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
    return subpage
end
function this.isKnownLanguage(frame)
    -- (this function isolated for debugging purpose)
    return mw.language.isKnownLanguageTag(frame.args['language'])
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
    local subpage = this.getLanguageSubpage()
    --[[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.
        Check first if there's an apostrophe, because they break the 
        isKnownLanguageTag function.
        ]]
    if (type(mw.ustring.match(subpage, "'")) == nil)
    then
        if (mw.language.isKnownLanguageTag(subpage))
        then
            local translation = mw.title.new(template .. '/' .. subpage, namespace)
            if (translation.id ~= 0)
            then
                langcode = subpage
            end
        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