Module:Unsubst
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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". A parameter "$N" may also be seen in some templates; this was required in an older version of the module, but is no longer necessary and may be removed. Such templates are automatically placed in Category:Calls to Module:Unsubst that use $N (1).
All other parameters passed to the #invoke will be copied to the generated template invocation as default values. If the value of any of these default parameters is "__DATE__", that value in the generated template invocation will be the current month and year.
Some templates have a <noinclude> but no matching </noinclude> at the end of the template. In such cases the missing </noinclude> must be added before the ending }}.
Example
Consider a template Template:Example containing the following code:
{{ {{{|safesubst:}}}#invoke:Unsubst||foo=bar |date=__DATE__ |$B=
[ ... Template code goes here ... ]
}}
| Original | Result |
|---|---|
| {{subst:example}} | {{Example|foo=bar|date=December 2024}} |
| {{subst:example|foo=X}} | {{Example|foo=X|date=December 2024}} |
| {{subst:example|baz=X}} | {{Example|foo=bar|baz=X|date=December 2024}} |
| {{subst:example|date=January 2001}} | {{Example|foo=bar|date=January 2001}} |
local p = {}
local specialParams = {
['$N'] = 'template name', -- Deprecated, but keeping until it is removed from transcluding templates
['$B'] = 'template content',
}
p[''] = function ( frame )
if not frame:getParent() then
error( '{{#invoke:Unsubst|}} makes no sense without a parent frame' )
end
if not frame.args['$B'] then
error( '{{#invoke:Unsubst|}} requires parameter $B (template content)' )
end
if mw.isSubsting() then
---- substing
-- Combine passed args with passed defaults
local args = {}
for k, v in pairs( frame.args ) do
if not specialParams[k] then
if v == '__DATE__' then
v = mw.getContentLanguage():formatDate( 'F Y' )
end
args[k] = v
end
end
for k, v in pairs( frame:getParent().args ) do
args[k] = v
end
-- Build an equivalent template invocation
-- First, find the title to use
local titleobj = mw.title.new(frame:getParent():getTitle())
local title
if titleobj.namespace == 10 then -- NS_TEMPLATE
title = titleobj.text
elseif titleobj.namespace == 0 then -- NS_MAIN
title = ':' .. titleobj.text
else
title = titleobj.prefixedText
end
-- Build the invocation body with numbered args first, then named
local ret = '{{' .. title
for k, v in ipairs( args ) do
if string.find( v, '=', 1, true ) then
-- likely something like 1=foo=bar, we need to do it as a named arg
break
end
ret = ret .. '|' .. v
args[k] = nil
end
for k, v in pairs( args ) do
ret = ret .. '|' .. k .. '=' .. v
end
return ret .. '}}'
else
---- Not substing
-- Just return the "body"
return frame.args['$B'] .. (frame.args['$N'] and frame:getParent():getTitle() == mw.title.getCurrentTitle().prefixedText and '[[Category:Calls to Module:Unsubst that use $N]]' or '')
end
end
return p