Extension:RevisionSlider

MediaWiki extensions manual

RevisionSlider Release status: stable
Implementation	User interface
Description	Adds a slider interface to the diff view allowing to easily move between revisions
Author(s)	Wikimedia Germany (WMDE)
Compatibility policy	Snapshots releases along with MediaWiki. Master is not backward compatible.
MediaWiki	1.25+
Database changes	No
License	GNU General Public License 2.0 or later
Download	Download extension Git [?]: Download Git master browse repository (GitHub) commit history repository contributors (GitHub) code review
Hooks used DifferenceEngineViewHeader GetPreferences
Translate the RevisionSlider extension if it is available at translatewiki.net
Check usage and version matrix.
Issues	Open tasks · Report a bug

The RevisionSlider extension adds a slider interface to the diff view, so that you can easily move between revisions.

Installation

• Download and place the file(s) in a directory called RevisionSlider in your extensions/ folder.
• Add the following code at the bottom of your LocalSettings.php:

  wfLoadExtension( 'RevisionSlider' );
  

•  Done – Navigate to Special:Version on your wiki to verify that the extension is successfully installed.

Usage

	When on a diff page, the slider is collapsed by default and only a narrow bar labelled "Browse history" is visible at the top of the page. Click on that bar to expand the RevisionSlider.
	Once expanded, the RevisionSlider fetches data about the revisions and allows you to navigate and compare revisions on the diff page.
	Each bar represents a page revision. Bars on the top show growth in size of the page, bars on the bottom show a reduction. In the image, revision 1 represents added content, while revision 2 represents removal of content.
	To select the revisions you want to compare, use the yellow and blue knobs. The blue knob controls the newer revision, the yellow knob maps to the older revision. There are several ways to do this: You can drag and drop the knob to the desired position on the slider. You can click on the desired position on the slider line. To select the newer revision, click on the blue line, and for selecting the older revision, click on the yellow line. To indicate which revision you're about to select, a preview of a blue or yellow knob appears and the bar turns blue or yellow. You can click into the bar above the middle line (to select the newer revision) or below the line (to select the older revision). This also gives you a preview of the knob on the middle line. If you move the blue knob to a position left of the yellow knob, the yellow knob is automatically moved along, and vice versa if you move the yellow knob to a position right of the blue knob.
	Use the backward and forward arrows to move through revision history and show older and newer revisions.

Opt-out

If you are not using the RevisionSlider at all and also don't want to see the collapsed RevisionSlider bar at the top of the diff page, you can opt-out by checking Don't show the RevisionSlider in your preferences under Appearance -> Diffs.

Technical Background

JavaScript Hooks

The RevisionSlider uses AJAX to reload the diff page when new revisions are selected. Once the page has been reloaded both the wikipage.content and wikipage.diff hooks are fired. If user JavaScript or extension JavaScript acts on the diff page you may need to listen to these hooks.

Examples

• The Thanks extension https://phabricator.wikimedia.org/rETHA0b241d4d296f488dc7d3a1f4260aa0e426b2d7f5#1493b925
• The English Wikipedia wikEdDiff gadget https://en.wikipedia.org/w/index.php?diff=741585034&oldid=630494053&title=User:Cacycle/wikEdDiff.js

API calls & fetching data

Unless expanded, the tool is not doing any API calls. Only when the user expands the slider, it fetches data about revisions (revision-id, timestamp, user, comment, size and flags). The tool only fetches data for revisions that are currently visible on the screen (maximum 500 revisions) and data about additional revisions is only loaded when the user navigates back or forth on the timeline using the arrows.

Background

The RevisionSlider is a feature to fulfill one of the top wishes of the German Community wishlist and is developed by WMDE's TCB team. It is inspired by DerHexer's revisionjumper gadget and based on a prototype by the WMF Community Tech team.

Notes (for rather technical audience) on RTL issues discovered while developing the extension have been published on the separate subpage.