--  submodule is used to generate the complete color contrast table in -- the documentation for Module:Gridiron color local contrast = {} local all_colors = {}  local contrast_mod = require("Module:Color contrast")  local function stripwhitespace(text) 	return text:match("^%s*(.-)%s*$") end  local function get_colors(team, unknown) 	team = stripwhitespace(team or ) 	unknown = unknown or {"DCDCDC", "000000"}   	local use_default = { 		[""] = 1, 		["retired"] = 1, 		["free agent"] = 1, 	}   	local colors = nil   	if ( team and use_default[team:lower()] ) then 		colors = {"DCDCDC", "000000"} 	else 		colors = all_colors[team] 		if ( colors and type(colors) == 'string' ) then 			colors = all_colors[colors] 		end 	end   	return colors or unknown end  local function color_contrast_ratio(hex1, hex2) 	if( hex1 and hex2) then 		local r = contrast_mod._ratio({ .. hex1,  .. hex2, error = 0}) 		if( r > 0 ) then 			r = (r > 1) and r or (1/r) 			r = math.floor(r * 100 + 0.5) / 100 			return  (r > 1) and r or (1/r) 		end 	end 	return  end  function contrast._testtable(args) 	local teamlist = {} 	local aliaslist = {} 	local style = args['style'] 	local data_module = args['data'] or ('Module:Gridiron color/' .. (args['sport'] or 'football')) 	local columns = tonumber(args['columns']) or 4 	all_colors = mw.loadData(data_module)  	-- helper function 	local function table_row(t, c) 		local res = mw.html.create() 		if( c[1] ) then 			res:tag('td'):wikitext(t) 		else 			res:tag('td'):wikitext(t .. ' ERROR') 		end 		for i=1,columns do 			res:tag('td') 				:css('background', c[i] or 'transparent') 				:wikitext(c[i] and  or 'X') 		end 		res:tag('td'):wikitext(color_contrast_ratio(c[1],c[2])) 		res:tag('td'):wikitext(color_contrast_ratio(c[columns],c[columns-1])) 		return tostring(res) 	end      -- list of teams 	if( args and args[1] ) then 		for k, team in pairs(args) do 			if type(k) == 'number' then 				table.insert(teamlist, team) 			end 		end 	else 		for team, colors in pairs( all_colors ) do 			if type(colors) == 'string' then 				aliaslist[colors] = (aliaslist[colors] or ) .. 'Also known as ' .. team 			else 				table.insert(teamlist, team) 			end 		end 		table.sort(teamlist) 		table.insert(teamlist, 'Free agent') 		table.insert(teamlist, 'Retired') 	end 	 	-- build table 	local root = mw.html.create('table') 	root:addClass('wikitable sortable') 		:css('background', 'transparent') 		:css('font-size', '90%') 		:css('line-height', '100%') 		:cssText(style) 	if args['caption'] then 		root:tag('caption'):wikitext(args['caption']) 	end 	local row = root:tag('tr') 	row:tag('th') 		:attr('rowspan',2) 		:wikitext('Team') 	for i=1,columns do 		row:tag('th') 			:addClass('unsortable') 			:attr('rowspan',2) 			:wikitext(i) 	end 	row:tag('th') 		:attr('colspan', 2) 		:wikitext('Contrast') 	row = root:tag('tr') 	row:tag('th'):wikitext('1/2') 	row:tag('th'):wikitext( tostring(columns) .. '/' .. tostring(columns - 1) ) 	for k, team in pairs( teamlist ) do 		row = root:tag('tr') 		row:wikitext(table_row(team .. (aliaslist[team] or ), get_colors(team))) 	end 	if style and style ~=  then 		style = 'font-size:90%; padding:0.4em; width:32em; border:1px #aaa solid;' .. style 	end 	local note = nil 	if args['note'] then 		note = args['note'] 	else 		note = 'The numeric columns are the calculated contrast ratio for colors' 		.. ' 1:2 and colors ' .. tostring(columns) .. ':' .. tostring(columns-1)  		.. '. Anything lower than 3 is' 		.. ' very poor contrast and should be changed in' 		.. ' the data module. For more' 		.. ' information, see Template:Color contrast ratio.' 	end 	if note ~=  then 		note = mw.html.create('div'):cssText(style):wikitext(note) 	end 	return tostring(root) .. tostring(note) end  function contrast.testtable(frame) 	return frame:preprocess(contrast._testtable(frame.args)) end  return contrast