Difference between revisions of "Module:Arguments"

(add a "wrappers" option and fix bug when frame:getParent() returns nil, per protected edit request by User:Jackmcbarn)
m (20 revisions)
 
(3 intermediate revisions by 2 users not shown)
Line 46: Line 46:
 
local function tidyValNoChange(key, val)
 
local function tidyValNoChange(key, val)
 
return 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
 
end
  
Line 82: Line 87:
 
local title = parent:getTitle():gsub('/sandbox$', '')
 
local title = parent:getTitle():gsub('/sandbox$', '')
 
local found = false
 
local found = false
if type(options.wrappers) == 'table' then
+
if matchesTitle(options.wrappers, title) then
 +
found = true
 +
elseif type(options.wrappers) == 'table' then
 
for _,v in pairs(options.wrappers) do
 
for _,v in pairs(options.wrappers) do
if v == title then
+
if matchesTitle(v, title) then
 
found = true
 
found = true
 
break
 
break
 
end
 
end
 
end
 
end
elseif options.wrappers == title then
 
found = true
 
 
end
 
end
if found then
+
 +
-- We test for false specifically here so that nil (the default) acts like true.
 +
if found or options.frameOnly == false then
 
pargs = parent.args
 
pargs = parent.args
else
+
end
 +
if not found or options.parentOnly == false then
 
fargs = frame.args
 
fargs = frame.args
 
end
 
end
Line 107: Line 115:
 
pargs = parent and parent.args or nil
 
pargs = parent and parent.args or nil
 
end
 
end
if options.parentFirst then
+
end
fargs, pargs = pargs, fargs
+
if options.parentFirst then
end
+
fargs, pargs = pargs, fargs
 
end
 
end
 
else
 
else
Line 162: Line 170:
 
setmetatable(args, metatable)
 
setmetatable(args, metatable)
  
local function mergeArgs(iterator, tables)
+
local function mergeArgs(tables)
 
--[[
 
--[[
 
-- Accepts multiple tables as input and merges their keys and values
 
-- Accepts multiple tables as input and merges their keys and values
-- into one table using the specified iterator. If a value is already
+
-- into one table. If a value is already present it is not overwritten;
-- present it is not overwritten; tables listed earlier have precedence.
+
-- tables listed earlier have precedence. We are also memoizing nil
-- We are also memoizing nil values, but those values can be
+
-- values, which can be overwritten if they are 's' (soft).
-- overwritten.
 
 
--]]
 
--]]
 
for _, t in ipairs(tables) do
 
for _, t in ipairs(tables) do
for key, val in iterator(t) do
+
for key, val in pairs(t) do
if metaArgs[key] == nil then
+
if metaArgs[key] == nil and nilArgs[key] ~= 'h' then
 
local tidiedVal = tidyVal(key, val)
 
local tidiedVal = tidyVal(key, val)
 
if tidiedVal == nil then
 
if tidiedVal == nil then
nilArgs[key] = true
+
nilArgs[key] = 's'
 
else
 
else
 
metaArgs[key] = tidiedVal
 
metaArgs[key] = tidiedVal
Line 216: Line 223:
 
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
nilArgs[key] = true
 
else
 
 
metaArgs[key] = argTableVal
 
metaArgs[key] = argTableVal
 
return argTableVal
 
return argTableVal
 
end
 
end
 
end
 
end
 +
nilArgs[key] = 'h'
 
return nil
 
return nil
 
end
 
end
Line 252: Line 258:
 
--]]
 
--]]
 
metaArgs[key] = nil
 
metaArgs[key] = nil
nilArgs[key] = true
+
nilArgs[key] = 'h'
 
else
 
else
 
metaArgs[key] = val
 
metaArgs[key] = val
Line 261: Line 267:
 
-- Called when pairs is run on the args table.
 
-- Called when pairs is run on the args table.
 
if not metatable.donePairs then
 
if not metatable.donePairs then
mergeArgs(pairs, argTables)
+
mergeArgs(argTables)
 
metatable.donePairs = true
 
metatable.donePairs = true
metatable.doneIpairs = true
 
 
end
 
end
 
return pairs(metaArgs)
 
return pairs(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
 
end
  
metatable.__ipairs = function ()
+
metatable.__ipairs = function (t)
 
-- Called when ipairs is run on the args table.
 
-- Called when ipairs is run on the args table.
if not metatable.doneIpairs then
+
return inext, t, 0
mergeArgs(ipairs, argTables)
 
metatable.doneIpairs = true
 
end
 
return ipairs(metaArgs)
 
 
end
 
end
  

Latest revision as of 13:03, 9 February 2015

-- 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

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 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. --]] 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 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

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