Module:Unsubst/doc
This is the documentation page for Module:Unsubst
 | This Lua module is used on 2,200,000+ pages, or roughly 40696% of all pages. To avoid major disruption and server load, any changes should be tested in the module's /sandbox or /testcases subpages, or in your own module sandbox. The tested changes can be added to this page in a single edit. Consider discussing changes on the talk page before implementing them. |
Helper module to facilitate a substituted template transform into a template transclusion.
Maintenance templates, such as {{Citation needed}} or {{Refimprove}}, should never be substituted. A trick to avoid that is to make a template substitute to its transcluded form.
Usage
To turn a template into a self-substituting template, wrap the existing template code with:
{{ {{{|safesubst:}}}#invoke:Unsubst||$B=
[ ... existing template code ... ]
}}
The wikitext to display when not substed must be given as "$B". All other parameters passed to the #invoke will be copied to the generated template invocation as default values. If the value of any of these default parameters is "__DATE__", that value in the generated template invocation will be the current month and year.
Some templates have a <noinclude> but no matching </noinclude> at the end of the template. In such cases the missing </noinclude> must be added before the ending }}.
Advanced
{{ {{{|safesubst:}}}#invoke:Unsubst||$params=[ parameters ]|$aliases=[ aliases ]|$flags=[ flags ]|$B=
[ ... existing template code ... ]
}}
Due to Lua limitations, parameters are normally ordered randomly when the template is substituted. |$params= can be used in #invoke:Unsubst to list template parameters in order, comma-separated (e.g. egg,bacon,sausage,cheese,spam). Numbered parameters should be before others in the list. Any remaining parameters are tacked onto the end of the generated invocation.
Parameter aliases can be listed in |$aliases= (and shouldn't be listed in |$params=), and will be replaced automatically. Each alias and its replacement should be formatted as alias>replacement, and each of those pairs should be comma-separated (e.g. œuf>egg,melt>cheese). Note that this parameter can function with or without |$params=.
Parameter |$flags= can be used to modify other facets of the module's behaviour; entries are comma-separated. Valid flags are override (allows parameters in the #invoke: to take precedence over parameters in the original template invocation); keep-whitespace (prevents whitespace from being trimmed from unnamed parameters); and remove-empty (removes empty parameters).
Example
Consider a template Template:Example containing the following code:
{{ {{{|safesubst:}}}#invoke:Unsubst||foo=bar |date=__DATE__ |$B=
[ ... Template code goes here ... ]
}}
| Original | Result |
|---|---|
| {{subst:example}} | {{Example|foo=bar|date=May 2024}} |
| {{subst:example|foo=X}} | {{Example|foo=X|date=May 2024}} |
| {{subst:example|baz=X}} | {{Example|foo=bar|baz=X|date=May 2024}} |
| {{subst:example|date=January 2001}} | {{Example|foo=bar|date=January 2001}} |
