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Module:Arguments: Difference between revisions
memoize nils, add type checks for frame and options, use string library functions instead of mw.text.trim and mw.ustring.find, define four different tidyVal functions to avoid checking options every time
(don't use "if frame == mw.getCurrentFrame()") |
(memoize nils, add type checks for frame and options, use string library functions instead of mw.text.trim and mw.ustring.find, define four different tidyVal functions to avoid checking options every time) |
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Line 1:
-- 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.
-- 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
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
if not options.parentOnly then
end
if not options.frameOnly then
pargs = frame:getParent().args
end
if options.parentFirst then
fargs, pargs = pargs, fargs
end
else
luaArgs =
end
Line 22 ⟶ 76:
setmetatable(args, metatable)
-- 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
error("bad value assigned to option 'valueFunc' (function expected, got " .. type(tidyVal) .. ')', 2)
if options.removeBlanks ~= false then
tidyVal = tidyValDefault
else
tidyVal = tidyValTrimOnly
end
else
if options.removeBlanks ~= false then
tidyVal = tidyValRemoveBlanksOnly
else
tidyVal = tidyValNoChange
end
end
Line 51 ⟶ 100:
-- 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
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
Line 61 ⟶ 117:
-- 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
-- argument tables once.
-- performance. Also, we keep a record in the metatable of when pairs and ipairs have been called, so we
--
-- 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
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
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
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