-- This module implements .  -- Get required modules. local getArgs = require('মডিউল:Arguments').getArgs  -- Get the config table. local cfg = mw.loadData('মডিউল:নথি/রূপরেখা')  local p = {}  -- Often-used functions. local ugsub = mw.ustring.gsub local format = mw.ustring.format  -- 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 format('%s', page, display) 	else 		return 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 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 format( 		'(%s)', 		message('toolbar-class'), 		table.concat(ret, ' | ') 	) 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)) 	-- 'মডিউল:নথি/শৈলী.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.canonicalUrl( 				'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["মডিউল: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' --> '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' --> 'template sandbox page' 	-- 'sandbox-notice-pagetype-module' --> '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' 	-- 'module-sandbox-category' --> 'Module sandboxes' 	-- 'other-sandbox-category' --> 'Sandboxes outside of template or module namespace' 	--]=] 	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 . 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, sandboxCat 	if subjectSpace == 10 then 		pagetype = message('sandbox-notice-pagetype-template') 		sandboxCat = message('sandbox-category') 	elseif subjectSpace == 828 then 		pagetype = message('sandbox-notice-pagetype-module') 		sandboxCat = message('module-sandbox-category') 	else 		pagetype = message('sandbox-notice-pagetype-other') 		sandboxCat = message('other-sandbox-category') 	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 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 .. '' .. 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 .. '' .. message('sandbox-notice-testcases-blurb', {testcasesLink}) 		end 	end 	 	-- Add the sandbox to the sandbox category. 	omargs.text = text .. makeCategoryLink(sandboxCat)  	-- 'documentation-clear' 	return '' 		.. require('মডিউল:বার্তার বাক্স').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 title = env.title 	local protectionLevels 	local protectionTemplate = message('protection-template') 	local namespace = title.namespace 	if not (protectionTemplate and (namespace == 10 or namespace == 828)) then 		-- Don't display the protection template if we are not in the template or module namespaces. 		return nil 	end 	protectionLevels = env.protectionLevels 	if not protectionLevels then 		return nil 	end 	local editLevels = protectionLevels.edit 	local moveLevels = protectionLevels.move 	if moveLevels and moveLevels[1] == 'sysop' or editLevels and editLevels[1] then 		-- The page is full-move protected, or full, template, or semi-protected. 		local frame = mw.getCurrentFrame() 		return frame:expandTemplate{title = protectionTemplate, args = message('protection-template-args', nil, 'table')} 	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  	-- 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 	 	return { 		title = title, 		docTitle = docTitle, 		-- View, display, edit, and purge links if /doc exists. 		viewLinkDisplay = message('view-link-display'), 		editLinkDisplay = message('edit-link-display'), 		historyLinkDisplay = message('history-link-display'), 		purgeLinkDisplay = message('purge-link-display'), 		preload = preload, 		createLinkDisplay = message('create-link-display') 	} 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 docTitle = data.docTitle 	-- yes, we do intend to purge the template page on which the documentation appears 	local purgeLink = makeWikilink("Special:Purge/" .. data.title.prefixedText, data.purgeLinkDisplay) 	 	if docTitle.exists then 		local viewLink = makeWikilink(docTitle.prefixedText, data.viewLinkDisplay) 		local editLink = makeWikilink("Special:EditPage/" .. docTitle.prefixedText, data.editLinkDisplay) 		local historyLink = makeWikilink("Special:PageHistory/" .. docTitle.prefixedText, data.historyLinkDisplay) 		return "[" .. viewLink .. "] [" .. editLink .. "] [" .. historyLink .. "] [" .. purgeLink .. "]" 	else 		local createLink = makeUrlLink(docTitle:canonicalUrl{action = 'edit', preload = data.preload}, data.createLinkDisplay) 		return  "[" .. 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' --> '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 				-- 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 ) .. '' 			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 documentation  	-- is 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 Scribunto module.' 	--]=] 	local docTitle = env.docTitle 	if not docTitle then 		return nil 	end 	if docTitle.exists then 		-- /doc exists; link to it. 		local docLink = makeWikilink(docTitle.prefixedText) 		local editDisplay = message('edit-link-display') 		local editLink = makeWikilink("Special:EditPage/" .. docTitle.prefixedText, editDisplay) 		local historyDisplay = message('history-link-display') 		local historyLink = makeWikilink("Special:PageHistory/" .. docTitle.prefixedText, historyDisplay) 		return message('transcluded-from-blurb', {docLink}) 			.. ' ' 			.. makeToolbar(editLink, historyLink) 			.. '' 	elseif env.subjectSpace == 828 then 		-- /doc does not exist; ask to create it. 		local createUrl = docTitle:canonicalUrl{action = 'edit', preload = message('module-preload')} 		local createDisplay = message('create-link-display') 		local createLink = makeUrlLink(createUrl, createDisplay) 		return message('create-module-doc-blurb', {createLink}) 			.. '' 	end 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 sandboxEditDisplay = message('sandbox-edit-link-display') 		local sandboxEditLink = makeWikilink("Special:EditPage/" .. sandboxPage, 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:canonicalUrl{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:canonicalUrl{action = 'edit', preload = mirrorPreload, summary = mirrorSummary} 		if subjectSpace == 828 then 			mirrorUrl = sandboxTitle:canonicalUrl{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:canonicalUrl{action = 'edit'} 		local testcasesEditDisplay = message('testcases-edit-link-display') 		local testcasesEditLink = makeWikilink("Special:EditPage/" .. testcasesPage, 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:canonicalUrl{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  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 	--  transcluded automatically. 	--]] 	local title = env.title 	local subjectSpace = env.subjectSpace 	if not title or not subjectSpace then 		return nil 	end 	local subpage = title.subpageText 	if message('display-strange-usage-category', nil, 'boolean') 		and ( 			subpage == message('doc-subpage') 			or subjectSpace ~= 828 and subpage == message('testcases-subpage') 		) 	then 		return makeCategoryLink(message('strange-usage-category')) 	end 	return  end  return p