Extension:Widgets

Please also consider contributing widgets you created. Thank you for sharing!

MediaWiki extensions manual

Widgets Release status: stable
Implementation	Parser function
Description	Allows adding free-type widgets to the wiki by editing pages in Widget namespace
Author(s)	Sergey Chernyshev Yaron Koren
Maintainer(s)	Yaron Koren
Latest version	1.6.0 (2024-08-02)
MediaWiki	1.38+
License	GNU General Public License 2.0 or later
Download	Download extension Git [?]: Download Git master browse repository (Phabricator · GitHub) commit history repository contributors (GitHub) code review
Example	Widgets on MediaWikiWidgets.org
Parameters $wgWidgetsCompileDir $wgWidgetsUseFlaggedRevs
Added rights editwidgets
Hooks used ParserAfterTidy ParserFirstCallInit
Quarterly downloads	145 (Ranked 43rd)
Public wikis using	1,122 (Ranked 207th)
Translate the Widgets extension if it is available at translatewiki.net
Vagrant role	widgets
Issues	Open tasks · Report a bug

The Widgets extension allows the creation of raw HTML pages that can be transcluded (similarly to templates) in normal wiki pages. You do this by creating pages in the Widget namespace. They avoid the security problems of raw HTML in editable wiki pages because the privilege to edit in the Widget namespace is managed. Many pre-written Widgets are available.

Download

To get the code with Git, type the following commands:

cd extensions
git clone https://gerrit.wikimedia.org/r/mediawiki/extensions/Widgets.git
cd Widgets
composer update --no-dev

Composer is a PHP dependency manager. For some MediaWiki installations, you may need to update Composer to version 2. Instructions here.

Installation

To invoke this extension, add the following to LocalSettings.php :

wfLoadExtension( 'Widgets' );

Folder permissions

Also, the $IP/extensions/Widgets/compiled_templates/ folder should be made writable by the web server. See Making a directory writable by the webserver. The compiled templates folder is where Smarty stores pre-compiled templates.

Configuration

The steps in this section are optional—the extension should work fine even without these changes, but they will give you more flexibility if you have a complex MediaWiki installation.

Using FlaggedRevs for widget review

You can use the FlaggedRevs extension to enable a widget security review process. See this version of the documentation for how to integrate the extension.

Changing the directory for storing the compiled widgets

You can use the $wgWidgetsCompileDir variable to change the directory for storing the compiled widgets ($compile_dir in the code). The default setting is

$wgWidgetsCompileDir = "$IP/extensions/Widgets/compiled_templates/";

If you change the location by setting the parameter with another directory, make sure that it exists and has the correct permissions.

User rights

This extension adds a namespace called "Widget", but due to potential security implications that can result from using insecure widget code, this namespace is only editable by users who have the editwidgets permission (the widgeteditor group is also created to add users to; see Help:User rights for more details).

Usage

To add a widget to your MediaWiki installation, create a page in the Widget: namespace. You can then use the {{#widget:...}} parser function to include it in any page in the wiki.

{{#widget}} parser function

To add a defined widget to pages, users can use the {{#widget}} parser function. The syntax is as follows:

{{#widget:WidgetName|param1=value1|param2=value2}}

Where WidgetName is a page name in the Widget namespace (e.g. Widget:WidgetName) and param=value pairs are the settable parameters, defined within the widget code.

Parameters can be expanded inside a widget using Smarty syntax, as follows:

<a href="<!--{$param1|escape:'url'}-->"><!--{$param2|escape:'html'}--></a>

The escape option specifies how the parameter will be 'escaped', or encoded, in the resultant Widget. It is critically important that all parameters are escaped to prevent cross-site scripting vulnerabilities. Some escape methods are ineffective. In general you should use one of escape:html, escape:url, escape:urlpathinfo or escape:javascript. See http://www.smarty.net/docsv2/en/language.modifier.escape for more information on this.

Pages in Widget namespace

All widgets in the wiki are defined by creating pages in the special "Widget:" namespace, like, e.g., "Widget:WidgetName".

To see all Widgets defined in your system, you can go to the page "Special:AllPages", select "Widget" in the namespace dropdown and click "Go".

For security reasons, these pages are only editable by wiki administrators - see User rights above for more info.

You can find many pre-defined widgets to install in your wiki at MediaWikiWidgets.org. If you are interested in creating widgets yourself, see the next section.

Widget page syntax

The Widgets extension uses the Smarty PHP templating engine to provide simple templating functionality within widget pages. All parameters passed to a widget are converted into Smarty parameters.

Important: Use escape modifiers on all passed-in parameters to prevent users from passing in raw HTML from normal wiki pages. Failure to protect against this will expose the hosting site to XSS (and other) attacks.

Arrays

If you use the same parameter multiple times, the widget will get an array of values. You can use foreach to go through the array.

Booleans (true/false)

In addition to PHP's default handling of Boolean conversions, you can (unlike in PHP) use the values "true" or "false" to set the Boolean value. The following would set the $popup parameter to false, for example:

{{#widget:WidgetName|popup=false}}

In addition, you can set Boolean parameters to true by just using a parameter name without a value, like this:

{{#widget:WidgetName|popup}}

Dotted notation

Parameter names can have dots, and Smarty will interpret them as associative arrays so that you can use foreach with both key and item attributes to traverse through them, or you can just use the same name with dots if you want to reference the parameter directly.

Example

Widget:AssocTest might look like this:

<includeonly><ul>
<!--{foreach from=$arg key=key item=item}-->
   <li><!--{$key|escape:'html'}-->: set to <!--{$item|escape:'html'}--></li>
<!--{/foreach}-->
</ul></includeonly>

...and you might call this Widget as follows:

{{#widget:AssocTest|arg.foo=bar|arg.bar=oni}}

..which would be displayed as:

• foo set to bar
• bar set to oni

Validate modifier

In addition to standard Smarty modifiers (like the heavily used escape), the Widgets extension implements the validate modifier, that uses PHP Data filtering to allow for validating widget parameters. Validating a parameter is not a replacement for escaping a parameter. You should still use an escape modifier even when validating. The following values for the validation are supported (mapping to PHP's validation filters):

• url — Validate as URL. This allows only URL schemes listed in $wgUrlProtocols , and, unlike PHP validation, does not allow URLs with characters dangerous in HTML.
• url-php (FILTER_VALIDATE_URL) — Warning: Validating as a URL still allows JavaScript URLs that can lead to XSS. It also allows URLs containing characters that are unsafe in HTML.
• int (FILTER_VALIDATE_INT) — Validates value as an integer, optionally from the specified range, and converts to int on success.
• boolean or bool (FILTER_VALIDATE_BOOLEAN) — Returns true for "1", "true", "on" and "yes". Returns false otherwise.
• float (FILTER_VALIDATE_FLOAT) — Validates value as float, optionally from the specified range, and converts to float on success.
• email (FILTER_VALIDATE_EMAIL) — Warning: Valid email address can still contain characters that are unsafe in HTML, be sure to escape in addition to validating
• ip (FILTER_VALIDATE_IP) — Validates value as IP address, optionally only IPv4 or IPv6 or not from private or reserved ranges.
• domain (FILTER_VALIDATE_DOMAIN) — Warning: Valid domains can still contain characters that are unsafe in HTML, be sure to escape in addition to validating.
• mac (FILTER_VALIDATE_MAC) — Validates value as MAC address.

Undefined parameters

If the widget expects a parameter but that parameter remains undefined in the parser function, a PHP error will be thrown. They're hidden by default, but if they're visible on your wiki, it might say something like Attempting to read property "value" on null in [...]. One way to prevent an error from showing despite undefined parameters is to add default:'' to widget parameters that are at risk of remaining undefined. For an example, see param2 below:

<a href="<!--{$param1|escape:'url'}-->" class="<!--{$param2|default:''|escape:'html'}-->"><!--{$param3|escape:'html'}--></a>

Refreshing a widget page

If you're using a call to the widget within the widget page itself, then you will not see the updated widget (and no widget at all when you just created a page). This happens because the page contents are not available to the Widgets extension until a page is saved, but the call to the {{#widget}} parser function is made before the page is saved. After saving the page, it's cached by MediaWiki, so you won't see the result even if you reload it via the browser. To make the latest edits to the widget code appear, you need to refresh the page in the cache; to do this, you need to use the Purge action (see also Purge extension), or wait a certain amount of time (up to 24 hours).

Widgets and templates

Placing widgets within templates makes them an invaluable tool for creating complex displays of data with minimal lines of code.

It is particularly helpful if you want to preset some parameters of the widget while allowing users to modify others (e.g. video ID for the YouTube widget or username for the Twitter widget).

Authors

The widgets extension was created and designed by Sergey Chernyshev. It is currently maintained by Yaron Koren, who has also contributed to the code base.

Other important contributions have been provided by Alexandre Emsenhuber, Jeroen De Dauw, Joshua Lerner, Majr, Sam Reed and Tim Starling.

Version history

The Widgets extension is currently at version 1.6.0. See the entire version history.

Contributing Widgets

If you created a widget and would like to share it, feel free to post it to MediaWikiWidgets.org website and to add a reference to it to the Widget library on this page.

Bugs and feature requests

If you found a problem, would like to contribute a patch or request a new feature, feel free to open a bug in the Wikimedia bug tracker:

https://phabricator.wikimedia.org/maniphest/task/create/?projects=MediaWiki-extensions-Widgets

Troubleshooting

There are a few common problems that users encounter when they start to use Widgets extension - we'll try to document them here:

• On a widget page, right after you just created it (or copied from MediaWikiWidgets.org), you see the message:

Warning: Smarty error: unable to read resource: "Widget:<your-widget-name>" /../extensions/Widgets/
smarty/Smarty.class.php on line 1095

This is most likely caused by the widget not yet existing at the moment when the widget page itself is being processed - to solve this purge the page, e.g., add &action=purge (or ?action=purge if you have nice URLs) to the URL.

It's also possible that you called the Widget incorrectly. Widget page names are case sensitive and must match the name of the widget you're calling. E.g. don't use {{#widget:Youtube|...}} when the widget is called "Widget:YouTube", or vice versa.

• If the page doesn't load and you see the following error message in the log file:

PHP Fatal error:  Smarty error: unable to write to $compile_dir '/../extensions/Widgets/compiled_templates'.
Be sure $compile_dir is writable by the web server user. in /../extensions/Widgets/smarty/Smarty.class.php on line 1095,
referer: https://your-wiki.com/Widget:<your-widget-name>

Check if you changed permissions and owner for Smarty to store compiled templates in. See also this post for further details.

• If your wiki began returning white pages or 500 errors when you updated MediaWiki to 1.20 or a later version, try setting the permissions on /../extensions/Widgets/compiled_templates to 777.

Widget library

MediaWikiWidgets.org contains a full library of ready-made widgets, including support for most of the major video sites. Any widget can be used simply by copying over the page's contents.

To get the most up-to-date list of widgets by purpose, e.g., social media, video, images, etc. click here.

Extensions that can be replaced with widgets

Let's collect a list of extensions that can be replaced with widgets because all they do is output some HTML/JS/CSS with parameters and simple logic that can be done using Smarty templates.

Maybe someone will create a widget to simplify deployment. Also, these lists of extensions are a good source for action:

• Extension:YouTube
• Extension:PDFEmbed

Frequently asked questions

How do I get a video to align to the right with the other images?

Use something like this. Note that the ‎<br /> line break tags will have to be added manually. 180px is used for width because that is the default for thumbnails. 150px is used for height because that keeps the same ratio as the default 350x420.

<div class="thumb tright">
<div class="thumbinner">
{{#widget: YouTube |width=180px |height=150px |id=qRhitIPEr0Y }}<br>
<div class="thumbcaption">
Seeing bad acting sully a good<br>
script can upset some people<br>
who place a high value on<br>
natural-seeming performances.<br>
</div>
</div>
</div>

See also

• HTML restriction - list of extensions that allow for the inclusion of raw HTML