Module:Documentation: Difference between revisions

    From Nonbinary Wiki
    m>Mr. Stradivarius
    (undo - frame:expandTemplates doesn't handle section headings correctly, so we need to use frame:preprocess)
    m (1 revision imported from wikipedia:Module:Documentation: see Topic:Vtixlm0q28eo6jtf)
     
    (65 intermediate revisions by 35 users not shown)
    Line 3: Line 3:
    -- Get required modules.
    -- Get required modules.
    local getArgs = require('Module:Arguments').getArgs
    local getArgs = require('Module:Arguments').getArgs
    local htmlBuilder = require('Module:HtmlBuilder')
    local messageBox = require('Module:Message box')


    -- Get the config table.
    -- Get the config table.
    Line 45: Line 43:
    end
    end


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


    Line 83: Line 80:
    ret[#ret + 1] = select(i, ...)
    ret[#ret + 1] = select(i, ...)
    end
    end
    return '<small style="font-style: normal;">(' .. table.concat(ret, ' &#124; ') .. ')</small>'
    -- 'documentation-toolbar'
    return '<span class="' .. message('toolbar-class') .. '">('
    .. table.concat(ret, ' &#124; ') .. ')</span>'
    end
    end


    Line 113: Line 112:


    ----------------------------------------------------------------------------
    ----------------------------------------------------------------------------
    -- Main function
    -- 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')
    p.main = makeInvokeFunc('_main')
    Line 122: Line 129:
    -- This function defines logic flow for the module.
    -- This function defines logic flow for the module.
    -- @args - table of arguments passed by the user
    -- @args - table of arguments passed by the user
    --
    -- Messages:
    -- 'main-div-id' --> 'template-documentation'
    -- 'main-div-classes' --> 'template-documentation iezoomfix'
    --]]
    --]]
    local env = p.getEnvironment(args)
    local env = p.getEnvironment(args)
    local root = htmlBuilder.create()
    local root = mw.html.create()
    root
    root
    .wikitext(p.protectionTemplate(env))
    :wikitext(p._getModuleWikitext(args, env))
    .wikitext(p.sandboxNotice(args, env))
    :wikitext(p.protectionTemplate(env))
    -- This div tag is from {{documentation/start box}}, but moving it here
    :wikitext(p.sandboxNotice(args, env))
    -- so that we don't have to worry about unclosed tags.
    :tag('div')
    .tag('div')
    -- 'documentation-container'
    .attr('id', message('main-div-id'))
    :addClass(message('container'))
    .addClass(message('main-div-classes'))
    :newline()
    .newline()
    :tag('div')
    .wikitext(p._startBox(args, env))
    -- 'documentation'
    .wikitext(p._content(args, env))
    :addClass(message('main-div-classes'))
    .tag('div')
    :newline()
    .css('clear', 'both') -- So right or left floating items don't stick out of the doc box.
    :wikitext(p._startBox(args, env))
    .newline()
    :wikitext(p._content(args, env))
    .done()
    :tag('div')
    .done()
    -- 'documentation-clear'
    .wikitext(p._endBox(args, env))
    :addClass(message('clear'))
    .newline()
    :done()
    .wikitext(p.addTrackingCategories(env))
    :newline()
    return tostring(root)
    :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
    end


    Line 157: Line 167:
    function p.getEnvironment(args)
    function p.getEnvironment(args)
    --[[
    --[[
    -- Returns a table with information about the environment, including title objects and other namespace- or
    -- Returns a table with information about the environment, including title
    -- path-related data.
    -- objects and other namespace- or path-related data.
    -- @args - table of arguments passed by the user
    -- @args - table of arguments passed by the user
    --
    --
    Line 170: Line 180:
    --
    --
    -- Data includes:
    -- Data includes:
    -- env.protectionLevels - the protection levels table of the title object.
    -- env.subjectSpace - the number of the title's subject namespace.
    -- env.subjectSpace - the number of the title's subject namespace.
    -- env.docSpace - the number of the namespace the title puts its documentation in.
    -- env.docSpace - the number of the namespace the title puts its documentation in.
    Line 269: Line 280:
    --]]
    --]]
    return env.templateTitle:subPageTitle(message('print-subpage'))
    return env.templateTitle:subPageTitle(message('print-subpage'))
    end
    function envFuncs.protectionLevels()
    -- The protection levels table of the title object.
    return env.title.protectionLevels
    end
    end


    Line 277: Line 293:


    function envFuncs.docSpace()
    function envFuncs.docSpace()
    -- The documentation namespace number. For most namespaces this is the same as the
    -- The documentation namespace number. For most namespaces this is the
    -- subject namespace. However, pages in the Article, File, MediaWiki or Category
    -- same as the subject namespace. However, pages in the Article, File,
    -- namespaces must have their /doc, /sandbox and /testcases pages in talk space.
    -- MediaWiki or Category namespaces must have their /doc, /sandbox and
    -- /testcases pages in talk space.
    local subjectSpace = env.subjectSpace
    local subjectSpace = env.subjectSpace
    if subjectSpace == 0 or subjectSpace == 6 or subjectSpace == 8 or subjectSpace == 14 then
    if subjectSpace == 0 or subjectSpace == 6 or subjectSpace == 8 or subjectSpace == 14 then
    Line 305: Line 322:
    local compareUrl = mw.uri.fullUrl(
    local compareUrl = mw.uri.fullUrl(
    'Special:ComparePages',
    'Special:ComparePages',
    {page1 = templateTitle.prefixedText, page2 = sandboxTitle.prefixedText}
    { page1 = templateTitle.prefixedText, page2 = sandboxTitle.prefixedText}
    )
    )
    return tostring(compareUrl)
    return tostring(compareUrl)
    Line 319: Line 336:
    -- Auxiliary templates
    -- 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)
    function p.sandboxNotice(args, env)
    Line 327: Line 356:
    --  
    --  
    -- Messages:
    -- Messages:
    -- 'sandbox-notice-image' --> '[[Image:Sandbox.png|50px|alt=|link=]]'
    -- 'sandbox-notice-image' --> '[[Image:Sandbox.svg|50px|alt=|link=]]'
    -- 'sandbox-notice-blurb' --> 'This is the $1 for $2.'
    -- 'sandbox-notice-blurb' --> 'This is the $1 for $2.'
    -- 'sandbox-notice-diff-blurb' --> 'This is the $1 for $2 ($3).'
    -- 'sandbox-notice-diff-blurb' --> 'This is the $1 for $2 ($3).'
    Line 342: Line 371:
    local templateTitle = env.templateTitle
    local templateTitle = env.templateTitle
    local subjectSpace = env.subjectSpace
    local subjectSpace = env.subjectSpace
    if not (subjectSpace and title and sandboxTitle and templateTitle and mw.title.equals(title, sandboxTitle)) then
    if not (subjectSpace and title and sandboxTitle and templateTitle
    and mw.title.equals(title, sandboxTitle)) then
    return nil
    return nil
    end
    end
    Line 351: Line 381:
    -- "This is the template sandbox for [[Template:Foo]] (diff)."
    -- "This is the template sandbox for [[Template:Foo]] (diff)."
    local text = ''
    local text = ''
    local frame = mw.getCurrentFrame()
    local isPreviewing = frame:preprocess('{{REVISIONID}}') == '' -- True if the page is being previewed.
    local pagetype
    local pagetype
    if subjectSpace == 10 then
    if subjectSpace == 10 then
    Line 363: Line 391:
    local templateLink = makeWikilink(templateTitle.prefixedText)
    local templateLink = makeWikilink(templateTitle.prefixedText)
    local compareUrl = env.compareUrl
    local compareUrl = env.compareUrl
    if isPreviewing or not compareUrl then
    if compareUrl then
    text = text .. message('sandbox-notice-blurb', {pagetype, templateLink})
    else
    local compareDisplay = message('sandbox-notice-compare-link-display')
    local compareDisplay = message('sandbox-notice-compare-link-display')
    local compareLink = makeUrlLink(compareUrl, compareDisplay)
    local compareLink = makeUrlLink(compareUrl, compareDisplay)
    text = text .. message('sandbox-notice-diff-blurb', {pagetype, templateLink, compareLink})
    text = text .. message('sandbox-notice-diff-blurb', {pagetype, templateLink, compareLink})
    else
    text = text .. message('sandbox-notice-blurb', {pagetype, templateLink})
    end
    end
    -- Get the test cases page blurb if the page exists. This is something like
    -- Get the test cases page blurb if the page exists. This is something like
    Line 374: Line 402:
    local testcasesTitle = env.testcasesTitle
    local testcasesTitle = env.testcasesTitle
    if testcasesTitle and testcasesTitle.exists then
    if testcasesTitle and testcasesTitle.exists then
    local testcasesLinkDisplay = message('sandbox-notice-testcases-link-display')
    if testcasesTitle.contentModel == "Scribunto" then
    local testcasesLink = makeWikilink(testcasesTitle.prefixedText, testcasesLinkDisplay)
    local testcasesLinkDisplay = message('sandbox-notice-testcases-link-display')
    text = text .. '<br />' .. message('sandbox-notice-testcases-blurb', {testcasesLink})
    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
    end
    -- Add the sandbox to the sandbox category.
    -- Add the sandbox to the sandbox category.
    text = text .. makeCategoryLink(message('sandbox-category'))
    omargs.text = text .. makeCategoryLink(message('sandbox-category'))
    omargs.text = text
     
    return messageBox.main('ombox', omargs)
    -- 'documentation-clear'
    return '<div class="' .. message('clear') .. '"></div>'
    .. require('Module:Message box').main('ombox', omargs)
    end
    end


    Line 390: Line 428:
    -- 'protection-template' --> 'pp-template'
    -- 'protection-template' --> 'pp-template'
    -- 'protection-template-args' --> {docusage = 'yes'}
    -- 'protection-template-args' --> {docusage = 'yes'}
    local title = env.title
    local protectionLevels = env.protectionLevels
    local protectionTemplate = message('protection-template')
    if not protectionLevels then
    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
    return nil
    end
    end
    local frame = mw.getCurrentFrame()
    local editProt = protectionLevels.edit and protectionLevels.edit[1]
    local function getProtectionLevel(protectionType, page)
    local moveProt = protectionLevels.move and protectionLevels.move[1]
    -- Gets the protection level for page, or for the current page if page is not specified.
    if editProt then
    local level = frame:callParserFunction('PROTECTIONLEVEL', protectionType, page)
    -- The page is edit-protected.
    if level ~= '' then
    return require('Module:Protection banner')._main{
    return level
    message('protection-reason-edit'), small = true
    else
    }
    return nil -- The parser function returns the blank string if there is no match.
    elseif moveProt and moveProt ~= 'autoconfirmed' then
    end
    -- The page is move-protected but not edit-protected. Exclude move
    end
    -- protection with the level "autoconfirmed", as this is equivalent to
    local prefixedTitle = title.prefixedText
    -- no move protection at all.
    if getProtectionLevel('move', prefixedTitle) == 'sysop' or getProtectionLevel('edit', prefixedTitle) then
    return require('Module:Protection banner')._main{
    -- The page is full-move protected, or full, template, or semi-protected.
    action = 'move', small = true
    return frame:expandTemplate{title = protectionTemplate, args = message('protection-template-args', nil, 'table')}
    }
    else
    return nil
    end
    end
    return nil
    end
    end


    Line 434: Line 470:
    local links
    local links
    local content = args.content
    local content = args.content
    if not content then
    if not content or args[1] then
    -- No need to include the links if the documentation is on the template page itself.
    -- No need to include the links if the documentation is on the template page itself.
    local linksData = p.makeStartBoxLinksData(args, env)
    local linksData = p.makeStartBoxLinksData(args, env)
    Line 472: Line 508:
    if not title or not docTitle then
    if not title or not docTitle then
    return nil
    return nil
    end
    if docTitle.isRedirect then
    docTitle = docTitle.redirectTarget
    end
    end


    Line 539: Line 578:
    --
    --
    -- Messages:
    -- Messages:
    -- 'documentation-icon-wikitext' --> '[[File:Template-info.png|50px|link=|alt=Documentation icon]]'
    -- 'documentation-icon-wikitext' --> '[[File:Test Template Info-Icon - Version (2).svg|50px|link=|alt=]]'
    -- 'template-namespace-heading' --> 'Template documentation'
    -- 'template-namespace-heading' --> 'Template documentation'
    -- 'module-namespace-heading' --> 'Module documentation'
    -- 'module-namespace-heading' --> 'Module documentation'
    -- 'file-namespace-heading' --> 'Summary'
    -- 'file-namespace-heading' --> 'Summary'
    -- 'other-namespaces-heading' --> 'Documentation'
    -- 'other-namespaces-heading' --> 'Documentation'
    -- 'start-box-linkclasses' --> 'mw-editsection-like plainlinks'
    -- 'start-box-link-id' --> 'doc_editlinks'
    -- 'testcases-create-link-display' --> 'create'
    -- 'testcases-create-link-display' --> 'create'
    --]=]
    --]=]
    Line 578: Line 615:
    if headingStyle then
    if headingStyle then
    data.headingStyleText = headingStyle
    data.headingStyleText = headingStyle
    elseif subjectSpace == 10 then
    -- We are in the template or template talk namespaces.
    data.headingFontWeight = 'bold'
    data.headingFontSize = '125%'
    else
    else
    data.headingFontSize = '150%'
    -- 'documentation-heading'
    data.headingClass = message('main-div-heading-class')
    end
    end
    -- Data for the [view][edit][history][purge] or [create] links.
    -- Data for the [view][edit][history][purge] or [create] links.
    if links then
    if links then
    data.linksClass = message('start-box-linkclasses')
    -- 'mw-editsection-like plainlinks'
    data.linksId = message('start-box-link-id')
    data.linksClass = message('start-box-link-classes')
    data.links = links
    data.links = links
    end
    end
    Line 599: Line 633:
    -- Renders the start box html.
    -- Renders the start box html.
    -- @data - a table of data generated by p.makeStartBoxData.
    -- @data - a table of data generated by p.makeStartBoxData.
    local sbox = htmlBuilder.create('div')
    local sbox = mw.html.create('div')
    sbox
    sbox
    .css('padding-bottom', '3px')
    -- 'documentation-startbox'
    .css('border-bottom', '1px solid #aaa')
    :addClass(message('start-box-class'))
    .css('margin-bottom', '1ex')
    :newline()
    .newline()
    :tag('span')
    .tag('span')
    :addClass(data.headingClass)
    .cssText(data.headingStyleText)
    :cssText(data.headingStyleText)
    .css('font-weight', data.headingFontWeight)
    :wikitext(data.heading)
    .css('font-size', data.headingFontSize)
    .wikitext(data.heading)
    local links = data.links
    local links = data.links
    if links then
    if links then
    sbox.tag('span')
    sbox:tag('span')
    .addClass(data.linksClass)
    :addClass(data.linksClass)
    .attr('id', data.linksId)
    :attr('id', data.linksId)
    .wikitext(links)
    :wikitext(links)
    end
    end
    return tostring(sbox)
    return tostring(sbox)
    Line 634: Line 666:
    local content = args.content
    local content = args.content
    if not content and docTitle and docTitle.exists then
    if not content and docTitle and docTitle.exists then
    local frame = mw.getCurrentFrame()
    content = args._content or mw.getCurrentFrame():expandTemplate{title = docTitle.prefixedText}
    content = frame:preprocess('{{ ' .. docTitle.prefixedText .. ' }}')
    end
    end
    -- The line breaks below are necessary so that "=== Headings ===" at the start and end
    -- The line breaks below are necessary so that "=== Headings ===" at the start and end
    -- of docs are interpreted correctly.
    -- of docs are interpreted correctly.
    return '\n' .. (content or '') .. '\n'  
    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


    Line 654: Line 697:
    -- @env - environment table containing title objects, etc., generated with p.getEnvironment
    -- @env - environment table containing title objects, etc., generated with p.getEnvironment
    --  
    --  
    -- Messages:
    -- 'fmbox-id' --> 'documentation-meta-data'
    -- 'fmbox-style' --> 'background-color: #ecfcf4'
    -- 'fmbox-textstyle' --> 'font-style: italic'
    --
    -- The HTML is generated by the {{fmbox}} template, courtesy of [[Module:Message box]].
    --]=]
    --]=]
    Line 685: Line 722:
    end
    end


    -- Assemble the arguments for {{fmbox}}.
    -- Assemble the link box.
    local fmargs = {}
    fmargs.id = message('fmbox-id') -- Sets 'documentation-meta-data'
    fmargs.image = 'none'
    fmargs.style = message('fmbox-style') -- Sets 'background-color: #ecfcf4'
    fmargs.textstyle = message('fmbox-textstyle') -- 'font-style: italic;'
     
    -- Assemble the fmbox text field.
    local text = ''
    local text = ''
    if linkBox then
    if linkBox then
    Line 702: Line 732:
    -- Add sandbox and testcases links.
    -- Add sandbox and testcases links.
    -- "Editors can experiment in this template's sandbox and testcases pages."
    -- "Editors can experiment in this template's sandbox and testcases pages."
    text = text .. p.makeExperimentBlurb(args, env)
    text = text .. (p.makeExperimentBlurb(args, env) or '') .. '<br />'
    text = text .. '<br />'
    if not args.content and not args[1] then
    if not args.content and not args[1] then
    -- "Please add categories to the /doc subpage."
    -- "Please add categories to the /doc subpage."
    Line 717: Line 746:
    end
    end
    end
    end
    fmargs.text = text
    local box = mw.html.create('div')
    -- 'documentation-metadata'
    box:addClass(message('end-box-class'))
    -- 'plainlinks'
    :addClass(message('end-box-plainlinks'))
    :wikitext(text)
    :done()


    return messageBox.main('fmbox', fmargs)
    return '\n' .. tostring(box)
    end
    end


    Line 733: Line 769:
    -- 'transcluded-from-blurb' -->  
    -- 'transcluded-from-blurb' -->  
    -- 'The above [[Wikipedia:Template documentation|documentation]]  
    -- 'The above [[Wikipedia:Template documentation|documentation]]  
    -- is [[Wikipedia:Transclusion|transcluded]] from $1.'
    -- is [[Help:Transclusion|transcluded]] from $1.'
    -- 'module-preload' --> 'Template:Documentation/preload-module-doc'
    -- 'module-preload' --> 'Template:Documentation/preload-module-doc'
    -- 'create-link-display' --> 'create'
    -- 'create-link-display' --> 'create'
    Line 783: Line 819:
    -- 'mirror-edit-summary' --> 'Create sandbox version of $1'
    -- 'mirror-edit-summary' --> 'Create sandbox version of $1'
    -- 'mirror-link-display' --> 'mirror'
    -- 'mirror-link-display' --> 'mirror'
    -- 'mirror-link-preload' --> 'Template:Documentation/mirror'
    -- 'sandbox-link-display' --> 'sandbox'
    -- 'sandbox-link-display' --> 'sandbox'
    -- 'testcases-link-display' --> 'testcases'
    -- 'testcases-link-display' --> 'testcases'
    -- 'testcases-edit-link-display'--> 'edit'
    -- 'testcases-edit-link-display'--> 'edit'
    -- 'module-testcases-preload' --> 'Template:Documentation/preload-module-testcases'
    -- 'template-sandbox-preload' --> 'Template:Documentation/preload-sandbox'
    -- 'template-sandbox-preload' --> 'Template:Documentation/preload-sandbox'
    -- 'testcases-create-link-display' --> 'create'
    -- 'testcases-create-link-display' --> 'create'
    Line 831: Line 867:
    local sandboxCreateLink = makeUrlLink(sandboxCreateUrl, sandboxCreateDisplay)
    local sandboxCreateLink = makeUrlLink(sandboxCreateUrl, sandboxCreateDisplay)
    local mirrorSummary = message('mirror-edit-summary', {makeWikilink(templatePage)})
    local mirrorSummary = message('mirror-edit-summary', {makeWikilink(templatePage)})
    local mirrorUrl = sandboxTitle:fullUrl{action = 'edit', preload = templatePage, summary = mirrorSummary}
    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 mirrorDisplay = message('mirror-link-display')
    local mirrorLink = makeUrlLink(mirrorUrl, mirrorDisplay)
    local mirrorLink = makeUrlLink(mirrorUrl, mirrorDisplay)
    Line 843: Line 883:
    local testcasesEditDisplay = message('testcases-edit-link-display')
    local testcasesEditDisplay = message('testcases-edit-link-display')
    local testcasesEditLink = makeUrlLink(testcasesEditUrl, testcasesEditDisplay)
    local testcasesEditLink = makeUrlLink(testcasesEditUrl, testcasesEditDisplay)
    testcasesLinks = testcasesLink .. ' ' .. makeToolbar(testcasesEditLink)
    -- 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
    else
    local testcasesPreload
    local testcasesPreload

    Latest revision as of 11:42, 21 May 2021

    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'))
    			: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.
    	-- env.printTitle - the print version of the template, located at the /Print 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.printTitle()
    		--[[
    		-- Title object for the /Print subpage.
    		-- Messages:
    		-- 'print-subpage' --> 'Print'
    		--]]
    		return env.templateTitle:subPageTitle(message('print-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' --> '[[Image: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'
    	-- 'file-docpage-preload' --> 'Template:Documentation/preload-filespace'
    	-- '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 == 6 then -- File namespace
    			preload = message('file-docpage-preload')
    		elseif 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] 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
    	if docTitle.exists then
    		local viewLink = makeWikilink(docTitle.prefixedText, data.viewLinkDisplay)
    		local editLink = makeUrlLink(docTitle:fullUrl{action = 'edit'}, data.editLinkDisplay)
    		local historyLink = makeUrlLink(docTitle:fullUrl{action = 'history'}, data.historyLinkDisplay)
    		local purgeLink = makeUrlLink(title:fullUrl{action = 'purge'}, data.purgeLinkDisplay)
    		ret = '[%s] [%s] [%s] [%s]'
    		ret = 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]'
    		ret = escapeBrackets(ret)
    		ret = mw.ustring.format(ret, createLink)
    	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)
    			: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"
    			local printBlurb = p.makePrintBlurb(args, env) -- Two-line blurb about print versions of templates.
    			if printBlurb then
    				text = text .. '<br />' .. printBlurb
    			end
    		end
    	end
    	
    	local box = mw.html.create('div')
    	-- 'documentation-metadata'
    	box: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
    
    function p.makePrintBlurb(args, env)
    	--[=[
    	-- Generates the blurb displayed when there is a print version of the template available.
    	-- @args - a table of arguments passed by the user
    	-- @env - environment table containing title objects, etc., generated with p.getEnvironment
    	--
    	-- Messages:
    	-- 'print-link-display' --> '/Print'
    	-- 'print-blurb' --> 'A [[Help:Books/for experts#Improving the book layout|print version]]'
    	--		.. ' of this template exists at $1.'
    	--		.. ' If you make a change to this template, please update the print version as well.'
    	-- 'display-print-category' --> true
    	-- 'print-category' --> 'Templates with print versions'
    	--]=]
    	local printTitle = env.printTitle
    	if not printTitle then
    		return nil
    	end
    	local ret
    	if printTitle.exists then
    		local printLink = makeWikilink(printTitle.prefixedText, message('print-link-display'))
    		ret = message('print-blurb', {printLink})
    		local displayPrintCategory = message('display-print-category', nil, 'boolean')
    		if displayPrintCategory then
    			ret = ret .. makeCategoryLink(message('print-category'))
    		end
    	end
    	return ret
    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