--- 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]] and i18n modules that can be loaded --  by it are editable through [[I18nEdit]]. --   --  @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 --  @see            [[I18n|I18n guide]] --  @see            [[I18n-js]] --  @see            [[I18nEdit]] --  <nowiki> local i18n, _i18n = {}, {}  --  Module variables & dependencies. local title = mw.title.getCurrentTitle() local fallbacks = require('Módulo:Fallbacklist') local entrypoint = require('Módulo: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  'Module:' .. 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>