-- 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 =
-- 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)
then return nil else return val end else return val endend
local function tidyValTrimOnly(key, val) if type(val)
local function tidyValRemoveBlanksOnly(key, val) if type(val)
local function tidyValNoChange(key, val) return valend
local function matchesTitle(given, title) local tp = type(given) return (tp
'number') and mw.title.new(given).prefixedText
local translate_mt =
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. -- options.translate = options.translate or if getmetatable(options.translate)
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)
---- 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)
'function' then if options.wrappers then -- 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)
-- We test for false specifically here so that nil (the default) acts like true. if found or options.frameOnly
false then fargs = frame.args end end 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 else luaArgs = frame end
-- Set the order of precedence of the argument tables. If the variables are -- nil, nothing will be added to the table, which is how we avoid clashes -- between the frame/parent args and the Lua args. local argTables = argTables[#argTables + 1] = pargs 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 tidyVal = tidyValTrimOnly end else if options.removeBlanks ~= false then tidyVal = tidyValRemoveBlanksOnly else tidyVal = tidyValNoChange end end
---- 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 key, val in pairs(t) do if metaArgs[key]
nil then nilArgs[key] = 's' else metaArgs[key] = tidiedVal end end end end end
---- 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 -- 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) ---- 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)
metatable.__newindex = function (t, key, val) -- 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)
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 end end
local function translatenext(invariant) local k, v = next(invariant.t, invariant.k) invariant.k = k if k
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
metatable.__pairs = function -- Called when pairs is run on the args table. if not metatable.donePairs then mergeArgs(argTables) metatable.donePairs = true end return translatenext, end
local function inext(t, i) -- This uses our __index metamethod local v = t[i + 1] if v ~= nil then return i + 1, v end end
metatable.__ipairs = function (t) -- Called when ipairs is run on the args table. return inext, t, 0 end
return argsend
return arguments