Module:Dir

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This documentation is transcluded from Module:Dir/doc.

-- This module implements [[Template:Dir]].

local rtlOverrides = mw.loadData('Module:Dir/RTL overrides')
local p = {}

local function trim(s)
    if s then
        return s:match('^%s*(.-)%s*$')
    else
        return nil
    end
end

local function trimAndRemoveBlanks(s)
    s = trim(s)
    if s ~= '' then
        return s
    end
    return nil
end

function p.rtlLangs()
    return rtlOverrides[' rtl'] or {}
end

function p.ltrLangs()
    return rtlOverrides[' ltr'] or {}
end

function p.isRTL(code)
    code = trimAndRemoveBlanks(code)
    local v = rtlOverrides[code]
    if v ~= nil then return v end
    local success, ret = pcall(function ()
        return mw.language.new(code):isRTL() -- expensive and limited to 20 languages per MediaWiki instance
    end)
    return success and ret
end

function p.main(frame)
    local args = frame:getParent().args
    local code = args[1]
    if p.isRTL(code) then
        return trim(args[2]) or 'rtl'
    else
        return trim(args[3]) or 'ltr'
    end
end

setmetatable(p, { quickTests = function ()
    rtlLangs = p.rtlLangs()
    ltrLangs = p.ltrLangs()
    -- utility: reverse order iterator on sequences
    local function revipairs(t)
        return function(t, i)
            i = i - 1
            local v = t[i]
            if v == nil then return nil end
            return i, v
        end, t, #t + 1
    end

    -- Basic check of data format
    local function checkLangs(name, langs)
        for k, lang in pairs(langs) do
            assert(type(k) == 'number' and k == math.floor(k)
                and type(lang) == 'string' and #lang >= 2 and #lang <= 16
                and lang:find('^[a-z][%-0-9a-z]*[0-9a-z]$') == 1,
                ": Invalid sequence of language codes, " .. name .. "['" .. k .. "'] = '" .. lang .. "'")
        end
        return true
    end
    local ok, msg
    ok, msg = pcall(checkLangs, 'rtlLangs', rtlLangs)
    if not ok then return false, msg end
    ok, msg = pcall(checkLangs, 'ltrLangs', ltrLangs)
    if not ok then return false, msg end

    -- Build inverse maps of languages having each direction
    local isrtl, isltr = {}, {}
    for _, lang in ipairs(rtlLangs) do isrtl[lang] = true end
    for _, lang in ipairs(ltrLangs) do isltr[lang] = true end
    -- Check conflicts using the two inverse maps
    for _, lang in ipairs(rtlLangs) do
        if isltr[lang] then return false, ": Direction conflict for '" .. lang .. "'" end
    end
    for _, lang in ipairs(ltrLangs) do
        if isrtl[lang] then return false, ": Direction conflict for '" .. lang .. "'" end
    end

    -- Log missing languages (allows filling the tables above) according to MediaWiki internal data
    langs = mw.language.fetchLanguageNames()
    for lang, _ in pairs(langs) do
         if p[lang] == nil then -- only if we still don't have data for this language
             -- Note: we cannot check more than 20 languages at once, then MediaWiki raises an error.
             -- So this test only runs on the Lua console, where you can update the tables at top.
             ok, value = pcall(function() return tostring(mw.language.new(lang):isRTL()) end)
             mw.log("Missing direction for language '" .. lang .. "', MediaWiki returns '" .. value .. "'")
         end
    end

    -- Sort and deduplicate language code values (by scanning backward) for data cleanup
    table.sort(rtlLangs)
    table.sort(ltrLangs)
    for i, lang in revipairs(rtlLangs) do
        if rtlLangs[i - 1] == rtlLangs[i] then table.remove(rtlLangs, i) end
    end
    for i, lang in revipairs(ltrLangs) do
        if ltrLangs[i - 1] == ltrLangs[i] then table.remove(ltrLangs, i) end
    end
    -- Final presentation of current lists, sorted and deduplicated
    mw.log("local rtlLangs = { '" .. table.concat(rtlLangs, "', '") .. "' }")
    mw.log("local ltrLangs = { '" .. table.concat(ltrLangs, "', '") .. "' }")
    return true
end })

return p