Template:Ifempty/doc

Description

This is the {{ifempty}} template.

This template is used inside other templates. It takes up to nine parameters (parameters 1-9), and returns the first one that is defined and non-empty, otherwise nothing. Typical usage is like this:

{{ifempty | {{{logo|}}} | {{{image|}}} | default.svg}}

This returns the first of the parameters logo and image that is defined and non-empty, otherwise "default.svg".

Background

The MediaWiki parameter default function doesn't return the default value for empty parameters. That is, {{{logo|default.svg}}} does not return "default.svg" if the template was called like this: {{template|logo=}}.

The usual workaround is to do like this:

{{#if: {{{logo|}}} | {{{logo}}} | default.svg}}

But this becomes complex when you want to check several parameters:

{{#if: {{{logo|}}} | {{{logo}}} | {{#if: {{{image|}}} | {{{image}}} | default.svg}}}}

Then it is easier to use this template instead:

{{ifempty | {{{logo|}}} | {{{image|}}} | default.svg}}

Note! The parameters to {{ifempty}} must use the pipe "|", like this: {{{logo|}}}. Or else {{ifempty}} will be fed and return the string "{{{logo}}}" if logo was not defined.