Lua code for inside of another template (e.g., an infobox). Creates a compact list out of a set of named arguments. For example, if the argument to this module is "foo", it searches for all arguments named "foo" followed by an optional underscore followed by one or more digits. It then assembles all of the named argument into a "pretty printed" list, in numerical order. If the list is short (<= 4 long), the module uses {{hlist}} to print in the "A·B·C·D" format. If it is long, it will use {{collapsible list}}. The threshold can be set with |_limit=.

Typical usage in a parent template, which gathers all arguments named "foo":

{{#invoke:Compact list|main|foo|_limit=4}}

Note: these examples have the named arguments passed to the module directly. In practice, these named arguments would be passed to the template that invokes the module.

{{#invoke:Compact list|main|ook|ook=A|spud=1234}} → A

{{#invoke:Compact list|main|ook|ook1=A|ook_2=B}}

  • A
  • B

{{#invoke:Compact list|main|ook|ook=A|ook1=B|ook2=C|ook3=D}}

  • A
  • B
  • C
  • D

{{#invoke:Compact list|main|ook|ook1=A|ook5=B|ook20=C|ook3000=D|ook342345=E|foofoofoo=234}}

List
  • A
  • B
  • C
  • D
  • E

{{#invoke:Compact list|main|ook|ook1=A|ook5=B|ook20=C|ook3000=D|ook342345=E|foofoofoo=234|_limit=5}}

  • A
  • B
  • C
  • D
  • E

{{#invoke:Compact list|main|ook|ook=A|ook1=B|ook2=C|ook3=D|ook4=E|ook5=F|ook6=G}}

List
  • A
  • B
  • C
  • D
  • E
  • F
  • G

local getArgs = require('Module:Arguments').getArgs
local clist = require('Module:Collapsible list').main
local hlist = require('Module:List').horizontal
local compressSparseArray = require('Module:TableTools').compressSparseArray
local p = {}

--[[
Combine named-and-numbered arguments into a pretty list.
"Named-and-numbered" means foo, foo0, foo_1, foo234: anything that matches foo_?%d+

Arguments:
  args[1] = name to search arguments
  rest of args = arguments to search
Returns:
  Pretty list, in order of argument number.
  "foo" comes first, then "foo0", "foo1", ... "fooN"
  The argument numbering does not have to be sequential
  
  If number of args that match <= args[_limit] (4 default),
     returns text list of the form "A, B, C and D"
  otherwise returns collapsible list ({{clist}})
--]]
function p._main(args)
	local pattern = "^"..args[1].."_?(%d+)$"  -- pattern to match
	local values = {}
	for k, v in pairs(args) do  --- loop through all arguments
		if k == args[1] then    --- if argument is just "foo", put it first
			values[1] = v
		else
			ord = tonumber(mw.ustring.match(k,pattern)) --- if "foo_?%d+", extract number
			if ord then
				values[ord+2] = v  --- put value into list at number+2 (to keep "foo" first, even for foo0)
			end
		end
	end
	values = compressSparseArray(values)  --- squeeze out gaps/nils in values, keep ordering
	local limit = tonumber(args._limit) or 4
	if #values == 0 then
		return ''
	end
	if #values == 1 then
		return values[1]
	end
	if #values > limit then
		return clist(values)   --- if longer than limit, call Module:Collapsible list
	end
	return hlist(values) --- otherwise create horizontal list
end

function p.main(frame)
	local args = getArgs(frame)
	return p._main(args)
end

return p