Module:Fallback

local p = {}

local langlist = require('Module:Fallbacklist')

function p.fblist(lang) -- list the full fallback chain from a language to en	local fbtable = p.fallbackloop{ lang:lower } table.insert(fbtable, 'default') table.insert(fbtable, 'en') return fbtable end

function _inArray(x, t)	for i, v in ipairs(t) do		if v == x then return i end end return -1 end

function p.fallbackloop(fbtable) --list of fallback languages in string format (more convenient than tables) local changes = false for i, j in ipairs(fbtable) do		local seq = langlist[j] if seq then for k, l in ipairs(seq) do				if _inArray(l, fbtable) == -1 then table.insert(fbtable, l)					changes = true end end end end if changes then return p.fallbackloop(fbtable) end return fbtable end

function p._langSwitch(args, lang) -- args: table of translations -- Return error if there is not default and no english version if not args.en and not args.default and args.nocat ~= '1' then return ' 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 accpetable language (lang + those in lang's fallback chain) and check their content local parselist = p.fblist(lang) for i, k in ipairs(parselist) do 		if args[k] == '~' then return '' end if args[k] and args[k] ~= '' then return args[k] end end end

function p.langSwitch(frame) -- version to be used from wikitext args = frame.args -- if no expected args provided than check parent template/module args if args.en==nil and args.default==nil and args.nocat==nil then args = mw.getCurrentFrame:getParent.args end if args.lang and args.lang ~= '' then lang = args.lang args.lang = nil else -- get user's chosen language lang = frame:preprocess( "" ) end return p._langSwitch(args, lang) 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 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 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.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( mw.getCurrentFrame: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