Module:Official website

This module is subject to page protection. It is a highly visible module in use by a very large number of pages, or is substituted very frequently. Because vandalism or mistakes would affect many pages, and even trivial editing might cause substantial load on the servers, it is protected from editing.
This module implements {{Official website}}. Please see the template page for documentation.
Tracking categories

local makeUrl = require('Module:URL')._url

local p = {}

-- Wrapper for pcall which returns nil on failure.
local function quickPcall(func)
	local success, result = pcall(func)
	if success then
		return result
	end
end

-- Gets the rank for a Wikidata property table. Returns 1, 0 or -1, in
-- order of rank.
local function getRank(prop)
	local rank = prop.rank
	if rank == 'preferred' then
		return 1
	elseif rank == 'normal' then
		return 0
	elseif rank == 'deprecated' then
		return -1
	else
		-- No rank or undefined rank is treated as "normal".
		return 0
	end
end

-- Finds whether a Wikidata property is qualified as being in English.
local function isEnglish(prop)
	local ret = quickPcall(function ()
		for i, lang in ipairs(prop.qualifiers.P407) do
			if lang.datavalue.value['numeric-id'] == 1860 then
				return true
			end
		end
		return false
	end)
	return ret == true
end

-- Fetches the official website URL from Wikidata.
local fetchWikidataUrl
fetchWikidataUrl = function()
	-- Get objects for all official sites on Wikidata.
	local websites = quickPcall(function ()
		return mw.wikibase.getEntityObject().claims.P856
	end)

	-- Clone the objects in case other code needs them in their original order.
	websites = websites and mw.clone(websites) or {}

	-- Add the table index to the objects in case it is needed in the sort.
	for i, website in ipairs(websites) do
		website._index = i
	end

	-- Sort the websites, first by highest rank, and then by websites in the
	-- English language, then by the website's original position in the
	-- property list. When we are done, get the URL from the highest-sorted
	-- object.
	table.sort(websites, function(ws1, ws2)
		local r1 = getRank(ws1)
		local r2 = getRank(ws2)
		if r1 ~= r2 then
			return r1 > r2
		end
		local e1 = isEnglish(ws1)
		local e2 = isEnglish(ws2)
		if e1 ~= e2 then
			return e1
		end
		return ws1._index < ws2._index		
	end)
	local url = quickPcall(function ()
		return websites[1].mainsnak.datavalue.value
	end)

	-- Cache the result so that we only do the heavy lifting once per #invoke.
	fetchWikidataUrl = function ()
		return url
	end

	return url
end

-- Render the URL link, plus other visible output.
local function renderUrl(options)
	if not options.url then
		return '<strong class="error">' ..
			'No URL found. Please specify a URL here or add one to Wikidata.' ..
			'</strong>'
	end
	local ret = {}
	ret[#ret + 1] = string.format(
		'<span class="official-website">%s</span>',
		makeUrl(options.url, options.display)
	)
	if options.format == 'flash' then
		ret[#ret + 1] = mw.getCurrentFrame():expandTemplate{
			title = 'Link note',
			args = {note = 'Requires [[Adobe Flash Player]]'}
		}
	end
	if options.mobile then
		ret[#ret + 1] = '(' .. makeUrl(options.mobile, 'Mobile') .. ')'
	end
	return table.concat(ret, ' ')
end

-- Render the tracking category.
local function renderTrackingCategory(url, wikidataurl)
	if mw.title.getCurrentTitle().namespace ~= 0 then
		return ''
	end
	local category
	if not url and not wikidataurl then
		category = 'Official website missing URL'
	elseif not url and wikidataurl then           
		return ''
	elseif url and wikidataurl then
		if url:gsub('/%s*$', '') ~= wikidataurl:gsub('/%s*$', '') then
			category = 'Official website different in Wikidata and Wikipedia'
		end
	else
		category = 'Official website not in Wikidata'
	end
	return category and string.format('[[Category:%s]]', category) or ''
end

function p._main(args)
	local wikidataurl = fetchWikidataUrl()
	local url = args[1] or args.URL or args.url or wikidataurl
	local formattedUrl = renderUrl{
		url = url,
		display = args[2] or args.name or 'Official website',
		mobile = args.mobile,
		format = args.format
	}
	return formattedUrl .. renderTrackingCategory(url, wikidataurl)
end

function p.main(frame)
	local args = require('Module:Arguments').getArgs(frame, {
		wrappers = 'Template:Official website'
	})
	return p._main(args)
end

return p