Module:Arguments
Documentation du Module:Arguments : v · d · m · h.
Ce module fournit un ensemble de fonctions utiles à la gestions des arguments passés avec #invoke, entre les modules et modèles. Il s’agit d’un meta-module susceptible de servir à d’autre modules, il ne doit pas être appelé directement par #Invoke
Le module propose :
- Suppressions des espaces dans les arguments et suppression des arguments vides.
- Les arguments peuvent provenir de l’objet frame courant et de l’objet frame parent, simultanément. (Voir plus de détails ci-dessous.)
- Les arguments peuvent être reçus directement depuis un autre module Lua, ou depuis la console debug.
- Les arguments sont rapportés comme il se doit, ce qui évite d’eventuels problèmes avec les marqueurs de références
<ref>…</ref>
. - La plupart des fonctions peuvent être personnalisées.
Usage Basique
modifierEn premier lieu, vous devez charger le module, il contient une fonction nommée getArgs
.
local getArgs = require('Module:Arguments').getArgs
Le scénario classique consiste à utilser getArgs dans votre fonction principale. La variable args
est une table, contenant les arguments depuis #invoke. (Voir les détails ci-dessous).
local getArgs = require('Module:Arguments').getArgs
local p = {}
function p.main(frame)
local args = getArgs(frame)
-- Ici, le code de la fonction principale du module .
end
return p
La pratique recommandée consiste à utiliser une fonction uniquement pour traiter les arguments depuis #invoke. Cela signifie que si quelqu’un appel votre module depuis un autre module Lua, vous n’avez pas besoin d’avoir un objet frame disponible, ceci améliore les performances.
local getArgs = require('Module:Arguments').getArgs
local p = {}
function p.main(frame)
local args = getArgs(frame)
return p._main(args)
end
function p._main(args)
-- Ici, le code principal du module.
end
return p
Si vous voulez que diverses fonctions puissent utiliser les arguments, tout en restant accessibles depuis #invoke, vous devez utiliser un wrapper c'est-à-dire une fonction d’encapsulation.
local getArgs = require('Module:Arguments').getArgs
local function makeInvokeFunc(funcName)
return function (frame)
local args = getArgs(frame)
return p[funcName](args)
end
end
local p = {}
p.func1 = makeInvokeFunc('_func1')
function p._func1(args)
-- Code for the first function goes here.
end
p.func2 = makeInvokeFunc('_func2')
function p._func2(args)
-- Code for the second function goes here.
end
return p
Options
modifierLes options suivantes sont disponibles, elles sont expliquées ci-dessous.
local args = getArgs(frame, {
trim = false,
removeBlanks = false,
valueFunc = function (key, value)
-- Code for processing one argument
end,
frameOnly = true,
parentOnly = true,
parentFirst = true,
wrappers = {
'Template:A wrapper template',
'Template:Another wrapper template'
},
readOnly = true,
noOverwrite = true
})
Trimming and removing blanks
modifierBlank arguments often trip up coders new to converting MediaWiki templates to Lua.
Selon la syntaxe des modèles, les chaines vides et chaines contenant uniquement des espaces sont considérés comme "faux". Cependant selon Lua, les chaines vides et chaines contenant uniquement des espaces sont considérés comme "vrai". Ceci signifie que si vous ne faites pas attention à de telles situations, vous risquez de traiter comme "vrai" quelque chose qui devrait être considéré comme "faux". Pour éviter cette confusion, le module supprime (par défaut), tous les arguments vides.
De la même façon les espaces peuvent causer des problèmes lors de l’utilisation d’arguments positionnels. Si les espaces inutiles sont supprimés lors du traitement d’argument nommé, ils sont préservés pour les arguments positionnés. Le plus souvent cet espace additionnel est indésirable ; donc ce module le supprime par défaut.
Malgré tout, parfois vous pouvez avoir besoin d’utiliser un argument "blanc" comme donnée, et d’autres fois vous avez besoin de laisser un espace additionnel. Cela peut être utile pour convertir certains modèles exactement comme ils ont été écris. Dans ces cas de figure, vous pouvez configurer les arguments trim
et removeBlanks
comme false
.
local args = getArgs(frame, {
trim = false,
removeBlanks = false
})
Custom formatting of arguments
modifierSometimes you want to remove some blank arguments but not others, or perhaps you might want to put all of the positional arguments in lower case. To do things like this you can use the valueFunc
option. The input to this option must be a function that takes two parameters, key
and value
, and returns a single value. This value is what you will get when you access the field key
in the args
table.
Example 1: this function preserves whitespace for the first positional argument, but trims all other arguments and removes all other blank arguments.
local args = getArgs(frame, {
valueFunc = function (key, value)
if key == 1 then
return value
elseif value then
value = mw.text.trim(value)
if value ~= '' then
return value
end
end
return nil
end
})
Example 2: this function removes blank arguments and converts all arguments to lower case, but doesn't trim whitespace from positional parameters.
local args = getArgs(frame, {
valueFunc = function (key, value)
if not value then
return nil
end
value = mw.ustring.lower(value)
if mw.ustring.find(value, '%S') then
return value
end
return nil
end
})
Note: the above functions will fail if passed input that is not of type string
or nil
. This might be the case if you use the getArgs
function in the main function of your module, and that function is called by another Lua module. In this case, you will need to check the type of your input. This is not a problem if you are using a function specially for arguments from #invoke (i.e. you have p.main
and p._main
functions, or something similar).
Modèle:Cot Example 1:
local args = getArgs(frame, {
valueFunc = function (key, value)
if key == 1 then
return value
elseif type(value) == 'string' then
value = mw.text.trim(value)
if value ~= '' then
return value
else
return nil
end
else
return value
end
end
})
Example 2:
local args = getArgs(frame, {
valueFunc = function (key, value)
if type(value) == 'string' then
value = mw.ustring.lower(value)
if mw.ustring.find(value, '%S') then
return value
else
return nil
end
else
return value
end
end
})
Also, please note that the valueFunc
function is called more or less every time an argument is requested from the args
table, so if you care about performance you should make sure you aren't doing anything inefficient with your code.
Frames and parent frames
modifierArguments in the args
table can be passed from the current frame or from its parent frame at the same time. To understand what this means, it is easiest to give an example. Let's say that we have a module called Module:ExampleArgs
. This module prints the first two positional arguments that it is passed.
local getArgs = require('Module:Arguments').getArgs
local p = {}
function p.main(frame)
local args = getArgs(frame)
return p._main(args)
end
function p._main(args)
local first = args[1] or ''
local second = args[2] or ''
return first .. ' ' .. second
end
return p
Module:ExampleArgs
is then called by Template:ExampleArgs
, which contains the code {{#invoke:ExampleArgs|main|firstInvokeArg}}
. This produces the result "firstInvokeArg".
Now if we were to call Template:ExampleArgs
, the following would happen:
Code | Result |
---|---|
{{ExampleArgs}}
|
firstInvokeArg |
{{ExampleArgs|firstTemplateArg}}
|
firstInvokeArg |
{{ExampleArgs|firstTemplateArg|secondTemplateArg}}
|
firstInvokeArg secondTemplateArg |
There are three options you can set to change this behaviour: frameOnly
, parentOnly
and parentFirst
. If you set frameOnly
then only arguments passed from the current frame will be accepted; if you set parentOnly
then only arguments passed from the parent frame will be accepted; and if you set parentFirst
then arguments will be passed from both the current and parent frames, but the parent frame will have priority over the current frame. Here are the results in terms of Template:ExampleArgs
:
- frameOnly
Code | Result |
---|---|
{{ExampleArgs}}
|
firstInvokeArg |
{{ExampleArgs|firstTemplateArg}}
|
firstInvokeArg |
{{ExampleArgs|firstTemplateArg|secondTemplateArg}}
|
firstInvokeArg |
- parentOnly
Code | Result |
---|---|
{{ExampleArgs}}
|
|
{{ExampleArgs|firstTemplateArg}}
|
firstTemplateArg |
{{ExampleArgs|firstTemplateArg|secondTemplateArg}}
|
firstTemplateArg secondTemplateArg |
- parentFirst
Code | Result |
---|---|
{{ExampleArgs}}
|
firstInvokeArg |
{{ExampleArgs|firstTemplateArg}}
|
firstTemplateArg |
{{ExampleArgs|firstTemplateArg|secondTemplateArg}}
|
firstTemplateArg secondTemplateArg |
Notes:
- If you set both the
frameOnly
andparentOnly
options, the module won't fetch any arguments at all from #invoke. This is probably not what you want. - In some situations a parent frame may not be available, e.g. if getArgs is passed the parent frame rather than the current frame. In this case, only the frame arguments will be used (unless parentOnly is set, in which case no arguments will be used) and the
parentFirst
andframeOnly
options will have no effect.
Wrappers
modifierThe wrappers option is used to specify a limited number of templates as wrapper templates, that is, templates whose only purpose is to call a module. If the module detects that it is being called from a wrapper template, it will only check for arguments in the parent frame; otherwise it will only check for arguments in the frame passed to getArgs. This allows modules to be called by either #invoke or through a wrapper template without the loss of performance associated with having to check both the frame and the parent frame for each argument lookup.
For example, the only content of Template:Side box (excluding content in Modèle:Tag tags) is {{#invoke:Side box|main}}
. There is no point in checking the arguments passed directly to the #invoke statement for this template, as no arguments will ever be specified there. We can avoid checking arguments passed to #invoke by using the parentOnly option, but if we do this then #invoke will not work from other pages either. If this were the case, the |text=Some text
in the code {{#invoke:Side box|main|text=Some text}}
would be ignored completely, no matter what page it was used from. By using the wrappers
option to specify 'Template:Side box' as a wrapper, we can make {{#invoke:Side box|main|text=Some text}}
work from most pages, while still not requiring that the module check for arguments on the Template:Side box page itself.
Wrappers can be specified either as a string, or as an array of strings.
local args = getArgs(frame, {
wrappers = 'Template:Wrapper template'
})
local args = getArgs(frame, {
wrappers = {
'Template:Wrapper 1',
'Template:Wrapper 2',
-- Any number of wrapper templates can be added here.
}
})
Notes:
- The module will automatically detect if it is being called from a wrapper template's /sandbox subpage, so there is no need to specify sandbox pages explicitly.
- The wrappers option effectively changes the default of the frameOnly and parentOnly options. If, for example, parentOnly were explicitly set to false with wrappers set, calls via wrapper templates would result in both frame and parent arguments being loaded, though calls not via wrapper templates would result in only frame arguments being loaded.
- If the wrappers option is set and no parent frame is available, the module will always get the arguments from the frame passed to
getArgs
.
Writing to the args table
modifierSometimes it can be useful to write new values to the args table. This is possible with the default settings of this module. (However, bear in mind that it is usually better coding style to create a new table with your new values and copy arguments from the args table as needed.)
args.foo = 'some value'
It is possible to alter this behaviour with the readOnly
and noOverwrite
options. If readOnly
is set then it is not possible to write any values to the args table at all. If noOverwrite
is set, then it is possible to add new values to the table, but it is not possible to add a value if it would overwrite any arguments that are passed from #invoke.
Ref tags
modifierThis module uses metatables to fetch arguments from #invoke. This allows access to both the frame arguments and the parent frame arguments without using the pairs()
function. This can help if your module might be passed Modèle:Tag tags as input.
As soon as Modèle:Tag tags are accessed from Lua, they are processed by the MediaWiki software and the reference will appear in the reference list at the bottom of the article. If your module proceeds to omit the reference tag from the output, you will end up with a phantom reference - a reference that appears in the reference list, but no number that links to it. This has been a problem with modules that use pairs()
to detect whether to use the arguments from the frame or the parent frame, as those modules automatically process every available argument.
This module solves this problem by allowing access to both frame and parent frame arguments, while still only fetching those arguments when it is necessary. The problem will still occur if you use pairs(args)
elsewhere in your module, however.
Known limitations
modifierThe use of metatables also has its downsides. Most of the normal Lua table tools won't work properly on the args table, including the #
operator, the next()
function, and the functions in the table library. If using these is important for your module, you should use your own argument processing function instead of this module.
Interwiki
-- 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