Lua-native alternative to popular flag templates. Can be used to reduce post-expand include size of pages with lots of templates, since it avoids calling multilevel templates.

Examples

change
Template Module
Code Output PEIS Code Output PEIS
{{flag|China}}  China 443b {{#invoke:flag|main|China}}  China 128b
{{flagcountry|China}}  China 577b {{#invoke:flag|country|China}}  China 128b
{{flagdeco|China}} 452b {{#invoke:flag|deco|China}} 107b
{{flagicon|China}} China 548b {{#invoke:flag|icon|China}} China 117b
{{flag+link|History of|China}}  China 663b {{#invoke:flag|+link|History of|China}}  China 139b

local p = {}

function p._main(frame, name, mode, check)
	local categories = {
		Flagicon = '[[Category:Flagicons with missing country data templates]]',
		Flagdeco = '[[Category:Flagdeco with missing country data templates]]',
	}

    local yesno = require('Module:Yesno')

	--Get input arguments
	local args = require('Module:Arguments').getArgs(frame,{frameOnly = ((frame.args.frameonly or '') ~= ''), valueFunc =
	function(key,value)
		if value then
			value = mw.text.trim(value)
			--Change empty string to nil for all args except 'image' and 'border'
			if key=="image" or key=="border" or value~="" then
				return value
			end
		end
		return nil
	end
	})
	
	local preftext = ""
	
	if name == 'Flag+link' then
		args.pref = args[1]
	elseif name == 'Flagathlete' then
		args.preftext = args[1]
		args[2] = args.code or args[2] or ""
		args.variant = args.variant or args[3]
	elseif name == 'Flagmedalist' then
		preftext = (args[1] or "") .. "<br/>"
		args[2] = args.code or args[2] or ""
		args.variant = args.variant or args[3]
	else
		args.variant = args.variant or args[2]
		args[2] = args[1] or ""
	end

	args[1] = mode .. (args.opts or '')
	args.missingcategory = categories[name]
	args.noredlink = args.noredlink or 'notext'

	if args.placeholder and yesno(args.placeholder) ~= true then
		args[1] = args[1] .. 'o'
	end

	if mw.title.getCurrentTitle().namespace == 0 then
		local unknown = '[[Category:Pages using ' .. mw.ustring.lower(name) .. ' template with unknown parameters|_VALUE_' ..
				frame:getParent():getTitle() .. ']]'
	else
		local unknown = ''
	end

	if check then
		local opts = {
            unknown=unknown,
            preview='Page using [[Template:' .. name .. ']] with unknown parameter "_VALUE_"',
            ignoreblank='y',
            '1',
            '2',
            'variant',
            'image',
            'size',
            'sz',
            'border',
            'align',
            'al',
            'width',
            'w',
            'alt',
            'ilink',
            'noredlink',
            'missingcategory',
            'name',
            'clink',
            'link',
            'pref',
            'suff',
            'plink',
            'the',
            'section',
            'altvar',
            'avar',
            'age',
            'nalign',
            'nal',
            'text',
            'nodata',
            'opts',
            'placeholder',
            'getParent'
		}

		check = require('Module:Check for unknown parameters')._check(opts,args)
	else
		check = ''
	end

	return preftext .. require('Module:Flagg').luaMain(frame,args) .. check
end

function p.main(frame) return p._main(frame,     'Flag',        'unc',  false) end
p.flag = p.main
p[''] = p.main
function p.deco(frame) return p._main(frame,     'Flagdeco',    'uxx',   false) end
p.flagdeco = p.deco
function p.icon(frame) return p._main(frame,     'Flagicon',    'cxxl',  true) end
p.flagicon = p.icon
function p.pluslink(frame) return p._main(frame, 'Flag+link',   'unpefo', false) end
p['+link'] = p.pluslink
p['flag+link'] = p.pluslink
function p.country(frame) return p._main(frame,  'Flagcountry', 'unce',  false) end
p.flagcountry = p.country
function p.athlete(frame) return p._main(frame,  'Flagathlete', 'unape',   false) end
p.flagathlete = p.athlete
function p.medalist(frame) return p._main(frame,  'Flagmedalist', 'unce',   false) end
p.flagmedalist = p.medalist

return p