Module:Template translation

Documentation for this module may be created at Module:Template translation/doc

local this = {}

function this.getLanguageSubpage()
    -- Get the last subpage (this function isolated for debugging purpose)
    local subpage = mw.title.getCurrentTitle().subpageText
    --[[Check first if there's an apostrophe, because they break the isKnownLanguageTag
        function. This test does not work with regexps, use plain search instead (no need
        to use Unicode parser, apostrophes can only appear isolated as one byte in UTF-8).
        ]]
    if (string.find(subpage, "'", 1, true) == nil)
    then
        --[[If the subpage is a valid language code, check if a translation of the
            template exists in that language; if so, put it in langcode.
            ]]
        if (mw.language.isKnownLanguageTag(subpage))
        then
            return subpage
        end
    end
    return ''
end

function this.renderTranslatedTemplate(frame)
    --[[If on a translation subpage (like Foobar/de), this function renders
        a given template in the same language, if the translation is available.
        Otherwise, the template is rendered in its default language, without
        modification.
        This is aimed at replacing the current implementation of Template:TNT.
        ]]
    local template = frame.args['template']
    --[[Check whether the template is actually in the Template namespace, or
        if we're transcluding a main-namespace page.
        (added for backward compatibility of Template:TNT)
        ]]
    local namespace = 'Template'
    local templateFullTitle = mw.title.new(template, namespace)
    if (templateFullTitle.id == 0)
    then -- not found in the Template namespace, assume the main namespace
        namespace = ''
    end
    local langcode = 'en'
    -- Get the last subpage and check if it matches a known language code
    local subpage = this.getLanguageSubpage()
    if (subpage ~= '')
    then
        local translation = mw.title.new(namespace .. template .. '/' .. subpage)
        if (translation.id ~= 0)
        then
            langcode = subpage
        end
    end
    -- Copy args pseudo-table to a proper table so we can feed it to expandTemplate
    local arguments = {}
    for k, v in pairs(frame.args) do
        arguments[k] = v
    end
    -- Render the template
    return frame:expandTemplate{title = namespace .. ':' .. template .. '/' .. langcode, args = arguments}
end

return this