Manual:Extending wiki markup

MediaWiki provides a standard text markup that can be easily customized. Extensions can customize wiki markup by:

• Adding standard token types – The standard approach to customized MediaWiki markup is to add new markup that looks like the built-in MediaWiki XML tags (<tag>), template ({{...}}), or link markup ([[...]]).
• Adding custom token types – Some extensions define new token types.
• Making fundamental changes to the parser – A few extensions attempt to fundamentally change the parsing strategy so that other markup languages can be used instead of the standard wiki markup.

The simplest way to extend wiki markup is by adding to a standard token type using one of these features.

A variable calls a PHP function that outputs a string of Wikitext that replaces the variable on the page. Variables are usually used to insert system information into wiki markup, such as the current time or the current page.

Syntax example:

{{VARIABLENAME}}

To define a variable, see Manual:Variables . For a list of extensions that define custom variables, see Category:Variable extensions .

Like variables, a parser function calls a PHP function and outputs a wikitext string that replaces the parser function on the page. Unlike variables, a parser function can pass parameters to the PHP function. Parser functions are used to handle wikitext generation that involves logic that is too complex or confusing to write using templates.

Syntax example:

{{#functionname: param1 | param2}}

To define a parser function, see Manual:Parser functions . For a list of extensions that define custom parser functions, see Category:Parser function extensions .

Unlike variables and parser functions, which output wikitext, parser tags output HTML. A parser tag is an XML tag that calls a PHP function, parses the contents of the tag, and outputs HTML that replaces the tag and its contents on the page. Parser tags can also pass arguments to the PHP function. For example, ‎<syntaxhighlight> is a parser tag defined by Extension:SyntaxHighlight .

Syntax example:

<tagnameparam1name="param1value"param2name="param2value">sometext</tagname>

To define a parser tag, see Manual:Tag extensions . For a list of extensions that define custom parser tags, see Category:Tag extensions .

A behavior switch calls a PHP function, but, unlike other methods of extending wiki markup, behavior switches usually do not output any content. Instead, they change the behavior of the page or set a page property. For example, adding __NOTOC__ to a page hides the table of contents.

Syntax example:

__SWITCHNAME__

To define a behavior switch, see Manual:Magic words . For a list of extensions that define custom behavior switches, see Help:Magic words .

Link markup customizations change the way MediaWiki interprets internal links.

Syntax example:

[[ ... ]]

For a list of extensions that define custom link markup, see Category:Link markup extensions .

To add new token types or to change the entire markup strategy, implementers need to add functions to one or more of the various parser and page output hooks:

• Category:ParserBeforeStrip extensions rely on the ParserBeforeStrip hook. (removed in 1.36)
• Category:ParserBeforeInternalParse extensions rely on the ParserBeforeInternalParse hook.
• Category:OutputPageBeforeHTML extensions rely on the OutputPageBeforeHTML hook.
• Category:ParserAfterTidy extensions rely on the ParserAfterTidy hook.

See also Category:Extensions by hook usage .

• Manual:Extensions - provides general instructions for finding, installing, and writing extensions.

• Parser extensions
• Customization techniques