Module:Check for unknown parameters

Module documentation This module is copied from the English Wikipedia page en:Module:Check for unknown parameters. It has no documentation, and relevant information may be found at the corresponding English Wikipedia documentation page. For more details see the editing history of the module. The above documentation is transcluded from Module:Check for unknown parameters/doc.

---

-- This module may be used to compare the arguments passed to the parent
-- with a list of arguments, returning a specified result if an argument is
-- not on the list
local p = {}

local function trim(s)
	return s:match('^%s*(.-)%s*$')
end

local function isnotempty(s)
	return s and s:match('%S')
end

local function clean(text)
	-- Return text cleaned for display and truncated if too long.
	-- Strip markers are replaced with dummy text representing the original wikitext.
	local pos, truncated
	local function truncate(text)
		if truncated then
			return ''
		end
		if mw.ustring.len(text) > 25 then
			truncated = true
			text = mw.ustring.sub(text, 1, 25) .. '...'
		end
		return mw.text.nowiki(text)
	end
	local parts = {}
	for before, tag, remainder in text:gmatch('([^\127]*)\127[^\127]*%-(%l+)%-[^\127]*\127()') do
		pos = remainder
		table.insert(parts, truncate(before) .. '<' .. tag .. '>...</' .. tag .. '>')
	end
	table.insert(parts, truncate(text:sub(pos or 1)))
	return table.concat(parts)
end

function p._check(args, pargs)
	if type(args) ~= "table" or type(pargs) ~= "table" then
		-- TODO: error handling
		return
	end

	-- create the list of known args, regular expressions, and the return string
	local knownargs = {}
	local regexps = {}
	for k, v in pairs(args) do
		if type(k) == 'number' then
			v = trim(v)
			knownargs[v] = 1
		elseif k:find('^regexp[1-9][0-9]*$') then
			table.insert(regexps, '^' .. v .. '$')
		end
	end

	-- loop over the parent args, and make sure they are on the list
	local ignoreblank = isnotempty(args['ignoreblank'])
	local showblankpos = isnotempty(args['showblankpositional'])
	local values = {}
	for k, v in pairs(pargs) do
		if type(k) == 'string' and knownargs[k] == nil then
			local knownflag = false
			for _, regexp in ipairs(regexps) do
				if mw.ustring.match(k, regexp) then
					knownflag = true
					break
				end
			end
			if not knownflag and ( not ignoreblank or isnotempty(v) )  then
				table.insert(values, clean(k))
			end
		elseif type(k) == 'number' and knownargs[tostring(k)] == nil then
			local knownflag = false
			for _, regexp in ipairs(regexps) do
				if mw.ustring.match(tostring(k), regexp) then
					knownflag = true
					break
				end
			end
			if not knownflag and ( showblankpos or isnotempty(v) ) then
				table.insert(values, k .. ' = ' .. clean(v))
			end
		end
	end

	-- add results to the output tables
	local res = {}
	if #values > 0 then
		local unknown_text = args['unknown'] or 'Found _VALUE_, '

		if mw.getCurrentFrame():preprocess( "{{REVISIONID}}" ) == "" then
			local preview_text = args['preview']
			if isnotempty(preview_text) then
				preview_text = require('Module:If preview')._warning({preview_text})
			elseif preview == nil then
				preview_text = unknown_text
			end
			unknown_text = preview_text
		end
		for _, v in pairs(values) do
			-- Fix odd bug for | = which gets stripped to the empty string and
			-- breaks category links
			if v == '' then v = ' ' end

			-- avoid error with v = 'example%2' ("invalid capture index")
			local r = unknown_text:gsub('_VALUE_', {_VALUE_ = v})
			table.insert(res, r)
		end
	end

	return table.concat(res)
end

function p.check(frame)
	local args = frame.args
	local pargs = frame:getParent().args
	return p._check(args, pargs)
end

return p