Module:Parameters

local export = {}

-- A helper function to escape magic characters in a string -- Magic characters: ^$%.[]*+-? local function plain(text) return mw.ustring.gsub(text, "([%^%$%(%)%%%.%[%]%*%+%-%?])", "%%%1") end

-- A helper function that removes empty numeric indexes in a table, -- so that the values are tightly packed like in a normal Lua table. function export.remove_holes(list) local new_list = {} for i = 1, list.maxindex do		table.insert(new_list, list[i]) end return new_list end

function export.process(args, params, return_unknown) local args_new = {} -- Process parameters for specific properties local required = {} local patterns = {} local list_from_index = nil for name, param in pairs(params) do		if param.required then required[name] = true end if param.list then if param.default ~= nil then args_new[type(name) == "string" and mw.ustring.gsub(name, "=", "") or name] = {param.default, maxindex = 1} else args_new[type(name) == "string" and mw.ustring.gsub(name, "=", "") or name] = {maxindex = 0} end if type(param.list) == "string" then -- If the list property is a string, then it represents the name -- to be used as the prefix for list items. This is for use with lists -- where the first item is a numbered parameter and the -- subsequent ones are named, such as 1, pl2, pl3. if mw.ustring.match(param.list, "=") then patterns["^" .. mw.ustring.gsub(plain(param.list), "=", "(%d+)") .. "$"] = name else patterns["^" .. plain(param.list) .. "(%d+)$"] = name end elseif type(name) == "number" then -- If the name is a number, then all indexed parameters from -- this number onwards go in the list. list_from_index = name else if mw.ustring.match(name, "=") then patterns["^" .. mw.ustring.gsub(plain(name), "=", "(%d+)") .. "$"] = mw.ustring.gsub(name, "=", "") else patterns["^" .. plain(name) .. "(%d+)$"] = mw.ustring.gsub(name, "=", "") end end if mw.ustring.match(name, "=") then params[mw.ustring.gsub(name, "=", "")] = params[name] params[name] = nil end elseif param.default ~= nil then args_new[name] = param.default end end -- Process the arguments local args_unknown = {} for name, val in pairs(args) do		local index = nil if type(name) == "number" then if list_from_index ~= nil and name >= list_from_index then index = name - list_from_index + 1 name = list_from_index end else -- Does this argument name match a pattern? for pattern, pname in pairs(patterns) do				index = mw.ustring.match(name, pattern) -- It matches, so store the parameter name and the -- numeric index extracted from the argument name. if index then index = tonumber(index) name = pname break end end end -- If no index was found, use 1 as the default index. -- This makes list parameters like g, g2, g3 put g at index 1. index = index or 1 local param = params[name] -- If the argument is not in the list of parameters, trigger an error. -- return_unknown suppresses the error, and stores it in a separate list instead. if not param then if return_unknown then args_unknown[name] = val else error("The parameter \"" .. name .. "\" is not used by this template.") end else -- Remove leading and trailing whitespace val = mw.text.trim(val) -- Empty string is equivalent to nil unless allow_empty is true. if val == "" and not param.allow_empty then val = nil end -- Convert to proper type if necessary. if param.type == "boolean" then val = not (not val or val == "" or val == "0" or val == "no" or val == "n" or val == "false") elseif param.type == "number" and val ~= nil then val = tonumber(val) end -- Can't use "if val" alone, because val may be a boolean false. if val ~= nil then -- Mark it as no longer required, as it is present. required[name] = nil -- Store the argument value. if param.list then -- If the parameter is an alias of another, store it as the original, -- but avoid overwriting it; the original takes precedence. if not param.alias_of then args_new[name][index] = val -- Store the highest index we find. args_new[name].maxindex = math.max(index, args_new[name].maxindex) elseif args[param.alias_of] == nil then if params[param.alias_of] and params[param.alias_of].list then args_new[param.alias_of][index] = val -- Store the highest index we find. args_new[param.alias_of].maxindex = math.max(1, args_new[param.alias_of].maxindex) else args_new[param.alias_of] = val end end else -- If the parameter is an alias of another, store it as the original, -- but avoid overwriting it; the original takes precedence. if not param.alias_of then args_new[name] = val elseif args[param.alias_of] == nil then if params[param.alias_of] and params[param.alias_of].list then args_new[param.alias_of][1] = val -- Store the highest index we find. args_new[param.alias_of].maxindex = math.max(1, args_new[param.alias_of].maxindex) else args_new[param.alias_of] = val end end end end end end -- The required table should now be empty. -- If any entry remains, trigger an error, unless we're in the template namespace. if mw.title.getCurrentTitle.nsText ~= "Template" then for name, param in pairs(required) do error("The parameter \"" .. name .. "\" is required.") end end -- Remove holes in any list parameters if needed. for name, val in pairs(args_new) do		if type(val) == "table" and not params[name].allow_holes then args_new[name] = export.remove_holes(val) end end if return_unknown then return args_new, args_unknown else return args_new end end

return export