Module:Documentation

-- 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
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|%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(
  '<span class="%s">(%s)</span>',
  message('toolbar-class'),
  table.concat(ret, ' &#124; ')
 )
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.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["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'
 -- '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 {{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, 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 [[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(sandboxCat)

 -- '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

 -- 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 "&#91;" .. viewLink .. "&#93; &#91;" .. editLink .. "&#93; &#91;" .. historyLink .. "&#93; &#91;" .. purgeLink .. "&#93;"
 else
  local createLink = makeUrlLink(docTitle:canonicalUrl{action = 'edit', preload = data.preload}, data.createLinkDisplay)
  return  "&#91;" .. createLink .. "&#93; &#91;" .. purgeLink .. "&#93;"
 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
 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)
   .. '<br />'
 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})
   .. '<br />'
 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 {{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
 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