Difference between revisions of "Module:Arguments"
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4 revisions imported from meta:Module:Arguments: See phab:T231001
>Mr. Stradivarius (check fargs and pargs before writing new values to args if options.noOverwrite is set) |
>AKlapper (WMF) m (4 revisions imported from meta:Module:Arguments: See phab:T231001) |
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(35 intermediate revisions by 21 users not shown) | |||
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-- This module provides easy processing of arguments passed to Scribunto from #invoke. | -- This module provides easy processing of arguments passed to Scribunto from | ||
-- #invoke. It is intended for use by other Lua modules, and should not be | |||
-- called from #invoke directly. | |||
local libraryUtil = require('libraryUtil') | |||
local checkType = libraryUtil.checkType | |||
local arguments = {} | local arguments = {} | ||
function | -- Generate four different tidyVal functions, so that we don't have to check the | ||
-- options every time we call it. | |||
local function tidyValDefault(key, val) | |||
if type(val) == 'string' then | |||
val = val:match('^%s*(.-)%s*$') | |||
if val == '' then | |||
return nil | |||
else | |||
return val | |||
end | |||
else | |||
return val | |||
end | |||
end | |||
local function tidyValTrimOnly(key, val) | |||
if type(val) == 'string' then | |||
return val:match('^%s*(.-)%s*$') | |||
else | |||
return val | |||
end | |||
end | |||
local function tidyValRemoveBlanksOnly(key, val) | |||
if type(val) == 'string' then | |||
if val:find('%S') then | |||
if | return val | ||
else | |||
return nil | |||
end | |||
else | else | ||
return val | |||
end | end | ||
end | |||
local function tidyValNoChange(key, val) | |||
return val | |||
end | |||
local function matchesTitle(given, title) | |||
local tp = type( given ) | |||
return (tp == 'string' or tp == 'number') and mw.title.new( given ).prefixedText == title | |||
end | |||
local translate_mt = { __index = function(t, k) return k end } | |||
function arguments.getArgs(frame, options) | |||
checkType('getArgs', 1, frame, 'table', true) | |||
checkType('getArgs', 2, options, 'table', true) | |||
frame = frame or {} | |||
options = options or {} | |||
--[[ | |||
-- Set up argument translation. | |||
--]] | |||
if | options.translate = options.translate or {} | ||
if options. | if getmetatable(options.translate) == nil then | ||
setmetatable(options.translate, translate_mt) | |||
end | |||
if options.backtranslate == nil then | |||
options.backtranslate = {} | |||
for k,v in pairs(options.translate) do | |||
options.backtranslate[v] = k | |||
end | |||
end | |||
if options.backtranslate and getmetatable(options.backtranslate) == nil then | |||
setmetatable(options.backtranslate, { | |||
__index = function(t, k) | |||
if options.translate[k] ~= k then | |||
return nil | |||
else | |||
return k | |||
end | |||
end | end | ||
if options. | }) | ||
end | |||
--[[ | |||
-- Get the argument tables. If we were passed a valid frame object, get the | |||
-- frame arguments (fargs) and the parent frame arguments (pargs), depending | |||
-- on the options set and on the parent frame's availability. If we weren't | |||
-- passed a valid frame object, we are being called from another Lua module | |||
-- or from the debug console, so assume that we were passed a table of args | |||
-- directly, and assign it to a new variable (luaArgs). | |||
--]] | |||
local fargs, pargs, luaArgs | |||
if type(frame.args) == 'table' and type(frame.getParent) == 'function' then | |||
if options.wrappers then | |||
--[[ | |||
-- The wrappers option makes Module:Arguments look up arguments in | |||
-- either the frame argument table or the parent argument table, but | |||
-- not both. This means that users can use either the #invoke syntax | |||
-- or a wrapper template without the loss of performance associated | |||
-- with looking arguments up in both the frame and the parent frame. | |||
-- Module:Arguments will look up arguments in the parent frame | |||
-- if it finds the parent frame's title in options.wrapper; | |||
-- otherwise it will look up arguments in the frame object passed | |||
-- to getArgs. | |||
--]] | |||
local parent = frame:getParent() | |||
if not parent then | |||
fargs = frame.args | |||
else | |||
local title = parent:getTitle():gsub('/sandbox$', '') | |||
local found = false | |||
if matchesTitle(options.wrappers, title) then | |||
found = true | |||
elseif type(options.wrappers) == 'table' then | |||
for _,v in pairs(options.wrappers) do | |||
if matchesTitle(v, title) then | |||
found = true | |||
break | |||
end | |||
end | |||
end | |||
-- We test for false specifically here so that nil (the default) acts like true. | |||
if found or options.frameOnly == false then | |||
pargs = parent.args | |||
end | |||
if not found or options.parentOnly == false then | |||
fargs = frame.args | |||
end | |||
end | end | ||
else | else | ||
-- options.wrapper isn't set, so check the other options. | |||
if not options.parentOnly then | |||
fargs = frame.args | |||
end | |||
if not options.frameOnly then | |||
local parent = frame:getParent() | |||
pargs = parent and parent.args or nil | |||
end | |||
end | |||
if options.parentFirst then | |||
fargs, pargs = pargs, fargs | |||
end | end | ||
else | |||
luaArgs = frame | |||
end | end | ||
-- | -- Set the order of precedence of the argument tables. If the variables are | ||
local | -- nil, nothing will be added to the table, which is how we avoid clashes | ||
if | -- between the frame/parent args and the Lua args. | ||
local argTables = {fargs} | |||
if | argTables[#argTables + 1] = pargs | ||
tidyVal = | argTables[#argTables + 1] = luaArgs | ||
--[[ | |||
-- Generate the tidyVal function. If it has been specified by the user, we | |||
-- use that; if not, we choose one of four functions depending on the | |||
-- options chosen. This is so that we don't have to call the options table | |||
-- every time the function is called. | |||
--]] | |||
local tidyVal = options.valueFunc | |||
if tidyVal then | |||
if type(tidyVal) ~= 'function' then | |||
error( | |||
"bad value assigned to option 'valueFunc'" | |||
.. '(function expected, got ' | |||
.. type(tidyVal) | |||
.. ')', | |||
2 | |||
) | |||
end | |||
elseif options.trim ~= false then | |||
if options.removeBlanks ~= false then | |||
tidyVal = tidyValDefault | |||
else | else | ||
tidyVal = tidyValTrimOnly | |||
end | |||
else | |||
if options.removeBlanks ~= false then | |||
tidyVal = tidyValRemoveBlanksOnly | |||
else | |||
tidyVal = tidyValNoChange | |||
end | end | ||
end | end | ||
local function mergeArgs( | --[[ | ||
-- Accepts multiple tables as input and merges their keys and values into one table | -- Set up the args, metaArgs and nilArgs tables. args will be the one | ||
-- accessed from functions, and metaArgs will hold the actual arguments. Nil | |||
-- arguments are memoized in nilArgs, and the metatable connects all of them | |||
-- together. | |||
--]] | |||
local args, metaArgs, nilArgs, metatable = {}, {}, {}, {} | |||
setmetatable(args, metatable) | |||
local function mergeArgs(tables) | |||
--[[ | |||
-- Accepts multiple tables as input and merges their keys and values | |||
-- into one table. If a value is already present it is not overwritten; | |||
-- tables listed earlier have precedence. We are also memoizing nil | |||
-- values, which can be overwritten if they are 's' (soft). | |||
--]] | |||
for _, t in ipairs(tables) do | for _, t in ipairs(tables) do | ||
for key, val in | for key, val in pairs(t) do | ||
if metaArgs[key] == nil then | if metaArgs[key] == nil and nilArgs[key] ~= 'h' then | ||
local tidiedVal = tidyVal(key, val) | |||
if tidiedVal == nil then | |||
nilArgs[key] = 's' | |||
else | |||
metaArgs[key] = tidiedVal | |||
end | |||
end | end | ||
end | end | ||
end | end | ||
end | end | ||
--[[ | --[[ | ||
-- Define metatable behaviour. Arguments are | -- Define metatable behaviour. Arguments are memoized in the metaArgs table, | ||
-- | -- and are only fetched from the argument tables once. Fetching arguments | ||
-- from the argument tables is the most resource-intensive step in this | |||
-- ipairs on fargs and pargs if pairs has already been run, as all the arguments will already have been | -- module, so we try and avoid it where possible. For this reason, nil | ||
-- arguments are also memoized, in the nilArgs table. Also, we keep a record | |||
-- in the metatable of when pairs and ipairs have been called, so we do not | |||
-- run pairs and ipairs on the argument tables more than once. We also do | |||
-- not run ipairs on fargs and pargs if pairs has already been run, as all | |||
-- the arguments will already have been copied over. | |||
--]] | --]] | ||
metatable.__index = function (t, key) | metatable.__index = function (t, key) | ||
--[[ | |||
-- Fetches an argument when the args table is indexed. First we check | |||
-- to see if the value is memoized, and if not we try and fetch it from | |||
-- the argument tables. When we check memoization, we need to check | |||
-- metaArgs before nilArgs, as both can be non-nil at the same time. | |||
-- If the argument is not present in metaArgs, we also check whether | |||
-- pairs has been run yet. If pairs has already been run, we return nil. | |||
-- This is because all the arguments will have already been copied into | |||
-- metaArgs by the mergeArgs function, meaning that any other arguments | |||
-- must be nil. | |||
--]] | |||
if type(key) == 'string' then | |||
key = options.translate[key] | |||
end | |||
local val = metaArgs[key] | local val = metaArgs[key] | ||
if val ~= nil then | if val ~= nil then | ||
return val | return val | ||
elseif metatable.donePairs or nilArgs[key] then | |||
local | return nil | ||
if | end | ||
for _, argTable in ipairs(argTables) do | |||
local argTableVal = tidyVal(key, argTable[key]) | |||
return | if argTableVal ~= nil then | ||
metaArgs[key] = argTableVal | |||
return argTableVal | |||
end | end | ||
end | end | ||
nilArgs[key] = 'h' | |||
return nil | |||
end | end | ||
metatable.__newindex = function (t, key, val) | metatable.__newindex = function (t, key, val) | ||
if | -- This function is called when a module tries to add a new value to the | ||
-- args table, or tries to change an existing value. | |||
if type(key) == 'string' then | |||
key = options.translate[key] | |||
end | |||
if options.readOnly then | |||
error( | |||
'could not write to argument table key "' | |||
.. tostring(key) | |||
.. '"; the table is read-only', | |||
2 | |||
) | |||
elseif options.noOverwrite and args[key] ~= nil then | |||
error( | |||
'could not write to argument table key "' | |||
.. tostring(key) | |||
.. '"; overwriting existing arguments is not permitted', | |||
2 | |||
) | |||
elseif val == nil then | |||
--[[ | |||
-- If the argument is to be overwritten with nil, we need to erase | |||
-- the value in metaArgs, so that __index, __pairs and __ipairs do | |||
-- not use a previous existing value, if present; and we also need | |||
-- to memoize the nil in nilArgs, so that the value isn't looked | |||
-- up in the argument tables if it is accessed again. | |||
--]] | |||
metaArgs[key] = nil | |||
nilArgs[key] = 'h' | |||
else | |||
metaArgs[key] = val | metaArgs[key] = val | ||
end | |||
end | |||
local function translatenext(invariant) | |||
local k, v = next(invariant.t, invariant.k) | |||
invariant.k = k | |||
if k == nil then | |||
return nil | |||
elseif type(k) ~= 'string' or not options.backtranslate then | |||
return k, v | |||
else | |||
local backtranslate = options.backtranslate[k] | |||
if backtranslate == nil then | |||
-- Skip this one. This is a tail call, so this won't cause stack overflow | |||
return translatenext(invariant) | |||
else | |||
return backtranslate, v | |||
end | |||
end | end | ||
end | end | ||
metatable.__pairs = function () | metatable.__pairs = function () | ||
-- Called when pairs is run on the args table. | |||
if not metatable.donePairs then | if not metatable.donePairs then | ||
mergeArgs( | mergeArgs(argTables) | ||
metatable.donePairs = true | metatable.donePairs = true | ||
end | end | ||
return | return translatenext, { t = metaArgs } | ||
end | end | ||
local function inext(t, i) | |||
if | -- This uses our __index metamethod | ||
local v = t[i + 1] | |||
if v ~= nil then | |||
return i + 1, v | |||
end | end | ||
end | end | ||
metatable.__ipairs = function (t) | |||
-- Called when ipairs is run on the args table. | |||
return inext, t, 0 | |||
end | |||
return args | return args | ||
end | end | ||
return arguments | return arguments |