Module:Arguments: Difference between revisions

Content added Content deleted
(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)
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)
options = type(options) == 'table' and options or {}
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) == 'table' and type(frame.args) == 'table' and type(frame.getParent) == 'function' then
if not options.parentOnly then
fargs = frame.args
pargs fargs = frame:getParent().args
end
if not options.frameOnly then
pargs = frame:getParent().args
end
if options.parentFirst then
fargs, pargs = pargs, fargs
end
else
luaArgs = type(frame) == 'table' and frame or {}
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
local function tidyVal(key, val)
-- depending on the options chosen. This is so that we don't have to call the options table every time the function is called.
-- Processes a value according to the options given to getArguments. Can trim whitespace and remove blanks.
local tidyVal = options.valueFunc
-- 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'tidyVal then
if options.trimtype(tidyVal) ~= false'function' then
error("bad value assigned to option 'valueFunc' (function expected, got " .. type(tidyVal) .. ')', 2)
val = mw.text.trim(val)
end
if elseif options.removeBlankstrim =~= false or mw.ustring.find(val, '%S') then
if options.removeBlanks ~= false then
return val
tidyVal = tidyValDefault
end
else
tidyVal = tidyValTrimOnly
return val
end
else
end
if options.removeBlanks ~= false then
 
tidyVal = tidyValRemoveBlanksOnly
-- 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
tidyVal = tidyValNoChange
error('type error in option "valueFunc": expected function, got ' .. valueFuncType, 2)
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
iflocal metaArgsVal = metaArgs[key] == nil then
if metaArgsVal == nil or metaArgsVal == nilArg then
metaArgs[key] = tidyVal(key, val)
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
if options.frameOnly then
argTables[#argTables + 1] = luaArgs
table.insert(argTables, fargs)
elseif options.parentOnly then
table.insert(argTables, pargs)
elseif options.parentFirst then
table.insert(argTables, pargs)
table.insert(argTables, fargs)
else
table.insert(argTables, fargs)
table.insert(argTables, pargs)
end
table.insert(argTables, luaArgs)
 
--[[
-- Define metatable behaviour. Arguments are storedmemoized in the metaArgs table, and are only fetched from the
-- argument tables once. Also,Nil wearguments keepare aalso recordmemoized inusing the metatablenilArg ofvariable when pairs and ipairsin haveorder beento called,increase
-- performance. Also, we keep a record in the metatable of when pairs and ipairs have been called, so we
-- so we do not run pairs and ipairs on fargs and pargs more than once. We also do not run ipairs on fargs
-- anddo pargsnot ifrun pairs hasand alreadyipairs beenon run,fargs asand allpargs themore argumentsthan willonce. alreadyWe havealso beendo copiednot over.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
returnif val == nilArg then
return nil
else
else
for i, argTable in ipairs(argTables) do
return val
local argTableVal = tidyVal(key, argTable[key])
if argTableVal ~= nil then
metaArgs[key] = argTableVal
return argTableVal
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
return nil
end
 
metatable.__newindex = function (t, key, val)
if not options.readOnly and (not options.noOverwrite or args[key] == nil) 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
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