Module:Hatnote

This is a meta-module that provides various functions for making hatnotes. It implements the {{hatnote}} template, for use in hatnotes at the top of pages, and the {{format link}} template, which is used to format a wikilink for use in hatnotes. It also contains a number of helper functions for use in other Lua hatnote modules.

Use from wikitext

The functions in this module cannot be used directly from #invoke, and must be used through templates instead. Please see Template:Hatnote and Template:Format link for documentation.

Use from other Lua modules

To load this module from another Lua module, use the following code.

<source lang="lua"> local mHatnote = require('Module:Hatnote') </source>

You can then use the functions as documented below.

Hatnote

<source lang="lua"> mHatnote._hatnote(s, options) </source>

Formats the string s as a hatnote. This encloses s in the tags <div class="hatnote">...</div>. Options are provided in the options table. Options include:

• options.extraclasses - a string of extra classes to provide
• options.selfref - if this is not nil or false, adds the class "selfref", used to denote self-references to Wikipedia (see Template:Selfref))

The CSS of the hatnote class is defined in MediaWiki:Common.css.

Example 1

<source lang="lua"> mHatnote._hatnote('This is a hatnote.') </source>

Produces: <div class="hatnote">This is a hatnote.</div>

Displays as: Template:Hatnote

Example 2

<source lang="lua"> mHatnote._hatnote('This is a hatnote.', {extraclasses = 'boilerplate seealso', selfref = true}) </source>

Produces: <div class="hatnote boilerplate seealso selfref">This is a hatnote.</div>

Displayed as: Template:Hatnote

Format link

<source lang="lua"> mHatnote._formatLink(link, display) </source>

Formats link as a wikilink for display in hatnote templates, with optional display value display. Categories and files are automatically escaped with the colon trick, and links to sections are automatically formatted as page § section, rather than the MediaWiki default of page#section.

Examples

Template:Code → [[Lion]] →

1. REDIRECT Template:Format link

Template:Code → [[Lion#Etymology|Lion § Etymology]] →

1. REDIRECT Template:Format link

Template:Code → [[:Category:Lions]] →

1. REDIRECT Template:Format link

Template:Code → [[Lion#Etymology|Etymology of lion]] →

1. REDIRECT Template:Format link

Format pages

<source lang="lua"> mHatnote.formatPages(...) </source>

Formats a list of pages using the _formatLink function, and returns the result as an array. For example, the code Template:Code would produce an array like Template:Code.

Format page tables

<source lang="lua"> mHatnote.formatPageTables(...) </source>

Takes a list of page/display tables, formats them with the _formatLink function, and returns the result as an array. Each item in the list must be a table. The first value in the table is the link, and is required. The second value in the table is the display value, and is optional. For example, the code Template:Code would produce an array like Template:Code.

Find namespace id

<source lang="lua"> mHatnote.findNamespaceId(link, removeColon) </source>

Finds the namespace id of the string link, which should be a valid page name, with or without the section name. This function will not work if the page name is enclosed with square brackets. When trying to parse the namespace name, colons are removed from the start of the link by default. This is helpful if users have specified colons when they are not strictly necessary. If you do not need to check for initial colons, set removeColon to false.

Examples

Template:Code → 0

Template:Code → 14

Template:Code → 14

Template:Code → 0 (the namespace is detected as ":Category", rather than "Category")

Make wikitext error

<source lang="lua"> mHatnote.makeWikitextError(msg, helpLink, addTrackingCategory) </source>

Formats the string msg as a red wikitext error message, with optional link to a help page helpLink. Normally this function also adds Category:Hatnote templates with errors (0); however, if addTrackingCategory is not false after being passed through Module:Yesno, then the category is suppressed. This means that the category can be suppressed with addTrackingCategory values including "no", "n", 0, "false", and Template:Code.

Examples:

Template:Code →

Template:Code →

Examples

For examples of how this module is used in other Lua modules, see the following (listed in order of complexity):

• Module:Details
• Module:Further
• Module:See also
• Module:Main

---

--------------------------------------------------------------------------------
--                              Module:Hatnote                                --
--                                                                            --
-- This module produces hatnote links and links to related articles. It       --
-- implements the {{hatnote}} and {{format hatnote link}} meta-templates, and --
-- includes helper functions for other Lua hatnote modules.                   --
--------------------------------------------------------------------------------

local libraryUtil = require('libraryUtil')
local checkType = libraryUtil.checkType
local mArguments -- lazily initialise [[Module:Arguments]]
local yesno -- lazily initialise [[Module:Yesno]]
local mCategoryHandler -- lazily initialise [[Module:Category handler]]

local p = {}

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

local function getArgs(frame)
	-- Fetches the arguments from the parent frame. Whitespace is trimmed and
	-- blanks are removed.
	mArguments = require('Module:Arguments')
	return mArguments.getArgs(frame, {parentOnly = true})
end

local function removeInitialColon(s)
	-- Removes the initial colon from a string, if present.
	return s:match('^:?(.*)')
end

function p.findNamespaceId(link, removeColon)
	-- Finds the namespace id (namespace number) of a link or a pagename. This
	-- function will not work if the link is enclosed in double brackets. Colons
	-- are trimmed from the start of the link by default. To skip colon
	-- trimming, set the removeColon parameter to true.
	checkType('findNamespaceId', 1, link, 'string')
	checkType('findNamespaceId', 2, removeColon, 'boolean', true)
	if removeColon ~= false then
		link = removeInitialColon(link)
	end
	local namespace = link:match('^(.-):')
	if namespace then
		local nsTable = mw.site.namespaces[namespace]
		if nsTable then
			return nsTable.id
		end
	end
	return 0
end

function p.formatPages(...)
	-- Formats a list of pages using formatLink and returns it as an array. Nil
	-- values are not allowed.
	local pages = {...}
	local ret = {}
	for i, page in ipairs(pages) do
		ret[i] = p._formatLink(page)
	end
	return ret
end

function p.formatPageTables(...)
	-- Takes a list of page/display tables and returns it as a list of
	-- formatted links. Nil values are not allowed.
	local pages = {...}
	local links = {}
	for i, t in ipairs(pages) do
		checkType('formatPageTables', i, t, 'table')
		local link = t[1]
		local display = t[2]
		links[i] = p._formatLink(link, display)
	end
	return links
end

function p.makeWikitextError(msg, demo)
	-- Formats an error message to be returned to wikitext. If demo is not nil
	-- or false, no error category is added.
	checkType('makeWikitextError', 1, msg, 'string')
	yesno = require('Module:Yesno')
	mCategoryHandler = require('Module:Category handler')
	local errorCategory = 'Hatnote templates with errors'
	local errorCategoryLink = string.format(
		'[[%s:%s]]',
		mw.site.namespaces[14].name,
		errorCategory
	)
	-- Feed the category link through [[Module:Category handler]] so we can
	-- use its blacklist.
	errorCategoryLink = mCategoryHandler.main{
		all = errorCategoryLink,
		nocat = demo
	}
	errorCategoryLink = errorCategoryLink or ''
	return string.format(
		'<strong class="error">Error: %s.</strong>%s',
		msg,
		errorCategoryLink
	)
end

--------------------------------------------------------------------------------
-- Format link
--
-- Makes a wikilink from the given link and display values. Links are escaped
-- with colons if necessary, and links to sections are detected and displayed
-- with " § " as a separator rather than the standard MediaWiki "#". Used in
-- the {{format hatnote link}} template.
--------------------------------------------------------------------------------

function p.formatLink(frame)
	local args = getArgs(frame)
	local link = args[1]
	local display = args[2]
	if not link then
		return p.makeWikitextError('no link specified')
	end
	return p._formatLink(link, display)
end

function p._formatLink(link, display)
	-- Find whether we need to use the colon trick or not. We need to use the
	-- colon trick for categories and files, as otherwise category links
	-- categorise the page and file links display the file.
	checkType('_formatLink', 1, link, 'string')
	checkType('_formatLink', 2, display, 'string', true)
	link = removeInitialColon(link)
	local namespace = p.findNamespaceId(link, false)
	local colon
	if namespace == 6 or namespace == 14 then
		colon = ':'
	else
		colon = ''
	end

	-- Find the display value.
	if not display then
		local page, section = link:match('^(.-)#(.*)$')
		if page then
			display = page .. ' § ' .. section
		end
	end

	-- Assemble the link.
	if display then
		return string.format('[[%s%s|%s]]', colon, link, display)
	else
		return string.format('[[%s%s]]', colon, link)
	end
end

--------------------------------------------------------------------------------
-- Hatnote
--
-- Produces standard hatnote text. Implements the {{hatnote}} template.
--------------------------------------------------------------------------------

function p.hatnote(frame)
	local args = getArgs(frame)
	local s = args[1]
	local options = {}
	if not s then
		return p.makeWikitextError('no text specified')
	end
	options.extraclasses = args.extraclasses
	options.selfref = args.selfref
	return p._hatnote(s, options)
end

function p._hatnote(s, options)
	checkType('_hatnote', 1, s, 'string')
	checkType('_hatnote', 2, options, 'table', true)
	local classes = {'hatnote'}
	local extraclasses = options.extraclasses
	local selfref = options.selfref
	if type(extraclasses) == 'string' then
		classes[#classes + 1] = extraclasses
	end
	if selfref then
		classes[#classes + 1] = 'selfref'
	end
	return string.format(
		'<div class="%s">%s</div>',
		table.concat(classes, ' '),
		s
	)
end

return p