Help:Reference Previews

The Reference Previews feature shows a preview of a footnote when you hover over its footnote marker. This feature is part of the MediaWiki extension, which is used for. It's currently a default feature on some wikis and a beta feature on many other wikis.

Background
The Reference Previews feature aims to fulfill a wish from the German-speaking community's Technical Wishlist and is developed by WMDE's Tech team, with support from the WMF’s Reading Web team. The design for this feature is being developed by the WMF. More information can be found on the main project page on Meta.

Overview
Reference Previews display a preview of the footnote as it appears at the bottom of the page. Within the preview, any and all footnote content (text, images, tables, …) can be displayed. At the top of the pop-up, the reference type is displayed. Reference Previews were designed to create an experience consistent with Page Previews, so that all pop-ups have the same design, regardless of whether you are hovering over a page link or a footnote marker.

Interactions
 * Hover over a footnote marker to open the pop-up.
 * Click on a footnote marker to jump to the References section (as you would do if there weren't any pop-ups).
 * For shorter references, the pop-up window adjusts to a smaller size.
 * If the reference size exceeds the maximum pop-up, you can scroll within the preview window.
 * External links inside a reference open in a new tab.

The preview functionality relies on JavaScript. If you don't have JavaScript activated, there is no hover effect, and footnote markers remain simple jump marks.

Opt-out feature
Reference Previews will be activated by default for everyone (logged-in users, logged-out/anonymous users, readers of a wiki).


 * You can toggle them off under the Appearance tab in your preferences.
 * You can also open this preference tab directly by clicking on the cog wheel in the pop-up.
 * Anonymous users/logged-out users/readers can turn the previews off by clicking the cog wheel and toggling the setting. This saves the preference via a cookie. They can be turned back on using the “Edit preview settings” link in the website footer.

Please note:


 * If you use the Reference Tooltips or Navigation Popups gadget – either because it’s a default gadget on your wiki or because you enabled it individually – you won’t see Reference Previews.
 * For wikis where Reference Previews are still a beta feature, you need to activate it in your beta settings.

Exposed reference types
At the top of each pop-up, Reference Previews prominently indicate what kind of source is being referenced. We currently define six reference types:


 * Reference (generic)
 * Web reference
 * Journal reference
 * Book reference
 * News reference
 * Note

How to assign a reference type to your reference
Each reference is defined by CSS classes, e.g., for journal references. These classes are set in the element in a reference's content. References without cite tags and classes (e.g., plain tags) are displayed as "Reference".

To assign a reference type:


 * The easiest way is to use a citation template that includes the  class. The English   templates, for example this one, specify the   class already, and derivations of these templates are used in many wikis. Other templates can also be updated to do so.
 * If you're not using templates to add references, another option is to add a  class directly into a   tag, like so:.

Deployment roadmap

 * ✅ test.wikipedia.org : 2019-02-28
 * beta feature on :
 * ✅ German Wikipedia: 2019-04-04
 * ✅ Arabic Wikipedia: 2019-04-04
 * all wikis that use the Popups extension (all Wikipedias & en, he and zh Wikivoyages): 2019-10-24
 * default feature:
 * ✅ German, Romanian, Estonian, Basque, Arabic, Hebrew, Gujarati, and Finnish Wikipedia: 2021-05-06
 * ✅ Marathi Wikipedia: 2021-05-10

Links

 * extension manual on MediaWiki.org

Reference Previews


 * project board on Phabricator


 * main project page on Meta


 * central feedback page on MediaWiki.org

Page Previews


 * main project page on MediaWiki.org


 * central feedback page on MediaWiki.org

Help with translation
The software messages for this feature can be translated on translatewiki.net. Any help is much appreciated!