Difference between revisions of "Module:Arguments"
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+ | -- 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 | ||
+ | |||
+ | local translate_mt = { __index = function(t, k) return k end } | ||
+ | |||
+ | function arguments.getArgs(frame, options) | ||
+ | checkType('getArgs', 1, frame, 'table', true) | ||
+ | checkType('getArgs', 2, options, 'table', true) | ||
+ | frame = frame or {} | ||
+ | options = options or {} | ||
+ | |||
+ | --[[ | ||
+ | -- Set up argument translation. | ||
+ | --]] | ||
+ | options.translate = options.translate or {} | ||
+ | if getmetatable(options.translate) == nil then | ||
+ | setmetatable(options.translate, translate_mt) | ||
+ | end | ||
+ | if options.backtranslate == nil then | ||
+ | options.backtranslate = {} | ||
+ | for k,v in pairs(options.translate) do | ||
+ | options.backtranslate[v] = k | ||
+ | end | ||
+ | end | ||
+ | if options.backtranslate and getmetatable(options.backtranslate) == nil then | ||
+ | setmetatable(options.backtranslate, { | ||
+ | __index = function(t, k) | ||
+ | if options.translate[k] ~= k then | ||
+ | return nil | ||
+ | else | ||
+ | return k | ||
+ | end | ||
+ | end | ||
+ | }) | ||
+ | end | ||
+ | |||
+ | --[[ | ||
+ | -- 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. | ||
+ | --]] | ||
+ | if type(key) == 'string' then | ||
+ | key = options.translate[key] | ||
+ | end | ||
+ | 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 type(key) == 'string' then | ||
+ | key = options.translate[key] | ||
+ | end | ||
+ | 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 | ||
+ | |||
+ | local function translatenext(invariant) | ||
+ | local k, v = next(invariant.t, invariant.k) | ||
+ | invariant.k = k | ||
+ | if k == nil then | ||
+ | return nil | ||
+ | elseif type(k) ~= 'string' or not options.backtranslate then | ||
+ | return k, v | ||
+ | else | ||
+ | local backtranslate = options.backtranslate[k] | ||
+ | if backtranslate == nil then | ||
+ | -- Skip this one. This is a tail call, so this won't cause stack overflow | ||
+ | return translatenext(invariant) | ||
+ | else | ||
+ | return backtranslate, v | ||
+ | end | ||
+ | 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 translatenext, { t = 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 |
Latest revision as of 19:00, 9 December 2021
Documentation for this module may be created at Module:Arguments/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 = {} -- 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 local translate_mt = { __index = function(t, k) return k end } function arguments.getArgs(frame, options) checkType('getArgs', 1, frame, 'table', true) checkType('getArgs', 2, options, 'table', true) frame = frame or {} options = options or {} --[[ -- Set up argument translation. --]] options.translate = options.translate or {} if getmetatable(options.translate) == nil then setmetatable(options.translate, translate_mt) end if options.backtranslate == nil then options.backtranslate = {} for k,v in pairs(options.translate) do options.backtranslate[v] = k end end if options.backtranslate and getmetatable(options.backtranslate) == nil then setmetatable(options.backtranslate, { __index = function(t, k) if options.translate[k] ~= k then return nil else return k end end }) end --[[ -- 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. --]] if type(key) == 'string' then key = options.translate[key] end 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 type(key) == 'string' then key = options.translate[key] end 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 local function translatenext(invariant) local k, v = next(invariant.t, invariant.k) invariant.k = k if k == nil then return nil elseif type(k) ~= 'string' or not options.backtranslate then return k, v else local backtranslate = options.backtranslate[k] if backtranslate == nil then -- Skip this one. This is a tail call, so this won't cause stack overflow return translatenext(invariant) else return backtranslate, v end 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 translatenext, { t = 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