastDotIndex + 1 );
1167                                                                 bytesAdded = moduleMap[prefix] !== undefined
1168                                                                         ? suffix.length + 3 // '%2C'.length == 3
1169                                                                         : modules[i].length + 3; // '%7C'.length == 3
1170
1171                                                                 // If the request would become too long, create a new one,
1172                                                                 // but don't create empty requests
1173                                                                 if ( maxQueryLength > 0 && !$.isEmptyObject( moduleMap ) && l + bytesAdded > maxQueryLength ) {
1174                                                                         // This request would become too long, create a new one
1175                                                                         // and fire off the old one
1176                                                                         doRequest( moduleMap, currReqBase, sourceLoadScript, async );
1177                                                                         moduleMap = {};
1178                                                                         async = true;
1179                                                                         l = currReqBaseLength + 9;
1180                                                                 }
1181                                                                 if ( moduleMap[prefix] === undefined ) {
1182                                                                         moduleMap[prefix] = [];
1183                                                                 }
1184                                                                 moduleMap[prefix].push( suffix );
1185                                                                 if ( !registry[modules[i]].async ) {
1186                                                                         // If this module is blocking, make the entire request blocking
1187                                                                         // This is slightly suboptimal, but in practice mixing of blocking
1188                                                                         // and async modules will only occur in debug mode.
1189                                                                         async = false;
1190                                                                 }
1191                                                                 l += bytesAdded;
1192                                                         }
1193                                                         // If there's anything left in moduleMap, request that too
1194                                                         if ( !$.isEmptyObject( moduleMap ) ) {
1195                                                                 doRequest( moduleMap, currReqBase, sourceLoadScript, async );
1196                                                         }
1197                                                 }
1198                                         }
1199                                 },
1200
1201                                 /**
1202                                  * Register a source.
1203                                  *
1204                                  * @param {string} id Short lowercase a-Z string representing a source, only used internally.
1205                                  * @param {Object} props Object containing only the loadScript property which is a url to
1206                                  *  the load.php location of the source.
1207                                  * @return {boolean}
1208                                  */
1209                                 addSource: function ( id, props ) {
1210                                         var source;
1211                                         // Allow multiple additions
1212                                         if ( typeof id === 'object' ) {
1213                                                 for ( source in id ) {
1214                                                         mw.loader.addSource( source, id[source] );
1215                                                 }
1216                                                 return true;
1217                                         }
1218
1219                                         if ( sources[id] !== undefined ) {
1220                                                 throw new Error( 'source already registered: ' + id );
1221                                         }
1222
1223                                         sources[id] = props;
1224
1225                                         return true;
1226                                 },
1227
1228                                 /**
1229                                  * Registers a module, letting the system know about it and its
1230                                  * properties. Startup modules contain calls to this function.
1231                                  *
1232                                  * @param module {String}: Module name
1233                                  * @param version {Number}: Module version number as a timestamp (falls backs to 0)
1234                                  * @param dependencies {String|Array|Function}: One string or array of strings of module
1235                                  *  names on which this module depends, or a function that returns that array.
1236                                  * @param group {String}: Group which the module is in (optional, defaults to null)
1237                                  * @param source {String}: Name of the source. Defaults to local.
1238                                  */
1239                                 register: function ( module, version, dependencies, group, source ) {
1240                                         var m;
1241                                         // Allow multiple registration
1242                                         if ( typeof module === 'object' ) {
1243                                                 for ( m = 0; m < module.length; m += 1 ) {
1244                                                         // module is an array of module names
1245                                                         if ( typeof module[m] === 'string' ) {
1246                                                                 mw.loader.register( module[m] );
1247                                                         // module is an array of arrays
1248                                                         } else if ( typeof module[m] === 'object' ) {
1249                                                                 mw.loader.register.apply( mw.loader, module[m] );
1250                                                         }
1251                                                 }
1252                                                 return;
1253                                         }
1254                                         // Validate input
1255                                         if ( typeof module !== 'string' ) {
1256                                                 throw new Error( 'module must be a string, not a ' + typeof module );
1257                                         }
1258                                         if ( registry[module] !== undefined ) {
1259                                                 throw new Error( 'module already registered: ' + module );
1260                                         }
1261                                         // List the module as registered
1262                                         registry[module] = {
1263                                                 version: version !== undefined ? parseInt( version, 10 ) : 0,
1264                                                 dependencies: [],
1265                                                 group: typeof group === 'string' ? group : null,
1266                                                 source: typeof source === 'string' ? source: 'local',
1267                                                 state: 'registered'
1268                                         };
1269                                         if ( typeof dependencies === 'string' ) {
1270                                                 // Allow dependencies to be given as a single module name
1271                                                 registry[module].dependencies = [ dependencies ];
1272                                         } else if ( typeof dependencies === 'object' || $.isFunction( dependencies ) ) {
1273                                                 // Allow dependencies to be given as an array of module names
1274                                                 // or a function which returns an array
1275                                                 registry[module].dependencies = dependencies;
1276                                         }
1277                                 },
1278
1279                                 /**
1280                                  * Implements a module, giving the system a course of action to take
1281                                  * upon loading. Results of a request for one or more modules contain
1282                                  * calls to this function.
1283                                  *
1284                                  * All arguments are required.
1285                                  *
1286                                  * @param {string} module Name of module
1287                                  * @param {Function|Array} script Function with module code or Array of URLs to
1288                                  *  be used as the src attribute of a new `<script>` tag.
1289                                  * @param {Object} style Should follow one of the following patterns:
1290                                  *     { "css": [css, ..] }
1291                                  *     { "url": { <media>: [url, ..] } }
1292                                  * And for backwards compatibility (needs to be supported forever due to caching):
1293                                  *     { <media>: css }
1294                                  *     { <media>: [url, ..] }
1295                                  *
1296                                  * The reason css strings are not concatenated anymore is bug 31676. We now check
1297                                  * whether it's safe to extend the stylesheet (see #canExpandStylesheetWith).
1298                                  *
1299                                  * @param {Object} msgs List of key/value pairs to be added to {@link mw#messages}.
1300                                  */
1301                                 implement: function ( module, script, style, msgs ) {
1302                                         // Validate input
1303                                         if ( typeof module !== 'string' ) {
1304                                                 throw new Error( 'module must be a string, not a ' + typeof module );
1305                                         }
1306                                         if ( !$.isFunction( script ) && !$.isArray( script ) ) {
1307                                                 throw new Error( 'script must be a function or an array, not a ' + typeof script );
1308                                         }
1309                                         if ( !$.isPlainObject( style ) ) {
1310                                                 throw new Error( 'style must be an object, not a ' + typeof style );
1311                                         }
1312                                         if ( !$.isPlainObject( msgs ) ) {
1313                                                 throw new Error( 'msgs must be an object, not a ' + typeof msgs );
1314                                         }
1315                                         // Automatically register module
1316                                         if ( registry[module] === undefined ) {
1317                                                 mw.loader.register( module );
1318                                         }
1319                                         // Check for duplicate implementation
1320                                         if ( registry[module] !== undefined && registry[module].script !== undefined ) {
1321                                                 throw new Error( 'module already implemented: ' + module );
1322                                         }
1323                                         // Attach components
1324                                         registry[module].script = script;
1325                                         registry[module].style = style;
1326                                         registry[module].messages = msgs;
1327                                         // The module may already have been marked as erroneous
1328                                         if ( $.inArray( registry[module].state, ['error', 'missing'] ) === -1 ) {
1329                                                 registry[module].state = 'loaded';
1330                                                 if ( allReady( registry[module].dependencies ) ) {
1331                                                         execute( module );
1332                                                 }
1333                                         }
1334                                 },
1335
1336                                 /**
1337                                  * Executes a function as soon as one or more required modules are ready
1338                                  *
1339                                  * @param dependencies {String|Array} Module name or array of modules names the callback
1340                                  *  dependends on to be ready before executing
1341                                  * @param ready {Function} callback to execute when all dependencies are ready (optional)
1342                                  * @param error {Function} callback to execute when if dependencies have a errors (optional)
1343                                  */
1344                                 using: function ( dependencies, ready, error ) {
1345                                         var tod = typeof dependencies;
1346                                         // Validate input
1347                                         if ( tod !== 'object' && tod !== 'string' ) {
1348                                                 throw new Error( 'dependencies must be a string or an array, not a ' + tod );
1349                                         }
1350                                         // Allow calling with a single dependency as a string
1351                                         if ( tod === 'string' ) {
1352                                                 dependencies = [ dependencies ];
1353                                         }
1354                                         // Resolve entire dependency map
1355                                         dependencies = resolve( dependencies );
1356                                         if ( allReady( dependencies ) ) {
1357                                                 // Run ready immediately
1358                                                 if ( $.isFunction( ready ) ) {
1359                                                         ready();
1360                                                 }
1361                                         } else if ( filter( ['error', 'missing'], dependencies ).length ) {
1362                                                 // Execute error immediately if any dependencies have errors
1363                                                 if ( $.isFunction( error ) ) {
1364                                                         error( new Error( 'one or more dependencies have state "error" or "missing"' ),
1365                                                                 dependencies );
1366                                                 }
1367                                         } else {
1368                                                 // Not all dependencies are ready: queue up a request
1369                                                 request( dependencies, ready, error );
1370                                         }
1371                                 },
1372
1373                                 /**
1374                                  * Loads an external script or one or more modules for future use
1375                                  *
1376                                  * @param modules {mixed} Either the name of a module, array of modules,
1377                                  *  or a URL of an external script or style
1378                                  * @param type {String} mime-type to use if calling with a URL of an
1379                                  *  external script or style; acceptable values are "text/css" and
1380                                  *  "text/javascript"; if no type is provided, text/javascript is assumed.
1381                                  * @param async {Boolean} (optional) If true, load modules asynchronously
1382                                  *  even if document ready has not yet occurred. If false (default),
1383                                  *  block before document ready and load async after. If not set, true will
1384                                  *  be assumed if loading a URL, and false will be assumed otherwise.
1385                                  */
1386                                 load: function ( modules, type, async ) {
1387                                         var filtered, m, module, l;
1388
1389                                         // Validate input
1390                                         if ( typeof modules !== 'object' && typeof modules !== 'string' ) {
1391                                                 throw new Error( 'modules must be a string or an array, not a ' + typeof modules );
1392                                         }
1393                                         // Allow calling with an external url or single dependency as a string
1394                                         if ( typeof modules === 'string' ) {
1395                                                 // Support adding arbitrary external scripts
1396                                                 if ( /^(https?:)?\/\//.test( modules ) ) {
1397                                                         if ( async === undefined ) {
1398                                                                 // Assume async for bug 34542
1399                                                                 async = true;
1400                                                         }
1401                                                         if ( type === 'text/css' ) {
1402                                                                 // IE7-8 throws security warnings when inserting a <link> tag
1403                                                                 // with a protocol-relative URL set though attributes (instead of
1404                                                                 // properties) - when on HTTPS. See also bug #.
1405                                                                 l = document.createElement( 'link' );
1406                                                                 l.rel = 'stylesheet';
1407                                                                 l.href = modules;
1408                                                                 $( 'head' ).append( l );
1409                                                                 return;
1410                                                         }
1411                                                         if ( type === 'text/javascript' || type === undefined ) {
1412                                                                 addScript( modules, null, async );
1413                                                                 return;
1414                                                         }
1415                                                         // Unknown type
1416                                                         throw new Error( 'invalid type for external url, must be text/css or text/javascript. not ' + type );
1417                                                 }
1418                                                 // Called with single module
1419                                                 modules = [ modules ];
1420                                         }
1421
1422                                         // Filter out undefined modules, otherwise resolve() will throw
1423                                         // an exception for trying to load an undefined module.
1424                                         // Undefined modules are acceptable here in load(), because load() takes
1425                                         // an array of unrelated modules, whereas the modules passed to
1426                                         // using() are related and must all be loaded.
1427                                         for ( filtered = [], m = 0; m < modules.length; m += 1 ) {
1428                                                 module = registry[modules[m]];
1429                                                 if ( module !== undefined ) {
1430                                                         if ( $.inArray( module.state, ['error', 'missing'] ) === -1 ) {
1431                                                                 filtered[filtered.length] = modules[m];
1432                                                         }
1433                                                 }
1434                                         }
1435
1436                                         if ( filtered.length === 0 ) {
1437                                                 return;
1438                                         }
1439                                         // Resolve entire dependency map
1440                                         filtered = resolve( filtered );
1441                                         // If all modules are ready, nothing to be done
1442                                         if ( allReady( filtered ) ) {
1443                                                 return;
1444                                         }
1445                                         // If any modules have errors: also quit.
1446                                         if ( filter( ['error', 'missing'], filtered ).length ) {
1447                                                 return;
1448                                         }
1449                                         // Since some modules are not yet ready, queue up a request.
1450                                         request( filtered, null, null, async );
1451                                 },
1452
1453                                 /**
1454                                  * Changes the state of a module
1455                                  *
1456                                  * @param module {String|Object} module name or object of module name/state pairs
1457                                  * @param state {String} state name
1458                                  */
1459                                 state: function ( module, state ) {
1460                                         var m;
1461
1462                                         if ( typeof module === 'object' ) {
1463                                                 for ( m in module ) {
1464                                                         mw.loader.state( m, module[m] );
1465                                                 }
1466                                                 return;
1467                                         }
1468                                         if ( registry[module] === undefined ) {
1469                                                 mw.loader.register( module );
1470                                         }
1471                                         if ( $.inArray( state, ['ready', 'error', 'missing'] ) !== -1
1472                                                 && registry[module].state !== state ) {
1473                                                 // Make sure pending modules depending on this one get executed if their
1474                                                 // dependencies are now fulfilled!
1475                                                 registry[module].state = state;
1476                                                 handlePending( module );
1477                                         } else {
1478                                                 registry[module].state = state;
1479                                         }
1480                                 },
1481
1482                                 /**
1483                                  * Gets the version of a module
1484                                  *
1485                                  * @param module string name of module to get version for
1486                                  */
1487                                 getVersion: function ( module ) {
1488                                         if ( registry[module] !== undefined && registry[module].version !== undefined ) {
1489                                                 return formatVersionNumber( registry[module].version );
1490                                         }
1491                                         return null;
1492                                 },
1493
1494                                 /**
1495                                  * @deprecated since 1.18 use mw.loader.getVersion() instead
1496                                  */
1497                                 version: function () {
1498                                         return mw.loader.getVersion.apply( mw.loader, arguments );
1499                                 },
1500
1501                                 /**
1502                                  * Gets the state of a module
1503                                  *
1504                                  * @param module string name of module to get state for
1505                                  */
1506                                 getState: function ( module ) {
1507                                         if ( registry[module] !== undefined && registry[module].state !== undefined ) {
1508                                                 return registry[module].state;
1509                                         }
1510                                         return null;
1511                                 },
1512
1513                                 /**
1514                                  * Get names of all registered modules.
1515                                  *
1516                                  * @return {Array}
1517                                  */
1518                                 getModuleNames: function () {
1519                                         return $.map( registry, function ( i, key ) {
1520                                                 return key;
1521                                         } );
1522                                 },
1523
1524                                 /**
1525                                  * For backwards-compatibility with Squid-cached pages. Loads mw.user
1526                                  */
1527                                 go: function () {
1528                                         mw.loader.load( 'mediawiki.user' );
1529                                 }
1530                         };
1531                 }() ),
1532
1533                 /**
1534                  * HTML construction helper functions
1535                  * @class mw.html
1536                  * @singleton
1537                  */
1538                 html: ( function () {
1539                         function escapeCallback( s ) {
1540                                 switch ( s ) {
1541                                         case '\'':
1542                                                 return '&#039;';
1543                                         case '"':
1544                                                 return '&quot;';
1545                                         case '<':
1546                                                 return '&lt;';
1547                                         case '>':
1548                                                 return '&gt;';
1549                                         case '&':
1550                                                 return '&amp;';
1551                                 }
1552                         }
1553
1554                         return {
1555                                 /**
1556                                  * Escape a string for HTML. Converts special characters to HTML entities.
1557                                  * @param {string} s The string to escape
1558                                  */
1559                                 escape: function ( s ) {
1560                                         return s.replace( /['"<>&]/g, escapeCallback );
1561                                 },
1562
1563                                 /**
1564                                  * Wrapper object for raw HTML passed to mw.html.element().
1565                                  * @class mw.html.Raw
1566                                  */
1567                                 Raw: function ( value ) {
1568                                         this.value = value;
1569                                 },
1570
1571                                 /**
1572                                  * Wrapper object for CDATA element contents passed to mw.html.element()
1573                                  * @class mw.html.Cdata
1574                                  */
1575                                 Cdata: function ( value ) {
1576                                         this.value = value;
1577                                 },
1578
1579                                 /**
1580                                  * Create an HTML element string, with safe escaping.
1581                                  *
1582                                  * @param name The tag name.
1583                                  * @param attrs An object with members mapping element names to values
1584                                  * @param contents The contents of the element. May be either:
1585                                  *  - string: The string is escaped.
1586                                  *  - null or undefined: The short closing form is used, e.g. <br/>.
1587                                  *  - this.Raw: The value attribute is included without escaping.
1588                                  *  - this.Cdata: The value attribute is included, and an exception is
1589                                  *   thrown if it contains an illegal ETAGO delimiter.
1590                                  *   See http://www.w3.org/TR/1999/REC-html401-19991224/appendix/notes.html#h-B.3.2
1591                                  *
1592                                  * Example:
1593                                  *      var h = mw.html;
1594                                  *      return h.element( 'div', {},
1595                                  *              new h.Raw( h.element( 'img', {src: '<'} ) ) );
1596                                  * Returns <div><img src="&lt;"/></div>
1597                                  */
1598                                 element: function ( name, attrs, contents ) {
1599                                         var v, attrName, s = '<' + name;
1600
1601                                         for ( attrName in attrs ) {
1602                                                 v = attrs[attrName];
1603                                                 // Convert name=true, to name=name
1604                                                 if ( v === true ) {
1605                                                         v = attrName;
1606                                                 // Skip name=false
1607                                                 } else if ( v === false ) {
1608                                                         continue;
1609                                                 }
1610                                                 s += ' ' + attrName + '="' + this.escape( String( v ) ) + '"';
1611                                         }
1612                                         if ( contents === undefined || contents === null ) {
1613                                                 // Self close tag
1614                                                 s += '/>';
1615                                                 return s;
1616                                         }
1617                                         // Regular open tag
1618                                         s += '>';
1619                                         switch ( typeof contents ) {
1620                                                 case 'string':
1621                                                         // Escaped
1622                                                         s += this.escape( contents );
1623                                                         break;
1624                                                 case 'number':
1625                                                 case 'boolean':
1626                                                         // Convert to string
1627                                                         s += String( contents );
1628                                                         break;
1629                                                 default:
1630                                                         if ( contents instanceof this.Raw ) {
1631                                                                 // Raw HTML inclusion
1632                                                                 s += contents.value;
1633                                                         } else if ( contents instanceof this.Cdata ) {
1634                                                                 // CDATA
1635                                                                 if ( /<\/[a-zA-z]/.test( contents.value ) ) {
1636                                                                         throw new Error( 'mw.html.element: Illegal end tag found in CDATA' );
1637                                                                 }
1638                                                                 s += contents.value;
1639                                                         } else {
1640                                                                 throw new Error( 'mw.html.element: Invalid type of contents' );
1641                                                         }
1642                                         }
1643                                         s += '</' + name + '>';
1644                                         return s;
1645                                 }
1646                         };
1647                 }() ),
1648
1649                 // Skeleton user object. mediawiki.user.js extends this
1650                 user: {
1651                         options: new Map(),
1652                         tokens: new Map()
1653                 }
1654         };
1655
1656 }( jQuery ) );
1657
1658 // Alias $j to jQuery for backwards compatibility
1659 window.$j = jQuery;
1660
1661 // Attach to window and globally alias
1662 window.mw = window.mediaWiki = mw;
1663
1664 // Auto-register from pre-loaded startup scripts
1665 if ( jQuery.isFunction( window.startUp ) ) {
1666         window.startUp();
1667         window.startUp = undefined;
1668 }