Module:Fallback

local p = {}

function p.fblist(lang) -- list the full fallback chain from a language to en	local fbtable = mw.language.getFallbacksFor(lang) table.insert(fbtable, 1, lang) table.insert(fbtable, 'message') table.insert(fbtable, 'default') return fbtable end

function p._langSwitch(args, lang) -- args: table of translations -- Return error if there is not default and no English version -- otherwise returns the message in the most appropriate, plus the lang code as a second value if not args.en and not args.default and not args.message and args.nocat ~= '1' then return error("langSwitch error: no default") end -- get language (either stated one or user's default language) if not lang then return ' LangSwitch Error: no lang ' -- must become proper error end -- get the list of acceptable language (lang + those in lang's fallback chain) and check their content for i, j in ipairs(p.fblist(lang)) do		if args[j] then if args[j] == '~' then return nil, j end if j == 'message' then return tostring(mw.message.new(args[j]):inLanguage(lang)) end -- if this is an interface message if args[j] ~= '' then return args[j], j end end end return nil end

function p.langSwitch(frame) -- version to be used from wikitext local args = frame.args -- if no expected args provided than check parent template/module args if not args.en and not args.default and not args.nocat then args = frame:getParent.args end local lang if args.lang and args.lang ~= '' then lang = args.lang args.lang = nil else -- get user's chosen language lang = frame:preprocess( "" ) end local str, language = p._langSwitch(args, lang) return str -- get the first value of the langSwitch, (the text) not the second (the language) end

function p.fallbackpage(base, lang, formatting) local languages = p.fblist(lang) for i, lng in ipairs(languages) do if mw.title.new(base .. '/' .. lng).exists then if formatting == 'table' then return {base .. '/' .. lng, lng} -- returns name of the page + name of the language else return base .. '/' .. lng -- returns only the page end end end return base end

function p.autotranslate(frame) -- logic for template:Autotranslate local args = frame.args if not args.lang or args.lang == '' then args.lang = frame:preprocess( "" )          -- get user's chosen language end

-- find base page local base = args.base if not base or base == '' then return ' Base page not provided for autotranslate ' end if string.sub(base, 2, 9) ~= 'emplate:' then base = 'Template:' .. base  -- base provided without 'Template:' part end

-- find base template language subpage local page = p.fallbackpage(base, args.lang) -- if (not page and base ~= args.base) then -- try the original args.base string. This case is only needed if base is not in template namespace page = p.fallbackpage(args.base, args.lang) end if not page then return string.format(' no fallback page found for autotranslate (base=%s, lang=%s) ', args.base, args.lang) end

-- repack args in a standard table local newargs = {} for field, value in pairs(args) do		if field ~= 'base' then newargs[field] = value end end

-- Transclude with template arguments the same as the ones passed to  template. return frame:expandTemplate{ title = page, args = newargs } end

function p.translate(page, key, lang) --translate data stored in a module if type(page) == 'string' then -- if the requested translation table is not yet loaded page = require('Module:' .. page) end

local val if page[key] then val = page[key] elseif page.keys and page.keys[key] then-- key 'keys" is an index of all keys, including redirects, see Module:i18n/datatype		val = page.keys[key]	end	if not val then		return '<' .. key .. '>'	end	return p._langSwitch(val, lang) end

function p.translatelua(frame) local lang = frame.args.lang local page = require('Module:' .. mw.text.trim(frame.args[1])) -- page should only contain a simple of translations if not lang or mw.text.trim(lang) == '' then lang = frame:preprocess( "" ) end if frame.args[2] then page = page[mw.text.trim(frame.args[2])] end return p._langSwitch(page, lang) end

function p.runTests local toFallbackTest = require('Module:Fallback/tests/fallbacks') local result = true

mw.log('Testing fallback chains') for i, t in ipairs(toFallbackTest) do		local fbtbl = table.concat(p.fblist(t.initial), ', ') local expected = table.concat(t.expected, ', ') local ret = (fbtbl == expected) mw.log(i, ret and 'passed' or 'FAILED', t.initial, (not ret) and ('FAILED\nis >>' .. fbtbl .. '<<\nbut should be >>' .. expected .. '<<\n') or '') result = result and ret end return result end

function p.showTemplateArguments(frame) -- list all input arguments of the template that calls "" local str = '' for name, value in pairs( frame:getParent.args ) do		if str == '' then str = string.format('%s=%s', name, value)         -- argument #1 else str = string.format('%s, %s=%s', str, name, value) -- the rest end end return str end

return p