ResourceLoader/Core modules

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This page lists modules that ship with MediaWiki core by default. It reflects the current development version of MediaWiki and may vary from the latest stable release.

The order of the modules should be kept similar to their definition in Resources.php.

The modules jquery and mediawiki together form the base environment ("startup") and are present always. They should not (and in fact, can not) be loaded as modules or dependencies. mediawiki is what provides the loader client itself. jQuery and the other base utilities provided by mediawiki are internal dependencies of the ResourceLoader client.



This is the mediawiki base module. It initialises the mediaWiki global object (with mw as alias). Alias mw is available everywhere and should be used.


For a complete list of configuration values in mw.config, check out Manual:Interface/JavaScript. By default, keys here are also reflected as global variables for backwards compatibility (since MediaWiki 1.17). A console message will be shown when the global variables are used, as they are deprecated. The keys are identical to the variables beginning in wg, such as wgSiteName, wgArticleId etc.

// Check existence
if ( mw.config.exists( 'wgGlobalGroups' ) ) {
	// CentralNotice has registered this variable...

// Or just a plain access for comparison
// (no need to check exists first, it falls back to null)
if ( mw.config.get( 'wgPageName' ) === 'ResourceLoader' ) {
	// Do stuff...

/* Access multiple ones for use throughout a larger code base
   Returns an array containing the variables requested.        */
var conf = mw.config.get([

if ( conf.wgCanonicalSpecialPageName === 'Blankpage' ) {
	// Do stuff...


MediaWiki version: 1.22

A framework for registering and firing events in JavaScript (as opposed to doing everything on document ready). For example, the snippet below provides a message once the categories on a page load:

mw.hook( 'wikipage.categories' ).add( function ( $content ) {
	if (mw.config.get("wgCategories").length === 0) {
		alert("Please add categories to this page");


Helper functions for escaping and creating strings of HTML.


See also Manual:Messages API#Using messages in JavaScript

If the mediawiki.jqueryMsg module is loaded, the behaviour of this module changes significantly. See above link.



Load one or more modules, a script or a stylesheet. To load an external script or stylesheet, the URL must start with either "http://", "https://" or "//" (protocol-relative), or "/" (local path). Provide a MIME-type as second parameter (either "text/javascript" or "text/css"). If no MIME-type is provided, the default "text/javascript" is assumed. mw.loader creates an asynchronous request, if you need to run code that depends on a module, use mw.loader.using instead (which provides a callback). If you need a callback from an external script, use jQuery.getScript.

Loader instructions represent the intent that a module by that name should be loaded. It will not load the same module a second time if has already been loaded previously.

// Module by name
mw.loader.load( 'oojs' );

// Multiple modules at once
mw.loader.load( ['oojs', 'mediawiki.Title'] );

// External javascript file
mw.loader.load( '' );

// External stylesheet
mw.loader.load( '', 'text/css' );

// Local script
mw.loader.load( '/w/index.php?title=MediaWiki:Gadget-HotCat.js&action=raw&ctype=text/javascript' );

// Local stylesheet
mw.loader.load( '/w/index.php?title=User:Example/custom-foo.css&action=raw&ctype=text/css', 'text/css' );

Loads modules and then executes a callback function. You may call using() with two or three arguments: dependencies, a callback function to execute when modules are successfully loaded, and a callback function to execute on error. Or you can call it with one argument and use a jQuery promise object returned by this function (since MediaWiki 1.23) to specify callbacks.

mw.loader.using( 'jquery.colorUtil' ).then( function () {
	var curColor, newColor;

	// This function will be called right away if the required modules are already loaded.
	// Otherwise the module(s) are loaded and if all successful, the function is called.
	curColor = 'rgb(70,140,210)';
	newColor = $.colorUtil.getColorBrightness( curColor, +0.2 );
	alert( '20% brigher than ' + curColor + ' is ' + newColor );
} );

Shows an ordered list of all ResourceLoader modules that are loaded on the page, sorted by the total size of each module's JavaScript and CSS assets. Can show css usage individually using mw.loader.inspect("css").[edit]

Get the current time, measured in milliseconds since January 1, 1970 (UTC). On browsers that implement the Navigation Timing API, this function will produce floating-point values with microsecond precision that are guaranteed to be monotonic. On all other browsers, it will fall back to using Date.

var totalTime, time =;
// some expensive code
totalTime = - time;

Introduced in MediaWiki 1.23.


Track an analytic event.

This method provides a generic means for MediaWiki JavaScript code to capture state information for analysis. Each logged event specifies a string topic name that describes the kind of event that it is. Topic names consist of dot-separated path components, arranged from most general to most specific. Each path component should have a clear and well-defined purpose. Data handlers are registered via `mw.trackSubscribe`, and receive the full set of events that match their subscription, including those that fired before the handler was bound.

The WikimediaEvents extension demonstrates how to add a subscriber for the "timing" and "counter" topics[1].

var totalTime, time =;
// some expensive code
totalTime = - time;
mw.track( '', totalTime );

Introduced in MediaWiki 1.23.


Collection of methods to help log messages to the console.


Module that represents information about the current user.



Contains the preferences of the user, or the defaults when logged out.

// Get a preference option and use it directly
alert( 'According to the preferences, your gender is ' + mw.user.options.get( 'gender' ) );

// Get several preferences and compare them with $.compareObject
if ( $.compareObject( mw.user.options.get( ['diffonly', 'showhiddencats'] ), { diffonly: 0, showhiddencats : 0 } ) ) {
	// User's preferences match the object
} else {
	// User's preferences don't match the given set

This module is loaded asynchronously, and it depends on the user.defaults module. The HTML itself contains only the options that are different than the wiki defaults, and a separate request is made to get the user.defaults. Due to that dependency, the mw.user.options object won't be populated until the user.defaults is actually loaded, to prevent the latter from overwriting the former.



MediaWiki version: 1.18

Is pre-populated with api tokens. Currently editToken, watchToken, and patrolToken.

var edittoken = mw.user.tokens.get( 'editToken' );
var watchtoken = mw.user.tokens.get( 'watchToken' );

See a live example from the module.


This module provides the mw.Api constructor. The main methods of the mw.Api object are get(), post(), and ajax(). The mediawiki.api module (and its plugins) return a Promise – similar to jQuery.ajax (and its derivatives such as jQuery.get, and jQuery.getJSON).

See the API documentation for the various plugins (implemented as modules depending on this one) that make it more convenient to use certain API actions by abstracting their input and output.


This module depends on mediawiki.api, and extends the mw.Api prototype with methods related to categorization:


Determines if a category exists.


Lists categories with a given prefix.


Gets the list of categories that a given page belongs to.


This module depends on mediawiki.api, and extends the mw.Api prototype with methods for editing:


MediaWiki version: 1.23

This posts to the edit WebAPI as specified by the parameters. It is intended for methods that require an edit token. It will used a cached edit token if one exists, or get one then post.

Warning: You have to specify the action: 'edit' parameter yourself.


MediaWiki version: 1.23

This is a low-level method used by api.postWithEditToken to get tokens.


Creates a new section on the given page, with the given section name and text. Note this will not work on pages that use other content representations, including LiquidThreads discussions (bug 41276) and Flow boards and topics (bug 57989).


This module depends on mediawiki.api, and extends the mw.Api prototype with a method for parsing wikitext:


Calls the server to parse the given wikitext. Example:

var api = new mw.Api();

api.parse( "'''Hello world'''" )
.done( function ( html ) {
	console.log( 'Parsed result:', html );
} );[edit]

This module depends on mediawiki.api, and extends the mw.Api prototype with methods related to the watchlist:


Watches a given title or titles.


Unwatches a given title or titles.


This module depends on mediawiki.api, and extends the mw.Api prototype with methods related to getting and setting user options:


Save the value of a single user option.


Save the value of several user options.


This module depends on mediawiki.api, and extends the mw.Api prototype with methods related to logging in:


Make the two-step login easier.


Cookie module that follows most of MediaWiki's cookie settings (except wgCookieSecure). Simple examples:

var value;

mw.cookie.set( 'cookieToSet', 'valueToSet' );

value = mw.cookie.get( 'cookieToGet' );

This module prepends the cookie names with $wgCookiePrefix (e.g. "enwikiname=value"). If you use this module only you shouldn't encounter issues, but you might do if you mix it with other cookie handling codes.

See the API documentation for available options.


User interface for collecting feedback, particularly on new features, using OOUI. This sets the mediaWiki.Feedback constructor. Example:

var feedback = new mw.Feedback();
$( '#myButton' ).click( function () { feedback.launch(); } );


Sets up feedback GUI.


Displays a particular part of the feedback interface.


Shows that the feedback is being added.


Shows information about bug tracker


Shows thank you message.


Displays the feedback form, with optional pre-filled contents.


Shows given error message.


Dismisses feedback form.


Submits feedback form using mw.Api.newSection.


Main entry point for displaying the feedback form, with optional pre-filled contents.


See also Manual:Messages API#Using messages in JavaScript

This module sets the mediawiki.jqueryMsg object. This is used for advanced message parsing. Use it only when mediaWiki.msg and mediaWiki.message do not meet your needs. For example, mediawiki.jqueryMsg is required for plural and gender support, the int: magic word and links.


Creates bubble notifications. Basic examples

mw.notify( 'This is a notification.' ); // Send a plaintext notification
mw.notify( mw.message( 'some-message' ) ); // Use an i18n message to send a notification
mw.notify( $( '<span>This is a <u>HTML</u> notification.</span>' ) ); // Send a html notification with a jQuery instance (a DOM node also works)

mw.notify( 'Test', { title: 'Title!' } ); // Give the notification a title
mw.notify( 'Test', { autoHide: false } ); // Don't automatically hide the notification
mw.notify( 'Test', { tag: 'foobar' } ); // Send a notification tagged with a tag
mw.notify( 'Test 2', { tag: 'foobar' } ); // This one will replace the previous 'foobar' notification.[edit]

Wrapper for HTML5 Web Storage.

// localStorage 'key' ); 'key', 'value' ); 'key' );

// sessionStorage 'key' ); 'key', 'value' ); 'key' );

If you need to replace $.jStorage, be aware saves only string values, so you must additonal use something like JSON.stringify() and JSON.parse() or parseInt/parseFloat.


MediaWiki version: 1.22

(deprecated in 1.29) Please use OOUI instead. UI module developed as part of the Agora project. It defines mw-ui-* CSS styles. It is used in the Login and Create account forms and several extensions. It provides one appearance for Vector and another for the rest of the skins. These are some commonly used features:


See section 2 of the living style guide for comprehensive code examples with their effects.

Note: in release 1.23 the button styles are in a separate mediawiki.ui.button module. If all you need is button styling, PHP code should only addModuleStyles( 'mediawiki.ui.button' ). The button module may be loaded on pages on a wiki but you should still load it as a dependency.

All buttons use the mw-ui-button class. The main button for a particular interface should generally also use an additional class, which varies by type. For example, "save all changes" is constructive, since it completes a process and changes state:

<input type="submit" name="mw-myextension-submit" value="Save all changes" class="mw-ui-button mw-ui-constructive">

It can also be used on other elements:

<span class="mw-ui-button mw-ui-constructive">Save all changes</span>

Conversely, mw-ui-destructive is for buttons that make destructive changes to state (such as deletion). You may also sometimes use the mw-ui-block class, which sets the CSS display property to block and width to 100%. The mw-ui-big class increases the font size of buttons.

In release 1.23 mw-ui-primary is deprecated. Instead use mw-ui-constructive for final actions and mw-ui-progressive for actions which lead to a next step in a process.


If a form has the mw-ui-vform class, it lays out its child divs in a compact vertical stack, and input elements will automatically take on certain styles. For example, text inputs will take on a blue border hue. Checkbox labels should use the mw-ui-checkbox-label class, and surround the actual checkbox.

If you use HTMLForm to create a form and setDisplayFormat( 'vform' ), it will apply this styling.



Adds a <style> element to the HEAD and returns the CSSStyleSheet object.

The CSSStyleSheet object can be used to disable the css rules at any later time and re-enable them as well. This can be done through the 'disabled' attribute. When setting this to true, the rules no longer apply. When setting to false, the rules apply again.

See also W3 on CSSStyleSheet for more info.

// Add a simple stylesheet rule
mw.util.addCSS( '.plainlinks { color: green; }' );

// Add a rule and set a variable to the sheet
var myCssRules = mw.util.addCSS( '.plainlinks { color: green; }' );
$( '#myButton' ).click( function () {
	// When button is clicked, toggle the stylesheet from true to non-true (false), or from false to non-false (true)
	myCssRules.disabled = !myCssRules.disabled;
} );


This function is ported from the legacy wikibits keeping it fully backwards compatible, with a few adjustments that support all core skins and with added support for a CSS-selector as nextnode.

Only the first three arguments are required.

// First wait for mediawiki.util to load, and the page to be ready.
$.when( mw.loader.using( 'mediawiki.util' ), $.ready ).then( function () { 
   // General usage:
    mw.util.addPortletLink( portletId, href, text [, id [, tooltip [, accesskey [, nextnode ]]]] );
} );

// Add in the toolbox before the Print-link
	'Go to',

// The old way of passing a DOM-node still works
	'Go to',	
	document.getElementById( 't-print' )

In case you need to execute a custom function when the user clicks on a portlet, do not use 'javascript:doSomeStuff();' for the href of the portlet. Instead, use the jQuery(...).click to specify the code which should be executed.

// Create portlet link
var portletLink = mw.util.addPortletLink( 'p-cactions', '#',
	'My new portlet link', 'ca-my-portlet',	'Click here to test the new portlet'
// Bind click handler
$( portletLink ).click( function ( e ) {
	// doSomeStuff();
	alert( 'It works!' );


A jQuery object for a page's overall content area regardless of the skin used. This is, for example, #content in the Vector-skin (before 1.20 it was #bodyContent). This variable is initialized from the module. Make sure to either add it to your dependencies or wrap it inline in mw.loader.using( '', ... );

This does not refer to the area where the page content goes. If you wish to work with that area of the page instead of the overall content area you should use $('#mw-content-text') instead.

/* Add some HTML to the page content */
mw.util.$content.append( '<h2>Lorem ipsum</h2><p>This section was just added to the bottom of the wiki page.</p>' );

/* Count number of tables in the page's content with a class of "wikitable" */
var $wikitablesInPage = mw.util.$content.find( 'table.wikitable' );

if ( $wikitablesInPage.length ) {
	alert( 'There are ' + $wikitablesInPage.length + ' wikitables on this page.' );
} else {
	alert( 'There are no wikitables on this page.' );

Here is a more advanced example involving loading in extra content with an AJAX request. Run this example on a page other than the main page.

/* Loads in main page (or any page for that matter) over AJAX (may be useful for Special:BlankPage) */

// Put a loading message on top of the page
mw.util.$content.prepend( '<p><em>Loading...</em></p><hr/>' );

// To get the article contents, use #mw-content-text instead.
$('#mw-content-text').load( mw.util.getUrl( mw.config.get( 'wgMainPageTitle' ) ) + ' #mw-content-text', function () {
	mw.notify( 'Load complete!' );
} );


This function returns the value of the specified URL parameter. By default it uses the current window's address. Optionally you can pass it a custom location.

It returns null if the parameter is not present. Returns an empty string("") if it was an empty parameter (such as /page.php?some=parameter&emptyparameter=&id=12

// Location:
// Suppose we're editing a page section, this will return the number of the edit section
mw.util.getParamValue( 'section' ); /* returns '28'; */

// Extract a value from a custom url
// For example on a diff page where there is: "← Older edit" and you need the oldid of the previous edit
var oldid = mw.util.getParamValue( 'oldid', '//' );
if ( oldid !== null ) {
	alert( 'The previous text version of this page has id: ' + oldid );
} else {
	alert( 'No "oldid" parameter found in the given address.' );


MediaWiki version: 1.18


MediaWiki version: 1.18


MediaWiki version: 1.18

(deprecated in 1.24) Use mw.notify instead. This function is ported from the legacy wikibits keeping it fully backwards compatible, with a few adjustments and with added support to hide the message by calling with no arguments or when passing null.

// Basic usage, replace/add the message on top
mw.util.jsMessage( 'This is something a <strong>message</strong> for the <strong>user</strong>' );

// Classed usage, adds/replaces the 'mw-js-message-foobar' as class for the message-box
mw.util.jsMessage( 'Foobar message 01255', 'foobar' );

// Any of the folllowing will empty and hide the box
mw.util.jsMessage( '' );
mw.util.jsMessage( null );


This function returns an encoded string in its raw form for use in urls.

var exFooUrl = '' + mw.util.rawurlencode( mw.config.get( 'wgPageName' ) );

For building query strings, you may want to use jQuery.param instead:

var query = {
	page: 'MyPage',
	value: mw.config.get( 'skin' ),
	action: 'foo'

var fooQuery = '' + $.param( query );


Returns true if its string parameter is a valid e-mail address according to HTML5 specification, false if not, and null if passed an empty string.

var isValid = mw.util.validateEmail( "" ) === true;


This function returns a "pretty" version of a URL encoded wiki page name. It keeps slashes and colons unencoded. The behavior differs from wfUrlencode on the PHP side.

// This url will end up in the user's addressbar, so prettification is useful.
var $histLink = $( '<a>' ).attr(
	mw.config.get( 'wgScript' ) + '?action=history&title=' + mw.util.wikiUrlencode( mw.config.get( 'wgPageName' ) ),

// This will never be shown, don't bother with string concatenation, just encode it regularly with $.param(), much easier.
	url: mw.config.get( 'wgScript' ) + '?' + $.param({ action: 'history', title: mw.config.get( 'wgPageName' ) }),
	dataType: 'html'
.done( function ( html ) {
	/* .. */


(deprecated in 1.23) Use mw.util.getUrl() instead.
This function returns the address to a local wiki page.
var sandboxLink = mw.html.element(
	'a', {
		href: mw.util.wikiGetlink( 'Sandbox 3000' ), // returns "/wiki/Sandbox_3000"
		title: 'Go to Sandbox'
	}, 'Click here to enter the sandbox!'


MediaWiki version: 1.18

This function returns the location of a script on the current wiki. Much like wfScript in GlobalFunctions.php.

Parameters: str - Name of the script (eg. 'api'), defaults to 'index'.

jQuery.getJSON( mw.util.wikiScript( 'api' ), {
	format: 'json',
	action: 'query',
	titles: 'Main Page',
	prop: 'revisions'
} ).done( function ( data ) {
	// data.query
} );


MediaWiki version: 1.26


Returns a string for literal use in a regular expressions by escaping characters that have a special meaning in a regex.


This sets the mediaWiki.Title constructor, which has several methods in its prototype. Basic example

var t = new mw.Title( 'Image: foo_bar baz.jpg' );
t.getMain(); // "Foo_bar_baz.jpg"
t.getNamespaceId(); // 6
t.getNamespacePrefix(); // "File:"


Basic examples

var uri = new mw.Uri(); // Instance for the location of the current window

// Add one or more URL parameters, automatically handling ? and & as needed.
// Note that this modifies it in place, rather than creating a new URI object.
uri.extend( { action: 'edit', section: 3 } );

var otheruri = new mw.Uri( '' ); // The trailing slash is *required*
otheruri.toString(); // ""

OOjs and OOUI[edit]

MediaWiki version: 1.23


OOjs is an API module which provides a consistent way of implementing object-oriented design in JS.


OOUI uses OOjs to implement a UI toolkit.

jQuery & plugins[edit]


More information about jQuery's presence in MediaWiki, see jQuery. For more about jQuery in general and all its core functions, refer to

ResourceLoader provides jQuery as part of its base environment (the loader client uses jQuery internally), therefore this module is always loaded and should not (and in fact can not) be loaded through ResourceLoader (as dependency or otherwise).




MediaWiki versions: 1.16 – 1.31

(removed in 1.31) Gerrit change 386469.


MediaWiki versions: 1.20 – 1.31

(removed in 1.31) Gerrit change 386029 (T178450)

The code is still available at Also, some wikis have it hacked in as a gadget, such as Wikimedia Commons.

This is a jQuery module that allows you to put a red notification "badge" on an item on the page.



This single-function plugin can be called to add this functionality to any number of checkboxes. By default (onload) it's applied to all input elements that have a type of checkbox, excluding any with a class of 'noshiftselect'. As it has a built-in prevention to avoid binding the CheckboxShiftClick twice to the same element you can simply run the line below under "Default" again at any time if you want to enable dynamically added checkboxes in the page to be shift-selectable as well. Or alternatively run it on the specific selector of choice (see second example below).

// Default:
$( 'input[type=checkbox]:not(.noshiftselect)' ).checkboxShiftClick();

// Enable the functionality for checkboxes in dynamically created form <form id="my-tool-form">
$( 'form#my-tool-form input[type=checkbox]' ).checkboxShiftClick();


“Chosen is a jQuery plugin that makes long, unwieldy select boxes much more user-friendly.” —

In fact, it turns a select into a combo box with autocomplete functionality by default but also supports grouping, and "tagging" (i.e. multiple values).

$("select").chosen({/* options */});


A plugin that extracts information about the client's browser, layout engine and operating system. Use this instead of jQuery.browser, which is deprecated and will be removed from jQuery in the near future.


The profile function is the main function here and returns (and caches) all the information in an object in. All possible values (except for version numbers) are predefined. A typical return looks like this:

/* jQuery.client.profile() */
	'name': 'firefox',
	'layout': 'gecko',
	'layoutVersion': '20100101',
	'platform': 'win'
	'version': '10.0.2',
	'versionBase': '10',
	'versionNumber': 10,

Here a few examples

if ( $.client.profile().layout == 'gecko' && $.client.profile().platform == 'linux' ) {
	// This will only run on Gecko browsers (ie. Mozilla Firefox) on Linux.

if ( $.client.profile().name == 'msie' ) {
	// Only for good ol' Internet Explorer

// Shortcut
var prof = $.client.profile();
if ( == 'firefox' && prof.versionBase == '2' && prof.platform == 'win' ) {
	// Target Mozilla Firefox 2.x on Windows

Check jquery.client.js for possible values of browser names, layout engines and platforms.




Used by the Vector extension.


MediaWiki version: 1.18


MediaWiki version: 1.17


You can use jquery.cookie or you can use mediawiki.cookie instead in new code, since it takes into account MediaWiki's cookie configuration settings for you.

This plugin allows you to set, get and delete cookies.

// Set cookie (simple, current page/path)
$.cookie( 'myName', 'Flower' );

// Set cookie (extra options)
$.cookie( 'myName', 'Flower', {
	expires: 7, // expires in 7 days
	path: '/' // domain-wide, entire wiki
} );

// Get cookie
var name = $.cookie( 'myName' );

// Delete cookie
// Deprecated since 1.2 please use $.removeCookie('foo') instead
$.cookie( 'myName', null );


When deleting a cookie, you must use the same path and domain used when the cookie was set.

Note that when MediaWiki server-side code sets a cookie it usually prefixes it with the database name; this prefix is available to JavaScript code as the mediaWiki.config variable wgCookiePrefix.

Note that users will likely get separate cookies for /wiki/ and /w/ paths in page URLs if you do not specify the extra option { path: '/' } when setting a cookie.


(removed in 1.24)




MediaWiki version: 1.24

(removed in 1.25)

Provides JSON encoding to old browsers which do not support JSON.stringify. Deprecated since MediaWiki 1.24[1]. Removed in MediaWiki 1.25, use the "json" module instead (which lazy-loads the json2.js polyfill).


(deprecated in 1.28) Please use

Project home page

var key = "myStorageKey",
	value = $.jStorage.get( key );

if ( !$.jStorage.storageAvailable() ) {
	throw new Error( 'No storage available. Fall back to ... or tell the user to install a real browser!' );

$.jStorage.listenKeyChange( key, function( key, action ) {
	if ( window.console && $.isFunction( console.log ) ) {
		console.log(key + " has been " + action);
} );

value = {a: 1, b: 2, c: [3, 4, 5]};
$.jStorage.set( key, value );


MediaWiki version: 1.17

Localizes the elements in a jQuery collection.


MediaWiki version: 1.18
See also Manual:Collapsible elements.

Makes elements collapsible. It supports lots of variations such as:

Add "mw-collapsible" to an element (a <div> for example) with some content and save the page. The inner content of this element will be treated as collapsible content. Prepended to the element, before the collapsible content, is a toggle-link with a localized label (collapsible-expand, collapsible-collapse)
Initial state
Adding "mw-collapsed" as additional class will cause the element to be initially collapsed when the page is loaded.
Custom label
HTML5 only Using the data-collapsetext and data-expandtext attributes one can define a custom text for the toggle labels added by the script. When added in wikitext these could be populated by a localized message like:
<div class="mw-collapsible" data-expandtext="{{int:show}}" data-collapsetext="{{int:hide}}">
Remote toggle
If you don't want the script to put the default toggle link (whether or not with a custom label) in your element, you can make one of your own. This could reside anywhere inside or outside the collapsible element. Its relationship to the collapsible element is detected by using an ID attribute with the prefix mw-customcollapsible and a corresponding class attribute with prefix mw-customtoggle for the collapsible element and the togglelink respectively.
Example: Simple collapsible div or table


{| class="infobox"
! Foo
| Bar
! Lorem
| Ipsum
! More info
{| class="wikitable mw-collapsible mw-collapsed" style="width: 100%;"
! Head
! Top
| Cell
| content
| This table is collapsible
| Because it has the "mw-collapsible" class
| It was initially hidden, because it
| had the "mw-collapsed" class

<div class="toccolours mw-collapsible" style="width: 400px;">
This is text is collapsible. {{Lorem}}


Foo Bar
Lorem Ipsum
More info
Head Top
Cell content
This table is collapsible Because it has the "mw-collapsible" class
It was initially hidden, because it had the "mw-collapsed" class
This is text is collapsible. Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

Example: Hide the collapsible element by default, the toggle element resides outside of it


<div class="mw-customtoggle-myDivision" style="background:#e0e8ff">Click here to toggle the element</div>

<div class="mw-collapsible mw-collapsed" id="mw-customcollapsible-myDivision">
<div class="toccolours mw-collapsible-content">Lorem ipsum dolor sit amet...</div>

<div class="mw-customtoggle-myDivision" style="background:#e8ffe0">Clicking will toggle it also!</div>


Click here to toggle the element
Lorem ipsum dolor sit amet...
Clicking will toggle it also!

For other live examples, see Test Wikipedia - Collapsing Testpage.


MediaWiki versions: 1.16 – 1.31

This plugin adds support for placeholder texts in input fields for browsers that don't support the HTML5 attribute yet. If the attribute is not supported it's applied to all input elements with a 'placeholder' attribute, on-load.

It has a built-in check for browser support, but for efficiency it's best to do this check (also) wrapped around to call.

// Default:
if ( !( 'placeholder' in document.createElement( 'input' ) ) ) {
	$( 'input[placeholder]' ).placeholder();

// Example for your dynamically added foobar fields
$( "form#foobar-ajax input[placeholder]" ).placeholder();


Testing framework. See



Assesses the completeness (coverage) of test suites for object oriented javascript libraries. Written to be used in environments with jQuery and QUnit.

This is also used by MediaWiki core when running the QUnit test suite with the completenesstest option enabled.





MediaWiki version: 1.18


mw.util.jsMessage( 'The selected text is "' + mw.html.escape( $( '#wpTextbox1' ).textSelection( 'getSelection' ) ) + '".' );


(deprecated in 1.28)

The library will be available for the forseeable future, but overlaps with functionality within OOUI and provides a suboptimal experience to mobile users. Where jQuery.tipsy is being used, we encourage developers to inspect OOUI and feedback on how the library might be improved to support the usecase that jquery.tipsy provides.

Example page; jQuery project page

Option Type Possible values Default Description
gravity string / call-back function 'nw' | 'n' | 'ne' | 'w' | 'e' | 'sw' | 's' | 'se' / $.fn.tipsy.autoNS | $.fn.tipsy.autoWE | pointer or anonymous 'n' sets the positioning of the tooltip relative to the element
fade bool true | false true use fading effect (fadeIn / fadeOut)
title string (an attribute) / call-back function style, class, id, ..., function () { return 'some string'; } title (or if not specified fallback-value; see below) Which string to display as a "tool-tip"?
fallback string 'valid string' used if an element has no tooltip
html bool true | false false interpret the tooltip text as HTML
delayIn number in ms 0, 1, 2, ... 0 How long to wait after onmouseover to show the tip?
delayOut number in ms 0, 1, 2, ... 0 How long to wait after onmouseout to close the tip?
trigger string 'focus' | 'manual' | 'hover' hover When to show the tooltip (useful for forms)
live bool true | false false dynamical add to selectors- see JQuery's live interpretation
offset number in px 0 offset from tooltip to element
opacity number (float) 1.0 opacity of the tooltip
mw.loader.using( 'jquery.tipsy', function () {
		$( '<span>', {
			title: 'Some tipsy test title'
		} )
		.append( 'Hover here' )
		.tipsy( {
			option: 'value',
			option2: 'value2'
		} )
} );


MediaWiki version: 1.17

There are several methods added to the jQuery object for older browsers serving as backwards-compatibility for new native prototypes in newer browser. Also several other convenience functions have been created such as isEmpty and escapeRE. In MediaWiki 1.17 and 1.18 these methods were part of the "jquery.mwPrototypes" module. In MediaWiki 1.19 this module was renamed to "jquery.mwExtension" (see rev:94227).


Trims whitespace from the left side of the string. Use instead: s.replace( /^\s+/, "" )


Trims whitespace from the right of the string. Use instead: s.replace( /\s+$/, "" )


Returns the string with the first character capitalized. Use instead: s.charAt( 0 ).toUpperCase() + s.substr( 1 )


Returns a string for literal use in a regular expressions by escaping characters that have a special meaning in a regex. In ≥ 1.26 use #mediawiki.RegExp instead.


Check whether a passed a variable is a direct link to an element.


MediaWiki version: 1.17

This function checks if a variable is empty. Supports strings, booleans, arrays and objects. The string "0" is considered empty. A string containing only whitespace (ie. " ") is considered not empty.


Compares two arrays and returns a boolean for whether they are in fact the same


MediaWiki version: 1.17

Compares two objects for it's properties and values (recursive).

 * Trim
$.trimLeft( '  foo bar  ' ); // "foo bar  ";
$.trimRight( '  foo bar  ' ); // "  foo bar";
$.trim( '  foo bar  ' ); // "foo bar";

 * isEmpty
$.isEmpty( 'string' ); // false
$.isEmpty( '0' ); // true
$.isEmpty( '' ); // true
$.isEmpty( [] ); // true

 * compareArray
$.compareArray( [1, "a", [], [2, 'b'] ], [1, 'a', [], [2, "b"] ] ); // true
$.compareArray( [1, 2], [8, 7] ); // false

 * isDomElement
// Sure, a plain normal dom element: True
$.isDomElement( document.getElementById( 'content' ) );

// This returns an array of dom elements, not a dom element itself: False
$.isDomElement( document.getElementsByClassName( 'portal' ) );

// This is a normal dom element: True
$.isDomElement( document.getElementsByClassName( 'portal' )[0] );

// jQuery objects are not dom elements: False
$.isDomElement( $( '#content' ) );

// jQuery.get(0) returns the raw dom element for the object: True
$.isDomElement( $( '#content' ).get(0) );

// Anything else: False
$.isDomElement( 'hello world' );

jQuery UI[edit]

(deprecated in 1.29) Please use OOUI instead. For more information on and demos for jQuery UI, refer to

The following components are available as individual ResourceLoader modules:

The module name of each jQuery UI component is the script name, without the .js extension. For example: jquery.ui.core for the jquery.ui.core.js script.

Documentation FeaturesResourceLoader/Features · VocabularyResourceLoader/Vocabulary · Migration guide (users)ResourceLoader/Migration guide (users) · Migration guide (developers)ResourceLoader/Migration guide for extension developers · Developing with ResourceLoaderResourceLoader/Developing with ResourceLoader · Core modulesResourceLoader/Modules · Mobile supportResourceLoader/Writing a MobileFrontend friendly ResourceLoader module
Project information Status updatesResourceLoader/status · Version 1 Design SpecificationResourceLoader/Version 1 Design Specification · Version 2 Design SpecificationResourceLoader/Version 2 Design Specification · RequirementsResourceLoader/Requirements
Other JavaScript DeprecationsResourceLoader/Legacy JavaScript
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