Extension:Gadgets

The Gadgets extension provides a way for users to pick JavaScript or CSS based "gadgets" that other wiki users provide.

Gadgets are made up of JavaScript and/or CSS snippets located on pages in the MediaWiki namespace. Each gadget is defined by a line in MediaWiki:Gadgets-definition, providing a name and description for the gadget, and a list of the JS and CSS snippets that it uses (see the Usage section below).

Since Gadgets reside in the MediaWiki namespace (the list defining the gadgets as well as the actual code snippets), only sysops (aka wiki admins) can edit the code. This is as should be: only users especially trusted by the wiki community should be able to edit JavaScript code that is used by other users, since JavaScript can easily be used to hijack accounts or spy on people.

Installing
Copy the Gadgets directory into the extensions folder of your MediaWiki installation. Then add the following lines to your LocalSettings.php file (near the end):

Usage
The list of available gadgets is defined on MediaWiki:Gadgets-definition. Gadgets defined there show up in the "Gadgets" section of Special:Preferences, so users can pick the gadgets they would like to use. An overview of the gadgets defined by MediaWiki:Gadgets-definition is also shown on Special:Gadgets, along with links to the respective system messages, for easy editing.

Each line in MediaWiki:Gadgets-definition that starts with one or more "*" (asterisk) characters defines a gadget; it must have the following form:

* mygadget|mygadget.js|mygadget.css

That is, each line consists of fields separated by a "|" (pipe) character. The first field ("mygadget" in the example) is the gadgets internal name, and references a system message (MediaWiki:Gadget-mygadget in the example) that contains a short description of the gadget, using wiki syntax.

The internal name must start with a ASCII letter, and must contain only ASCII letter and numbers!

The remaining fields on the line refer to the JavaScript or CSS code that makes up the gadget, contained in system messages (MediaWiki:Gadget-mygadget.js and MediaWiki:Gadget-mygadget.css in the example); the names of those messages must end with ".js" or ".css", respectively. A gadget can use any number of code messages, specifically, common code can be put into a code message used by several gadgets, in addition to their own specific code, e.g:

* frobinator|commonStuff.js|frob.js|frob.css|pretty.css * l33t|commonStuff.js|tools.js|l33t.js

The list of gadgets in MediaWiki:Gadgets-definition can be broken into sections using lines that start and end with two or more "=" (equals) characters, enclosing the name of a system message that defines the section's name - for example:

== editing-gadgets ==

This would define a new section, with the title defined on the page MediaWiki:Gadget-section-editing-gadgets

Caveats

 * Requires MediaWiki 1.11alpha, 24477 or later.
 * Gadgets do not apply to Special:Preferences, so users can always disable any broken gadgets they may have enabled.
 * Uses BeforePageDisplay hook, thus only works with MonoBook based skins;  specifically, does not work with CologneBlue.
 * Gadget code is included after user code - that means that user JS has no  access to things defined in gadgets, and user CSS is overwritten by CSS   from gadgets. (pending a better way to insert things into the HTML head, see 10184)
 * MediaWiki:Gadgets-definition is parsed for every page request by a logged in user. It would be nice to make the MessageCache more flexible, so it can store  a parsed version of the MediaWiki:Gadgets-definition. uses $wgMemc now.
 * on Wikimedia wikis you need to edit MediaWiki:Gadgets-definition twice in order to add a new entry/remove an entry from the resulting "Gadgets" tab in Special:Preferences, see 12128.