Module:parameters
Documentation for this module may be created at Module:parameters/doc
local export = {}
-- A helper function to escape magic characters in a string
-- Magic characters: ^$()%.[]*+-?
local plain = require("Module:string").pattern_escape
-- A helper function that removes empty numeric indexes in a table,
-- so that the values are tightly packed like in a normal Lua table.
local remove_holes = require("Module:table").compressSparseArray
function export.process(args, params, return_unknown)
local args_new = {}
-- Process parameters for specific properties
local required = {}
local patterns = {}
local names_with_equal_sign = {}
local list_from_index = nil
for name, param in pairs(params) do
if param.required then
if param.alias_of then
require("Module:debug").track("parameters/required alias")
end
required[name] = true
end
if param.list then
local key = name
if type(name) == "string" then
key = string.gsub(name, "=", "")
end
if param.default ~= nil then
args_new[key] = {param.default, maxindex = 1}
else
args_new[key] = {maxindex = 0}
end
if type(param.list) == "string" then
-- If the list property is a string, then it represents the name
-- to be used as the prefix for list items. This is for use with lists
-- where the first item is a numbered parameter and the
-- subsequent ones are named, such as 1, pl2, pl3.
if string.find(param.list, "=") then
patterns["^" .. string.gsub(plain(param.list), "=", "(%%d+)") .. "$"] = name
else
patterns["^" .. plain(param.list) .. "(%d+)$"] = name
end
elseif type(name) == "number" then
-- If the name is a number, then all indexed parameters from
-- this number onwards go in the list.
list_from_index = name
else
if string.find(name, "=") then
patterns["^" .. string.gsub(plain(name), "=", "(%%d+)") .. "$"] = string.gsub(name, "=", "")
else
patterns["^" .. plain(name) .. "(%d+)$"] = name
end
end
if string.find(name, "=") then
-- DO NOT SIDE-EFFECT A TABLE WHILE ITERATING OVER IT.
-- Some elements may be skipped or processed twice if you do.
-- Instead, track the changes we want to make to `params`, and
-- do them after the iteration over `params` is done.
table.insert(names_with_equal_sign, name)
end
elseif param.default ~= nil then
args_new[name] = param.default
end
end
--Process required changes to `params`
for _, name in ipairs(names_with_equal_sign) do
require("Module:debug").track("parameters/name with equals")
params[string.gsub(name, "=", "")] = params[name]
params[name] = nil
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
local param = params[name]
-- If a parameter without the trailing index was found, and
-- require_index is set on the param, set the param to nil to treat it
-- as if it isn't recognized.
if not index and param and param.require_index then
param = nil
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
-- 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.", 2)
end
else
-- Remove leading and trailing whitespace unless allow_whitespace is true.
if not param.allow_whitespace then
val = mw.text.trim(val)
end
-- 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" then
val = tonumber(val)
elseif param.type then
require("Module:debug").track {
"parameters/unrecognized type",
"parameters/unrecognized type/" .. tostring(param.type)
}
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[param.alias_of or 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
local list = {}
for name, param in pairs(required) do
table.insert(list, name)
end
local count = #list
if count == 1 then
error('The parameter "' .. list[1] .. '" is required.', 2)
elseif count == 2 then
error('The parameters "' .. table.concat(list, '" and "') .. '" are required.', 2)
elseif count > 2 then
error('The parameters "' .. mw.text.listToText(list, '", "', '", and "') .. '" are required.', 2)
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] = remove_holes(val)
end
end
if return_unknown then
return args_new, args_unknown
else
return args_new
end
end
return export