Module:Arguments: Difference between revisions

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-- This module provides easy processing of arguments passed to Scribunto from #invoke.
-- This module provides easy processing of arguments passed to Scribunto from
-- It is intended for use by other Lua modules, and should not be called from #invoke directly.
-- #invoke. It is intended for use by other Lua modules, and should not be
-- called from #invoke directly.
 
local libraryUtil = require('libraryUtil')
local libraryUtil = require('libraryUtil')
local checkType = libraryUtil.checkType
local checkType = libraryUtil.checkType
 
local arguments = {}
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.
-- 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)
local function tidyValDefault(key, val)
if type(val) == 'string' then
if type(val) == 'string' then
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end
end
end
end
 
local function tidyValTrimOnly(key, val)
local function tidyValTrimOnly(key, val)
if type(val) == 'string' then
if type(val) == 'string' then
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end
end
end
end
 
local function tidyValRemoveBlanksOnly(key, val)
local function tidyValRemoveBlanksOnly(key, val)
if type(val) == 'string' then
if type(val) == 'string' then
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end
end
end
end
 
local function tidyValNoChange(key, val)
local function tidyValNoChange(key, val)
return val
return val
end
end
 
function arguments.getArgs(frame, options)
function arguments.getArgs(frame, options)
checkType('getArgs', 1, frame, 'table', true)
checkType('getArgs', 1, frame, 'table', true)
Line 53: Line 53:
frame = frame or {}
frame = frame or {}
options = options 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 assign the args to a new variable so we can differentiate them.
-- 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
local fargs, pargs, luaArgs
if type(frame.args) == 'table' and type(frame.getParent) == 'function' then
if type(frame.args) == 'table' and type(frame.getParent) == 'function' then
if not options.parentOnly then
if options.wrappers then
fargs = frame.args
--[[
end
-- The wrappers option makes Module:Arguments look up arguments in
if not options.frameOnly then
-- either the frame argument table or the parent argument table, but
pargs = frame:getParent().args
-- not both. This means that users can use either the #invoke syntax
end
-- or a wrapper template without the loss of performance associated
if options.parentFirst then
-- with looking arguments up in both the frame and the parent frame.
fargs, pargs = pargs, fargs
-- 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 type(options.wrappers) == 'table' then
for _,v in pairs(options.wrappers) do
if v == title then
found = true
break
end
end
elseif options.wrappers == title then
found = true
end
if found then
pargs = parent.args
else
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
if options.parentFirst then
fargs, pargs = pargs, fargs
end
end
end
else
else
luaArgs = frame
luaArgs = frame
end
end
-- Set up the args and metaArgs tables. args will be the one accessed from functions, and metaArgs will hold the actual arguments.
-- Set the order of precedence of the argument tables. If the variables are
-- The metatable connects the two together.
-- nil, nothing will be added to the table, which is how we avoid clashes
local args, metaArgs, metatable = {}, {}, {}
-- between the frame/parent args and the Lua args.
setmetatable(args, metatable)
local argTables = {fargs}
argTables[#argTables + 1] = pargs
-- Generate the tidyVal function. If it has been specified by the user, we use that; if not, we choose one of four functions
argTables[#argTables + 1] = luaArgs
-- depending on the options chosen. This is so that we don't have to call the options table every time the function is called.
 
--[[
-- 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
local tidyVal = options.valueFunc
if tidyVal then
if tidyVal then
if type(tidyVal) ~= 'function' then
if type(tidyVal) ~= 'function' then
error("bad value assigned to option 'valueFunc' (function expected, got " .. type(tidyVal) .. ')', 2)
error(
"bad value assigned to option 'valueFunc'"
.. '(function expected, got '
.. type(tidyVal)
.. ')',
2
)
end
end
elseif options.trim ~= false then
elseif options.trim ~= false then
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end
end
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(iterator, tables)
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 precedence.
-- Accepts multiple tables as input and merges their keys and values
-- We are also memoizing nil values, but those values can be overwritten.
-- into one table using the specified iterator. If a value is already
-- present it is not overwritten; tables listed earlier have precedence.
-- 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
local metaArgsVal = metaArgs[key]
if metaArgs[key] == nil then
if metaArgsVal == nil or metaArgsVal == nilArg then
local tidiedVal = tidyVal(key, val)
local tidiedVal = tidyVal(key, val)
if tidiedVal == nil then
if tidiedVal == nil then
metaArgs[key] = nilArg
nilArgs[key] = true
else
else
metaArgs[key] = tidiedVal
metaArgs[key] = tidiedVal
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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
-- Define metatable behaviour. Arguments are memoized in the metaArgs table,
-- argument tables once. Nil arguments are also memoized using the nilArg variable in order to increase
-- and are only fetched from the argument tables once. Fetching arguments
-- performance. Also, we keep a record in the metatable of when pairs and ipairs have been called, so we
-- from the argument tables is the most resource-intensive step in this
-- do not run pairs and ipairs on fargs and pargs more than once. We also do not run ipairs on fargs and
-- module, so we try and avoid it where possible. For this reason, nil
-- pargs if pairs has already been run, as all the arguments will already have been copied over.
-- 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)
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.
--]]
local val = metaArgs[key]
local val = metaArgs[key]
if val ~= nil then
if val ~= nil then
if val == nilArg then
return val
return nil
elseif metatable.donePairs or nilArgs[key] then
else
return nil
return val
end
end
end
for _, argTable in ipairs(argTables) do
for _, argTable in ipairs(argTables) do
local argTableVal = tidyVal(key, argTable[key])
local argTableVal = tidyVal(key, argTable[key])
if argTableVal == nil then
if argTableVal == nil then
metaArgs[key] = nilArg
nilArgs[key] = true
else
else
metaArgs[key] = argTableVal
metaArgs[key] = argTableVal
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return nil
return nil
end
end
 
metatable.__newindex = function (t, key, val)
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 options.readOnly then
if options.readOnly then
error('could not write to argument table key "' .. tostring(key) .. '"; the table is read-only', 2)
error(
'could not write to argument table key "'
.. tostring(key)
.. '"; the table is read-only',
2
)
elseif options.noOverwrite and args[key] ~= nil then
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)
error(
'could not write to argument table key "'
.. tostring(key)
.. '"; overwriting existing arguments is not permitted',
2
)
elseif val == nil then
elseif val == nil then
metaArgs[key] = nilArg -- Memoize nils.
--[[
-- 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] = true
else
else
metaArgs[key] = val
metaArgs[key] = val
end
end
end
end
 
metatable.__pairs = function ()
metatable.__pairs = function ()
-- Called when pairs is run on the args table.
if not metatable.donePairs then
if not metatable.donePairs then
mergeArgs(pairs, argTables)
mergeArgs(pairs, argTables)
Line 169: Line 265:
metatable.doneIpairs = true
metatable.doneIpairs = true
end
end
return function (t, k)
return pairs(metaArgs)
local nk, val = next(metaArgs, k)
if val == nilArg then
val = nil
end
return nk, val
end
end
end
 
metatable.__ipairs = function ()
metatable.__ipairs = function ()
-- Called when ipairs is run on the args table.
if not metatable.doneIpairs then
if not metatable.doneIpairs then
mergeArgs(ipairs, argTables)
mergeArgs(ipairs, argTables)
metatable.doneIpairs = true
metatable.doneIpairs = true
end
end
return function (t, i)
return ipairs(metaArgs)
local val = metaArgs[i + 1]
if val == nil then
return nil
elseif val == nilArg then
val = nil
end
return i + 1, val
end, nil, 0
end
end
 
return args
return args
end
end
 
return arguments
return arguments

Revision as of 09:53, 9 June 2014

-- 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

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 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 type(options.wrappers) == 'table' then for _,v in pairs(options.wrappers) do if v == title then found = true break end end elseif options.wrappers == title then found = true end if found then pargs = parent.args else 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 if options.parentFirst then fargs, pargs = pargs, fargs end 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(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 precedence. -- 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 metaArgs[key] == nil then local tidiedVal = tidyVal(key, val) if tidiedVal == nil then nilArgs[key] = true 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. --]] 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 nilArgs[key] = true else metaArgs[key] = argTableVal return argTableVal end end 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 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] = true else metaArgs[key] = val end end

metatable.__pairs = function () -- Called when pairs is run on the args table. if not metatable.donePairs then mergeArgs(pairs, argTables) metatable.donePairs = true metatable.doneIpairs = true end return pairs(metaArgs) end

metatable.__ipairs = function () -- Called when ipairs is run on the args table. if not metatable.doneIpairs then mergeArgs(ipairs, argTables) metatable.doneIpairs = true end return ipairs(metaArgs) end

return args end

return arguments