Module:Category main article

This module produces hatnote saying "The main article for this category is x." It implements the {{Category main article}} template.

Use from wikitext

This module should usually be used via the {{Category main article}} template. However, it can also be used from #invoke with the syntax {{#invoke:Category main article|catMain|parameters}}. Please see the {{Category main article}} template documentation for available parameters.

Use from other Lua modules

Load the module:

local mCatMain = require('Module:Category main article')

You can then use the _catMain function like this:

mCatMain._catMain(options, ...)

options is an optional table that can be used to configure the function's output. There are two available options, "article" and "selfref".

• article - if this is set to false, "no", "n", "false", or 0, the module outputs "The main page" rather than "The main article". Use the code {article = false}.
• selfref - this is used when the output is a self-reference to Wikipedia. To set this option, use {selfref = true}. (See the {{selfref}} template for more details on self-references.)

The remaining arguments are page names to be turned into link(s) following the text "The main article for this category is". If no page names are specified, the current page name (minus the namespace name) is used for the first link.

Example 1

mCatMain._catMain(nil, 'Foo')

Produces:

<div class="hatnote relarticle mainarticle">The main article for this [[Help:Categories|category]] is '''[[Foo]]'''.</div>

Displays as:

The main article for this category is Foo.

Example 2

mCatMain._catMain(nil, 'Foo', 'Bar', 'Baz')

Produces:

<div class="hatnote relarticle mainarticle">The main articles for this [[Help:Categories|category]] are '''[[Foo]]''', '''[[Bar]]''' and '''[[Baz]]'''.</div>

Displays as:

The main articles for this category are Foo, Bar and Baz.

Example 3

mCatMain._catMain({article = false}, 'Foo')

Produces:

<div class="hatnote relarticle mainarticle">The main page for this [[Help:Categories|category]] is '''[[Foo]]'''.</div>

Displays as:

The main page for this category is Foo.

Technical details

This module uses Module:Hatnote to format the hatnote text.

Text output

This module has five lines that must be translated when exported to wikis in other languages.

Variable	Code	Translatable text
pagetype	pagetype = yesno(options.article) ~= false and 'article' or 'page'	article	page
	pagetype = mw.title.new(page).namespace == 0 and "article" or "page"	article	page
	pagetype = "article"	article
stringToFormat	stringToFormat = 'The main %ss for this [[Help:Categories|category]] are %s.'	The main %ss for this [[Help:Categories|category]] are %s.
	stringToFormat = 'The main %s for this [[Help:Categories|category]] is %s.'	The main %s for this [[Help:Categories|category]] is %s.

---

-- This module implements {{Category main article}}.

local mHatnote = require('Module:Hatnote')
local mFormatLink = require('Module:Format link')
local yesno = require('Module:Yesno')
local mTableTools -- lazily initialise
local mArguments -- lazily initialise

local p = {}

-- Helper: true if the page is in Template: or Module: namespace
local function isTemplateOrModule(title)
	local t = (type(title) == 'string' and title) or (title and title.prefixedText) or ''
	if t == '' then
		return false
	end
	local ok, tt = pcall(mw.title.new, t)
	if not ok or not tt then
		return false
	end
	local ns = tt.namespace
	return ns == 10 or ns == 828
end

function p.catMain(frame)
	mTableTools = require('Module:TableTools')
	mArguments = require('Module:Arguments')

	-- Grab args
	local args = mArguments.getArgs(frame, {wrappers = 'Template:Category main article'})
	local pages = mTableTools.compressSparseArray(args)
	if #pages == 0 and args[1] then
		pages = { args[1] }
	end

	local options = {
		article = args.article,
		selfref = args.selfref,
		_rawPages = pages,
	}

	-- Determine the outer page (the page using the template)
	local thisTitle = frame and frame.getParent and frame:getParent() and frame:getParent().title or mw.title.getCurrentTitle()
	local titleText = thisTitle and thisTitle.prefixedText or ''
	local ns = thisTitle and thisTitle.namespace or nil

	-- Skip tracking categories on template/module pages
	local isTemplate = isTemplateOrModule(titleText)

	-- Remember original arg count
	local origCount = #pages

	-- Generate hatnote text
	local text, firstLink, usedAutoFill = p._catMain(options, thisTitle, unpack(pages))

	if isTemplate then
		-- On templates/modules, just return the hatnote (no tracking categories)
		return text
	end

	-- Add tracking categories
	local cats = {}

	-- Wrong namespace detection (Article, Draft)
	if ns == 0 or ns == 118 then
		table.insert(cats, '[[Category:Articles using category hatnotes]]')
	end

	-- Title mismatch detection
	if firstLink and (origCount == 1 or (origCount == 0 and usedAutoFill)) then
		local function normalizeTitle(s)
			return (s or ''):gsub('^%s+', ''):gsub('%s+$', ''):gsub('^[^:]*:', ''):gsub('%s+', ' '):gsub('^%l', string.upper)
		end
		local compareStr
		if usedAutoFill then
			compareStr = normalizeTitle(firstLink)
		else
			local raw = (options._rawPages and options._rawPages[1]) or firstLink
			compareStr = normalizeTitle(raw:gsub("|.*", ""))
		end
		local catName = normalizeTitle(thisTitle and thisTitle.text or '')
		if compareStr ~= catName then
			table.insert(cats, '[[Category:Category main article does not match category title]]')
		end
	end

	if #cats > 0 then
		text = text .. '\n' .. table.concat(cats, '\n')
	end

	return text
end

function p._catMain(options, thisTitle, ...)
	options = options or {}
	local pages = {...}

	thisTitle = thisTitle or mw.title.getCurrentTitle()
	local fullTitle = thisTitle and thisTitle.prefixedText or ''
	local thisText = thisTitle and thisTitle.text or (pages[1] or '')

	local isTemplate = isTemplateOrModule(fullTitle)

	-- Red link detection
	local rawLinks = mFormatLink.formatPages({
		categorizeMissing = not isTemplate and 'Categories with hatnote templates targeting a non-existent page' or nil
	}, pages)

	-- Convert to plain strings
	local links = {}
	for i, link in ipairs(rawLinks or {}) do
		links[i] = tostring(link)
	end

	-- Auto-fill if empty
	local firstOutputLink = nil
	local usedAutoFill = false

	if not links[1] or links[1] == '' then
		local title = mw.title.new(thisText)
		if title and title.isRedirect then
			title = title.redirectTarget
		end
		firstOutputLink = title and title.text or thisText
		usedAutoFill = true
		links[1] = tostring(mFormatLink._formatLink{
			link = firstOutputLink,
			categorizeMissing = not isTemplate and 'Categories with hatnote templates targeting a non-existent page' or nil
		})
		pages = { firstOutputLink }
	else
		local visible = links[1]
		visible = visible:gsub("^'''", ""):gsub("'''$", "")
		visible = visible:gsub("%[%[", ""):gsub("%]%]", "")
		visible = visible:gsub("|.*$", "")
		visible = visible:gsub("#.*$", "")
		firstOutputLink = visible
		usedAutoFill = false
	end

	-- Bold links
	for i, link in ipairs(links) do
		links[i] = string.format("'''%s'''", link)
	end

	-- Determine pagetype
	local pagetype
	if options.article ~= nil then
		pagetype = yesno(options.article) ~= false and 'article' or 'page'
	elseif pages and pages[1] then
		local page = pages[1]:gsub("|.*","")
		local tt = mw.title.new(page)
		pagetype = tt and tt.namespace == 0 and "article" or "page"
	else
		pagetype = "article"
	end

	-- Work out whether we need to be singular or plural
	local stringToFormat
	if #links > 1 then
		stringToFormat = 'The main %ss for this [[Help:Categories|category]] are %s.'
	else
		stringToFormat = 'The main %s for this [[Help:Categories|category]] is %s.'
	end

	-- Build hatnote text
	local text = string.format(
		stringToFormat,
		pagetype,
		mw.text.listToText(links)
	)

	-- Pass through Module:Hatnote
	local hnOptions = { selfref = options.selfref }
	text = mHatnote._hatnote(text, hnOptions)

	return text, firstOutputLink, usedAutoFill
end

return p