Module:Pg

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

require('strict')

local p = {}

-- Return a title using [[Special:MyLanguage]], which resolves to user language
-- at read time if that exists, or English otherwise
local function getMyLanguage(title)
	return mw.title.new('Special:MyLanguage/' .. title.fullText)
end

-- Get display title for pages translated using the Translate extension
local function getDisplayTitle(title, lang)
	local titlepage = mw.title.makeTitle('Translations', title.prefixedText .. '/Page display title/' .. lang)
	if titlepage.exists then
		local display = mw.getCurrentFrame():expandTemplate{ title = titlepage }
		if title.fragment ~= '' then
			display = display .. '#' .. title.fragment
		end
		return display
	else
		return nil
	end
end

function p.getLink(page, display, anchor, lang, useMyLanguage)
	-- Sort out things like nil, object etc. It is likely to be invalid title,
	-- but c’est la vie.
	local title = mw.title.new(tostring(page or ''))
	if not title then
		return '[['  .. page .. ']]'
	end
	if anchor then
		title.fragment = anchor
	end
	if title.isRedirect then
		local fragment = title.fragment
		title = title.redirectTarget
		if fragment ~= '' then
			title.fragment = fragment
		end
	end
	if useMyLanguage then
		if not display then
			display = getDisplayTitle(title, lang) or title.fullText
		end
		title = getMyLanguage(title)
	else
		if lang ~= 'en' then
			local subpage = title:subPageTitle(lang)
			if subpage.exists then
				-- version of target page exists in current page language, return that version
				subpage.fragment = title.fragment
				if not display then
					-- try to use translated page title
					display = getDisplayTitle(title, lang)
				end
				title = subpage
			else
				-- prepend Special:MyLanguage/ to return the target page in
				-- user’s preferred language if available
				if not display then
					display = title.fullText
				end
				title = getMyLanguage(title)
			end
		end
	end
	return '[['  .. title.fullText .. (display and '|' .. display or '') .. ']]'
end


function p.main(frame)
	local args = require('Module:Arguments').getArgs(frame, {frameOnly = true})
	local lang = args.lang or mw.getCurrentFrame():preprocess('{{PAGELANGUAGE}}')
	return p.getLink(args.page, args.display, args.anchor, lang, false)
end

function p.pg2(frame)
	local args = require('Module:Arguments').getArgs(frame, {frameOnly = true})
	local lang = args.lang or mw.getCurrentFrame():preprocess('{{int:lang}}')
	return p.getLink(args[1], args[2], args.anchor, lang, true)
end

return p