Difference between revisions of "Module:Arguments/sandbox"
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blackwiki>Mr. Stradivarius (start at replacing argTables - still need to convert mergeArgs though) |
blackwiki>Mr. Stradivarius (partially revert back to the argTables code, with a few improvements - code without argTables always seems to turn ugly) |
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Line 29: | Line 29: | ||
end | end | ||
else | else | ||
− | luaArgs = | + | luaArgs = frame |
end | end | ||
Line 67: | Line 67: | ||
-- Accepts multiple tables as input and merges their keys and values into one table using the specified iterator. | -- Accepts multiple tables as input and merges their keys and values into one table using the specified iterator. | ||
-- If a value is already present it is not overwritten; tables listed earlier have precendence. | -- If a value is already present it is not overwritten; tables listed earlier have precendence. | ||
+ | -- We are also memoizing nil values, but those values can be overwritten. | ||
for _, t in ipairs(tables) do | for _, t in ipairs(tables) do | ||
for key, val in iterator(t) do | for key, val in iterator(t) do | ||
Line 82: | Line 83: | ||
end | 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 | |
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
--[[ | --[[ | ||
Line 113: | Line 106: | ||
end | end | ||
end | end | ||
− | + | for _, argTable in ipairs(argTables) do | |
− | + | local argTableVal = tidyVal(key, argTable[key]) | |
− | + | if argTableVal == nil then | |
− | + | metaArgs[key] = nilArg | |
− | + | else | |
− | + | metaArgs[key] = argTableVal | |
− | + | return argTableVal | |
− | + | end | |
− | |||
− | |||
− | |||
− | |||
end | end | ||
return nil | return nil |
Revision as of 11:50, 11 December 2013
Documentation for this module may be created at Module:Arguments/sandbox/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 = {}
local nilArg = {} -- Used for memoizing nil arguments in metaArgs.
function arguments.getArgs(frame, options)
checkType('getArgs', 1, frame, 'table', true)
checkType('getArgs', 2, options, 'table', true)
frame = frame or {}
options = options or {}
-- Get the arguments from the frame object if available. If the frame object is not available, we are being called
-- from another Lua module or from the debug console, so put the args in a special table so we can differentiate them.
local fargs, pargs, luaArgs
if type(frame.args) == 'table' and type(frame.getParent) == 'function' then
if not options.parentOnly then
fargs = frame.args
end
if not options.frameOnly then
pargs = frame:getParent().args
end
if options.parentFirst then
fargs, pargs = pargs, fargs
end
else
luaArgs = frame
end
-- Set up the args and metaArgs tables. args will be the one accessed from functions, and metaArgs will hold the actual arguments.
-- The metatable connects the two together.
local args, metaArgs, metatable = {}, {}, {}
setmetatable(args, metatable)
local function tidyVal(key, val)
-- Processes a value according to the options given to getArguments. Can trim whitespace and remove blanks.
-- Keys are not used here, but they can be used by user-generated functions, so defining it here to avoid breakage.
if type(val) == 'string' then
if options.trim ~= false then
val = val:match('^%s*(.-)%s*$')
end
if options.removeBlanks == false or val:find('%S') then
return val
end
else
return val
end
return nil
end
-- Use a user-generated function to tidy the values if specified.
local valueFunc = options.valueFunc
if valueFunc then
local valueFuncType = type(valueFunc)
if valueFuncType == 'function' then
tidyVal = valueFunc
else
error('type error in option "valueFunc": expected function, got ' .. valueFuncType, 2)
end
end
local function mergeArgs(iterator, tables)
-- Accepts multiple tables as input and merges their keys and values into one table using the specified iterator.
-- If a value is already present it is not overwritten; tables listed earlier have precendence.
-- We are also memoizing nil values, but those values can be overwritten.
for _, t in ipairs(tables) do
for key, val in iterator(t) do
local metaArgsVal = metaArgs[key]
if metaArgsVal == nil or metaArgsVal == nilArg then
local tidiedVal = tidyVal(key, val)
if tidiedVal == nil then
metaArgs[key] = nilArg
else
metaArgs[key] = tidiedVal
end
end
end
end
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
--[[
-- Define metatable behaviour. Arguments are memoized in the metaArgs table, and are only fetched from the
-- argument tables once. Nil arguments are also memoized using the nilArg variable in order to increase
-- performance. 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 fargs and pargs 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)
local val = metaArgs[key]
if val ~= nil then
if val == nilArg then
return nil
else
return val
end
end
for _, argTable in ipairs(argTables) do
local argTableVal = tidyVal(key, argTable[key])
if argTableVal == nil then
metaArgs[key] = nilArg
else
metaArgs[key] = argTableVal
return argTableVal
end
end
return nil
end
metatable.__newindex = function (t, key, val)
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
metaArgs[key] = nilArg -- Memoize nils.
else
metaArgs[key] = val
end
end
metatable.__pairs = function ()
if not metatable.donePairs then
mergeArgs(pairs, argTables)
metatable.donePairs = true
metatable.doneIpairs = true
end
return pairs(metaArgs)
end
metatable.__ipairs = function ()
if not metatable.doneIpairs then
mergeArgs(ipairs, argTables)
metatable.doneIpairs = true
end
return ipairs(metaArgs)
end
return args
end
return arguments