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Modul:Arguments

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Dokumentasi untuk modul ini dapat dibuat di Modul:Arguments/doc

-- 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) == '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

return val

else

return nil

end

else

return val

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.

--]]

options.translate = options.translate or {}

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

--[[

-- 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

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 = {fargs}

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 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

--[[

-- 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) == 'string' then

key = options.translate[key]

end

local val = metaArgs[key]

if val ~= nil then

return val

elseif metatable.donePairs or nilArgs[key] then

return nil

end

for _, argTable in ipairs(argTables) do

local argTableVal = tidyVal(key, argTable[key])

if argTableVal ~= nil then

metaArgs[key] = argTableVal

return argTableVal

end

end

nilArgs[key] = 'h'

return nil

end

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) == '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

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

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, { t = metaArgs }

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 args

end

return arguments