Help:Macro

From QED

The #macro parser function is intended for use in templates in which template variables must be expanded before XML-style tags are processed.

Syntax

{{#macro:TAGNAME|TEXT}}

or

{{#macro:TAGNAME|ASSIGNMENTS|TEXT}}

The effect is as though <TAGNAME ASSIGNMENTS>TEXT</TAGNAME> had been specified after any template variables in TAGNAME and ASSIGNMENTS had been expanded.

Example

On QED, <image> is defined as an XML-style tag (see QED:image). If template variables were expanded before such tags, we would be able to write expressions such as:

<image src={{{1}}} width={{{width|{{{3|450}}}}}}>{{{2|}}}</image>

To achieve the intended effect, we would instead write:

{{#macro:image|src={{{1}}}
 width={{{width|{{{3|450}}}}}}
 | {{{2|}}} }}

This is in fact how Template:Transclude is defined.

Notes

Prior to MediaWiki version 1.12, template variables were processed before XML-style extensions.