Module:Dev/I18n
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Documentation for this module may be created at Module:Dev/I18n/doc
--- I18n library for message storage in Lua datastores.
-- The module is designed to enable message separation from modules &
-- templates. It has support for handling language fallbacks. This
-- module is a Lua port of [[I18n-js]].
--
-- @module i18n
-- @version 1.4.0
-- @require Module:Entrypoint
-- @require Module:Fallbacklist
-- @author [[User:KockaAdmiralac|KockaAdmiralac]]
-- @author [[User:Speedit|Speedit]]
-- @attribution [[User:Cqm|Cqm]]
-- @release stable
-- @todo Add Lua i18n file support in the [[I18n-js#Editing
-- your messages|I18n-js editor]].
-- @see [[I18n|I18n guide]]
-- @see [[I18n-js]]
-- <nowiki>
local i18n, _i18n = {}, {}
-- Module variables & dependencies.
local title = mw.title.getCurrentTitle()
local fallbacks = require('Dev/Fallbacklist')
local entrypoint = require('Dev/Entrypoint')
local uselang
--- Argument substitution as $n where n > 0.
-- @function _i18n.handleArgs
-- @param {string} msg Message to substitute arguments into.
-- @param {table} args Arguments table to substitute.
-- @return {string} Resulting message.
-- @local
function _i18n.handleArgs(msg, args)
for i, a in ipairs(args) do
msg = (string.gsub(msg, '%$' .. tostring(i), tostring(a)))
end
return msg
end
--- Checks whether a language code is valid.
-- @function _i18n.isValidCode
-- @param {string} code Language code to check.
-- @return {boolean} Whether the language code is valid.
-- @local
function _i18n.isValidCode(code)
return type(code) == 'string' and #mw.language.fetchLanguageName(code) ~= 0
end
--- Checks whether a message contains unprocessed wikitext.
-- Used to optimise message getter by not preprocessing pure text.
-- @function _i18n.isWikitext
-- @param {string} msg Message to check.
-- @return {boolean} Whether the message contains wikitext.
function _i18n.isWikitext(msg)
return
type(msg) == 'string' and
(
msg:find('%-%-%-%-') or
msg:find('%f[^\n%z][;:*#] ') or
msg:find('%f[^\n%z]==* *[^\n|]+ =*=%f[\n]') or
msg:find('%b<>') or msg:find('\'\'') or
msg:find('%[%b[]%]') or msg:find('{%b{}}')
)
end
--- I18n datastore class.
-- This is used to control language translation and access to individual
-- messages. The datastore instance provides language and message
-- getter-setter methods, which can be used to internationalize Lua modules.
-- The language methods (any ending in `Lang`) are all **chainable**.
-- @type Data
local Data = {}
Data.__index = Data
--- Datastore message getter utility.
-- This method returns localized messages from the datastore corresponding
-- to a `key`. These messages may have `$n` parameters, which can be
-- replaced by optional argument strings supplied by the `msg` call.
--
-- This function supports [[Lua reference manual#named_arguments|named
-- arguments]]. The named argument syntax is more versatile despite its
-- verbosity; it can be used to select message language & source(s).
-- @function Data:msg
-- @usage
--
-- ds:msg{
-- key = 'message-name',
-- lang = '',
-- args = {...},
-- sources = {}
-- }
--
-- @usage
--
-- ds:msg('message-name', ...)
--
-- @param {string|table} opts Message configuration or key.
-- @param[opt] {string} opts.key Message key to return from the
-- datastore.
-- @param[opt] {table} opts.args Arguments to substitute into the
-- message (`$n`).
-- @param[opt] {table} opts.sources Source names to limit to (see
-- `Data:fromSources`).
-- @param[opt] {table} opts.lang Temporary language to use (see
-- `Data:inLang`).
-- @param[opt] {string} ... Arguments to substitute into the message
-- (`$n`).
-- @error[115] {string} 'missing arguments in Data:msg'
-- @return {string} Localised datastore message or `'<key>'`.
function Data:msg(opts, ...)
local frame = mw.getCurrentFrame()
-- Argument normalization.
if not self or not opts then
error('missing arguments in Data:msg')
end
local key = type(opts) == 'table' and opts.key or opts
local args = opts.args or {...}
-- Configuration parameters.
if opts.sources then
self:fromSources(unpack(opts.sources))
end
if opts.lang then
self:inLang(opts.lang)
end
-- Source handling.
local source_n = self.tempSources or self._sources
local source_i = {}
for n, i in pairs(source_n) do
source_i[i] = n
end
self.tempSources = nil
-- Language handling.
local lang = self.tempLang or self.defaultLang
self.tempLang = nil
-- Message fetching.
local msg
for i, messages in ipairs(self._messages) do
-- Message data.
local msg = (messages[lang] or {})[key]
-- Fallback support (experimental).
for _, l in ipairs((fallbacks[lang] or {})) do
if msg == nil then
msg = (messages[l] or {})[key]
end
end
-- Internal fallback to 'en'.
msg = msg ~= nil and msg or messages.en[key]
-- Handling argument substitution from Lua.
if msg and source_i[i] and #args > 0 then
msg = _i18n.handleArgs(msg, args)
end
if msg and source_i[i] and lang ~= 'qqx' then
return frame and _i18n.isWikitext(msg)
and frame:preprocess(mw.text.trim(msg))
or mw.text.trim(msg)
end
end
return mw.text.nowiki('<' .. key .. '>')
end
--- Datastore template parameter getter utility.
-- This method, given a table of arguments, tries to find a parameter's
-- localized name in the datastore and returns its value, or nil if
-- not present.
--
-- This method always uses the wiki's content language.
-- @function Data:parameter
-- @param {string} parameter Parameter's key in the datastore
-- @param {table} args Arguments to find the parameter in
-- @error[176] {string} 'missing arguments in Data:parameter'
-- @return {string|nil} Parameter's value or nil if not present
function Data:parameter(key, args)
-- Argument normalization.
if not self or not key or not args then
error('missing arguments in Data:parameter')
end
local contentLang = mw.language.getContentLanguage():getCode()
-- Message fetching.
for i, messages in ipairs(self._messages) do
local msg = (messages[contentLang] or {})[key]
if msg ~= nil and args[msg] ~= nil then
return args[msg]
end
for _, l in ipairs((fallbacks[contentLang] or {})) do
if msg == nil or args[msg] == nil then
-- Check next fallback.
msg = (messages[l] or {})[key]
else
-- A localized message was found.
return args[msg]
end
end
-- Fallback to English.
msg = messages.en[key]
if msg ~= nil and args[msg] ~= nil then
return args[msg]
end
end
end
--- Datastore temporary source setter to a specificed subset of datastores.
-- By default, messages are fetched from the datastore in the same
-- order of priority as `i18n.loadMessages`.
-- @function Data:fromSource
-- @param {string} ... Source name(s) to use.
-- @return {Data} Datastore instance.
function Data:fromSource(...)
local c = select('#', ...)
if c ~= 0 then
self.tempSources = {}
for i = 1, c do
local n = select(i, ...)
if type(n) == 'string' and type(self._sources[n]) == 'number' then
self.tempSources[n] = self._sources[n]
end
end
end
return self
end
--- Datastore default language getter.
-- @function Data:getLang
-- @return {string} Default language to serve datastore messages in.
function Data:getLang()
return self.defaultLang
end
--- Datastore language setter to `wgUserLanguage`.
-- @function Data:useUserLang
-- @return {Data} Datastore instance.
-- @note Scribunto only registers `wgUserLanguage` when an
-- invocation is at the top of the call stack.
function Data:useUserLang()
self.defaultLang = i18n.getLang() or self.defaultLang
return self
end
--- Datastore language setter to `wgContentLanguage`.
-- @function Data:useContentLang
-- @return {Data} Datastore instance.
function Data:useContentLang()
self.defaultLang = mw.language.getContentLanguage():getCode()
return self
end
--- Datastore language setter to specificed language.
-- @function Data:useLang
-- @param {string} code Language code to use.
-- @return {Data} Datastore instance.
function Data:useLang(code)
self.defaultLang = _i18n.isValidCode(code)
and code
or self.defaultLang
return self
end
--- Temporary datastore language setter to `wgUserLanguage`.
-- The datastore language reverts to the default language in the next
-- @{Data:msg} call.
-- @function Data:inUserLang
-- @return {Data} Datastore instance.
function Data:inUserLang()
self.tempLang = i18n.getLang() or self.tempLang
return self
end
--- Temporary datastore language setter to `wgContentLanguage`.
-- Only affects the next @{Data:msg} call.
-- @function Data:inContentLang
-- @return {Data} Datastore instance.
function Data:inContentLang()
self.tempLang = mw.language.getContentLanguage():getCode()
return self
end
--- Temporary datastore language setter to a specificed language.
-- Only affects the next @{Data:msg} call.
-- @function Data:inLang
-- @param {string} code Language code to use.
-- @return {Data} Datastore instance.
function Data:inLang(code)
self.tempLang = _i18n.isValidCode(code)
and code
or self.tempLang
return self
end
-- Package functions.
--- Localized message getter by key.
-- Can be used to fetch messages in a specific language code through `uselang`
-- parameter. Extra numbered parameters can be supplied for substitution into
-- the datastore message.
-- @function i18n.getMsg
-- @param {table} frame Frame table from invocation.
-- @param {table} frame.args Metatable containing arguments.
-- @param {string} frame.args[1] ROOTPAGENAME of i18n submodule.
-- @param {string} frame.args[2] Key of i18n message.
-- @param[opt] {string} frame.args.lang Default language of message.
-- @error[271] 'missing arguments in i18n.getMsg'
-- @return {string} I18n message in localised language.
-- @usage {{i18n|getMsg|source|key|arg1|arg2|uselang {{=}} code}}
function i18n.getMsg(frame)
if
not frame or
not frame.args or
not frame.args[1] or
not frame.args[2]
then
error('missing arguments in i18n.getMsg')
end
local source = frame.args[1]
local key = frame.args[2]
-- Pass through extra arguments.
local repl = {}
for i, a in ipairs(frame.args) do
if i >= 3 then
repl[i-2] = a
end
end
-- Load message data.
local ds = i18n.loadMessages(source)
-- Pass through language argument.
ds:inLang(frame.args.uselang)
-- Return message.
return ds:msg { key = key, args = repl }
end
--- I18n message datastore loader.
-- @function i18n.loadMessages
-- @param {string} ... ROOTPAGENAME/path for target i18n
-- submodules.
-- @error[322] {string} 'no source supplied to i18n.loadMessages'
-- @return {table} I18n datastore instance.
-- @usage require('Dev:I18n').loadMessages('1', '2')
function i18n.loadMessages(...)
local ds
local i = 0
local s = {}
for j = 1, select('#', ...) do
local source = select(j, ...)
if type(source) == 'string' and source ~= '' then
i = i + 1
s[source] = i
if not ds then
-- Instantiate datastore.
ds = {}
ds._messages = {}
-- Set default language.
setmetatable(ds, Data)
ds:useUserLang()
end
source = string.gsub(source, '^.', mw.ustring.upper)
source = mw.ustring.find(source, ':')
and source
or 'Dev:' .. source .. '/i18n'
ds._messages[i] = mw.loadData(source)
end
end
if not ds then
error('no source supplied to i18n.loadMessages')
else
-- Attach source index map.
ds._sources = s
-- Return datastore instance.
return ds
end
end
--- Language code getter.
-- Can validate a template's language code through `uselang` parameter.
-- @function i18n.getLang
-- @usage {{i18n|getLang|uselang {{=}} code}}
-- @return {string} Language code.
function i18n.getLang()
local frame = mw.getCurrentFrame() or {}
local parentFrame = frame.getParent and frame:getParent() or {}
local code = mw.language.getContentLanguage():getCode()
local subPage = title.subpageText
-- Language argument test.
local langOverride =
(frame.args or {}).uselang or
(parentFrame.args or {}).uselang
if _i18n.isValidCode(langOverride) then
code = langOverride
-- Subpage language test.
elseif title.isSubpage and _i18n.isValidCode(subPage) then
code = _i18n.isValidCode(subPage) and subPage or code
-- User language test.
elseif parentFrame.preprocess or frame.preprocess then
uselang = uselang
or parentFrame.preprocess
and parentFrame:preprocess('{{int:lang}}')
or frame:preprocess('{{int:lang}}')
local decodedLang = mw.text.decode(uselang)
if decodedLang ~= '<lang>' and decodedLang ~= '⧼lang⧽' then
code = decodedLang == '(lang)'
and 'qqx'
or uselang
end
end
return code
end
--- Template wrapper for [[Template:I18n]].
-- @function i18n.main
-- @param {table} frame Frame invocation object.
-- @return {string} Module output in template context.
-- @usage {{#invoke:i18n|main}}
i18n.main = entrypoint(i18n)
return i18n
-- </nowiki>