From HGWiki

Documentation

Purpose and Function

Provides if then else functionality.

• Parameter else is optional.
• This template has undefined behaviour, if parameter test or then (or both) are missing.
• This template also has undefined behaviour, if any parameter (be it named or unnamed) that is different from test, then or else is defined when calling the template.

Note that {{qif}} does not work when subst'ed (like {{ifndef}}, the then part alone as in {{ifdef}} can be substituted). Of course it's impossible to use vertical bars in parameter values directly, use either | or {{!}} - the latter is only relevant for Wiki table delimiters.

Usage

{{qif
  |test=VARIABLE_OR_PARAMETER_TO_TEST
  |then=code if 'test' is not empty
  |else=code if 'test' is empty
}}

Parameter else is optional. So you may also do:

{{qif
  |test=VARIABLE_OR_PARAMETER_TO_TEST
  |then=code if 'test' is not empty
}}

Example

{{qif
  |test={{boolne|foo|bar}}
  |then=true
  |else=false
}}

{{qif
  |test={{booleq|foo|bar}}
  |then=true
  |else=false
}}

{{qif
  |test=
  |then=bar
}}

{{qif
  |test=foo
  |then=bar
}}