Module:Link

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

-- This module is a replacement for [[Template:Lw]] and other link templates.

local p = {}

-- getSubpageLink tests to see if the subpage exists.  If it does, it returns a link to the subpage.  If not, it returns nil.
local function getSubpageLink(link)
	local title
	local prefixedText
	local result
	
	title = mw.title.getCurrentTitle()
	prefixedText = title.prefixedText
	
	title = mw.title.new(prefixedText .. '/' .. link)
	if title.exists then
		result = '[[/' .. link .. '/]]'
	else
		error()
	end
	
	return result
end

-- getWikiversityLink tests to see if the resource page exists.  If it does, it returns a link to the page.  If not, it returns nil.
local function getWikiversityLink(link)
	local title
	local result
	
	title = mw.title.new(link)
	if title.exists then
		result = '[[' .. link .. ']]'
	else
		error()
	end
	
	return result
end

-- getWikipediaLink returns a link to Wikipedia as w:.
local function getWikipediaLink(link)
	return '[[w:' .. link .. ']]'
end

-- getSilentWikipediaLink returns a link to Wikipedia without displaying the w:.
local function getSilentWikipediaLink(link)
	return '[[w:' .. link .. '|' .. link .. ']]'
end

-- lsw takes two parameters.  The first is a link title.  The second is either nil or not.
-- The function will return either a subpage link if it exists, or a Wikiversity link if it exists,
-- or a Wikipedia link if no Wikiversity link exists.  If the second parameter is not nil, the
-- Wikipedia link is a silent redirect (no w: displayed).
function p.lsw(frame)
	local link
	local result
	
	link = mw.text.trim(frame.args[1])
	
	if pcall(function () result = getSubpageLink(link) end) then
		return result
	end

	if pcall(function () result = getWikiversityLink(link) end) then
		return result
	end

	if frame.args[2] == nil then
		return getWikipediaLink(link)
	else
		return getSilentWikipediaLink(link)
	end
end

-- lw takes two parameters.  The first is a link title.  The second is either nil or not.
-- The function will return either a Wikiversity link if it exists, or a Wikipedia link if 
-- no Wikiversity link exists.  If the second parameter is not nil, the Wikipedia link is 
-- a silent redirect (no w: displayed).
function p.lw(frame)
	local link
	local result
	
	link = mw.text.trim(frame.args[1])

	if pcall(function () result = getWikiversityLink(link) end) then
		return result
	end

	if frame.args[2] == nil then
		return getWikipediaLink(link)
	else
		return getSilentWikipediaLink(link)
	end
end
 
return p