Module:List

Documentation for this module may be created at Module:List/doc

-- This module outputs different kinds of lists. At the moment, bulleted, unbulleted, horizontal, and numbered lists are supported.

local p = {}

local function getListItem(data, style, itemStyle)
	if not data then
		return nil
	end
	if style or itemStyle then
		style = style or ''
		itemStyle = itemStyle or ''
		return mw.ustring.format(
			'<li style="%s%s">%s</li>',
			style, itemStyle, data
		)
	else
		return mw.ustring.format(
			'<li>%s</li>',
			data
		)
	end
end

local function getArgNums(args)
	-- Returns an array containing the keys of all positional arguments
	-- that contain data (i.e. non-whitespace values).
	local nums = {}
	for k, v in pairs(args) do
		if type(k) == 'number' and 
			k >= 1 and 
			math.floor(k) == k and 
			mw.ustring.match(v, '%S') then
				table.insert(nums, k)
		end
	end
	table.sort(nums)
	return nums
end

local function getClass(listType, class)
	local classes = {}
	if listType == 'horizontal' then
		table.insert(classes, 'hlist')
	elseif listType == 'unbulleted' then
		table.insert(classes, 'plainlist')
	end
	table.insert(classes, class)
	local ret
	if #classes == 0 then
		return nil
	end
	return mw.ustring.format(' class="%s"', table.concat(classes, ' '))
end

local function getStyle(listType, indent, style)
	local styles = {}
	if listType == 'horizontal' then
		indent = indent and tonumber(indent)
		indent = tostring((indent and indent * 1.6) or 0)
		table.insert(styles, 'margin-left: ' .. indent .. 'em;')
	end
	table.insert(styles, style)
	if #styles == 0 then
		return nil
	end
	return mw.ustring.format(' style="%s"', table.concat(styles, ' '))
end

function p.makeList(listType, args)
	-- This is the main function to be called from other Lua modules.
	-- First, get the list items.
	local listItems = {}
	local argNums = getArgNums(args)
	for i, num in ipairs(argNums) do
		local item = getListItem(
			args[num],
			args.item_style or args.li_style, -- li_style is included for backwards compatibility. item_style was included to be easier to understand for non-coders.
			args['item_style' .. tostring(num)] or args['li_style' .. tostring(num)]
		)
		table.insert(listItems, item)
	end
	if #listItems == 0 then
		return ''
	end
	-- Check if we need a ul tag or an ol tag.
	local listTag = 'ul'
	if listType == 'numbered' then
		listTag = 'ol'
	end
	-- Get the classes and styles and output the list.
	local class = getClass(listType, args.class) or ''
	local style = getStyle(listType, args.indent, args.style) or ''
	local list_style = args.list_style or args.ul_style -- ul_style is included for backwards compatibility, and will work even with ordered lists.
	list_style = list_style and (' style="' .. list_style .. '"') or ''
	return mw.ustring.format(
		'<div%s%s><%s%s>%s</%s></div>',
		class, style, listTag, list_style, table.concat(listItems), listTag
	)
end

local function makeWrapper(listType)
	return function(frame)
		local origArgs
		if frame == mw.getCurrentFrame() then
			origArgs = frame:getParent().args
			for k, v in pairs(frame.args) do
				origArgs = frame.args
				break
			end
		else
			origArgs = frame
		end
		
		local args = {}
		for k, v in pairs(origArgs) do
			if type(k) == 'number' or v ~= '' then
				args[k] = v
			end
		end
		return p.makeList(listType, args)
	end
end

local funcNames = {'bulleted', 'unbulleted', 'horizontal', 'numbered'}

for _, funcName in ipairs(funcNames) do
	p[funcName] = makeWrapper(funcName)
end

return p