[RL] Stand-alone ResourceLoader front-end
authorKrinkle <krinkle@users.mediawiki.org>
Sat, 17 Sep 2011 20:15:24 +0000 (20:15 +0000)
committerKrinkle <krinkle@users.mediawiki.org>
Sat, 17 Sep 2011 20:15:24 +0000 (20:15 +0000)
* In preparation of this, duplicating the entire file as-is in order to preserve svn history.

(Part of bug 30956)

resources/ResourceLoader.js [new file with mode: 0644]

diff --git a/resources/ResourceLoader.js b/resources/ResourceLoader.js
new file mode 100644 (file)
index 0000000..7da2821
--- /dev/null
@@ -0,0 +1,1304 @@
+/*
+ * Core MediaWiki JavaScript Library
+ */
+
+// Attach to window and globally alias
+window.mw = window.mediaWiki = new ( function( $ ) {
+
+       /* Private Members */
+
+       /**
+        * @var object List of messages that have been requested to be loaded.
+        */
+       var messageQueue = {};
+
+       /* Object constructors */
+
+       /**
+        * Map
+        *
+        * Creates an object that can be read from or written to from prototype functions
+        * that allow both single and multiple variables at once.
+        *
+        * @param global boolean Whether to store the values in the global window
+        *  object or a exclusively in the object property 'values'.
+        * @return Map
+        */
+       function Map( global ) {
+               this.values = ( global === true ) ? window : {};
+               return this;
+       }
+
+       Map.prototype = {
+               /**
+                * Get the value of one or multiple a keys.
+                *
+                * If called with no arguments, all values will be returned.
+                *
+                * @param selection mixed String key or array of keys to get values for.
+                * @param fallback mixed Value to use in case key(s) do not exist (optional).
+                * @return mixed If selection was a string returns the value or null,
+                *  If selection was an array, returns an object of key/values (value is null if not found),
+                *  If selection was not passed or invalid, will return the 'values' object member (be careful as
+                *  objects are always passed by reference in JavaScript!).
+                * @return Values as a string or object, null if invalid/inexistant.
+                */
+               get: function( selection, fallback ) {
+                       if ( $.isArray( selection ) ) {
+                               selection = $.makeArray( selection );
+                               var results = {};
+                               for ( var i = 0; i < selection.length; i++ ) {
+                                       results[selection[i]] = this.get( selection[i], fallback );
+                               }
+                               return results;
+                       } else if ( typeof selection === 'string' ) {
+                               if ( this.values[selection] === undefined ) {
+                                       if ( fallback !== undefined ) {
+                                               return fallback;
+                                       }
+                                       return null;
+                               }
+                               return this.values[selection];
+                       }
+                       if ( selection === undefined ) {
+                               return this.values;
+                       } else {
+                               return null; // invalid selection key
+                       }
+               },
+
+               /**
+                * Sets one or multiple key/value pairs.
+                *
+                * @param selection mixed String key or array of keys to set values for.
+                * @param value mixed Value to set (optional, only in use when key is a string)
+                * @return bool This returns true on success, false on failure.
+                */
+               set: function( selection, value ) {
+                       if ( $.isPlainObject( selection ) ) {
+                               for ( var s in selection ) {
+                                       this.values[s] = selection[s];
+                               }
+                               return true;
+                       } else if ( typeof selection === 'string' && value !== undefined ) {
+                               this.values[selection] = value;
+                               return true;
+                       }
+                       return false;
+               },
+
+               /**
+                * Checks if one or multiple keys exist.
+                *
+                * @param selection mixed String key or array of keys to check
+                * @return boolean Existence of key(s)
+                */
+               exists: function( selection ) {
+                       if ( typeof selection === 'object' ) {
+                               for ( var s = 0; s < selection.length; s++ ) {
+                                       if ( !( selection[s] in this.values ) ) {
+                                               return false;
+                                       }
+                               }
+                               return true;
+                       } else {
+                               return selection in this.values;
+                       }
+               }
+       };
+
+       /**
+        * Message
+        *
+        * Object constructor for messages,
+        * similar to the Message class in MediaWiki PHP.
+        *
+        * @param map Map Instance of mw.Map
+        * @param key String
+        * @param parameters Array
+        * @return Message
+        */
+       function Message( map, key, parameters ) {
+               this.format = 'plain';
+               this.map = map;
+               this.key = key;
+               this.parameters = parameters === undefined ? [] : $.makeArray( parameters );
+               return this;
+       }
+
+       Message.prototype = {
+               /**
+                * Appends (does not replace) parameters for replacement to the .parameters property.
+                *
+                * @param parameters Array
+                * @return Message
+                */
+               params: function( parameters ) {
+                       for ( var i = 0; i < parameters.length; i++ ) {
+                               this.parameters.push( parameters[i] );
+                       }
+                       return this;
+               },
+
+               /**
+                * Converts message object to it's string form based on the state of format.
+                *
+                * @return string Message as a string in the current form or <key> if key does not exist.
+                */
+               toString: function() {
+
+                       if ( !this.map.exists( this.key ) ) {
+                               // Use <key> as text if key does not exist
+                               if ( this.format !== 'plain' ) {
+                                       // format 'escape' and 'parse' need to have the brackets and key html escaped
+                                       return mw.html.escape( '<' + this.key + '>' );
+                               }
+                               return '<' + this.key + '>';
+                       }
+                       var     text = this.map.get( this.key ),
+                               parameters = this.parameters;
+
+                       text = text.replace( /\$(\d+)/g, function( string, match ) {
+                               var index = parseInt( match, 10 ) - 1;
+                               return index in parameters ? parameters[index] : '$' + match;
+                       } );
+
+                       if ( this.format === 'plain' ) {
+                               return text;
+                       }
+                       if ( this.format === 'escaped' ) {
+                               // According to Message.php this needs {{-transformation, which is
+                               // still todo
+                               return mw.html.escape( text );
+                       }
+
+                       /* This should be fixed up when we have a parser
+                       if ( this.format === 'parse' && 'language' in mw ) {
+                               text = mw.language.parse( text );
+                       }
+                       */
+                       return text;
+               },
+
+               /**
+                * Changes format to parse and converts message to string
+                *
+                * @return {string} String form of parsed message
+                */
+               parse: function() {
+                       this.format = 'parse';
+                       return this.toString();
+               },
+
+               /**
+                * Changes format to plain and converts message to string
+                *
+                * @return {string} String form of plain message
+                */
+               plain: function() {
+                       this.format = 'plain';
+                       return this.toString();
+               },
+
+               /**
+                * Changes the format to html escaped and converts message to string
+                *
+                * @return {string} String form of html escaped message
+                */
+               escaped: function() {
+                       this.format = 'escaped';
+                       return this.toString();
+               },
+
+               /**
+                * Checks if message exists
+                *
+                * @return {string} String form of parsed message
+                */
+               exists: function() {
+                       return this.map.exists( this.key );
+               }
+       };
+
+       /* Public Members */
+
+       /*
+        * Dummy function which in debug mode can be replaced with a function that
+        * emulates console.log in console-less environments.
+        */
+       this.log = function() { };
+
+       /**
+        * @var constructor Make the Map constructor publicly available.
+        */
+       this.Map = Map;
+
+       /**
+        * List of configuration values
+        *
+        * Dummy placeholder. Initiated in startUp module as a new instance of mw.Map().
+        * If $wgLegacyJavaScriptGlobals is true, this Map will have its values
+        * in the global window object.
+        */
+       this.config = null;
+
+       /**
+        * @var object
+        *
+        * Empty object that plugins can be installed in.
+        */
+       this.libs = {};
+
+       /*
+        * Localization system
+        */
+       this.messages = new this.Map();
+
+       /* Public Methods */
+
+       /**
+        * Gets a message object, similar to wfMessage()
+        *
+        * @param key string Key of message to get
+        * @param parameter_1 mixed First argument in a list of variadic arguments,
+        *  each a parameter for $N replacement in messages.
+        * @return Message
+        */
+       this.message = function( key, parameter_1 /* [, parameter_2] */ ) {
+               var parameters;
+               // Support variadic arguments
+               if ( parameter_1 !== undefined ) {
+                       parameters = $.makeArray( arguments );
+                       parameters.shift();
+               } else {
+                       parameters = [];
+               }
+               return new Message( mw.messages, key, parameters );
+       };
+
+       /**
+        * Gets a message string, similar to wfMsg()
+        *
+        * @param key string Key of message to get
+        * @param parameters mixed First argument in a list of variadic arguments,
+        *  each a parameter for $N replacement in messages.
+        * @return String.
+        */
+       this.msg = function( key, parameters ) {
+               return mw.message.apply( mw.message, arguments ).toString();
+       };
+
+       /**
+        * Client-side module loader which integrates with the MediaWiki ResourceLoader
+        */
+       this.loader = new ( function() {
+
+               /* Private Members */
+
+               /**
+                * Mapping of registered modules
+                *
+                * The jquery module is pre-registered, because it must have already
+                * been provided for this object to have been built, and in debug mode
+                * jquery would have been provided through a unique loader request,
+                * making it impossible to hold back registration of jquery until after
+                * mediawiki.
+                *
+                * For exact details on support for script, style and messages, look at
+                * mw.loader.implement.
+                *
+                * Format:
+                *      {
+                *              'moduleName': {
+                *                      'version': ############## (unix timestamp),
+                *                      'dependencies': ['required.foo', 'bar.also', ...], (or) function() {}
+                *                      'group': 'somegroup', (or) null,
+                *                      'source': 'local', 'someforeignwiki', (or) null
+                *                      'state': 'registered', 'loading', 'loaded', 'ready', or 'error'
+                *                      'script': ...,
+                *                      'style': ...,
+                *                      'messages': { 'key': 'value' },
+                *              }
+                *      }
+                */
+               var     registry = {},
+                       /**
+                        * Mapping of sources, keyed by source-id, values are objects.
+                        * Format:
+                        *      {
+                        *              'sourceId': {
+                        *                      'loadScript': 'http://foo.bar/w/load.php'
+                        *              }
+                        *      }
+                        */
+                       sources = {},
+                       // List of modules which will be loaded as when ready
+                       batch = [],
+                       // List of modules to be loaded
+                       queue = [],
+                       // List of callback functions waiting for modules to be ready to be called
+                       jobs = [],
+                       // Flag inidicating that document ready has occured
+                       ready = false,
+                       // Selector cache for the marker element. Use getMarker() to get/use the marker!
+                       $marker = null;
+
+               /* Private Methods */
+
+               function getMarker(){
+                       // Cached ?
+                       if ( $marker ) {
+                               return $marker;
+                       } else {
+                               $marker = $( 'meta[name="ResourceLoaderDynamicStyles"]' );
+                               if ( $marker.length ) {
+                                       return $marker;
+                               }
+                               mw.log( 'getMarker> No <meta name="ResourceLoaderDynamicStyles"> found, inserting dynamically.' );
+                               $marker = $( '<meta>' ).attr( 'name', 'ResourceLoaderDynamicStyles' ).appendTo( 'head' );
+                               return $marker;
+                       }
+               }
+
+               function compare( a, b ) {
+                       if ( a.length !== b.length ) {
+                               return false;
+                       }
+                       for ( var i = 0; i < b.length; i++ ) {
+                               if ( $.isArray( a[i] ) ) {
+                                       if ( !compare( a[i], b[i] ) ) {
+                                               return false;
+                                       }
+                               }
+                               if ( a[i] !== b[i] ) {
+                                       return false;
+                               }
+                       }
+                       return true;
+               }
+
+               /**
+                * Generates an ISO8601 "basic" string from a UNIX timestamp
+                */
+               function formatVersionNumber( timestamp ) {
+                       var     pad = function( a, b, c ) {
+                                       return [a < 10 ? '0' + a : a, b < 10 ? '0' + b : b, c < 10 ? '0' + c : c].join( '' );
+                               },
+                               d = new Date();
+                       d.setTime( timestamp * 1000 );
+                       return [
+                               pad( d.getUTCFullYear(), d.getUTCMonth() + 1, d.getUTCDate() ), 'T',
+                               pad( d.getUTCHours(), d.getUTCMinutes(), d.getUTCSeconds() ), 'Z'
+                       ].join( '' );
+               }
+
+               /**
+                * Recursively resolves dependencies and detects circular references
+                */
+               function recurse( module, resolved, unresolved ) {
+                       if ( registry[module] === undefined ) {
+                               throw new Error( 'Unknown dependency: ' + module );
+                       }
+                       // Resolves dynamic loader function and replaces it with its own results
+                       if ( $.isFunction( registry[module].dependencies ) ) {
+                               registry[module].dependencies = registry[module].dependencies();
+                               // Ensures the module's dependencies are always in an array
+                               if ( typeof registry[module].dependencies !== 'object' ) {
+                                       registry[module].dependencies = [registry[module].dependencies];
+                               }
+                       }
+                       // Tracks down dependencies
+                       for ( var n = 0; n < registry[module].dependencies.length; n++ ) {
+                               if ( $.inArray( registry[module].dependencies[n], resolved ) === -1 ) {
+                                       if ( $.inArray( registry[module].dependencies[n], unresolved ) !== -1 ) {
+                                               throw new Error(
+                                                       'Circular reference detected: ' + module +
+                                                       ' -> ' + registry[module].dependencies[n]
+                                               );
+                                       }
+                                       recurse( registry[module].dependencies[n], resolved, unresolved );
+                               }
+                       }
+                       resolved[resolved.length] = module;
+                       unresolved.splice( $.inArray( module, unresolved ), 1 );
+               }
+
+               /**
+                * Gets a list of module names that a module depends on in their proper dependency order
+                *
+                * @param module string module name or array of string module names
+                * @return list of dependencies
+                * @throws Error if circular reference is detected
+                */
+               function resolve( module ) {
+                       // Allow calling with an array of module names
+                       if ( typeof module === 'object' ) {
+                               var modules = [];
+                               for ( var m = 0; m < module.length; m++ ) {
+                                       var dependencies = resolve( module[m] );
+                                       for ( var n = 0; n < dependencies.length; n++ ) {
+                                               modules[modules.length] = dependencies[n];
+                                       }
+                               }
+                               return modules;
+                       } else if ( typeof module === 'string' ) {
+                               // Undefined modules have no dependencies
+                               if ( !( module in registry ) ) {
+                                       return [];
+                               }
+                               var resolved = [];
+                               recurse( module, resolved, [] );
+                               return resolved;
+                       }
+                       throw new Error( 'Invalid module argument: ' + module );
+               }
+
+               /**
+                * Narrows a list of module names down to those matching a specific
+                * state. Possible states are 'undefined', 'registered', 'loading',
+                * 'loaded', or 'ready'
+                *
+                * @param states string or array of strings of module states to filter by
+                * @param modules array list of module names to filter (optional, all modules
+                *  will be used by default)
+                * @return array list of filtered module names
+                */
+               function filter( states, modules ) {
+                       // Allow states to be given as a string
+                       if ( typeof states === 'string' ) {
+                               states = [states];
+                       }
+                       // If called without a list of modules, build and use a list of all modules
+                       var list = [], module;
+                       if ( modules === undefined ) {
+                               modules = [];
+                               for ( module in registry ) {
+                                       modules[modules.length] = module;
+                               }
+                       }
+                       // Build a list of modules which are in one of the specified states
+                       for ( var s = 0; s < states.length; s++ ) {
+                               for ( var m = 0; m < modules.length; m++ ) {
+                                       if ( registry[modules[m]] === undefined ) {
+                                               // Module does not exist
+                                               if ( states[s] === 'undefined' ) {
+                                                       // OK, undefined
+                                                       list[list.length] = modules[m];
+                                               }
+                                       } else {
+                                               // Module exists, check state
+                                               if ( registry[modules[m]].state === states[s] ) {
+                                                       // OK, correct state
+                                                       list[list.length] = modules[m];
+                                               }
+                                       }
+                               }
+                       }
+                       return list;
+               }
+
+               /**
+                * Executes a loaded module, making it ready to use
+                *
+                * @param module string module name to execute
+                */
+               function execute( module, callback ) {
+                       if ( registry[module] === undefined ) {
+                               throw new Error( 'Module has not been registered yet: ' + module );
+                       } else if ( registry[module].state === 'registered' ) {
+                               throw new Error( 'Module has not been requested from the server yet: ' + module );
+                       } else if ( registry[module].state === 'loading' ) {
+                               throw new Error( 'Module has not completed loading yet: ' + module );
+                       } else if ( registry[module].state === 'ready' ) {
+                               throw new Error( 'Module has already been loaded: ' + module );
+                       }
+                       // Add styles
+                       var style;
+                       if ( $.isPlainObject( registry[module].style ) ) {
+                               for ( var media in registry[module].style ) {
+                                       style = registry[module].style[media];
+                                       if ( $.isArray( style ) ) {
+                                               for ( var i = 0; i < style.length; i++ ) {
+                                                       getMarker().before( mw.html.element( 'link', {
+                                                               'type': 'text/css',
+                                                               'media': media,
+                                                               'rel': 'stylesheet',
+                                                               'href': style[i]
+                                                       } ) );
+                                               }
+                                       } else if ( typeof style === 'string' ) {
+                                               getMarker().before( mw.html.element( 'style', {
+                                                       'type': 'text/css',
+                                                       'media': media
+                                               }, new mw.html.Cdata( style ) ) );
+                                       }
+                               }
+                       }
+                       // Add localizations to message system
+                       if ( $.isPlainObject( registry[module].messages ) ) {
+                               mw.messages.set( registry[module].messages );
+                       }
+                       // Execute script
+                       try {
+                               var     script = registry[module].script,
+                                       markModuleReady = function() {
+                                               registry[module].state = 'ready';
+                                               handlePending( module );
+                                               if ( $.isFunction( callback ) ) {
+                                                       callback();
+                                               }
+                                       },
+                                       nestedAddScript = function( arr, callback, i ) {
+                                               // Recursively call addScript() in its own callback
+                                               // for each element of arr.
+                                               if ( i >= arr.length ) {
+                                                       // We're at the end of the array
+                                                       callback();
+                                                       return;
+                                               }
+                                               
+                                               addScript( arr[i], function() {
+                                                       nestedAddScript( arr, callback, i + 1 );
+                                               } );
+                                       };
+
+                               if ( $.isArray( script ) ) {
+                                       registry[module].state = 'loading';
+                                       nestedAddScript( script, markModuleReady, 0 );
+                               } else if ( $.isFunction( script ) ) {
+                                       script( $ );
+                                       markModuleReady();
+                               }
+                       } catch ( e ) {
+                               // This needs to NOT use mw.log because these errors are common in production mode
+                               // and not in debug mode, such as when a symbol that should be global isn't exported
+                               if ( window.console && typeof window.console.log === 'function' ) {
+                                       console.log( 'mw.loader::execute> Exception thrown by ' + module + ': ' + e.message );
+                               }
+                               registry[module].state = 'error';
+                               throw e;
+                       }
+               }
+
+               /**
+                * Automatically executes jobs and modules which are pending with satistifed dependencies.
+                *
+                * This is used when dependencies are satisfied, such as when a module is executed.
+                */
+               function handlePending( module ) {
+                       try {
+                               // Run jobs who's dependencies have just been met
+                               for ( var j = 0; j < jobs.length; j++ ) {
+                                       if ( compare(
+                                               filter( 'ready', jobs[j].dependencies ),
+                                               jobs[j].dependencies ) )
+                                       {
+                                               if ( $.isFunction( jobs[j].ready ) ) {
+                                                       jobs[j].ready();
+                                               }
+                                               jobs.splice( j, 1 );
+                                               j--;
+                                       }
+                               }
+                               // Execute modules who's dependencies have just been met
+                               for ( var r in registry ) {
+                                       if ( registry[r].state === 'loaded' ) {
+                                               if ( compare(
+                                                       filter( ['ready'], registry[r].dependencies ),
+                                                       registry[r].dependencies ) )
+                                               {
+                                                       execute( r );
+                                               }
+                                       }
+                               }
+                       } catch ( e ) {
+                               // Run error callbacks of jobs affected by this condition
+                               for ( var j = 0; j < jobs.length; j++ ) {
+                                       if ( $.inArray( module, jobs[j].dependencies ) !== -1 ) {
+                                               if ( $.isFunction( jobs[j].error ) ) {
+                                                       jobs[j].error();
+                                               }
+                                               jobs.splice( j, 1 );
+                                               j--;
+                                       }
+                               }
+                       }
+               }
+
+               /**
+                * Adds a dependencies to the queue with optional callbacks to be run
+                * when the dependencies are ready or fail
+                *
+                * @param dependencies string module name or array of string module names
+                * @param ready function callback to execute when all dependencies are ready
+                * @param error function callback to execute when any dependency fails
+                */
+               function request( dependencies, ready, error ) {
+                       // Allow calling by single module name
+                       if ( typeof dependencies === 'string' ) {
+                               dependencies = [dependencies];
+                               if ( dependencies[0] in registry ) {
+                                       // Cache repetitively accessed deep level object member
+                                       var     regItemDeps = registry[dependencies[0]].dependencies,
+                                               // Cache to avoid looped access to length property
+                                               regItemDepLen = regItemDeps.length;
+                                       for ( var n = 0; n < regItemDepLen; n++ ) {
+                                               dependencies[dependencies.length] = regItemDeps[n];
+                                       }
+                               }
+                       }
+                       // Add ready and error callbacks if they were given
+                       if ( arguments.length > 1 ) {
+                               jobs[jobs.length] = {
+                                       'dependencies': filter(
+                                               ['undefined', 'registered', 'loading', 'loaded'],
+                                               dependencies
+                                       ),
+                                       'ready': ready,
+                                       'error': error
+                               };
+                       }
+                       // Queue up any dependencies that are undefined or registered
+                       dependencies = filter( ['undefined', 'registered'], dependencies );
+                       for ( var n = 0; n < dependencies.length; n++ ) {
+                               if ( $.inArray( dependencies[n], queue ) === -1 ) {
+                                       queue[queue.length] = dependencies[n];
+                               }
+                       }
+                       // Work the queue
+                       mw.loader.work();
+               }
+
+               function sortQuery(o) {
+                       var sorted = {}, key, a = [];
+                       for ( key in o ) {
+                               if ( o.hasOwnProperty( key ) ) {
+                                       a.push( key );
+                               }
+                       }
+                       a.sort();
+                       for ( key = 0; key < a.length; key++ ) {
+                               sorted[a[key]] = o[a[key]];
+                       }
+                       return sorted;
+               }
+
+               /**
+                * Converts a module map of the form { foo: [ 'bar', 'baz' ], bar: [ 'baz, 'quux' ] }
+                * to a query string of the form foo.bar,baz|bar.baz,quux
+                */
+               function buildModulesString( moduleMap ) {
+                       var arr = [], p;
+                       for ( var prefix in moduleMap ) {
+                               p = prefix === '' ? '' : prefix + '.';
+                               arr.push( p + moduleMap[prefix].join( ',' ) );
+                       }
+                       return arr.join( '|' );
+               }
+
+               /**
+                * Adds a script tag to the body, either using document.write or low-level DOM manipulation,
+                * depending on whether document-ready has occured yet.
+                *
+                * @param src String: URL to script, will be used as the src attribute in the script tag
+                * @param callback Function: Optional callback which will be run when the script is done
+                */
+               function addScript( src, callback ) {
+                       var done = false, script;
+                       if ( ready ) {
+                               // jQuery's getScript method is NOT better than doing this the old-fashioned way
+                               // because jQuery will eval the script's code, and errors will not have sane
+                               // line numbers.
+                               script = document.createElement( 'script' );
+                               script.setAttribute( 'src', src );
+                               script.setAttribute( 'type', 'text/javascript' );
+                               if ( $.isFunction( callback ) ) {
+                                       // Attach handlers for all browsers -- this is based on jQuery.ajax
+                                       script.onload = script.onreadystatechange = function() {
+
+                                               if (
+                                                       !done
+                                                       && (
+                                                               !script.readyState
+                                                               || /loaded|complete/.test( script.readyState )
+                                                       )
+                                               ) {
+
+                                                       done = true;
+
+                                                       // Handle memory leak in IE
+                                                       script.onload = script.onreadystatechange = null;
+
+                                                       callback();
+
+                                                       if ( script.parentNode ) {
+                                                               script.parentNode.removeChild( script );
+                                                       }
+
+                                                       // Dereference the script
+                                                       script = undefined;
+                                               }
+                                       };
+                               }
+                               document.body.appendChild( script );
+                       } else {
+                               document.write( mw.html.element(
+                                       'script', { 'type': 'text/javascript', 'src': src }, ''
+                               ) );
+                               if ( $.isFunction( callback ) ) {
+                                       // Document.write is synchronous, so this is called when it's done
+                                       callback();
+                               }
+                       }
+               }
+
+               /**
+                * Asynchronously append a script tag to the end of the body
+                * that invokes load.php
+                * @param moduleMap {Object}: Module map, see buildModulesString()
+                * @param currReqBase {Object}: Object with other parameters (other than 'modules') to use in the request
+                * @param sourceLoadScript {String}: URL of load.php
+                */
+               function doRequest( moduleMap, currReqBase, sourceLoadScript ) {
+                       var request = $.extend(
+                               { 'modules': buildModulesString( moduleMap ) },
+                               currReqBase
+                       );
+                       request = sortQuery( request );
+                       // Asynchronously append a script tag to the end of the body
+                       // Append &* to avoid triggering the IE6 extension check
+                       addScript( sourceLoadScript + '?' + $.param( request ) + '&*' );
+               }
+
+               /* Public Methods */
+
+               /**
+                * Requests dependencies from server, loading and executing when things when ready.
+                */
+               this.work = function() {
+                               // Build a list of request parameters common to all requests.
+                       var     reqBase = {
+                                       skin: mw.config.get( 'skin' ),
+                                       lang: mw.config.get( 'wgUserLanguage' ),
+                                       debug: mw.config.get( 'debug' )
+                               },
+                               // Split module batch by source and by group.
+                               splits = {},
+                               maxQueryLength = mw.config.get( 'wgResourceLoaderMaxQueryLength', -1 );
+
+                       // Appends a list of modules from the queue to the batch
+                       for ( var q = 0; q < queue.length; q++ ) {
+                               // Only request modules which are undefined or registered
+                               if ( !( queue[q] in registry ) || registry[queue[q]].state === 'registered' ) {
+                                       // Prevent duplicate entries
+                                       if ( $.inArray( queue[q], batch ) === -1 ) {
+                                               batch[batch.length] = queue[q];
+                                               // Mark registered modules as loading
+                                               if ( queue[q] in registry ) {
+                                                       registry[queue[q]].state = 'loading';
+                                               }
+                                       }
+                               }
+                       }
+                       // Early exit if there's nothing to load...
+                       if ( !batch.length ) {
+                               return;
+                       }
+
+                       // The queue has been processed into the batch, clear up the queue.
+                       queue = [];
+
+                       // Always order modules alphabetically to help reduce cache
+                       // misses for otherwise identical content.
+                       batch.sort();
+
+                       // Split batch by source and by group.
+                       for ( var b = 0; b < batch.length; b++ ) {
+                               var     bSource = registry[batch[b]].source,
+                                       bGroup = registry[batch[b]].group;
+                               if ( !( bSource in splits ) ) {
+                                       splits[bSource] = {};
+                               }
+                               if ( !( bGroup in splits[bSource] ) ) {
+                                       splits[bSource][bGroup] = [];
+                               }
+                               var bSourceGroup = splits[bSource][bGroup];
+                               bSourceGroup[bSourceGroup.length] = batch[b];
+                       }
+
+                       // Clear the batch - this MUST happen before we append any
+                       // script elements to the body or it's possible that a script
+                       // will be locally cached, instantly load, and work the batch
+                       // again, all before we've cleared it causing each request to
+                       // include modules which are already loaded.
+                       batch = [];
+
+                       var source, group, modules, maxVersion, sourceLoadScript;
+
+                       for ( source in splits ) {
+
+                               sourceLoadScript = sources[source].loadScript;
+
+                               for ( group in splits[source] ) {
+
+                                       // Cache access to currently selected list of
+                                       // modules for this group from this source.
+                                       modules = splits[source][group];
+
+                                       // Calculate the highest timestamp
+                                       maxVersion = 0;
+                                       for ( var g = 0; g < modules.length; g++ ) {
+                                               if ( registry[modules[g]].version > maxVersion ) {
+                                                       maxVersion = registry[modules[g]].version;
+                                               }
+                                       }
+
+                                       var     currReqBase = $.extend( { 'version': formatVersionNumber( maxVersion ) }, reqBase ),
+                                               currReqBaseLength = $.param( currReqBase ).length,
+                                               moduleMap = {},
+                                               // We may need to split up the request to honor the query string length limit,
+                                               // so build it piece by piece.
+                                               l = currReqBaseLength + 9; // '&modules='.length == 9
+
+                                       moduleMap = {}; // { prefix: [ suffixes ] }
+
+                                       for ( var i = 0; i < modules.length; i++ ) {
+                                                       // Determine how many bytes this module would add to the query string
+                                               var     lastDotIndex = modules[i].lastIndexOf( '.' ),
+                                                       // Note that these substr() calls work even if lastDotIndex == -1
+                                                       prefix = modules[i].substr( 0, lastDotIndex ),
+                                                       suffix = modules[i].substr( lastDotIndex + 1 ),
+                                                       bytesAdded = prefix in moduleMap
+                                                               ? suffix.length + 3 // '%2C'.length == 3
+                                                               : modules[i].length + 3; // '%7C'.length == 3
+
+                                               // If the request would become too long, create a new one,
+                                               // but don't create empty requests
+                                               if ( maxQueryLength > 0 && !$.isEmptyObject( moduleMap ) && l + bytesAdded > maxQueryLength ) {
+                                                       // This request would become too long, create a new one
+                                                       // and fire off the old one
+                                                       doRequest( moduleMap, currReqBase, sourceLoadScript );
+                                                       moduleMap = {};
+                                                       l = currReqBaseLength + 9;
+                                               }
+                                               if ( !( prefix in moduleMap ) ) {
+                                                       moduleMap[prefix] = [];
+                                               }
+                                               moduleMap[prefix].push( suffix );
+                                               l += bytesAdded;
+                                       }
+                                       // If there's anything left in moduleMap, request that too
+                                       if ( !$.isEmptyObject( moduleMap ) ) {
+                                               doRequest( moduleMap, currReqBase, sourceLoadScript );
+                                       }
+                               }
+                       }
+               };
+
+               /**
+                * Register a source.
+                *
+                * @param id {String}: Short lowercase a-Z string representing a source, only used internally.
+                * @param props {Object}: Object containing only the loadScript property which is a url to
+                * the load.php location of the source.
+                * @return {Boolean}
+                */
+               this.addSource = function( id, props ) {
+                       // Allow multiple additions
+                       if ( typeof id === 'object' ) {
+                               for ( var source in id ) {
+                                       mw.loader.addSource( source, id[source] );
+                               }
+                               return true;
+                       }
+
+                       if ( sources[id] !== undefined ) {
+                               throw new Error( 'source already registered: ' + id );
+                       }
+
+                       sources[id] = props;
+
+                       return true;
+               };
+
+               /**
+                * Registers a module, letting the system know about it and its
+                * properties. Startup modules contain calls to this function.
+                *
+                * @param module {String}: Module name
+                * @param version {Number}: Module version number as a timestamp (falls backs to 0)
+                * @param dependencies {String|Array|Function}: One string or array of strings of module
+                *  names on which this module depends, or a function that returns that array.
+                * @param group {String}: Group which the module is in (optional, defaults to null)
+                * @param source {String}: Name of the source. Defaults to local.
+                */
+               this.register = function( module, version, dependencies, group, source ) {
+                       // Allow multiple registration
+                       if ( typeof module === 'object' ) {
+                               for ( var m = 0; m < module.length; m++ ) {
+                                       // module is an array of module names
+                                       if ( typeof module[m] === 'string' ) {
+                                               mw.loader.register( module[m] );
+                                       // module is an array of arrays
+                                       } else if ( typeof module[m] === 'object' ) {
+                                               mw.loader.register.apply( mw.loader, module[m] );
+                                       }
+                               }
+                               return;
+                       }
+                       // Validate input
+                       if ( typeof module !== 'string' ) {
+                               throw new Error( 'module must be a string, not a ' + typeof module );
+                       }
+                       if ( registry[module] !== undefined ) {
+                               throw new Error( 'module already implemented: ' + module );
+                       }
+                       // List the module as registered
+                       registry[module] = {
+                               'version': version !== undefined ? parseInt( version, 10 ) : 0,
+                               'dependencies': [],
+                               'group': typeof group === 'string' ? group : null,
+                               'source': typeof source === 'string' ? source: 'local',
+                               'state': 'registered'
+                       };
+                       if ( typeof dependencies === 'string' ) {
+                               // Allow dependencies to be given as a single module name
+                               registry[module].dependencies = [dependencies];
+                       } else if ( typeof dependencies === 'object' || $.isFunction( dependencies ) ) {
+                               // Allow dependencies to be given as an array of module names
+                               // or a function which returns an array
+                               registry[module].dependencies = dependencies;
+                       }
+               };
+
+               /**
+                * Implements a module, giving the system a course of action to take
+                * upon loading. Results of a request for one or more modules contain
+                * calls to this function.
+                *
+                * All arguments are required.
+                *
+                * @param module String: Name of module
+                * @param script Mixed: Function of module code or String of URL to be used as the src
+                *  attribute when adding a script element to the body
+                * @param style Object: Object of CSS strings keyed by media-type or Object of lists of URLs
+                *  keyed by media-type
+                * @param msgs Object: List of key/value pairs to be passed through mw.messages.set
+                */
+               this.implement = function( module, script, style, msgs ) {
+                       // Validate input
+                       if ( typeof module !== 'string' ) {
+                               throw new Error( 'module must be a string, not a ' + typeof module );
+                       }
+                       if ( !$.isFunction( script ) && !$.isArray( script ) ) {
+                               throw new Error( 'script must be a function or an array, not a ' + typeof script );
+                       }
+                       if ( !$.isPlainObject( style ) ) {
+                               throw new Error( 'style must be an object, not a ' + typeof style );
+                       }
+                       if ( !$.isPlainObject( msgs ) ) {
+                               throw new Error( 'msgs must be an object, not a ' + typeof msgs );
+                       }
+                       // Automatically register module
+                       if ( registry[module] === undefined ) {
+                               mw.loader.register( module );
+                       }
+                       // Check for duplicate implementation
+                       if ( registry[module] !== undefined && registry[module].script !== undefined ) {
+                               throw new Error( 'module already implemented: ' + module );
+                       }
+                       // Mark module as loaded
+                       registry[module].state = 'loaded';
+                       // Attach components
+                       registry[module].script = script;
+                       registry[module].style = style;
+                       registry[module].messages = msgs;
+                       // Execute or queue callback
+                       if ( compare(
+                               filter( ['ready'], registry[module].dependencies ),
+                               registry[module].dependencies ) )
+                       {
+                               execute( module );
+                       } else {
+                               request( module );
+                       }
+               };
+
+               /**
+                * Executes a function as soon as one or more required modules are ready
+                *
+                * @param dependencies string or array of strings of modules names the callback
+                *  dependencies to be ready before executing
+                * @param ready function callback to execute when all dependencies are ready (optional)
+                * @param error function callback to execute when if dependencies have a errors (optional)
+                */
+               this.using = function( dependencies, ready, error ) {
+                       var tod = typeof dependencies;
+                       // Validate input
+                       if ( tod !== 'object' && tod !== 'string' ) {
+                               throw new Error( 'dependencies must be a string or an array, not a ' + tod );
+                       }
+                       // Allow calling with a single dependency as a string
+                       if ( tod === 'string' ) {
+                               dependencies = [dependencies];
+                       }
+                       // Resolve entire dependency map
+                       dependencies = resolve( dependencies );
+                       // If all dependencies are met, execute ready immediately
+                       if ( compare( filter( ['ready'], dependencies ), dependencies ) ) {
+                               if ( $.isFunction( ready ) ) {
+                                       ready();
+                               }
+                       }
+                       // If any dependencies have errors execute error immediately
+                       else if ( filter( ['error'], dependencies ).length ) {
+                               if ( $.isFunction( error ) ) {
+                                       error();
+                               }
+                       }
+                       // Since some dependencies are not yet ready, queue up a request
+                       else {
+                               request( dependencies, ready, error );
+                       }
+               };
+
+               /**
+                * Loads an external script or one or more modules for future use
+                *
+                * @param modules mixed either the name of a module, array of modules,
+                *  or a URL of an external script or style
+                * @param type string mime-type to use if calling with a URL of an
+                *  external script or style; acceptable values are "text/css" and
+                *  "text/javascript"; if no type is provided, text/javascript is assumed.
+                */
+               this.load = function( modules, type ) {
+                       // Validate input
+                       if ( typeof modules !== 'object' && typeof modules !== 'string' ) {
+                               throw new Error( 'modules must be a string or an array, not a ' + typeof modules );
+                       }
+                       // Allow calling with an external script or single dependency as a string
+                       if ( typeof modules === 'string' ) {
+                               // Support adding arbitrary external scripts
+                               if ( /^(https?:)?\/\//.test( modules ) ) {
+                                       if ( type === 'text/css' ) {
+                                               $( 'head' ).append( $( '<link/>', {
+                                                       rel: 'stylesheet',
+                                                       type: 'text/css',
+                                                       href: modules
+                                               } ) );
+                                               return true;
+                                       } else if ( type === 'text/javascript' || type === undefined ) {
+                                               addScript( modules );
+                                               return true;
+                                       }
+                                       // Unknown type
+                                       return false;
+                               }
+                               // Called with single module
+                               modules = [modules];
+                       }
+                       // Resolve entire dependency map
+                       modules = resolve( modules );
+                       // If all modules are ready, nothing dependency be done
+                       if ( compare( filter( ['ready'], modules ), modules ) ) {
+                               return true;
+                       }
+                       // If any modules have errors return false
+                       else if ( filter( ['error'], modules ).length ) {
+                               return false;
+                       }
+                       // Since some modules are not yet ready, queue up a request
+                       else {
+                               request( modules );
+                               return true;
+                       }
+               };
+
+               /**
+                * Changes the state of a module
+                *
+                * @param module string module name or object of module name/state pairs
+                * @param state string state name
+                */
+               this.state = function( module, state ) {
+                       if ( typeof module === 'object' ) {
+                               for ( var m in module ) {
+                                       mw.loader.state( m, module[m] );
+                               }
+                               return;
+                       }
+                       if ( !( module in registry ) ) {
+                               mw.loader.register( module );
+                       }
+                       registry[module].state = state;
+               };
+
+               /**
+                * Gets the version of a module
+                *
+                * @param module string name of module to get version for
+                */
+               this.getVersion = function( module ) {
+                       if ( module in registry && 'version' in registry[module] ) {
+                               return formatVersionNumber( registry[module].version );
+                       }
+                       return null;
+               };
+
+               /**
+               * @deprecated use mw.loader.getVersion() instead
+               */
+               this.version = function() {
+                       return mw.loader.getVersion.apply( mw.loader, arguments );
+               };
+
+               /**
+                * Gets the state of a module
+                *
+                * @param module string name of module to get state for
+                */
+               this.getState = function( module ) {
+                       if ( module in registry && 'state' in registry[module] ) {
+                               return registry[module].state;
+                       }
+                       return null;
+               };
+
+               /**
+                * Get names of all registered modules.
+                *
+                * @return {Array}
+                */
+               this.getModuleNames = function() {
+                       var names = $.map( registry, function( i, key ) {
+                               return key;
+                       } );
+                       return names;
+               };
+
+               /* Cache document ready status */
+
+               $(document).ready( function() { ready = true; } );
+       } )();
+
+       /** HTML construction helper functions */
+       this.html = new ( function () {
+               var escapeCallback = function( s ) {
+                       switch ( s ) {
+                               case "'":
+                                       return '&#039;';
+                               case '"':
+                                       return '&quot;';
+                               case '<':
+                                       return '&lt;';
+                               case '>':
+                                       return '&gt;';
+                               case '&':
+                                       return '&amp;';
+                       }
+               };
+
+               /**
+                * Escape a string for HTML. Converts special characters to HTML entities.
+                * @param s The string to escape
+                */
+               this.escape = function( s ) {
+                       return s.replace( /['"<>&]/g, escapeCallback );
+               };
+
+               /**
+                * Wrapper object for raw HTML passed to mw.html.element().
+                */
+               this.Raw = function( value ) {
+                       this.value = value;
+               };
+
+               /**
+                * Wrapper object for CDATA element contents passed to mw.html.element()
+                */
+               this.Cdata = function( value ) {
+                       this.value = value;
+               };
+
+               /**
+                * Create an HTML element string, with safe escaping.
+                *
+                * @param name The tag name.
+                * @param attrs An object with members mapping element names to values
+                * @param contents The contents of the element. May be either:
+                *  - string: The string is escaped.
+                *  - null or undefined: The short closing form is used, e.g. <br/>.
+                *  - this.Raw: The value attribute is included without escaping.
+                *  - this.Cdata: The value attribute is included, and an exception is
+                *   thrown if it contains an illegal ETAGO delimiter.
+                *   See http://www.w3.org/TR/1999/REC-html401-19991224/appendix/notes.html#h-B.3.2
+                *
+                * Example:
+                *      var h = mw.html;
+                *      return h.element( 'div', {},
+                *              new h.Raw( h.element( 'img', {src: '<'} ) ) );
+                * Returns <div><img src="&lt;"/></div>
+                */
+               this.element = function( name, attrs, contents ) {
+                       var v, s = '<' + name;
+                       for ( var attrName in attrs ) {
+                               v = attrs[attrName];
+                               // Convert name=true, to name=name
+                               if ( v === true ) {
+                                       v = attrName;
+                               // Skip name=false
+                               } else if ( v === false ) {
+                                       continue;
+                               }
+                               s += ' ' + attrName + '="' + this.escape( '' + v ) + '"';
+                       }
+                       if ( contents === undefined || contents === null ) {
+                               // Self close tag
+                               s += '/>';
+                               return s;
+                       }
+                       // Regular open tag
+                       s += '>';
+                       switch ( typeof contents ) {
+                               case 'string':
+                                       // Escaped
+                                       s += this.escape( contents );
+                                       break;
+                               case 'number':
+                               case 'boolean':
+                                       // Convert to string
+                                       s += '' + contents;
+                                       break;
+                               default:
+                                       if ( contents instanceof this.Raw ) {
+                                               // Raw HTML inclusion
+                                               s += contents.value;
+                                       } else if ( contents instanceof this.Cdata ) {
+                                               // CDATA
+                                               if ( /<\/[a-zA-z]/.test( contents.value ) ) {
+                                                       throw new Error( 'mw.html.element: Illegal end tag found in CDATA' );
+                                               }
+                                               s += contents.value;
+                                       } else {
+                                               throw new Error( 'mw.html.element: Invalid type of contents' );
+                                       }
+                       }
+                       s += '</' + name + '>';
+                       return s;
+               };
+       } )();
+
+       /* Extension points */
+
+       this.legacy = {};
+
+} )( jQuery );
+
+// Alias $j to jQuery for backwards compatibility
+window.$j = jQuery;
+
+// Auto-register from pre-loaded startup scripts
+if ( typeof startUp !== 'undefined' && jQuery.isFunction( startUp ) ) {
+       startUp();
+       delete startUp;
+}