Extension:Semantic Rating

The Semantic Rating extension adds three parser functions to display a star rating:


 * #rating: displays a rating inline
 * #ratingBeforeTitle: displays a rating to the left of the title at the top of the page
 * #ratingAfterTitle: displays a rating to the right of the title at the top of the page

The parser functions are capable of displaying empty (gray), full (yellow), and half stars.

By default, the #ratingBeforeTitle and #ratingAfterTitle parser functions will insert the rating in the title at the top of a page for any skin that puts the title in an HTML element with id   such as the default Vector skin. This can be changed for other skins using the  configuration variable. This approach can also be used to have the rating appear at other places in the page by using a  and appropriate choice of.

Special thanks to Bernadette Clemente for the original idea that inspired this extension and to Kelly Hatfield for an early implementation of this extension.

Installation
This extension requires Semantic MediaWiki and Semantic Forms to be installed first.

Version 4.0

 * Removed form input, since it is now part of the Page Forms extension

Version 3.0

 * Removed use of inline JavaScript that caused issues in MediaWiki 1.26
 * Converted to new extension registration style
 * Removed support for old style i18n and extension registration
 * Renamed configuration variables with $wg prefix to support new extension registration format

Version 2.2.1

 * Minor changes: improved coding style, several internal tweaks, license to show on "Special:Version"

Version 2.2

 * Added  and updated coding style.

Displaying a Rating
The following displays a 3 star rating inline using the default maximum number of stars:

If the default maximum is 5, it will display 3 yellow stars and 2 gray stars. If the default maximum is 10, it will display 3 yellow stars and 7 gray stars.

To explicitly set the maximum number of stars to 10, use the following:

To display the rating at the top of the page with the page title instead, use (again with an optional maximum value):

or

Displaying a Rating Using a Template Parameter
For the form field defined in the example above, the value of the rating will be passed into the template associated with the form field as a named parameter. Because the form field is given the name Rating, that will be the name of the paramter as well. Therefore, in the template, the rating can be displayed as:

Displaying the Result of a Semantic Query as a Five Star Rating
Below are several more advanced examples that illustrate how this extension can be used with Semantic MediaWiki.

Consider the case where users can review a wiki page. In this example, each review is itself a wiki page in category Reviews. Each review page has a property, Item, that is a link to the page being reviewed. Each review page also has a property, Rating, that has a value between 1 and 5 (with 0 being reserved for the case where no rating is assigned).

On the page being reviewed, the page's average rating can be displayed by the following query:

Further, assume that each page being reviewed has a property, Author, pointing to a page for the author of the page being reviewed. On the author's page, using the ParserFunctions and Arrays extensions, the average rating for all pages authored by that author (an average of the average page ratings) can be displayed by the following: