Working With MediaWiki

hard-coded to one language: if someone is viewing your wiki and has another language specified in their user preferences, they’ll normally see the entire interface in their language. But any messages that you modify will show up as that exact text to everyone, regardless of their language. (Whether it’s useful to view a wiki’s interface in one language if all the content is in another language, is a separate issue). But you can in fact set translations at the same time that you set a new value; that’s covered in the next section.
    The most common usage of this functionality is to modify the sidebar. The sidebar, as odd as it sounds, is represented by a single "message". Here is the default value of the sidebar in the English language, in MediaWiki 1.20:
* navigation
** mainpage|mainpage-description
** portal-url|portal
** currentevents-url|currentevents
** recentchanges-url|recentchanges
** randompage-url|randompage
** helppage|help
* SEARCH
* TOOLBOX
* LANGUAGES
    The last three lines are standard elements that have special handling, so their connection to the display is not obvious, but Figure 13.1 shows how that appears in the sidebar within the standard Vector skin (and with the Semantic MediaWiki extension installed, which adds the “Browse properties” link).
    Figure 13.1 Default sidebar display, in the Vector skin, with Semantic MediaWiki installed
    The structure is fairly simple: a single asterisk indicates a section header, while two asterisks indicate an item within that section. Each item can be thought of as a MediaWiki link: it can either be a single string, in which case the link text and the linked page are the same, or it can be two strings separated by a pipe, with the first string as the page being linked to and the second, the link text. The only difference between the strings in the sidebar and regular MediaWiki links is that strings in the sidebar can be (and often are) language messages themselves. Note the "recentchanges" string in the sidebar, for instance: when displaying the sidebar, the system searches for a language value for "recentchanges" — it finds it ("Recent changes"), and substitutes that in. If no value had been found, the text "recentchanges" would simply have appeared as is.
    Another popular usage of this functionality is to change the copyright text in the edit page, at MediaWiki:copyrightwarning. By default it looks like:
Please note that all contributions to {{SITENAME}} are considered to be released under the $2 (see $1 for details). If you do not want your writing to be edited mercilessly and redistributed at will, then do not submit it here.
You are also promising us that you wrote this yourself, or copied it from a public domain or similar free resource. '''Do not submit copyrighted work without permission!'''
    Whenever you see values like $1, etc., it means that they’re placeholders to be filled in by the PHP code that displays those messages. In the case of the copyright warning, the values $1 and $2 are filled in with values derived from a combination of various global variables, settable in LocalSettings.php: $wgRightsPage, $wgRightsText and $wgRightsUrl.
    How can you find out the name of a certain message? Since version 1.18, MediaWiki has offered a clever way to do it — if you add "?uselang=qqx" to the URL of any page in the wiki (or "&uselang=qqx", if there was already a question mark in the URL), it will show the name of every message, in place of the value. So all you have to do to find the name of a message is go to a page that contains that message, add the "uselang=qqx" to the URL, and see what shows up in place of that message.
    A special page, "Special:AllMessages", also exists, that shows the full set of message names and their values in the wiki’s current language.
    Deleting a message page will revert that message back to its original value.
Customizing the site’s CSS and JavaScript
    Some pages in the MediaWiki namespace are used for something other than defining interface text: adding additional JavaScript and CSS to the wiki’s pages. The most important of these are MediaWiki:Common.css and MediaWiki:Common.js. MediaWiki:Common.css contains CSS that is applied to every page in the wiki. Very often, this file is used to define ’prettytable’ and ’wikitable’, two CSS classes that are usually defined as synonyms of one another, used to make tables look nicer than the HTML default (MediaWiki skins rarely apply any special