Module:Documentation

This module displays a box containing documentation for templates, Lua modules and other pages. The {{Documentation}} template invokes it.

Normal usage

For most uses, you should use the {{Documentation}} template; please see that template's page for its usage instructions and parameters.

Use in other modules

To use this module from another Lua module, first load it with require:

local documentation = require('Module:Documentation').main

Then you can simply call it using a table of arguments.

documentation{content = 'Some documentation', ['link box'] = 'My custom link box'}

Please refer to the template documentation for usage instructions and a list of parameters.

Porting to other wikis

The module has a configuration file at Module:Documentation/config which is intended to allow easy translation and porting from Wikipedia to other wikis. Please see the code comments in the config page for instructions. If you have any questions, or you need a feature which is not currently implemented, please leave a message at Template talk:Documentation to get the attention of a developer.

---

-- This module implements {{documentation}}.

-- Get required modules.
local getArgs = require('Module:Arguments').getArgs
local htmlBuilder = require('Module:HtmlBuilder')
local messageBox = require('Module:Message box')

-- Get the config table.
local cfg = mw.loadData('Module:Documentation/config')

local p = {}

-- Often-used functions.
local gsub = mw.ustring.gsub

----------------------------------------------------------------------------
-- Helper functions
--
-- These are defined as local functions, but are made available in the p
-- table for testing purposes.
----------------------------------------------------------------------------

local function message(cfgKey, expectType, valArray)
	--[[
	-- Gets a message from the cfg table and formats it if appropriate.
	-- The function raises an error if the value from the cfg table is not
	-- of the type expectType.
	-- If the table valArray is present, strings such as $1, $2 etc. in the
	-- message are substituted with values from the table keys [1], [2] etc.
	-- For example, if the message cfg.fooMessage had the value 'Foo $2 bar $1.',
	-- message('fooMessage', 'string', {'baz', 'qux'}) would return "Foo qux bar baz."
	--]]
	local msg = cfg[cfgKey]
	if expectType and type(msg) ~= expectType then
		error('message: type error in message cfg.' .. cfgKey .. ' (' .. expectType .. ' expected, got ' .. type(msg) .. ')', 2)
	end
	if not valArray then
		return msg
	end

	local function getMessageVal(match)
		match = tonumber(match)
		return valArray[match] or error('message: no value found for key $' .. match .. ' in message cfg.' .. cfgKey, 4)
	end

	local ret = gsub(msg, '$([1-9][0-9]*)', getMessageVal)
	return ret
end

p.message = message

local function makeWikilink(page, display)
	if display then
		return mw.ustring.format('[[%s|%s]]', page, display)
	else
		return mw.ustring.format('[[%s]]', page)
	end
end

p.makeWikilink = makeWikilink

local function makeCategoryLink(cat, sort)
	local catns = mw.site.namespaces[14].name
	return makeWikilink(catns .. ':' .. cat, sort)
end

p.makeCategoryLink = makeCategoryLink

local function makeUrlLink(url, display)
	return mw.ustring.format('[%s %s]', url, display)
end

p.makeUrlLink = makeUrlLink

local function makeToolbar(...)
	local ret = {}
	local lim = select('#', ...)
	if lim < 1 then
		return nil
	end
	for i = 1, lim do
		ret[#ret + 1] = select(i, ...)
	end
	return '<small style="font-style: normal;">(' .. table.concat(ret, ' &#124; ') .. ')</small>'
end	

p.makeToolbar = makeToolbar

local function err(msg)
	return string.format(
		'<strong class="error">%s %s</strong>%s',
		message('errorPrefix', 'string'),
		msg,
		makeCategoryLink(message('errorCategory', 'string'))
	)
end

p.err = err

----------------------------------------------------------------------------
-- Argument processing
----------------------------------------------------------------------------

local function makeInvokeFunc(funcName)
	return function (frame)
		local args = getArgs(frame, {
			valueFunc = function (key, value)
				if type(value) == 'string' then
					value = value:match('^%s*(.-)%s*$') -- Remove whitespace.
					if key == 'heading' or value ~= '' then
						return value
					else
						return nil
					end
				else
					return value
				end
			end
		})
		return p[funcName](args)
	end
end

----------------------------------------------------------------------------
-- Main function
----------------------------------------------------------------------------

p.main = makeInvokeFunc('_main')

function p._main(args)
	local env = p.getEnvironment(args)
	local root = htmlBuilder.create()
	root
		.wikitext(p.protectionTemplate(env))
		.wikitext(p.sandboxNotice(args, env))
		 -- This div tag is from {{documentation/start box}}, but moving it here
		 -- so that we don't have to worry about unclosed tags.
		.tag('div')
			.attr('id', message('mainDivId', 'string'))
			.addClass(message('mainDivClasses', 'string'))
			.newline()
			.wikitext(p._startBox(args, env))
			.wikitext(p._content(args, env))
			.tag('div')
				.css('clear', 'both') -- So right or left floating items don't stick out of the doc box.
				.newline()
				.done()
			.done()
		.wikitext(p._endBox(args, env))
		.newline()
		.wikitext(p.addTrackingCategories(env))
	return tostring(root)
end

----------------------------------------------------------------------------
-- Environment settings
----------------------------------------------------------------------------

function p.getEnvironment(args)
	-- Returns a table with information about the environment, including the title to use, the subject namespace, etc.
	-- This is called from p._main using pcall in case we get any errors from exceeding the expensive function count
	-- limit, or other perils unknown.
	--
	-- Data includes:
	-- env.title - the title object of the page we are making documentation for (usually the current title)
	-- env.subjectSpace - the number of the title's subject namespace.
	-- env.docspace - the name of the namespace the title puts its documentation in.
	-- env.templatePage - the name of the template page with no namespace or interwiki prefixes.
	local env, envFuncs = {}, {}

	-- Set up the metatable. If a nil value is called, we call that function in the envFuncs table and memoize it
	-- in the env table so we don't have to call any of the functions more than once.
	setmetatable(env, {
		__index = function (t, key)
			local envFunc = envFuncs[key]
			if envFunc then
				local val = envFunc()
				env[key] = val
				return val
			else
				return nil
			end
		end
	})	

	function envFuncs.title()
		-- The title object for the current page, or a test page passed with args.page.
		local title
		local titleArg = args.page
		if titleArg then
			title = mw.title.new(titleArg)
			if not title then
				error(message('titleArgError', 'string', {titleArg}))
			end
		else
			title = mw.title.getCurrentTitle()
		end
		return title
	end

	function envFuncs.subjectSpace()
		-- The subject namespace number.
		return mw.site.namespaces[env.title.namespace].subject.id
	end

	function envFuncs.docspace()
		-- The name of the documentation namespace.
		local subjectSpace = env.subjectSpace
		if subjectSpace == 0 or subjectSpace == 6 or subjectSpace == 8 or subjectSpace == 14 then
			-- Pages in the Article, File, MediaWiki or Category namespaces must have their
			-- /doc, /sandbox and /testcases pages in talk space.
			return mw.site.namespaces[subjectSpace].talk.name 
		else
			return env.title.subjectNsText
		end
	end

	function envFuncs.templatePage()
		-- The template page with no namespace or interwiki prefixes.
		local title = env.title
		local subpage = title.subpageText
		if subpage == message('sandboxSubpage', 'string') or subpage == message('testcasesSubpage', 'string') then
			return title.baseText
		else
			return title.text
		end
	end

	function envFuncs.templateTitle()
		-- The template (or module, etc.) title object.
		local title = env.title
		local subpage = title.subpageText
		local ret
		if subpage == message('sandboxSubpage', 'string') or subpage == message('testcasesSubpage', 'string') then
			ret = title.basePageTitle
		else
			ret = title
		end
		if not ret then
			error(message('titleArgError', 'string', {titleArg}))
		end
		return ret
	end

	function envFuncs.docTitle()
		-- Title object of the /doc subpage.
		local title = env.title
		local docname = args[1] -- User-specified doc page.
		local docpage
		if docname then
			docpage = docname
		else
			docpage = env.docpageRoot .. '/' .. message('docSubpage', 'string')
		end
		return mw.title.new(docpage)
	end
	
	function envFuncs.docpageRoot()
		-- The base page of the /doc, /sandbox, and /testcases subpages.
		-- For some namespaces this is the talk page, rather than the template page.
		local title = env.title
		return (env.docspace or title.nsText) .. ':' .. (env.templatePage or title.text)
	end
	
	function envFuncs.sandboxTitle()
		-- Title object for the /sandbox subpage.
		local titleArg = env.docpageRoot .. '/' .. message('sandboxSubpage', 'string')
		local title = mw.title.new(titleArg)
		if not title then
			error(message('titleArgError', 'string', {titleArg}))
		end
		return title
	end
	
	function envFuncs.testcasesTitle()
		-- Title object for the /testcases subpage.
		local titleArg = env.docpageRoot .. '/' .. message('testcasesSubpage', 'string')
		local title = mw.title.new(titleArg)
		if not title then
			error(message('titleArgError', 'string', {titleArg}))
		end
		return title
	end
	
	function envFuncs.printTitle()
		-- Title object for the /Print subpage.
		local titleArg = env.templatePage .. '/' .. message('printSubpage', 'string')
		local title = mw.title.new(titleArg)
		if not title then
			error(message('titleArgError', 'string', {titleArg}))
		end
		return title
	end
	
	function env:grab(key)
		local success, val = pcall(function() return self[key] end)
		return success, val
	end

	return env
end	

----------------------------------------------------------------------------
-- Auxiliary templates
----------------------------------------------------------------------------

function p.sandboxNotice(args, env)
	local sandboxNoticeTemplate = message('sandboxNoticeTemplate', 'string')
	if not (sandboxNoticeTemplate and env.title.subpageText == message('sandboxSubpage', 'string')) then
		return nil
	end
	local frame = mw.getCurrentFrame()
	local notice = htmlBuilder.create()
	notice
		.tag('div')
			.css('clear', 'both')
			.done()
		.wikitext(frame:expandTemplate{title = sandboxNoticeTemplate, args = {[message('sandboxNoticeLivepageParam')] = args.livepage}})
	return tostring(notice)
end

function p.protectionTemplate(env)
	local title = env.title
	local protectionTemplate = message('protectionTemplate', 'string')
	if not (protectionTemplate and title.namespace == 10) then
		-- Don't display the protection template if we are not in the template namespace.
		return nil
	end
	local frame = mw.getCurrentFrame()
	local function getProtectionLevel(protectionType, page)
		-- Gets the protection level for page, or for the current page if page is not specified.
		local level = frame:callParserFunction('PROTECTIONLEVEL', protectionType, page)
		if level ~= '' then
			return level
		else
			return nil -- The parser function returns the blank string if there is no match.
		end
	end
	local prefixedTitle = title.prefixedText
	if getProtectionLevel('move', prefixedTitle) == 'sysop' or getProtectionLevel('edit', prefixedTitle) then
		-- The page is full-move protected, or full, template, or semi-protected.
		return frame:expandTemplate{title = protectionTemplate, args = message('protectionTemplateArgs', 'table')}
	end
	return nil
end

----------------------------------------------------------------------------
-- Start box
----------------------------------------------------------------------------

p.startBox = makeInvokeFunc('_startBox')

function p._startBox(args, env)
	-- Generate [view][edit][history][purge] or [create] links.
	local links
	local content = args.content
	if not content then
		-- No need to include the links if the documentation is on the template page itself.
		local linksData = p.makeStartBoxLinksData(args, env)
		if linksData then
			links = p.renderStartBoxLinks(linksData)
		end
	end
	-- Generate the start box html.
	local data = p.makeStartBoxData(args, env, links)
	if type(data) == 'table' then
		return p.renderStartBox(data)
	elseif type(data) == 'string' then
		-- data is an error message.
		return data
	else
		-- User specified no heading.
		return nil
	end
end

function p.makeStartBoxLinksData(args, env)
	local data = {}
	-- Get title objects.
	local titleSuccess, title = env:grab('title')
	if titleSuccess then
		data.title = title
	else
		return err(title)
	end
	local docTitleSuccess, docTitle = env:grab('docTitle')
	if docTitleSuccess then
		data.docTitle = docTitle
	else
		return err(docTitle)
	end
	-- View, display, edit, and purge links if /doc exists.
	data.viewLinkDisplay = message('viewLinkDisplay', 'string')
	data.editLinkDisplay = message('editLinkDisplay', 'string')
	data.historyLinkDisplay = message('historyLinkDisplay', 'string')
	data.purgeLinkDisplay = message('purgeLinkDisplay', 'string')
	-- Create link if /doc doesn't exist.
	local preload = args.preload
	if not preload then
		if env.subjectSpace == 6 then -- File namespace
			preload = message('fileDocpagePreload', 'string')
		else
			preload = message('docpagePreload', 'string')
		end
	end
	data.preload = preload
	data.createLinkDisplay = message('createLinkDisplay', 'string')
	return data
end

function p.renderStartBoxLinks(data)
	-- Render the [view][edit][history][purge] or [create] links.
	local ret
	local docTitle = data.docTitle
	local title = data.title
	if docTitle.exists then
		local viewLink = makeWikilink(docTitle.prefixedText, data.viewLinkDisplay)
		local editLink = makeUrlLink(docTitle:fullUrl{action = 'edit'}, data.editLinkDisplay)
		local historyLink = makeUrlLink(docTitle:fullUrl{action = 'history'}, data.historyLinkDisplay)
		local purgeLink = makeUrlLink(title:fullUrl{action = 'purge'}, data.purgeLinkDisplay)
		ret = '[%s] [%s] [%s] [%s]'
		ret = ret:gsub('%[', '&#91;') -- Replace square brackets with HTML entities.
		ret = ret:gsub('%]', '&#93;')
		ret = mw.ustring.format(ret, viewLink, editLink, historyLink, purgeLink)
	else
		ret = makeUrlLink(docTitle:fullUrl{action = 'edit', preload = data.preload}, data.createLinkDisplay)
	end
end

function p.makeStartBoxData(args, env, links)
	local subjectSpace = env.subjectSpace
	local data = {}
	
	-- Heading
	local heading = args.heading -- Blank values are not removed.
	if heading == '' then
		-- Don't display the start box if the heading arg is defined but blank.
		return nil
	end
	if heading then
		data.heading = heading
	elseif subjectSpace == 10 then -- Template namespace
		data.heading = message('documentationIconWikitext', 'string') .. ' ' .. message('templateNamespaceHeading', 'string')
	elseif subjectSpace == 828 then -- Module namespace
		data.heading = message('documentationIconWikitext', 'string') .. ' ' .. message('moduleNamespaceHeading', 'string')
	elseif subjectSpace == 6 then -- File namespace
		data.heading = message('fileNamespaceHeading', 'string')
	else
		data.heading = message('otherNamespacesHeading', 'string')
	end
	
	-- Heading CSS
	local headingStyle = args['heading-style']
	if headingStyle then
		data.headingStyleText = headingStyle
	elseif subjectSpace == 10 then
		-- We are in the template or template talk namespaces.
		data.headingFontWeight = 'bold'
		data.headingFontSize = '125%'
	else
		data.headingFontSize = '150%'
	end
	
	-- [view][edit][history][purge] or [create] links.
	if links then
		data.linksClass = message('startBoxLinkclasses', 'string')
		data.linksId = message('startBoxLinkId', 'string')
		data.links = links
	end
	
	return data
end

function p.renderStartBox(data)
	-- Renders the start box html.
	local sbox = htmlBuilder.create('div')
	sbox
		.css('padding-bottom', '3px')
		.css('border-bottom', '1px solid #aaa')
		.css('margin-bottom', '1ex')
		.newline()
		.tag('span')
			.cssText(data.headingStyleText)
			.css('font-weight', data.headingFontWeight)
			.css('font-size', data.headingFontSize)
			.wikitext(data.heading)
	local links = data.links
	if links then
		sbox.tag('span')
			.addClass(data.linksClass)
			.attr('id', data.linksId)
			.wikitext(links)
	end
	return tostring(sbox)
end

----------------------------------------------------------------------------
-- Documentation content
----------------------------------------------------------------------------

p.content = makeInvokeFunc('_content')

function p._content(args, env)
	local content = args.content
	if not content then
		local docpage = args[1]
		if docpage and mw.title.new(docpage).exists then
			local frame = mw.getCurrentFrame()
			content = frame:preprocess('{{ ' .. docpage .. ' }}')
		else
			docpage = env.docspace .. ':' .. env.templatePage .. '/' .. message('docSubpage', 'string')
			if mw.title.new(docpage).exists then
				local frame = mw.getCurrentFrame()
				content = frame:preprocess('{{ ' .. docpage .. ' }}')
			end
		end
	end
	-- The line breaks below are necessary so that "=== Headings ===" at the start and end
	-- of docs are interpreted correctly.
	return '\n' .. (content or '') .. '\n' 
end

----------------------------------------------------------------------------
-- End box
----------------------------------------------------------------------------

p.endBox = makeInvokeFunc('_endBox')

function p._endBox(args, env)
	local title = env.title
	local subjectSpace = env.subjectSpace

	-- Argument processing in {{documentation}}.
	local content = args.content
	local linkBox = args['link box'] -- So "link box=off" works.
	local docspace = env.docspace
	local docname = args[1] -- Other docname, if fed.
	local templatePage = env.templatePage

	-- Argument processing in {{documentation/end box2}}.
	local docpageRoot = (docspace or title.nsText) .. ':' .. (templatePage or title.text)
	local docpage
	if docname then
		docpage = docname
	else
		docpage = docpageRoot .. '/' .. message('docSubpage', 'string')
	end
	local docTitle = mw.title.new(docpage)
	local docExist = docTitle.exists
	local docnameFed = args[1] and true
	local sandbox = docpageRoot .. '/' .. message('sandboxSubpage', 'string')
	local testcases = docpageRoot .. '/' .. message('testcasesSubpage', 'string')
	templatePage = title.nsText .. ':' .. templatePage

	-- Output from {{documentation/end box}}
	
	-- First, check whether we should output the end box at all. Add the end box by default if the documentation
	-- exists or if we are in the user, module or template namespaces.
	if linkBox == 'off' or not (docExist or subjectSpace == 2 or subjectSpace == 828 or subjectSpace == 10) then
		return nil
	end

	-- Assemble the arguments for {{fmbox}}.
	local fmargs = {}
	fmargs.id = message('fmboxId', 'string') -- Sets 'documentation-meta-data'
	fmargs.image = message('fmboxImageNone', 'string') -- Sets 'none'
	fmargs.style = message('fmboxStyle', 'string') -- Sets 'background-color: #ecfcf4'
	fmargs.textstyle = message('fmboxTextstyle', 'string') -- 'font-style: italic;'

	-- Assemble the fmbox text field.
	local text = ''
	if linkBox then
		-- Use custom link box content if it is defined.
		text = text .. linkBox
	else
		text = text .. (p.makeDocPageBlurb(args, env) or '')
		-- Add links to /sandbox and /testcases when appropriate.
		if subjectSpace == 2 or subjectSpace == 828 or subjectSpace == 10 then
			-- We are in the user, module or template namespaces. 
			text = text .. p.makeEndBoxExperimentBlurb(args, env)
			text = text .. '<br />'
			-- Show the categories text, but not if "content" fed or "docname fed" since then it is unclear where to add the categories.
			if not content and not docnameFed then
				local docPathLink = makeWikilink(docpage, message('docLinkDisplay', 'string'))
				text = text .. message('addCategoriesBlurb', 'string', {docPathLink})
			end
			-- Show the "subpages" link.
			if subjectSpace ~= 6 then -- Don't show the link in file space.
				local pagetype
				if subjectSpace == 10 then
					pagetype = message('templatePagetype', 'string')
				elseif subjectSpace == 828 then
					pagetype = message('modulePagetype', 'string')
				else
					pagetype = message('defaultPagetype', 'string')
				end
				text = text .. ' ' .. makeWikilink('Special:PrefixIndex/' .. templatePage .. '/', message('subpagesLinkDisplay', 'string', {pagetype}))
			end
			-- Show the "print" link if it exists.
			local printPage = templatePage .. '/' .. message('printSubpage', 'string')
			local printTitle = mw.title.new(printPage)
			if printTitle.exists then
				local printLink = makeWikilink(printPage, message('printLinkDisplay', 'string'))
				text = text .. '<br />' .. message('printBlurb', 'string', {printLink})
					.. (message('displayPrintCategory', 'boolean') and makeCategoryLink(message('printCategory', 'string')) or '')
			end
		end
	end
	fmargs.text = text

	-- Return the fmbox output.
	return messageBox.main('fmbox', fmargs)
end

function p.makeCategoriesBlurb(args, env)
	-- Get the title object.
	local success, docTitle = env:grab('docTitle')
	if not success then
		-- docTitle is the error message.
		return docTitle
	end
	-- Make the blurb.
	local docPathLink = makeWikilink(docTitle.prefixedText, message('docLinkDisplay', 'string'))
	return message('addCategoriesBlurb', 'string', {docPathLink})
end

function p.makeDocPageBlurb(args, env)
	-- Get the title object.
	local success, docTitle = env:grab('docTitle')
	if not success then
		-- docTitle is the error message.
		return docTitle
	end
	-- Make the blurb.
	local ret
	if docTitle.exists then
		-- /doc exists; link to it.
		local docLink = makeWikilink(docTitle.prefixedText)
		local editUrl = docTitle:fullUrl{action = 'edit'}
		local editDisplay = message('editLinkDisplay', 'string')
		local editLink = makeUrlLink(editUrl, editDisplay)
		local historyUrl = docTitle:fullUrl{action = 'history'}
		local historyDisplay = message('historyLinkDisplay', 'string')
		local historyLink = makeUrlLink(historyUrl, historyDisplay)
		ret = message('transcludedFromBlurb', 'string', {docLink})
			.. ' '
			.. makeToolbar(editLink, historyLink)
			.. '<br />'
	elseif env.subjectSpace == 828 then
		-- /doc does not exist; ask to create it.
		local createUrl = docTitle:fullUrl{action = 'edit', preload = message('modulePreload', 'string')}
		local createDisplay = message('createLinkDisplay', 'string')
		local createLink = makeUrlLink(createUrl, createDisplay)
		ret = message('createModuleDocBlurb', 'string', {createLink})
			.. '<br />'
	end
	return ret
end

function p.makeEndBoxExperimentBlurb(args, env)
	-- Renders the text "Editors can experiment in this template's sandbox (edit | diff) and testcases (edit) pages."
	local subjectSpace = env.subjectSpace
	local templatePage = env.templatePage
	-- Get title objects.
	local templateSuccess, templateTitle = env:grab('templateTitle')
	if not templateSuccess then
		return err(templateTitle)
	end
	local sandboxSuccess, sandboxTitle = env:grab('sandboxTitle')
	if not sandboxSuccess then
		return err(sandboxTitle)
	end
	local testcasesSuccess, testcasesTitle = env:grab('testcasesTitle')
	if not testcasesSuccess then
		return err(testcasesTitle)
	end
	-- Make links.
	local sandboxLinks, testcasesLinks
	if sandboxTitle.exists then
		local sandboxPage = sandboxTitle.prefixedText
		local sandboxDisplay = message('sandboxLinkDisplay', 'string')
		local sandboxLink = makeWikilink(sandboxPage, sandboxDisplay)
		local sandboxEditUrl = sandboxTitle:fullUrl{action = 'edit'}
		local sandboxEditDisplay = message('sandboxEditLinkDisplay', 'string')
		local sandboxEditLink = makeUrlLink(sandboxEditUrl, sandboxEditDisplay)
		local compareUrl = mw.uri.fullUrl('Special:ComparePages', {page1 = templateTitle.prefixedText, page2 = sandboxPage})
		compareUrl = tostring(compareUrl)
		local compareDisplay = message('compareLinkDisplay', 'string')
		local compareLink = makeUrlLink(compareUrl, compareDisplay)
		sandboxLinks = sandboxLink .. ' ' .. makeToolbar(sandboxEditLink, compareLink)
	else
		local sandboxPreload
		if subjectSpace == 828 then
			sandboxPreload = message('moduleSandboxPreload', 'string')
		else
			sandboxPreload = message('templateSandboxPreload', 'string')
		end
		local sandboxCreateUrl = sandboxTitle:fullUrl{action = 'edit', preload = sandboxPreload}
		local sandboxCreateDisplay = message('sandboxCreateLinkDisplay', 'string')
		local sandboxCreateLink = makeUrlLink(sandboxCreateUrl, sandboxCreateDisplay)
		local mirrorSummary = message('mirrorEditSummary', 'string', {makeWikilink(templatePage)})
		local mirrorUrl = sandboxTitle:fullUrl{action = 'edit', preload = templatePage, summary = mirrorSummary}
		local mirrorDisplay = message('mirrorLinkDisplay', 'string')
		local mirrorLink = makeUrlLink(mirrorUrl, mirrorDisplay)
		sandboxLinks = message('sandboxLinkDisplay', 'string') .. ' ' .. makeToolbar(sandboxCreateLink, mirrorLink)
	end
	if testcasesTitle.exists then
		local testcasesPage = testcasesTitle.prefixedText
		local testcasesDisplay = message('testcasesLinkDisplay', 'string')
		local testcasesLink = makeWikilink(testcasesPage, testcasesDisplay)
		local testcasesEditUrl = testcasesTitle:fullUrl{action = 'edit'}
		local testcasesEditDisplay = message('testcasesEditLinkDisplay', 'string')
		local testcasesEditLink = makeUrlLink(testcasesEditUrl, testcasesEditDisplay)
		testcasesLinks = testcasesLink .. ' ' .. makeToolbar(testcasesEditLink)
	else
		local testcasesPreload
		if subjectSpace == 828 then
			testcasesPreload = message('moduleTestcasesPreload', 'string')
		else
			testcasesPreload = message('templateTestcasesPreload', 'string')
		end
		local testcasesCreateUrl = testcasesTitle:fullUrl{action = 'edit', preload = testcasesPreload}
		local testcasesCreateDisplay = message('testcasesCreateLinkDisplay', 'string')
		local testcasesCreateLink = makeUrlLink(testcasesCreateUrl, testcasesCreateDisplay)
		testcasesLinks = message('testcasesLinkDisplay', 'string') .. ' ' .. makeToolbar(testcasesCreateLink)
	end
	local messageName
	if subjectSpace == 828 then
		messageName = 'experimentBlurbModule'
	else
		messageName = 'experimentBlurbTemplate'
	end
	return message(messageName, 'string', {sandboxLinks, testcasesLinks})
end

----------------------------------------------------------------------------
-- Tracking categories
----------------------------------------------------------------------------

function p.addTrackingCategories(env)
	-- Check if {{documentation}} is transcluded on a /doc or /testcases page.
	local title = env.title
	local ret = ''
	local subpage = title.subpageText
	if message('displayStrangeUsageCategory', 'boolean') and (subpage == message('docSubpage', 'string') or subpage == message('testcasesSubpage', 'string')) then
		local sort = (title.namespace == 0 and message('strangeUsageCategoryMainspaceSort', 'string') or '') .. title.prefixedText -- Sort on namespace.
		ret = ret .. makeCategoryLink(message('strangeUsageCategory', 'string'), sort)
	end
	return ret
end

return p