Module:Check for unknown parameters

-- 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*$') end local function isnotempty(s) return s and trim(s) ~= '' end function p.check (frame) local args = frame.args local pargs = frame:getParent.args local ignoreblank = isnotempty(frame.args['ignoreblank']) local showblankpos = isnotempty(frame.args['showblankpositional']) local knownargs = {} local unknown = frame.args['unknown'] or 'Found _VALUE_, ' local preview = frame.args['preview'] local values = {} local res = {} local regexps = {} -- create the list of known args, regular expressions, and the return string for k, v in pairs(args) do		if type(k) == 'number' then v = trim(v) knownargs[v] = 1 elseif k:find('^regexp[1-9][0-9]*$') then table.insert(regexps, '^' .. v .. '$') end end if isnotempty(preview) then preview = ' Warning: ' .. preview .. ' (this message is shown only in preview). '	elseif preview == nil then preview = unknown end -- loop over the parent args, and make sure they are on the list for k, v in pairs(pargs) do		if type(k) == 'string' and knownargs[k] == nil then local knownflag = false for i, 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 k = mw.ustring.gsub(k, '[^%w\-_ ]', '?') table.insert(values, k)			end elseif type(k) == 'number' and knownargs[tostring(k)] == nil and ( showblankpos or isnotempty(v) ) then local vlen = mw.ustring.len(v) v = mw.ustring.sub(v, 1, (vlen < 25) and vlen or 25) v = mw.ustring.gsub(v, '[^%w\-_ ]', '?') table.insert(values, k .. ' = ' .. v .. ((vlen >= 25) and ' ...' or '')) end end -- add resuls to the output tables if #values > 0 then if frame:preprocess( "" ) == "" then unknown = preview end for k, v in pairs(values) do			if v == '' then -- Fix odd bug for | = which gets stripped to the empty string and -- breaks category links v = ' ' end local r = unknown:gsub('_VALUE_', v)			table.insert(res, r)		end end return table.concat(res) end return p