Module:Documentation

    From Wikinoor

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

    -- This module implements {{documentation}}.
    
    -- Get required modules.
    local getArgs = require('Module:Arguments').getArgs
    
    -- Get the config table.
    local cfg = mw.loadData('Module:Documentation/config')
    
    local p = {}
    
    -- Often-used functions.
    local ugsub = 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, valArray, expectType)
    	--[[
    	-- 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. The default type for expectType is 'string'.
    	-- 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 "foo-message" had the value 'Foo $2 bar $1.',
    	-- message('foo-message', {'baz', 'qux'}) would return "Foo qux bar baz."
    	--]]
    	local msg = cfg[cfgKey]
    	expectType = expectType or 'string'
    	if 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
    
    	return ugsub(msg, '$([1-9][0-9]*)', getMessageVal)
    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
    	-- 'documentation-toolbar'
    	return '<span class="' .. message('toolbar-class') .. '">('
    		.. table.concat(ret, ' &#124; ') .. ')</span>'
    end	
    
    p.makeToolbar = makeToolbar
    
    ----------------------------------------------------------------------------
    -- 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
    
    ----------------------------------------------------------------------------
    -- Entry points
    ----------------------------------------------------------------------------
    
    function p.nonexistent(frame)
    	if mw.title.getCurrentTitle().subpageText == 'testcases' then
    		return frame:expandTemplate{title = 'module test cases notice'}
    	else
    		return p.main(frame)
    	end
    end
    
    p.main = makeInvokeFunc('_main')
    
    function p._main(args)
    	--[[
    	-- This function defines logic flow for the module.
    	-- @args - table of arguments passed by the user
    	--]]
    	local env = p.getEnvironment(args)
    	local root = mw.html.create()
    	root
    		:wikitext(p._getModuleWikitext(args, env))
    		:wikitext(p.protectionTemplate(env))
    		:wikitext(p.sandboxNotice(args, env))
    		:tag('div')
    			-- 'documentation-container'
    			:addClass(message('container'))
    			:attr('role', 'complementary')
    			:attr('aria-labelledby', args.heading ~= '' and 'documentation-heading' or nil)
    			:attr('aria-label', args.heading == '' and 'Documentation' or nil)
    			:newline()
    			:tag('div')
    				-- 'documentation'
    				:addClass(message('main-div-classes'))
    				:newline()
    				:wikitext(p._startBox(args, env))
    				:wikitext(p._content(args, env))
    				:tag('div')
    					-- 'documentation-clear'
    					:addClass(message('clear'))
    					:done()
    				:newline()
    				:done()
    			:wikitext(p._endBox(args, env))
    			:done()
    		:wikitext(p.addTrackingCategories(env))
    	-- 'Module:Documentation/styles.css'
    	return mw.getCurrentFrame():extensionTag (
    		'templatestyles', '', {src=cfg['templatestyles']
    	}) .. tostring(root)
    end
    
    ----------------------------------------------------------------------------
    -- Environment settings
    ----------------------------------------------------------------------------
    
    function p.getEnvironment(args)
    	--[[
    	-- Returns a table with information about the environment, including title
    	-- objects and other namespace- or path-related data.
    	-- @args - table of arguments passed by the user
    	--
    	-- Title objects include:
    	-- env.title - the page we are making documentation for (usually the current title)
    	-- env.templateTitle - the template (or module, file, etc.)
    	-- env.docTitle - the /doc subpage.
    	-- env.sandboxTitle - the /sandbox subpage.
    	-- env.testcasesTitle - the /testcases subpage.
    	--
    	-- Data includes:
    	-- env.protectionLevels - the protection levels table of the title object.
    	-- env.subjectSpace - the number of the title's subject namespace.
    	-- env.docSpace - the number of the namespace the title puts its documentation in.
    	-- env.docpageBase - the text of the base page of the /doc, /sandbox and /testcases pages, with namespace.
    	-- env.compareUrl - URL of the Special:ComparePages page comparing the sandbox with the template.
    	-- 
    	-- All table lookups are passed through pcall so that errors are caught. If an error occurs, the value
    	-- returned will be nil.
    	--]]
    	
    	local env, envFuncs = {}, {}
    
    	-- Set up the metatable. If triggered we call the corresponding function in the envFuncs table. The value
    	-- returned by that function is memoized in the env table so that we don't call any of the functions
    	-- more than once. (Nils won't be memoized.)
    	setmetatable(env, {
    		__index = function (t, key)
    			local envFunc = envFuncs[key]
    			if envFunc then
    				local success, val = pcall(envFunc)
    				if success then
    					env[key] = val -- Memoise the value.
    					return val
    				end
    			end
    			return nil
    		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)
    		else
    			title = mw.title.getCurrentTitle()
    		end
    		return title
    	end
    
    	function envFuncs.templateTitle()
    		--[[
    		-- The template (or module, etc.) title object.
    		-- Messages:
    		-- 'sandbox-subpage' --> 'sandbox'
    		-- 'testcases-subpage' --> 'testcases'
    		--]]
    		local subjectSpace = env.subjectSpace
    		local title = env.title
    		local subpage = title.subpageText
    		if subpage == message('sandbox-subpage') or subpage == message('testcases-subpage') then
    			return mw.title.makeTitle(subjectSpace, title.baseText)
    		else
    			return mw.title.makeTitle(subjectSpace, title.text)
    		end
    	end
    
    	function envFuncs.docTitle()
    		--[[
    		-- Title object of the /doc subpage.
    		-- Messages:
    		-- 'doc-subpage' --> 'doc'
    		--]]
    		local title = env.title
    		local docname = args[1] -- User-specified doc page.
    		local docpage
    		if docname then
    			docpage = docname
    		else
    			docpage = env.docpageBase .. '/' .. message('doc-subpage')
    		end
    		return mw.title.new(docpage)
    	end
    	
    	function envFuncs.sandboxTitle()
    		--[[
    		-- Title object for the /sandbox subpage.
    		-- Messages:
    		-- 'sandbox-subpage' --> 'sandbox'
    		--]]
    		return mw.title.new(env.docpageBase .. '/' .. message('sandbox-subpage'))
    	end
    	
    	function envFuncs.testcasesTitle()
    		--[[
    		-- Title object for the /testcases subpage.
    		-- Messages:
    		-- 'testcases-subpage' --> 'testcases'
    		--]]
    		return mw.title.new(env.docpageBase .. '/' .. message('testcases-subpage'))
    	end
    
    	function envFuncs.protectionLevels()
    		-- The protection levels table of the title object.
    		return env.title.protectionLevels
    	end
    
    	function envFuncs.subjectSpace()
    		-- The subject namespace number.
    		return mw.site.namespaces[env.title.namespace].subject.id
    	end
    
    	function envFuncs.docSpace()
    		-- The documentation namespace number. For most namespaces this is the
    		-- same as the subject namespace. However, pages in the Article, File,
    		-- MediaWiki or Category namespaces must have their /doc, /sandbox and
    		-- /testcases pages in talk space.
    		local subjectSpace = env.subjectSpace
    		if subjectSpace == 0 or subjectSpace == 6 or subjectSpace == 8 or subjectSpace == 14 then
    			return subjectSpace + 1
    		else
    			return subjectSpace
    		end
    	end
    
    	function envFuncs.docpageBase()
    		-- The base page of the /doc, /sandbox, and /testcases subpages.
    		-- For some namespaces this is the talk page, rather than the template page.
    		local templateTitle = env.templateTitle
    		local docSpace = env.docSpace
    		local docSpaceText = mw.site.namespaces[docSpace].name
    		-- Assemble the link. docSpace is never the main namespace, so we can hardcode the colon.
    		return docSpaceText .. ':' .. templateTitle.text
    	end
    	
    	function envFuncs.compareUrl()
    		-- Diff link between the sandbox and the main template using [[Special:ComparePages]].
    		local templateTitle = env.templateTitle
    		local sandboxTitle = env.sandboxTitle
    		if templateTitle.exists and sandboxTitle.exists then
    			local compareUrl = mw.uri.fullUrl(
    				'Special:ComparePages',
    				{ page1 = templateTitle.prefixedText, page2 = sandboxTitle.prefixedText}
    			)
    			return tostring(compareUrl)
    		else
    			return nil
    		end
    	end		
    
    	return env
    end	
    
    ----------------------------------------------------------------------------
    -- Auxiliary templates
    ----------------------------------------------------------------------------
    
    p.getModuleWikitext = makeInvokeFunc('_getModuleWikitext')
    
    function p._getModuleWikitext(args, env)
    	local currentTitle = mw.title.getCurrentTitle()
    	if currentTitle.contentModel ~= 'Scribunto' then return end
    	pcall(require, currentTitle.prefixedText) -- if it fails, we don't care
    	local moduleWikitext =  package.loaded["Module:Module wikitext"]
    	if moduleWikitext then
    		return moduleWikitext.main()
    	end
    end
    
    function p.sandboxNotice(args, env)
    	--[=[
    	-- Generates a sandbox notice for display above sandbox pages.
    	-- @args - a table of arguments passed by the user
    	-- @env - environment table containing title objects, etc., generated with p.getEnvironment
    	-- 
    	-- Messages:
    	-- 'sandbox-notice-image' --> '[[File:Sandbox.svg|50px|alt=|link=]]'
    	-- 'sandbox-notice-blurb' --> 'This is the $1 for $2.'
    	-- 'sandbox-notice-diff-blurb' --> 'This is the $1 for $2 ($3).'
    	-- 'sandbox-notice-pagetype-template' --> '[[Wikipedia:Template test cases|template sandbox]] page'
    	-- 'sandbox-notice-pagetype-module' --> '[[Wikipedia:Template test cases|module sandbox]] page'
    	-- 'sandbox-notice-pagetype-other' --> 'sandbox page'
    	-- 'sandbox-notice-compare-link-display' --> 'diff'
    	-- 'sandbox-notice-testcases-blurb' --> 'See also the companion subpage for $1.'
    	-- 'sandbox-notice-testcases-link-display' --> 'test cases'
    	-- 'sandbox-category' --> 'Template sandboxes'
    	--]=]
    	local title = env.title
    	local sandboxTitle = env.sandboxTitle
    	local templateTitle = env.templateTitle
    	local subjectSpace = env.subjectSpace
    	if not (subjectSpace and title and sandboxTitle and templateTitle
    		and mw.title.equals(title, sandboxTitle)) then
    		return nil
    	end
    	-- Build the table of arguments to pass to {{ombox}}. We need just two fields, "image" and "text".
    	local omargs = {}
    	omargs.image = message('sandbox-notice-image')
    	-- Get the text. We start with the opening blurb, which is something like
    	-- "This is the template sandbox for [[Template:Foo]] (diff)."
    	local text = ''
    	local pagetype
    	if subjectSpace == 10 then
    		pagetype = message('sandbox-notice-pagetype-template')
    	elseif subjectSpace == 828 then
    		pagetype = message('sandbox-notice-pagetype-module')
    	else
    		pagetype = message('sandbox-notice-pagetype-other')
    	end
    	local templateLink = makeWikilink(templateTitle.prefixedText)
    	local compareUrl = env.compareUrl
    	if compareUrl then
    		local compareDisplay = message('sandbox-notice-compare-link-display')
    		local compareLink = makeUrlLink(compareUrl, compareDisplay)
    		text = text .. message('sandbox-notice-diff-blurb', {pagetype, templateLink, compareLink})
    	else
    		text = text .. message('sandbox-notice-blurb', {pagetype, templateLink})
    	end
    	-- Get the test cases page blurb if the page exists. This is something like
    	-- "See also the companion subpage for [[Template:Foo/testcases|test cases]]."
    	local testcasesTitle = env.testcasesTitle
    	if testcasesTitle and testcasesTitle.exists then
    		if testcasesTitle.contentModel == "Scribunto" then
    			local testcasesLinkDisplay = message('sandbox-notice-testcases-link-display')
    			local testcasesRunLinkDisplay = message('sandbox-notice-testcases-run-link-display')
    			local testcasesLink = makeWikilink(testcasesTitle.prefixedText, testcasesLinkDisplay)
    			local testcasesRunLink = makeWikilink(testcasesTitle.talkPageTitle.prefixedText, testcasesRunLinkDisplay)
    			text = text .. '<br />' .. message('sandbox-notice-testcases-run-blurb', {testcasesLink, testcasesRunLink})
    		else
    			local testcasesLinkDisplay = message('sandbox-notice-testcases-link-display')
    			local testcasesLink = makeWikilink(testcasesTitle.prefixedText, testcasesLinkDisplay)
    			text = text .. '<br />' .. message('sandbox-notice-testcases-blurb', {testcasesLink})
    		end
    	end
    	-- Add the sandbox to the sandbox category.
    	omargs.text = text .. makeCategoryLink(message('sandbox-category'))
    
    	-- 'documentation-clear'
    	return '<div class="' .. message('clear') .. '"></div>'
    		.. require('Module:Message box').main('ombox', omargs)
    end
    
    function p.protectionTemplate(env)
    	-- Generates the padlock icon in the top right.
    	-- @env - environment table containing title objects, etc., generated with p.getEnvironment
    	-- Messages:
    	-- 'protection-template' --> 'pp-template'
    	-- 'protection-template-args' --> {docusage = 'yes'}
    	local protectionLevels = env.protectionLevels
    	if not protectionLevels then
    		return nil
    	end
    	local editProt = protectionLevels.edit and protectionLevels.edit[1]
    	local moveProt = protectionLevels.move and protectionLevels.move[1]
    	if editProt then
    		-- The page is edit-protected.
    		return require('Module:Protection banner')._main{
    			message('protection-reason-edit'), small = true
    		}
    	elseif moveProt and moveProt ~= 'autoconfirmed' then
    		-- The page is move-protected but not edit-protected. Exclude move
    		-- protection with the level "autoconfirmed", as this is equivalent to
    		-- no move protection at all.
    		return require('Module:Protection banner')._main{
    			action = 'move', small = true
    		}
    	else
    		return nil
    	end
    end
    
    ----------------------------------------------------------------------------
    -- Start box
    ----------------------------------------------------------------------------
    
    p.startBox = makeInvokeFunc('_startBox')
    
    function p._startBox(args, env)
    	--[[
    	-- This function generates the start box.
    	-- @args - a table of arguments passed by the user
    	-- @env - environment table containing title objects, etc., generated with p.getEnvironment
    	-- 
    	-- The actual work is done by p.makeStartBoxLinksData and p.renderStartBoxLinks which make
    	-- the [view] [edit] [history] [purge] links, and by p.makeStartBoxData and p.renderStartBox
    	-- which generate the box HTML.
    	--]]
    	env = env or p.getEnvironment(args)
    	local links
    	local content = args.content
    	if not content or args[1] 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 data then
    		return p.renderStartBox(data)
    	else
    		-- User specified no heading.
    		return nil
    	end
    end
    
    function p.makeStartBoxLinksData(args, env)
    	--[[
    	-- Does initial processing of data to make the [view] [edit] [history] [purge] links.
    	-- @args - a table of arguments passed by the user
    	-- @env - environment table containing title objects, etc., generated with p.getEnvironment
    	-- 
    	-- Messages:
    	-- 'view-link-display' --> 'view'
    	-- 'edit-link-display' --> 'edit'
    	-- 'history-link-display' --> 'history'
    	-- 'purge-link-display' --> 'purge'
    	-- 'module-preload' --> 'Template:Documentation/preload-module-doc'
    	-- 'docpage-preload' --> 'Template:Documentation/preload'
    	-- 'create-link-display' --> 'create'
    	--]]
    	local subjectSpace = env.subjectSpace
    	local title = env.title
    	local docTitle = env.docTitle
    	if not title or not docTitle then
    		return nil
    	end
    	if docTitle.isRedirect then 
    		docTitle = docTitle.redirectTarget
    	end
    
    	local data = {}
    	data.title = title
    	data.docTitle = docTitle
    	-- View, display, edit, and purge links if /doc exists.
    	data.viewLinkDisplay = message('view-link-display')
    	data.editLinkDisplay = message('edit-link-display')
    	data.historyLinkDisplay = message('history-link-display')
    	data.purgeLinkDisplay = message('purge-link-display')
    	-- Create link if /doc doesn't exist.
    	local preload = args.preload
    	if not preload then
    		if subjectSpace == 828 then -- Module namespace
    			preload = message('module-preload')
    		else
    			preload = message('docpage-preload')
    		end
    	end
    	data.preload = preload
    	data.createLinkDisplay = message('create-link-display')
    	return data
    end
    
    function p.renderStartBoxLinks(data)
    	--[[
    	-- Generates the [view][edit][history][purge] or [create][purge] links from the data table.
    	-- @data - a table of data generated by p.makeStartBoxLinksData
    	--]]
    	
    	local function escapeBrackets(s)
    		-- Escapes square brackets with HTML entities.
    		s = s:gsub('%[', '&#91;') -- Replace square brackets with HTML entities.
    		s = s:gsub('%]', '&#93;')
    		return s
    	end
    
    	local ret
    	local docTitle = data.docTitle
    	local title = data.title
    	local purgeLink = makeUrlLink(title:fullUrl{action = 'purge'}, data.purgeLinkDisplay)
    	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)
    		ret = '[%s] [%s] [%s] [%s]'
    		ret = escapeBrackets(ret)
    		ret = mw.ustring.format(ret, viewLink, editLink, historyLink, purgeLink)
    	else
    		local createLink = makeUrlLink(docTitle:fullUrl{action = 'edit', preload = data.preload}, data.createLinkDisplay)
    		ret = '[%s] [%s]'
    		ret = escapeBrackets(ret)
    		ret = mw.ustring.format(ret, createLink, purgeLink)
    	end
    	return ret
    end
    
    function p.makeStartBoxData(args, env, links)
    	--[=[
    	-- Does initial processing of data to pass to the start-box render function, p.renderStartBox.
    	-- @args - a table of arguments passed by the user
    	-- @env - environment table containing title objects, etc., generated with p.getEnvironment
    	-- @links - a string containing the [view][edit][history][purge] links - could be nil if there's an error.
    	--
    	-- Messages:
    	-- 'documentation-icon-wikitext' --> '[[File:Test Template Info-Icon - Version (2).svg|50px|link=|alt=]]'
    	-- 'template-namespace-heading' --> 'Template documentation'
    	-- 'module-namespace-heading' --> 'Module documentation'
    	-- 'file-namespace-heading' --> 'Summary'
    	-- 'other-namespaces-heading' --> 'Documentation'
    	-- 'testcases-create-link-display' --> 'create'
    	--]=]
    	local subjectSpace = env.subjectSpace
    	if not subjectSpace then
    		-- Default to an "other namespaces" namespace, so that we get at least some output
    		-- if an error occurs.
    		subjectSpace = 2
    	end
    	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('documentation-icon-wikitext') .. ' ' .. message('template-namespace-heading')
    	elseif subjectSpace == 828 then -- Module namespace
    		data.heading = message('documentation-icon-wikitext') .. ' ' .. message('module-namespace-heading')
    	elseif subjectSpace == 6 then -- File namespace
    		data.heading = message('file-namespace-heading')
    	else
    		data.heading = message('other-namespaces-heading')
    	end
    	
    	-- Heading CSS
    	local headingStyle = args['heading-style']
    	if headingStyle then
    		data.headingStyleText = headingStyle
    	else
    		-- 'documentation-heading'
    		data.headingClass = message('main-div-heading-class')
    	end
    	
    	-- Data for the [view][edit][history][purge] or [create] links.
    	if links then
    		-- 'mw-editsection-like plainlinks'
    		data.linksClass = message('start-box-link-classes')
    		data.links = links
    	end
    	
    	return data
    end
    
    function p.renderStartBox(data)
    	-- Renders the start box html.
    	-- @data - a table of data generated by p.makeStartBoxData.
    	local sbox = mw.html.create('div')
    	sbox
    		-- 'documentation-startbox'
    		:addClass(message('start-box-class'))
    		:newline()
    		:tag('span')
    			:addClass(data.headingClass)
    			:attr('id', 'documentation-heading')
    			:cssText(data.headingStyleText)
    			: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)
    	-- Displays the documentation contents
    	-- @args - a table of arguments passed by the user
    	-- @env - environment table containing title objects, etc., generated with p.getEnvironment
    	env = env or p.getEnvironment(args)
    	local docTitle = env.docTitle
    	local content = args.content
    	if not content and docTitle and docTitle.exists then
    		content = args._content or mw.getCurrentFrame():expandTemplate{title = docTitle.prefixedText}
    	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
    
    p.contentTitle = makeInvokeFunc('_contentTitle')
    
    function p._contentTitle(args, env)
    	env = env or p.getEnvironment(args)
    	local docTitle = env.docTitle
    	if not args.content and docTitle and docTitle.exists then
    		return docTitle.prefixedText
    	else
    		return ''
    	end
    end
    
    ----------------------------------------------------------------------------
    -- End box
    ----------------------------------------------------------------------------
    
    p.endBox = makeInvokeFunc('_endBox')
    
    function p._endBox(args, env)
    	--[=[
    	-- This function generates the end box (also known as the link box).
    	-- @args - a table of arguments passed by the user
    	-- @env - environment table containing title objects, etc., generated with p.getEnvironment
    	-- 
    	--]=]
    	
    	-- Get environment data.
    	env = env or p.getEnvironment(args)
    	local subjectSpace = env.subjectSpace
    	local docTitle = env.docTitle
    	if not subjectSpace or not docTitle then
    		return nil
    	end
    		
    	-- 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.
    	local linkBox = args['link box']
    	if linkBox == 'off'
    		or not (
    			docTitle.exists
    			or subjectSpace == 2
    			or subjectSpace == 828
    			or subjectSpace == 10
    		)
    	then
    		return nil
    	end
    
    	-- Assemble the link box.
    	local text = ''
    	if linkBox then
    		text = text .. linkBox
    	else
    		text = text .. (p.makeDocPageBlurb(args, env) or '') -- "This documentation is transcluded from [[Foo]]." 
    		if subjectSpace == 2 or subjectSpace == 10 or subjectSpace == 828 then
    			-- We are in the user, template or module namespaces.
    			-- Add sandbox and testcases links.
    			-- "Editors can experiment in this template's sandbox and testcases pages."
    			text = text .. (p.makeExperimentBlurb(args, env) or '') .. '<br />'
    			if not args.content and not args[1] then
    				-- "Please add categories to the /doc subpage."
    				-- Don't show this message with inline docs or with an explicitly specified doc page,
    				-- as then it is unclear where to add the categories.
    				text = text .. (p.makeCategoriesBlurb(args, env) or '')
    			end
    			text = text .. ' ' .. (p.makeSubpagesBlurb(args, env) or '') --"Subpages of this template"
    		end
    	end
    	
    	local box = mw.html.create('div')
    	-- 'documentation-metadata'
    	box:attr('role', 'note')
    		:addClass(message('end-box-class'))
    		-- 'plainlinks'
    		:addClass(message('end-box-plainlinks'))
    		:wikitext(text)
    		:done()
    
    	return '\n' .. tostring(box)
    end
    
    function p.makeDocPageBlurb(args, env)
    	--[=[
    	-- Makes the blurb "This documentation is transcluded from [[Template:Foo]] (edit, history)".
    	-- @args - a table of arguments passed by the user
    	-- @env - environment table containing title objects, etc., generated with p.getEnvironment
    	-- 
    	-- Messages:
    	-- 'edit-link-display' --> 'edit'
    	-- 'history-link-display' --> 'history'
    	-- 'transcluded-from-blurb' --> 
    	-- 'The above [[Wikipedia:Template documentation|documentation]] 
    	-- is [[Help:Transclusion|transcluded]] from $1.'
    	-- 'module-preload' --> 'Template:Documentation/preload-module-doc'
    	-- 'create-link-display' --> 'create'
    	-- 'create-module-doc-blurb' -->
    	-- 'You might want to $1 a documentation page for this [[Wikipedia:Lua|Scribunto module]].'
    	--]=]
    	local docTitle = env.docTitle
    	if not docTitle then
    		return nil
    	end
    	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('edit-link-display')
    		local editLink = makeUrlLink(editUrl, editDisplay)
    		local historyUrl = docTitle:fullUrl{action = 'history'}
    		local historyDisplay = message('history-link-display')
    		local historyLink = makeUrlLink(historyUrl, historyDisplay)
    		ret = message('transcluded-from-blurb', {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('module-preload')}
    		local createDisplay = message('create-link-display')
    		local createLink = makeUrlLink(createUrl, createDisplay)
    		ret = message('create-module-doc-blurb', {createLink})
    			.. '<br />'
    	end
    	return ret
    end
    
    function p.makeExperimentBlurb(args, env)
    	--[[
    	-- Renders the text "Editors can experiment in this template's sandbox (edit | diff) and testcases (edit) pages."
    	-- @args - a table of arguments passed by the user
    	-- @env - environment table containing title objects, etc., generated with p.getEnvironment
    	-- 
    	-- Messages:
    	-- 'sandbox-link-display' --> 'sandbox'
    	-- 'sandbox-edit-link-display' --> 'edit'
    	-- 'compare-link-display' --> 'diff'
    	-- 'module-sandbox-preload' --> 'Template:Documentation/preload-module-sandbox'
    	-- 'template-sandbox-preload' --> 'Template:Documentation/preload-sandbox'
    	-- 'sandbox-create-link-display' --> 'create'
    	-- 'mirror-edit-summary' --> 'Create sandbox version of $1'
    	-- 'mirror-link-display' --> 'mirror'
    	-- 'mirror-link-preload' --> 'Template:Documentation/mirror'
    	-- 'sandbox-link-display' --> 'sandbox'
    	-- 'testcases-link-display' --> 'testcases'
    	-- 'testcases-edit-link-display'--> 'edit'
    	-- 'template-sandbox-preload' --> 'Template:Documentation/preload-sandbox'
    	-- 'testcases-create-link-display' --> 'create'
    	-- 'testcases-link-display' --> 'testcases'
    	-- 'testcases-edit-link-display' --> 'edit'
    	-- 'module-testcases-preload' --> 'Template:Documentation/preload-module-testcases'
    	-- 'template-testcases-preload' --> 'Template:Documentation/preload-testcases'
    	-- 'experiment-blurb-module' --> 'Editors can experiment in this module's $1 and $2 pages.'
    	-- 'experiment-blurb-template' --> 'Editors can experiment in this template's $1 and $2 pages.'
    	--]]
    	local subjectSpace = env.subjectSpace
    	local templateTitle = env.templateTitle
    	local sandboxTitle = env.sandboxTitle
    	local testcasesTitle = env.testcasesTitle
    	local templatePage = templateTitle.prefixedText
    	if not subjectSpace or not templateTitle or not sandboxTitle or not testcasesTitle then
    		return nil
    	end
    	-- Make links.
    	local sandboxLinks, testcasesLinks
    	if sandboxTitle.exists then
    		local sandboxPage = sandboxTitle.prefixedText
    		local sandboxDisplay = message('sandbox-link-display')
    		local sandboxLink = makeWikilink(sandboxPage, sandboxDisplay)
    		local sandboxEditUrl = sandboxTitle:fullUrl{action = 'edit'}
    		local sandboxEditDisplay = message('sandbox-edit-link-display')
    		local sandboxEditLink = makeUrlLink(sandboxEditUrl, sandboxEditDisplay)
    		local compareUrl = env.compareUrl
    		local compareLink
    		if compareUrl then
    			local compareDisplay = message('compare-link-display')
    			compareLink = makeUrlLink(compareUrl, compareDisplay)
    		end
    		sandboxLinks = sandboxLink .. ' ' .. makeToolbar(sandboxEditLink, compareLink)
    	else
    		local sandboxPreload
    		if subjectSpace == 828 then
    			sandboxPreload = message('module-sandbox-preload')
    		else
    			sandboxPreload = message('template-sandbox-preload')
    		end
    		local sandboxCreateUrl = sandboxTitle:fullUrl{action = 'edit', preload = sandboxPreload}
    		local sandboxCreateDisplay = message('sandbox-create-link-display')
    		local sandboxCreateLink = makeUrlLink(sandboxCreateUrl, sandboxCreateDisplay)
    		local mirrorSummary = message('mirror-edit-summary', {makeWikilink(templatePage)})
    		local mirrorPreload = message('mirror-link-preload')
    		local mirrorUrl = sandboxTitle:fullUrl{action = 'edit', preload = mirrorPreload, summary = mirrorSummary}
    		if subjectSpace == 828 then
    			mirrorUrl = sandboxTitle:fullUrl{action = 'edit', preload = templateTitle.prefixedText, summary = mirrorSummary}
    		end
    		local mirrorDisplay = message('mirror-link-display')
    		local mirrorLink = makeUrlLink(mirrorUrl, mirrorDisplay)
    		sandboxLinks = message('sandbox-link-display') .. ' ' .. makeToolbar(sandboxCreateLink, mirrorLink)
    	end
    	if testcasesTitle.exists then
    		local testcasesPage = testcasesTitle.prefixedText
    		local testcasesDisplay = message('testcases-link-display')
    		local testcasesLink = makeWikilink(testcasesPage, testcasesDisplay)
    		local testcasesEditUrl = testcasesTitle:fullUrl{action = 'edit'}
    		local testcasesEditDisplay = message('testcases-edit-link-display')
    		local testcasesEditLink = makeUrlLink(testcasesEditUrl, testcasesEditDisplay)
    		-- for Modules, add testcases run link if exists
    		if testcasesTitle.contentModel == "Scribunto"  and testcasesTitle.talkPageTitle and testcasesTitle.talkPageTitle.exists then
    			local testcasesRunLinkDisplay = message('testcases-run-link-display')
    			local testcasesRunLink = makeWikilink(testcasesTitle.talkPageTitle.prefixedText, testcasesRunLinkDisplay)
    			testcasesLinks = testcasesLink .. ' ' .. makeToolbar(testcasesEditLink, testcasesRunLink)
    		else
    			testcasesLinks = testcasesLink .. ' ' .. makeToolbar(testcasesEditLink)
    		end
    	else
    		local testcasesPreload
    		if subjectSpace == 828 then
    			testcasesPreload = message('module-testcases-preload')
    		else
    			testcasesPreload = message('template-testcases-preload')
    		end
    		local testcasesCreateUrl = testcasesTitle:fullUrl{action = 'edit', preload = testcasesPreload}
    		local testcasesCreateDisplay = message('testcases-create-link-display')
    		local testcasesCreateLink = makeUrlLink(testcasesCreateUrl, testcasesCreateDisplay)
    		testcasesLinks = message('testcases-link-display') .. ' ' .. makeToolbar(testcasesCreateLink)
    	end
    	local messageName
    	if subjectSpace == 828 then
    		messageName = 'experiment-blurb-module'
    	else
    		messageName = 'experiment-blurb-template'
    	end
    	return message(messageName, {sandboxLinks, testcasesLinks})
    end
    
    function p.makeCategoriesBlurb(args, env)
    	--[[
    	-- Generates the text "Please add categories to the /doc subpage."
    	-- @args - a table of arguments passed by the user
    	-- @env - environment table containing title objects, etc., generated with p.getEnvironment
    	-- Messages:
    	-- 'doc-link-display' --> '/doc'
    	-- 'add-categories-blurb' --> 'Please add categories to the $1 subpage.'
    	--]]
    	local docTitle = env.docTitle
    	if not docTitle then
    		return nil
    	end
    	local docPathLink = makeWikilink(docTitle.prefixedText, message('doc-link-display'))
    	return message('add-categories-blurb', {docPathLink})
    end
    
    function p.makeSubpagesBlurb(args, env)
    	--[[
    	-- Generates the "Subpages of this template" link.
    	-- @args - a table of arguments passed by the user
    	-- @env - environment table containing title objects, etc., generated with p.getEnvironment
    	
    	-- Messages:
    	-- 'template-pagetype' --> 'template'
    	-- 'module-pagetype' --> 'module'
    	-- 'default-pagetype' --> 'page'
    	-- 'subpages-link-display' --> 'Subpages of this $1'
    	--]]
    	local subjectSpace = env.subjectSpace
    	local templateTitle = env.templateTitle
    	if not subjectSpace or not templateTitle then
    		return nil
    	end
    	local pagetype
    	if subjectSpace == 10 then
    		pagetype = message('template-pagetype')
    	elseif subjectSpace == 828 then
    		pagetype = message('module-pagetype')
    	else
    		pagetype = message('default-pagetype')
    	end
    	local subpagesLink = makeWikilink(
    		'Special:PrefixIndex/' .. templateTitle.prefixedText .. '/',
    		message('subpages-link-display', {pagetype})
    	)
    	return message('subpages-blurb', {subpagesLink})
    end
    
    ----------------------------------------------------------------------------
    -- Tracking categories
    ----------------------------------------------------------------------------
    
    function p.addTrackingCategories(env)
    	--[[
    	-- Check if {{documentation}} is transcluded on a /doc or /testcases page.
    	-- @env - environment table containing title objects, etc., generated with p.getEnvironment
    	
    	-- Messages:
    	-- 'display-strange-usage-category' --> true
    	-- 'doc-subpage' --> 'doc'
    	-- 'testcases-subpage' --> 'testcases'
    	-- 'strange-usage-category' --> 'Wikipedia pages with strange ((documentation)) usage'
    	-- 
    	-- /testcases pages in the module namespace are not categorised, as they may have
    	-- {{documentation}} transcluded automatically.
    	--]]
    	local title = env.title
    	local subjectSpace = env.subjectSpace
    	if not title or not subjectSpace then
    		return nil
    	end
    	local subpage = title.subpageText
    	local ret = ''
    	if message('display-strange-usage-category', nil, 'boolean')
    		and (
    			subpage == message('doc-subpage')
    			or subjectSpace ~= 828 and subpage == message('testcases-subpage')
    		)
    	then
    		ret = ret .. makeCategoryLink(message('strange-usage-category'))
    	end
    	return ret
    end
    
    return p