Modul:Portal

This module has two functions, portal and image. The portal produces a box with links to a portal or to multiple portals, and is used by the {{portal}} template. It is most often used in the "See also" section of an article. The image function produces the name of the image used by the specified portal.

See here, here, and here for test cases.

Portal function

The portal function produces a box of portal links. Templat:Portal/doc

Image function

The image function produces the name of the image used by the specified portal.

Usage

{{#invoke:Portal|image|portal}}

Example

• {{#invoke:Portal|image|Art}} →

Image dupes function

The image dupes function returns a list of all images that are being used by more than one portal (aliases are not included). This can be helpful in identifying image entries that should be changed to use aliases.

Usage

{{#invoke:Portal|imageDupes}}

Display all function

The display all function returns a box containing all portals that have images. This is used for maintenance, and should not be displayed in articles, because a) there are around 1000 portals with images, and displaying 1000 images on one page takes up a lot of server resources, and b) the module has no way to know the correct capitalisation of a portal name, so some links to portals will be broken. The output of this function can be seen at Template:Portal/doc/all.

Usage

{{#invoke:Portal|displayAll}}

---

--[==[ This module is a Lua implementation of the old {{Portal}} template. As of February 2019 it is used on nearly 7,900,000 articles.
-- Please take care when updating it! It outputs two functions: p.portal, which generates a list of portals, and p.image, which
-- produces the image name for an individual portal.

-- The portal image data is kept in submodules of [[Module:Portal/images]], listed below:
-- [[Module:Portal/images/a]]		- for portal names beginning with "A".
-- [[Module:Portal/images/b]]		- for portal names beginning with "B".
-- [[Module:Portal/images/c]]		- for portal names beginning with "C".
-- [[Module:Portal/images/d]]		- for portal names beginning with "D".
-- [[Module:Portal/images/e]]		- for portal names beginning with "E".
-- [[Module:Portal/images/f]]		- for portal names beginning with "F".
-- [[Module:Portal/images/g]]		- for portal names beginning with "G".
-- [[Module:Portal/images/h]]		- for portal names beginning with "H".
-- [[Module:Portal/images/i]]		- for portal names beginning with "I".
-- [[Module:Portal/images/j]]		- for portal names beginning with "J".
-- [[Module:Portal/images/k]]		- for portal names beginning with "K".
-- [[Module:Portal/images/l]]		- for portal names beginning with "L".
-- [[Module:Portal/images/m]]		- for portal names beginning with "M".
-- [[Module:Portal/images/n]]		- for portal names beginning with "N".
-- [[Module:Portal/images/o]]		- for portal names beginning with "O".
-- [[Module:Portal/images/p]]		- for portal names beginning with "P".
-- [[Module:Portal/images/q]]		- for portal names beginning with "Q".
-- [[Module:Portal/images/r]]		- for portal names beginning with "R".
-- [[Module:Portal/images/s]]		- for portal names beginning with "S".
-- [[Module:Portal/images/t]]		- for portal names beginning with "T".
-- [[Module:Portal/images/u]]		- for portal names beginning with "U".
-- [[Module:Portal/images/v]]		- for portal names beginning with "V".
-- [[Module:Portal/images/w]]		- for portal names beginning with "W".
-- [[Module:Portal/images/x]]		- for portal names beginning with "X".
-- [[Module:Portal/images/y]]		- for portal names beginning with "Y".
-- [[Module:Portal/images/z]]		- for portal names beginning with "Z".
-- [[Module:Portal/images/other]]	- for portal names beginning with any other letters. This includes numbers,
-- 									  letters with diacritics, and letters in non-Latin alphabets.
-- [[Module:Portal/images/aliases]]	- for adding aliases for existing portal names. Use this page for variations
-- 									  in spelling and diacritics, etc., no matter what letter the portal begins with.
--
-- The images data pages are separated by the first letter to reduce server load when images are added, changed, or removed.
-- Previously all the images were on one data page at [[Module:Portal/images]], but this had the disadvantage that all
-- 5,000,000 pages using this module needed to be refreshed every time an image was added or removed.
]==]

local p = {}

-- determine whether we're being called from a sandbox
local isSandbox = mw.getCurrentFrame():getTitle():find('sandbox', 1, true)
local sandbox = isSandbox and '/sandbox' or ''

local function sandboxVersion(s)
	return isSandbox and s..'-sand' or s
end

local templatestyles = 'Module:Portal'..sandbox..'/styles.css'

local getArgs = require('Module:Arguments').getArgs
local yesno = require('Module:Yesno')

-- List of non-talk namespaces which should not be tracked (Talk pages are never tracked)
local badNamespaces = {'user','template','draft','wikipedia'}

-- Check whether to do tracking in this namespace
-- Returns true unless the page is one of the banned namespaces
local function checkTracking(title)
	local thisPage = title or mw.title.getCurrentTitle()
	if thisPage.isTalkPage then
		return false
	end
	local ns = thisPage.nsText:lower()
	for _, v in ipairs(badNamespaces) do
		if ns == v then
			return false
		end
	end
	return true
end

local function matchImagePage(s)
	-- Finds the appropriate image subpage given a lower-case
	-- portal name plus the first letter of that portal name.
	if type(s) ~= 'string' or #s < 1 then return end
	local firstLetter = mw.ustring.sub(s, 1, 1)
	local imagePage
	if mw.ustring.find(firstLetter, '^[a-z]') then
		imagePage = 'Module:Portal/images/' .. firstLetter .. sandbox
	else
		imagePage = 'Module:Portal/images/other' .. sandbox
	end
	return mw.loadData(imagePage)[s]
end

local function getAlias(s)
	-- Gets an alias from the image alias data page.
	local aliasData = mw.loadData('Module:Portal/images/aliases'..sandbox)
	for portal, aliases in pairs(aliasData) do
		for _, alias in ipairs(aliases) do
			if alias == s then
				return portal
			end
		end
	end
end

local defaultImage = 'Portal-puzzle.svg|link=|alt='

local function getImageName(s)
	-- Gets the image name for a given string.
	if type(s) ~= 'string' or #s < 1 then
		return defaultImage
	end
	s = mw.ustring.lower(s)
	return matchImagePage(s) or matchImagePage(getAlias(s)) or defaultImage
end
local function exists(title) 
	local success, exists = pcall(function() return title.exists end)
	-- If success = false, then we're out of expensive parser function calls and can't check whether it exists
	-- in that case, don't throw a Lua error
	return not success or exists
end

 -- Function to check argument portals for errors, generate tracking categories if needed
 --     Function first checks for too few/many portals provided
 --     Then checks the portal list to purge any portals that don't exist
 -- Arguments:
 --   portals: raw list of portals
 --   args.tracking: is tracking requested? (will not track on bad titles or namespaces)
 --   args.redlinks: should redlinks be displayed?
 --   args.minPortals: minimum number of portal arguments
 --   args.maxPortals: maximum number of portal arguments
 -- Returns:
 --   portals = list of portals, with redlinks purged (if args.redlinks=false)
 --   trackingCat = possible tracking category
 --   errorMsg = error message
function p._checkPortals(portals, args)
	local trackingCat = ''
	local errMsg = nil
	
	-- Tracking is on by default.
	-- It is disabled if any of the following is true
	-- 1/ the parameter "tracking" is set to 'no, 'n', or 'false'
	-- 2/ the current page fails the namespace or pagename tests 
	local trackingEnabled = args.tracking and checkTracking()
	
	args.minPortals = args.minPortals or 1
	args.maxPortals = args.maxPortals or -1
	-- check for too few portals
	if #portals < args.minPortals then
		errMsg = 'please specify at least '..args.minPortals..' portal'..(args.minPortals > 1 and 's' or '')
		trackingCat = (trackingEnabled and '[[Category:Portal templates with too few portals]]' or '')
		return portals, trackingCat, errMsg
	end
	-- check for too many portals
	if args.maxPortals >= 0 and #portals > args.maxPortals then
		errMsg = 'too many portals (maximum = '..args.maxPortals..')'
		trackingCat = (trackingEnabled and '[[Category:Portal templates with too many portals]]' or '')
		return portals, trackingCat, errMsg
	end
	if not args.redlinks or trackingEnabled then
		-- make new list of portals that exist
		local existingPortals = {}
		for _, portal in ipairs(portals) do
			local portalTitle = mw.title.new(portal,"Portal")
			-- if portal exists, put it into list
			if portalTitle and exists(portalTitle) then
				table.insert(existingPortals,portal)
			-- otherwise set tracking cat
			elseif trackingEnabled then
				trackingCat = "[[Category:Portal templates with redlinked portals]]"
			end
		end
		-- If redlinks is off, use portal list purged of redlinks
		portals = args.redlinks and portals or existingPortals
		-- if nothing left after purge, set tracking cat
		if #portals == 0 and trackingEnabled then
			trackingCat = trackingCat.."[[Category:Pages with empty portal template]]" 
		end
	end
	return portals, trackingCat, errMsg
end

local function portalBox(args)
	return mw.html.create('ul')
		:attr('role', 'navigation')
		:attr('aria-label', 'Portals')
		:addClass('noprint')
		:addClass(args.error and '' or sandboxVersion('portalbox'))
		:addClass(args.border and sandboxVersion('portalborder') or '')
		:addClass(sandboxVersion(args.left and 'portalleft' or 'portalright'))
		:css('margin', args.margin or nil)
		:newline()
end

local function fillBox(root, contents)
	for _, item in ipairs(contents) do
		local entry = root:tag('li')
		entry:addClass(sandboxVersion('portalbox-entry'))
		local image = entry:tag('span')
		image:addClass(sandboxVersion('portalbox-image'))
		image:wikitext(item[1])
		local link = entry:tag('span')
		link:addClass(sandboxVersion('portalbox-link'))
		link:wikitext(item[2])
	end
	return root
end

function p._portal(portals, args)
	-- This function builds the portal box used by the {{portal}} template.
	
	-- Normalize all arguments
	if args.redlinks == 'include' then args.redlinks = true end
	args.addBreak = args['break']
	for key, default in pairs({left=false,tracking=true,nominimum=false,
		                       redlinks=false,addBreak=false,border=true}) do
		if args[key] == nil then args[key] = default end
		args[key] = yesno(args[key], default)
	end

	local root = portalBox(args)

	local trackingCat = ''
	local errMsg = nil
	args.minPortals = args.nominimum and 0 or 1
	args.maxPortals = -1
	portals, trackingCat, errMsg = p._checkPortals(portals, args)
	root:wikitext(trackingCat)
	-- if error message, put it in the box and return
	if errMsg then
		if args.border then -- suppress error message when border=no
			args.error = true  -- recreate box without fancy formatting
			root = portalBox(args)
			root:wikitext(trackingCat)
			local errTag = root:tag('strong')
			errTag:addClass('error')
			errTag:css('padding','0.2em')
			errTag:wikitext('Error: '..errMsg)
		end
		return tostring(root)
	end
	-- if no portals (and no error), just return tracking category
	if #portals == 0 then
		return trackingCat
	end

	local contents = {}
	-- Display the portals specified in the positional arguments.
	local defaultUsed = nil
	for _, portal in ipairs(portals) do
		local portalImage = getImageName(portal)
		if portalImage == defaultImage then
			defaultUsed = portal
		end
		local image = string.format('[[File:%s|32x28px|class=noviewer]]',
			portalImage)
		local link = string.format('[[Portal:%s|%s%sportal]]',
			portal, portal, args.addBreak and '<br />' or ' ')
		table.insert(contents, {image, link})
	end
	if defaultUsed and args.tracking and checkTracking() then
		local cat = string.format('[[Category:Portal templates with default image|%s]]',
			                      defaultUsed)
		root:wikitext(cat)
	end
	return tostring(fillBox(root, contents))
end

function p._demo(imageList, args)
	for key, default in pairs({left=false,border=true}) do
		if args[key] == nil then args[key] = default end
		args[key] = yesno(args[key], default)
	end
	
	local root = portalBox(args)

	local contents = {}
	-- Display the portals specified in the positional arguments.
	for _, fn in ipairs(imageList) do
		local image = string.format('[[File:%s|32x28px|class=noviewer]]',fn)
		local link = string.format('[[:File:%s|%s]]',fn,fn)
		table.insert(contents,{image,link})
	end

	return tostring(fillBox(root,contents))
end

function p._image(portal,keep)
	-- Wrapper function to allow getImageName() to be accessed through #invoke.
	-- backward compatibility: if table passed, take first element
	if type(portal) == 'table' then
		portal = portal[1]
	end
	local name = getImageName(portal)
	-- If keep is yes (or equivalent), then allow all metadata (like image borders) to be returned
	local keepargs = yesno(keep)
	local args = mw.text.split(name, "|", true)
	local result = {args[1]}  -- the filename always comes first
	local category = ''
	-- parse name, looking for category arguments
	for i = 2,#args do
		local m = mw.ustring.match(args[i],  "^%s*category%s*=")
		if keepargs or m then
			table.insert(result, args[i])
		end
	end
	-- reassemble arguments
	return table.concat(result,"|")
end


local function getAllImageTable()
	-- Returns an array containing all image subpages (minus aliases) as loaded by mw.loadData.
	local images = {}
	for i, subpage in ipairs{'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', 'other'} do
		local imageTable = mw.loadData('Module:Portal/images/' .. subpage .. sandbox)
		for portal, image in pairs(imageTable) do
			local args = mw.text.split(image,"|")
			images[portal] = args[1] -- just use image filename
		end
	end
	return images
end

function p._displayAll(portals, args)
	-- This function displays all portals that have portal images. This function is for maintenance purposes and should not be used in
	-- articles, for two reasons: 1) there are over 1500 portals with portal images, and 2) the module doesn't record how the portal
	-- names are capitalized, so the portal links may be broken.
	local lang = mw.language.getContentLanguage()
	portals = portals or {}
	for portal in pairs(getAllImageTable()) do
		table.insert(portals,lang:ucfirst(portal))
	end
	table.sort(portals)
	args.redlinks = args.redlinks or "yes"
	return p._portal(portals, args)
end

function p._imageDupes()
	-- This function searches the image subpages to find duplicate images. If duplicate images exist, it is not necessarily a bad thing,
	-- as different portals might just happen to choose the same image. However, this function is helpful in identifying images that
	-- should be moved to a portal alias for ease of maintenance.
	local exists, dupes = {}, {}
	for portal, image in pairs(getAllImageTable()) do
		if not exists[image] then
			exists[image] = portal
		else
			table.insert(dupes, string.format('The image "[[:File:%s|%s]]" is used for both portals "%s" and "%s".', image, image, exists[image], portal))
		end
	end
	if #dupes < 1 then
		return 'No duplicate images found.'
	else
		return 'The following duplicate images were found:\n* ' .. table.concat(dupes, '\n* ')
	end
end

local function processPortalArgs(args)
	-- This function processes a table of arguments and returns two tables: an array of portal names for processing by ipairs, and a table of
	-- the named arguments that specify style options, etc. We need to use ipairs because we want to list all the portals in the order
	-- they were passed to the template, but we also want to be able to deal with positional arguments passed explicitly, for example
	-- {{portal|2=Politics}}. The behaviour of ipairs is undefined if nil values are present, so we need to make sure they are all removed.
	args = type(args) == 'table' and args or {}
	local portals = {}
	local namedArgs = {}
	for k, v in pairs(args) do
		if type(k) == 'number' and type(v) == 'string' then -- Make sure we have no non-string portal names.
			table.insert(portals, k)
		elseif type(k) ~= 'number' then
			namedArgs[k] = v
		end
	end
	table.sort(portals)
	for i, v in ipairs(portals) do
		portals[i] = args[v]
	end
	return portals, namedArgs
end

-- Entry point for sorting portals from other named arguments
function p._processPortalArgs(args)
	return processPortalArgs(args)
end

function p.image(frame)
	local origArgs = getArgs(frame)
	local portals, args = processPortalArgs(origArgs)
	return p._image(portals[1],args.border)
end

function p.demo(frame)
	local args = getArgs(frame)
	local styles = frame:extensionTag{ name = 'templatestyles', args = { src = templatestyles} }
	return styles..p._demo(args,args)
end

local function makeWrapper(funcName)
	-- Processes external arguments and sends them to the other functions.
	return function (frame)
		-- If called via #invoke, use the args passed into the invoking
		-- template, or the args passed to #invoke if any exist. Otherwise
		-- assume args are being passed directly in from the debug console
		-- or from another Lua module. 
		-- Also: trim whitespace and remove blank arguments
		local origArgs = getArgs(frame)
		-- create two tables to pass to func: an array of portal names, and a table of named arguments.
		local portals, args = processPortalArgs(origArgs)
		local results = ''
		if funcName == '_portal' or funcName == '_displayAll' then
			results = frame:extensionTag{ name = 'templatestyles', args = { src = templatestyles} }
		end
		return results .. p[funcName](portals, args) 
	end
end

for _, funcName in ipairs{'portal', 'imageDupes', 'displayAll'} do
	p[funcName] = makeWrapper('_' .. funcName)
end

return p