Module:Subject bar

 require('strict')

 local getArgs = require('Module:Arguments').getArgs
 local yesNo = require('Module:Yesno')

 -- Determine whether we're being called from a sandbox
 local isSandbox = mw.getCurrentFrame():getTitle():find('sandbox', 1, true)
 local sandbox = isSandbox and '/sandbox' or ''

 local p = {}

 local sisters = {'commons','species','voy','n','wikt','b','q','s','v','iw','iw1','iw2','d','f'}

 local function findNumericArgs(key, args)
	local pattern = "^"..key.."_?(%d+)$" -- pattern to match
	local values = {}
	for k, v in pairs(args) do --- loop through all arguments
		local ord = tonumber(mw.ustring.match(k,pattern)) --- if "foo_?%d+", extract number
		if ord then
			values[ord] = v
		end
	end
	if args[key] ~= nil then
		values[1] = args[key]
	end
	local compressSparseArray = require('Module:TableTools').compressSparseArray
	values = compressSparseArray(values) --- squeeze out gaps/nils in values, keep ordering
	return values
 end

 function p._main(args)
	local result = ""
		
	local hasPortal = false
	for key, _ in pairs(args) do
		if mw.ustring.sub(key,1,6) == 'portal' or tonumber(key) then
			hasPortal = true
			break
		end
	end
	
	local hasSister = yesNo(args.auto,true) or yesNo(args.author,true) or yesNo(args.cookbook,true)
	for _, sister in ipairs(sisters) do
		if hasSister then
			break
		end
		if yesNo(args[sister],true) or yesNo(args[sister..'-search'],true) then
			hasSister = true
		end
	end

	if hasPortal then
		local portalList = findNumericArgs("portal",args)
		for _, positional in ipairs(args) do
			table.insert(portalList, positional)
		end
		local portalBar = require('Module:Portal bar'..sandbox)._main
		result = result..portalBar(portalList, {tracking=args.tracking, qid=args.qid})
	end
	
	if hasSister then
		local sisterArgs = {auto=1, bar=1, trackSingle=not hasPortal}
		sisterArgs[1] = args.search
		for _, k in ipairs({'author','commonscat','cookbook','display','tracking','qid'}) do
			sisterArgs[k] = args[k]
		end
 	for _, t in ipairs(sisters) do
 		sisterArgs[t] = args[t..'-search'] or args[t]
 	end
 	local sisterBar = require('Module:Sister project links'..sandbox)._main
		result = result..sisterBar(sisterArgs)
	end
	
	return result
 end

 function p.main(frame)
 -- If called via #invoke, use the args passed into the invoking template,
 -- or the args passed to #invoke if any exist. Otherwise assume args are
 -- being passed directly in from the debug console or from another Lua module.
 local args = getArgs(frame)
 return p._main(args)
 end

 return p