This module is rated as beta, and is ready for widespread use. It is still new and should be used with some caution to ensure the results are as expected.

This Lua module is used on approximately 1,220,000 pages, or roughly 3156% of all pages. To avoid major disruption and server load, any changes should be tested in the module's /sandbox or /testcases subpages, or in your own module sandbox. The tested changes can be added to this page in a single edit. Consider discussing changes on the talk page before implementing them.

This module depends on the following other modules: Module:If preview

This module may be appended to a template to check for uses of tuples of conflicting parameters.

((#invoke:Check for clobbered parameters|check
|nested=1
|template=Some template name
|cat=((main other|Category:Some tracking category))
|arg1a; arg1b|arg2a; arg2b; arg2c|...|argNa; argNb))

Here, (arg1a, arg1b), (arg2a, arg2b, arg2c), are tuples of the conflicting parameters.

By default, the module ignores blank parameters which is useful for ((if empty)) chains of parameters. For nested chains of parameters, use |nested=1 to consider blank parameters as well.

By default, the delimiter for the tuples is ; but this can be changed with |delimiter=.

The value of |template= is used to for the text of the preview warning message. When omitted, the module will use a generic message.

((Infobox
| above = (({name|))}

| label1 = Founder((#if:(({founders|))}|s))
| data1 = ((if empty| (({founders|))} | (({founder|))} ))

| label2 = Headquarters
| data2 = ((if empty| (({headquarters|))} | (({hq|))} | (({location|))} ))

))<!-- 
  end infobox, start tracking
-->((#invoke:Check for clobbered parameters|check
| template = Infobox example
| cat = ((main other|Category:Pages using infobox example with conflicting parameters))
| founders; founder
| headquarters; hq; location
))

((Infobox
| above = (({name|))}

| label1 = Founder(s)
| data1 = (({founders|(({founder|))))))

| label2 = Headquarters
| data2 = (({headquarters|(({hq|(({location|))))))))}

))<!-- 
  end infobox, start tracking
-->((#invoke:Check for clobbered parameters|check
| nested = 1
| template = Infobox example
| cat = ((main other|Category:Pages using infobox example with conflicting parameters))
| founders; founder
| headquarters; hq; location
))

• Module:Check for unknown parameters
• Module:Check for deprecated parameters
• Template:Conflicting parameters category (for use on category pages)

local p = {}

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

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

function p.check(frame)
	local args = frame.args
	local pargs = frame:getParent().args
	local checknested = isnotempty(args['nested'])
	local delimiter = isnotempty(args['delimiter']) and args['delimiter'] or ';'
	local argpairs = {}
	
	for k, v in pairs(args) do
		if type(k) == 'number' then
			local plist = mw.text.split(v, delimiter)
			local pfound = {}
			local count = 0
			for ii, vv in ipairs(plist) do
				vv = trim(vv)
				if checknested and pargs[vv] or isnotempty(pargs[vv]) then
					count = count + 1
					table.insert(pfound, vv)
				end
			end
			if count > 1 then
				table.insert(argpairs, pfound)
			end
		end
	end
	
	local warnmsg = {}
	local res = ''
	local cat = ''
	if args['cat'] and mw.ustring.match(args['cat'],'^[Cc][Aa][Tt][Ee][Gg][Oo][Rr][Yy]:') then
		cat = args['cat']
	end
	local template = args['template'] and ' in ' .. args['template']  or ''
	if #argpairs > 0 then
		for i, v in ipairs( argpairs ) do
			table.insert(
				warnmsg,
				mw.ustring.format(
					'Using more than one of the following parameters%s: <code>%s</code>.',
					template,
					table.concat(v, '</code>, <code>')
				)
			)
			if cat ~= '' then
				res = res .. '[[' .. cat .. '|' .. (v[1] == '' and ' ' or '') .. v[1] .. ']]'
			end	
		end
	end
	
	if #warnmsg > 0 then
		res = require('Module:If preview')._warning({
			table.concat(warnmsg, '<br>')
		}) .. res
	end
	
	return res
end

return p