Module:Protection banner

This module creates protection banners and padlock icons that are placed at the top of protected pages.

Usage

Most users will not need to use this module directly. For adding protection templates to pages you can use the {{pp}} template, or you may find it more convenient to use one of the more specific protection templates in the table below.

From wikitext

{{#invoke:Protection banner|main
| 1        = reason
| small    = yes/no
| action   = action
| date     = protection date
| user     = username
| section  = talk page section name
| category = yes
}}

The #invoke syntax can be used for creating protection templates more specific than {{pp}}. For example, it is possible to create a protection template which always shows a padlock icon by using the code {{#invoke:Protection banner|main|small=yes}}. Pages which call this template will still be able to use other arguments, like action. However, this only works one level deep; a page calling a template which calls another template containing the above code will not automatically be able to use parameters like action.

Note: You should no longer specify the expiry, as it is automatically retrieved in all cases.

From Lua

First, load the module.

local mProtectionBanner = require('Module:Protection banner')

Then you can make protection banners by using the _main function.

mProtectionBanner._main(args, cfg, titleObj)

args is a table of arguments to pass to the module. For possible keys and values for this table, see the parameters section. The cfg and titleObj variables are intended only for testing; cfg specifies a customised config table to use instead of Module:Protection banner/config, and titleObj specifies a mw.title object to use instead of the current title. args, cfg and titleObj are all optional.

Parameters

All parameters are optional.

• 1 – the reason that the page was protected. If set, this must be one of the values listed in the reasons table.
• small – if set to "yes", "y", "1", or "true", a padlock icon is generated instead of a full protection banner.
• action – the protection action. Must be one of "edit" (for normal protection), "move" (for move-protection) or "autoreview" (for pending changes). The default value is "edit".
• date – the protection date. This must be valid input to the second parameter of the #time parser function. This argument has an effect for reasons that use the PROTECTIONDATE parameter in their configuration. As of July 2014, those were the "office" and "reset" reasons.
• user – the username of the user to generate links for. As of July 2014, this only has an effect when the "usertalk" reason is specified.
• section – the section name of the protected page's talk page where discussion is taking place. This works for most, but not all, values of reason.
• category – categories are suppressed if this is set to "no", "n", "0", or "false".
• catonly – if set to "yes", "y", "1", or "true", will only return the protection categories, and not return the banner or padlock. This has no visible output.

Reasons

The following table contains the available reasons, plus the actions for which they are available.

Reason	Action	Description
blp	edit	For pages protected to promote compliance with the biographies of living persons policy
dispute	edit	For pages protected due to editing disputes
dmca	edit	For pages protected by the Wikimedia Foundation due to Digital Millennium Copyright Act takedown requests
ecp	edit	For articles in topic areas authorized by ArbCom or meets the criteria for community use
mainpage	edit	For pages protected for being displayed on the Main Page
office	edit	For pages protected by the Wikimedia Foundation
reset	edit	For pages protected by the Wikimedia Foundation and "reset" to a bare-bones version
sock	edit	For pages protected due to sock puppetry
template	edit	For high-risk templates and Lua modules
usertalk	edit	For pages protected against disruptive edits by a particular user
vandalism	edit	For pages protected against vandalism
dispute	move	For pages protected against page moves due to disputes over the page title
vandalism	move	For pages protected against page-move vandalism

Errors

Below is a list of some of the common errors that this module can produce, and how to fix them.

Invalid protection date

This error is produced if you supply a |date= parameter value that is not recognised as a valid date by the #time parser function. If in doubt, you can just use a date in the format "dd Month YYYY", e.g. "28 December 2024". To see a full range of valid inputs, see the #time documentation (only the first parameter, the format string, may be specified).

Invalid action

This error is produced if you specify an invalid protection action. There are only three valid actions: edit (the default, for normal protection), move (for move-protection), and autoreview (for pending changes). This should only be possible if you are using a template that supports manually specifying the protection action, such as {{pp}}, or if you are using #invoke directly. If this is not the case, please leave a message on Module talk:Protection banner.

Reasons cannot contain the pipe character

This error is produced if you specify a reason using the |1= parameter that includes a pipe character ("|"). Please check that you are not entering the {{!}} template into this parameter by mistake. The pipe character is disallowed as the module uses it internally. A list of valid reasons can be seen in the reasons section.

Other errors

If you see an error other than the ones above, it is likely to either be a bug in the module or mistake in the configuration. Please post a message about it at Module talk:Protection banner.

Technical details

This module uses configuration data from Module:Protection banner/config. Most of the module's behaviour can be configured there, making it easily portable across different wikis and different languages.

General test cases for the module can be found at Module:Protection banner/testcases, and test cases specific to enwiki's config can be found at Module:Protection banner/config/testcases.

Bug reports and feature requests should be made on the module's talk page.

---

-- This module implements {{pp-meta}} and its daughter templates such as
-- {{pp-dispute}}, {{pp-vandalism}} and {{pp-sock}}.

-- Initialise necessary modules.
require('Module:No globals')
local makeFileLink = require('Module:File link')._main
local effectiveProtectionLevel = require('Module:Effective protection level')._main
local effectiveProtectionExpiry = require('Module:Effective protection expiry')._main
local yesno = require('Module:Yesno')

-- Lazily initialise modules and objects we don't always need.
local getArgs, makeMessageBox, lang

-- Set constants.
local CONFIG_MODULE = 'Module:Protection banner/config'

--------------------------------------------------------------------------------
-- Helper functions
--------------------------------------------------------------------------------

local function makeCategoryLink(cat, sort)
	local nsText = mw.site.namespaces[14].name
	if cat and sort then
		return string.format(
			'[[%s:%s|%s]]',
			nsText,
			cat,
			sort
		)
	elseif cat then
		return string.format(
			'[[%s:%s]]',
			nsText,
			cat
		)
	else
		return ''
	end
end

-- Validation function for the expiry and the protection date
local function validateDate(dateString, dateType)
	lang = lang or mw.language.getContentLanguage()
	local success, result = pcall(lang.formatDate, lang, 'U', dateString)
	if success then
		result = tonumber(result)
		if result then
			return result
		end
	end
	error(string.format(
		'invalid %s ("%s")',
		dateType,
		tostring(dateString)
	), 4)
end

local function makeFullUrl(page, query, display)
	return string.format(
		'[%s %s]',
		tostring(mw.uri.fullUrl(page, query)),
		display
	)
end

local function toTableEnd(t, pos)
	-- Sends the value at position pos to the end of array t, and shifts the
	-- other items down accordingly.
	return table.insert(t, table.remove(t, pos))
end

local function walkHierarchy(hierarchy, start)
	local toWalk, retval = {[start] = true}, {}
	while true do
		-- Can't use pairs() since we're adding and removing things as we're iterating
		local k = next(toWalk) -- This always gets the "first" key
		if k == nil then break end
		toWalk[k] = nil
		retval[k] = true
		for _,v in ipairs(hierarchy[k]) do
			if not retval[v] then
				toWalk[v] = true
			end
		end
	end
	return retval
end

--------------------------------------------------------------------------------
-- Protection class
--------------------------------------------------------------------------------

local Protection = {}
Protection.__index = Protection

Protection.supportedActions = {
	edit = true,
	move = true,
	autoreview = true,
	upload = true
}

Protection.bannerConfigFields = {
	'text',
	'explanation',
	'tooltip',
	'alt',
	'link',
	'image'
}

function Protection.new(args, cfg, title)
	local obj = {}
	obj._cfg = cfg
	obj.title = title or mw.title.getCurrentTitle()

	-- Set action
	if not args.action then
		obj.action = 'edit'
	elseif Protection.supportedActions[args.action] then
		obj.action = args.action
	else
		error(string.format(
			'invalid action ("%s")',
			tostring(args.action)
		), 3)
	end

	-- Set level
	obj.level = args.demolevel or effectiveProtectionLevel(obj.action, obj.title)
	if not obj.level or (obj.action == 'move' and obj.level == 'autoconfirmed') then
		-- Users need to be autoconfirmed to move pages anyway, so treat
		-- semi-move-protected pages as unprotected.
		obj.level = '*'
	end

	-- Set expiry
	local effectiveExpiry = effectiveProtectionExpiry(obj.action, obj.title)
	if effectiveExpiry == 'infinity' then
		obj.expiry = 'indef'
	elseif effectiveExpiry ~= 'unknown' then
		obj.expiry = validateDate(effectiveExpiry, 'expiry date')
	elseif args.expiry then
		if cfg.indefStrings[args.expiry] then
			obj.expiry = 'indef'
		elseif type(args.expiry) == 'number' then
			obj.expiry = args.expiry
		else
			obj.expiry = validateDate(args.expiry, 'expiry date')
		end
	end

	-- Set reason
	if args[1] then
		obj.reason = mw.ustring.lower(args[1])
		if obj.reason:find('|') then
			error('reasons cannot contain the pipe character ("|")', 3)
		end
	end

	-- Set protection date
	if args.date then
		obj.protectionDate = validateDate(args.date, 'protection date')
	end
	
	-- Set banner config
	do
		obj.bannerConfig = {}
		local configTables = {}
		if cfg.banners[obj.action] then
			configTables[#configTables + 1] = cfg.banners[obj.action][obj.reason]
		end
		if cfg.defaultBanners[obj.action] then
			configTables[#configTables + 1] = cfg.defaultBanners[obj.action][obj.level]
			configTables[#configTables + 1] = cfg.defaultBanners[obj.action].default
		end
		configTables[#configTables + 1] = cfg.masterBanner
		for i, field in ipairs(Protection.bannerConfigFields) do
			for j, t in ipairs(configTables) do
				if t[field] then
					obj.bannerConfig[field] = t[field]
					break
				end
			end
		end
	end
	return setmetatable(obj, Protection)
end

function Protection:isProtected()
	return self.level ~= '*'
end

function Protection:isTemporary()
	return type(self.expiry) == 'number'
end

function Protection:makeProtectionCategory()
	local cfg = self._cfg
	local title = self.title
	
	-- Exit if the page is not protected.
	if not self:isProtected() then
		return ''
	end
	
	-- Get the expiry key fragment.
	local expiryFragment
	if self.expiry == 'indef' then
		expiryFragment = self.expiry
	elseif type(self.expiry) == 'number' then
		expiryFragment = 'temp'
	end

	-- Get the namespace key fragment.
	local namespaceFragment
	do
		namespaceFragment = cfg.categoryNamespaceKeys[title.namespace]
		if not namespaceFragment and title.namespace % 2 == 1 then
				namespaceFragment = 'talk'
		end
	end
 
	-- Define the order that key fragments are tested in. This is done with an
	-- array of tables containing the value to be tested, along with its
	-- position in the cfg.protectionCategories table.
	local order = {
		{val = expiryFragment,    keypos = 1},
		{val = namespaceFragment, keypos = 2},
		{val = self.reason,       keypos = 3},
		{val = self.level,        keypos = 4},
		{val = self.action,       keypos = 5}
	}

	--[[
	-- The old protection templates used an ad-hoc protection category system,
	-- with some templates prioritising namespaces in their categories, and
	-- others prioritising the protection reason. To emulate this in this module
	-- we use the config table cfg.reasonsWithNamespacePriority to set the
	-- reasons for which namespaces have priority over protection reason.
	-- If we are dealing with one of those reasons, move the namespace table to
	-- the end of the order table, i.e. give it highest priority. If not, the
	-- reason should have highest priority, so move that to the end of the table
	-- instead.
	--]]
	if self.reason and cfg.reasonsWithNamespacePriority[self.reason] then
		-- table.insert(order, 3, table.remove(order, 2))
		toTableEnd(order, 2)
	else
		toTableEnd(order, 3)
	end
 
	--[[
	-- Define the attempt order. Inactive subtables (subtables with nil "value"
	-- fields) are moved to the end, where they will later be given the key
	-- "all". This is to cut down on the number of table lookups in
	-- cfg.protectionCategories, which grows exponentially with the number of
	-- non-nil keys. We keep track of the number of active subtables with the
	-- noActive parameter.
	--]]
	local noActive, attemptOrder
	do
		local active, inactive = {}, {}
		for i, t in ipairs(order) do
			if t.val then
				active[#active + 1] = t
			else
				inactive[#inactive + 1] = t
			end
		end
		noActive = #active
		attemptOrder = active
		for i, t in ipairs(inactive) do
			attemptOrder[#attemptOrder + 1] = t
		end
	end
 
	--[[
	-- Check increasingly generic key combinations until we find a match. If a
	-- specific category exists for the combination of key fragments we are
	-- given, that match will be found first. If not, we keep trying different
	-- key fragment combinations until we match using the key
	-- "all-all-all-all-all".
	--
	-- To generate the keys, we index the key subtables using a binary matrix
	-- with indexes i and j. j is only calculated up to the number of active
	-- subtables. For example, if there were three active subtables, the matrix
	-- would look like this, with 0 corresponding to the key fragment "all", and
	-- 1 corresponding to other key fragments.
	-- 
	--   j 1  2  3
	-- i  
	-- 1   1  1  1
	-- 2   0  1  1
	-- 3   1  0  1
	-- 4   0  0  1
	-- 5   1  1  0
	-- 6   0  1  0
	-- 7   1  0  0
	-- 8   0  0  0
	-- 
	-- Values of j higher than the number of active subtables are set
	-- to the string "all".
	--
	-- A key for cfg.protectionCategories is constructed for each value of i.
	-- The position of the value in the key is determined by the keypos field in
	-- each subtable.
	--]]
	local cats = cfg.protectionCategories
	for i = 1, 2^noActive do
		local key = {}
		for j, t in ipairs(attemptOrder) do
			if j > noActive then
				key[t.keypos] = 'all'
			else
				local quotient = i / 2 ^ (j - 1)
				quotient = math.ceil(quotient)
				if quotient % 2 == 1 then
					key[t.keypos] = t.val
				else
					key[t.keypos] = 'all'
				end
			end
		end
		key = table.concat(key, '|')
		local attempt = cats[key]
		if attempt then
			return makeCategoryLink(attempt, title.text)
		end
	end
	return ''
end

function Protection:needsExpiry()
	local cfg = self._cfg
	local actionNeedsCheck = cfg.expiryCheckActions[self.action]
	return not self.expiry and (
		actionNeedsCheck or (
			actionNeedsCheck == nil
			and self.reason -- the old {{pp-protected}} didn't check for expiry
			and not cfg.reasonsWithoutExpiryCheck[self.reason]
		)
	)
end

function Protection:isIncorrect()
	local expiry = self.expiry
	return not self:isProtected()
		or type(expiry) == 'number' and expiry < os.time()
end

function Protection:isTemplateProtectedNonTemplate()
	local action, namespace = self.action, self.title.namespace
	return self.level == 'templateeditor'
		and (
			(action ~= 'edit' and action ~= 'move')
			or (namespace ~= 10 and namespace ~= 828)
		)
end

function Protection:makeCategoryLinks()
	local msg = self._cfg.msg
	local ret = { self:makeProtectionCategory() }
	if self:needsExpiry() then
		ret[#ret + 1] = makeCategoryLink(
			msg['tracking-category-expiry'],
			self.title.text
		)
	end
	if self:isIncorrect() then
		ret[#ret + 1] = makeCategoryLink(
			msg['tracking-category-incorrect'],
			self.title.text
		)
	end
	if self:isTemplateProtectedNonTemplate() then
		ret[#ret + 1] = makeCategoryLink(
			msg['tracking-category-template'],
			self.title.text
		)
	end
	return table.concat(ret)
end

--------------------------------------------------------------------------------
-- Blurb class
--------------------------------------------------------------------------------

local Blurb = {}
Blurb.__index = Blurb

Blurb.bannerTextFields = {
	text = true,
	explanation = true,
	tooltip = true,
	alt = true,
	link = true
}

function Blurb.new(protectionObj, args, cfg)
	return setmetatable({
		_cfg = cfg,
		_protectionObj = protectionObj,
		_args = args
	}, Blurb)
end

-- Private methods --

function Blurb:_formatDate(num)
	-- Formats a Unix timestamp into dd Month, YYYY format.
	lang = lang or mw.language.getContentLanguage()
	local success, date = pcall(
		lang.formatDate,
		lang,
		self._cfg.msg['expiry-date-format'] or 'j F Y',
		'@' .. tostring(num)
	)
	if success then
		return date
	end
end

function Blurb:_getExpandedMessage(msgKey)
	return self:_substituteParameters(self._cfg.msg[msgKey])
end

function Blurb:_substituteParameters(msg)
	if not self._params then
		local parameterFuncs = {}

		parameterFuncs.CURRENTVERSION     = self._makeCurrentVersionParameter
		parameterFuncs.EDITREQUEST        = self._makeEditRequestParameter
		parameterFuncs.EXPIRY             = self._makeExpiryParameter
		parameterFuncs.EXPLANATIONBLURB   = self._makeExplanationBlurbParameter
		parameterFuncs.IMAGELINK          = self._makeImageLinkParameter
		parameterFuncs.INTROBLURB         = self._makeIntroBlurbParameter
		parameterFuncs.INTROFRAGMENT      = self._makeIntroFragmentParameter
		parameterFuncs.PAGETYPE           = self._makePagetypeParameter
		parameterFuncs.PROTECTIONBLURB    = self._makeProtectionBlurbParameter
		parameterFuncs.PROTECTIONDATE     = self._makeProtectionDateParameter
		parameterFuncs.PROTECTIONLEVEL    = self._makeProtectionLevelParameter
		parameterFuncs.PROTECTIONLOG      = self._makeProtectionLogParameter
		parameterFuncs.TALKPAGE           = self._makeTalkPageParameter
		parameterFuncs.TOOLTIPBLURB       = self._makeTooltipBlurbParameter
		parameterFuncs.TOOLTIPFRAGMENT    = self._makeTooltipFragmentParameter
		parameterFuncs.VANDAL             = self._makeVandalTemplateParameter
		
		self._params = setmetatable({}, {
			__index = function (t, k)
				local param
				if parameterFuncs[k] then
					param = parameterFuncs[k](self)
				end
				param = param or ''
				t[k] = param
				return param
			end
		})
	end
	
	msg = msg:gsub('${(%u+)}', self._params)
	return msg
end

function Blurb:_makeCurrentVersionParameter()
	-- A link to the page history or the move log, depending on the kind of
	-- protection.
	local pagename = self._protectionObj.title.prefixedText
	if self._protectionObj.action == 'move' then
		-- We need the move log link.
		return makeFullUrl(
			'Special:Log',
			{type = 'move', page = pagename},
			self:_getExpandedMessage('current-version-move-display')
		)
	else
		-- We need the history link.
		return makeFullUrl(
			pagename,
			{action = 'history'},
			self:_getExpandedMessage('current-version-edit-display')
		)
	end
end

function Blurb:_makeEditRequestParameter()
	local mEditRequest = require('Module:Submit an edit request')
	local action = self._protectionObj.action
	local level = self._protectionObj.level
	
	-- Get the edit request type.
	local requestType
	if action == 'edit' then
		if level == 'autoconfirmed' then
			requestType = 'semi'
		elseif level == 'templateeditor' then
			requestType = 'template'
		end
	end
	requestType = requestType or 'full'
	
	-- Get the display value.
	local display = self:_getExpandedMessage('edit-request-display')

	return mEditRequest._link{type = requestType, display = display}
end

function Blurb:_makeExpiryParameter()
	local expiry = self._protectionObj.expiry
	if type(expiry) == 'number' then
		return self:_formatDate(expiry)
	else
		return expiry
	end
end

function Blurb:_makeExplanationBlurbParameter()
	-- Cover special cases first.
	if self._protectionObj.title.namespace == 8 then
		-- MediaWiki namespace
		return self:_getExpandedMessage('explanation-blurb-nounprotect')
	end

	-- Get explanation blurb table keys
	local action = self._protectionObj.action
	local level = self._protectionObj.level
	local talkKey = self._protectionObj.title.isTalkPage and 'talk' or 'subject'

	-- Find the message in the explanation blurb table and substitute any
	-- parameters.
	local explanations = self._cfg.explanationBlurbs
	local msg
	if explanations[action][level] and explanations[action][level][talkKey] then
		msg = explanations[action][level][talkKey]
	elseif explanations[action][level] and explanations[action][level].default then
		msg = explanations[action][level].default
	elseif explanations[action].default and explanations[action].default[talkKey] then
		msg = explanations[action].default[talkKey]
	elseif explanations[action].default and explanations[action].default.default then
		msg = explanations[action].default.default
	else
		error(string.format(
			'could not find explanation blurb for action "%s", level "%s" and talk key "%s"',
			action,
			level,
			talkKey
		), 8)
	end
	return self:_substituteParameters(msg)
end

function Blurb:_makeImageLinkParameter()
	local imageLinks = self._cfg.imageLinks
	local action = self._protectionObj.action
	local level = self._protectionObj.level
	local msg
	if imageLinks[action][level] then
		msg = imageLinks[action][level]
	elseif imageLinks[action].default then
		msg = imageLinks[action].default
	else
		msg = imageLinks.edit.default
	end
	return self:_substituteParameters(msg)
end

function Blurb:_makeIntroBlurbParameter()
	if self._protectionObj:isTemporary() then
		return self:_getExpandedMessage('intro-blurb-expiry')
	else
		return self:_getExpandedMessage('intro-blurb-noexpiry')
	end
end

function Blurb:_makeIntroFragmentParameter()
	if self._protectionObj:isTemporary() then
		return self:_getExpandedMessage('intro-fragment-expiry')
	else
		return self:_getExpandedMessage('intro-fragment-noexpiry')
	end
end

function Blurb:_makePagetypeParameter()
	local pagetypes = self._cfg.pagetypes
	return pagetypes[self._protectionObj.title.namespace]
		or pagetypes.default
		or error('no default pagetype defined', 8)
end

function Blurb:_makeProtectionBlurbParameter()
	local protectionBlurbs = self._cfg.protectionBlurbs
	local action = self._protectionObj.action
	local level = self._protectionObj.level
	local msg
	if protectionBlurbs[action][level] then
		msg = protectionBlurbs[action][level]
	elseif protectionBlurbs[action].default then
		msg = protectionBlurbs[action].default
	elseif protectionBlurbs.edit.default then
		msg = protectionBlurbs.edit.default
	else
		error('no protection blurb defined for protectionBlurbs.edit.default', 8)
	end
	return self:_substituteParameters(msg)
end

function Blurb:_makeProtectionDateParameter()
	local protectionDate = self._protectionObj.protectionDate
	if type(protectionDate) == 'number' then
		return self:_formatDate(protectionDate)
	else
		return protectionDate
	end
end

function Blurb:_makeProtectionLevelParameter()
	local protectionLevels = self._cfg.protectionLevels
	local action = self._protectionObj.action
	local level = self._protectionObj.level
	local msg
	if protectionLevels[action][level] then
		msg = protectionLevels[action][level]
	elseif protectionLevels[action].default then
		msg = protectionLevels[action].default
	elseif protectionLevels.edit.default then
		msg = protectionLevels.edit.default
	else
		error('no protection level defined for protectionLevels.edit.default', 8)
	end
	return self:_substituteParameters(msg)
end

function Blurb:_makeProtectionLogParameter()
	local pagename = self._protectionObj.title.prefixedText
	if self._protectionObj.action == 'autoreview' then
		-- We need the pending changes log.
		return makeFullUrl(
			'Special:Log',
			{type = 'stable', page = pagename},
			self:_getExpandedMessage('pc-log-display')
		)
	else
		-- We need the protection log.
		return makeFullUrl(
			'Special:Log',
			{type = 'protect', page = pagename},
			self:_getExpandedMessage('protection-log-display')
		)
	end
end

function Blurb:_makeTalkPageParameter()
	return string.format(
		'[[%s:%s#%s|%s]]',
		mw.site.namespaces[self._protectionObj.title.namespace].talk.name,
		self._protectionObj.title.text,
		self._args.section or 'top',
		self:_getExpandedMessage('talk-page-link-display')
	)
end

function Blurb:_makeTooltipBlurbParameter()
	if self._protectionObj:isTemporary() then
		return self:_getExpandedMessage('tooltip-blurb-expiry')
	else
		return self:_getExpandedMessage('tooltip-blurb-noexpiry')
	end
end

function Blurb:_makeTooltipFragmentParameter()
	if self._protectionObj:isTemporary() then
		return self:_getExpandedMessage('tooltip-fragment-expiry')
	else
		return self:_getExpandedMessage('tooltip-fragment-noexpiry')
	end
end

function Blurb:_makeVandalTemplateParameter()
	return require('Module:Vandal-m')._main{
		self._args.user or self._protectionObj.title.baseText
	}
end

-- Public methods --

function Blurb:makeBannerText(key)
	-- Validate input.
	if not key or not Blurb.bannerTextFields[key] then
		error(string.format(
			'"%s" is not a valid banner config field',
			tostring(key)
		), 2)
	end

	-- Generate the text.
	local msg = self._protectionObj.bannerConfig[key]
	if type(msg) == 'string' then
		return self:_substituteParameters(msg)
	elseif type(msg) == 'function' then
		msg = msg(self._protectionObj, self._args)
		if type(msg) ~= 'string' then
			error(string.format(
				'bad output from banner config function with key "%s"'
					.. ' (expected string, got %s)',
				tostring(key),
				type(msg)
			), 4)
		end
		return self:_substituteParameters(msg)
	end
end

--------------------------------------------------------------------------------
-- BannerTemplate class
--------------------------------------------------------------------------------

local BannerTemplate = {}
BannerTemplate.__index = BannerTemplate

function BannerTemplate.new(protectionObj, cfg)
	local obj = {}
	obj._cfg = cfg

	-- Set the image filename.
	local imageFilename = protectionObj.bannerConfig.image
	if imageFilename then
		obj._imageFilename = imageFilename
	else
		-- If an image filename isn't specified explicitly in the banner config,
		-- generate it from the protection status and the namespace.
		local action = protectionObj.action
		local level = protectionObj.level
		local namespace = protectionObj.title.namespace
		local reason = protectionObj.reason
		
		-- Deal with special cases first.
		if (
			namespace == 10
			or namespace == 828
			or reason and obj._cfg.indefImageReasons[reason]
			)
			and action == 'edit'
			and level == 'sysop'
			and not protectionObj:isTemporary()
		then
			-- Fully protected modules and templates get the special red "indef"
			-- padlock.
			obj._imageFilename = obj._cfg.msg['image-filename-indef']
		else
			-- Deal with regular protection types.
			local images = obj._cfg.images
			if images[action] then
				if images[action][level] then
					obj._imageFilename = images[action][level]
				elseif images[action].default then
					obj._imageFilename = images[action].default
				end
			end
		end
	end
	return setmetatable(obj, BannerTemplate)
end

function BannerTemplate:setImageWidth(width)
	self._imageWidth = width
end

function BannerTemplate:setImageTooltip(tooltip)
	self._imageCaption = tooltip
end

function BannerTemplate:renderImage()
	local filename = self._imageFilename
		or self._cfg.msg['image-filename-default']
		or 'Transparent.gif'
	return makeFileLink{
		file = filename,
		size = (self._imageWidth or 20) .. 'px',
		alt = self._imageAlt,
		link = self._imageLink,
		caption = self._imageCaption
	}
end

--------------------------------------------------------------------------------
-- Banner class
--------------------------------------------------------------------------------

local Banner = setmetatable({}, BannerTemplate)
Banner.__index = Banner

function Banner.new(protectionObj, blurbObj, cfg)
	local obj = BannerTemplate.new(protectionObj, cfg) -- This doesn't need the blurb.
	obj:setImageWidth(40)
	obj:setImageTooltip(blurbObj:makeBannerText('alt')) -- Large banners use the alt text for the tooltip.
	obj._reasonText = blurbObj:makeBannerText('text')
	obj._explanationText = blurbObj:makeBannerText('explanation')
	obj._page = protectionObj.title.prefixedText -- Only makes a difference in testing.
	return setmetatable(obj, Banner)
end

function Banner:__tostring()
	-- Renders the banner.
	makeMessageBox = makeMessageBox or require('Module:Message box').main
	local reasonText = self._reasonText or error('no reason text set', 2)
	local explanationText = self._explanationText
	local mbargs = {
		page = self._page,
		type = 'protection',
		image = self:renderImage(),
		text = string.format(
			"'''%s'''%s",
			reasonText,
			explanationText and '<br />' .. explanationText or ''
		)
	}
	return makeMessageBox('mbox', mbargs)
end

--------------------------------------------------------------------------------
-- Padlock class
--------------------------------------------------------------------------------

local Padlock = setmetatable({}, BannerTemplate)
Padlock.__index = Padlock

function Padlock.new(protectionObj, blurbObj, cfg)
	local obj = BannerTemplate.new(protectionObj, cfg) -- This doesn't need the blurb.
	obj:setImageWidth(20)
	obj:setImageTooltip(blurbObj:makeBannerText('tooltip'))
	obj._imageAlt = blurbObj:makeBannerText('alt')
	obj._imageLink = blurbObj:makeBannerText('link')
	obj._indicatorName = cfg.padlockIndicatorNames[protectionObj.action]
		or cfg.padlockIndicatorNames.default
		or 'pp-default'
	return setmetatable(obj, Padlock)
end

function Padlock:__tostring()
	local frame = mw.getCurrentFrame()
	-- The nowiki tag helps prevent whitespace at the top of articles.
	local nowiki = frame:extensionTag{name = 'nowiki'}
	local indicator = frame:extensionTag{
		name = 'indicator',
		args = {name = self._indicatorName},
		content = self:renderImage()
	}
	return nowiki .. indicator
end

--------------------------------------------------------------------------------
-- Exports
--------------------------------------------------------------------------------

local p = {}

function p._exportClasses()
	-- This is used for testing purposes.
	return {
		Protection = Protection,
		Blurb = Blurb,
		BannerTemplate = BannerTemplate,
		Banner = Banner,
		Padlock = Padlock,
	}
end

function p._main(args, cfg, title)
	args = args or {}
	cfg = cfg or require(CONFIG_MODULE)

	local protectionObj = Protection.new(args, cfg, title)

	local ret = {}

	-- If a page's edit protection is equally or more restrictive than its
	-- protection from some other action, then don't bother displaying anything
	-- for the other action (except categories).
	if protectionObj.action == 'edit' or
		args.demolevel or
		not walkHierarchy(
			cfg.hierarchy,
			protectionObj.level
		)[effectiveProtectionLevel('edit', protectionObj.title)]
	then
		-- Initialise the blurb object
		local blurbObj = Blurb.new(protectionObj, args, cfg)
	
		-- Render the banner
		if protectionObj:isProtected() then
			ret[#ret + 1] = tostring(
				(yesno(args.small) and Padlock or Banner)
				.new(protectionObj, blurbObj, cfg)
			)
		end
	end

	-- Render the categories
	if yesno(args.category) ~= false then
		ret[#ret + 1] = protectionObj:makeCategoryLinks()
	end
	
	return table.concat(ret)	
end

function p.main(frame, cfg)
	cfg = cfg or require(CONFIG_MODULE)

	-- Find default args, if any.
	local parent = frame.getParent and frame:getParent()
	local defaultArgs = parent and cfg.wrappers[parent:getTitle():gsub('/sandbox$', '')]

	-- Find user args, and use the parent frame if we are being called from a
	-- wrapper template.
	getArgs = getArgs or require('Module:Arguments').getArgs
	local userArgs = getArgs(frame, {
		parentOnly = defaultArgs,
		frameOnly = not defaultArgs
	})

	-- Build the args table. User-specified args overwrite default args.
	local args = {}
	for k, v in pairs(defaultArgs or {}) do
		args[k] = v
	end
	for k, v in pairs(userArgs) do
		args[k] = v
	end
	return p._main(args, cfg)
end

return p