Module:Hatnote list

This Lua module is used in MediaWiki:Wantedpages-summary, and on approximately 1,120,000 pages, or roughly 6048% of all pages.
Changes to it can cause immediate changes to the Wikipedia user interface.
To avoid major disruption and server load, any changes should be tested in the module's /sandbox or /testcases subpages, or in your own module sandbox. The tested changes can be added to this page in a single edit. Please discuss changes on the talk page before implementing them.

Usage from wikitext

This module is not designed be used directly from wikitext even though forSee does take an initial frame argument and could potentially be used from wikitext, e.g.:

{{hatnote|PREFIX {{#invoke:Hatnote list|forSee|{{tl|For}}|Module:For|{{tl|About}}|Module:About}} POSTFIX}} →

Usage from Lua

To call the module, use

local mHatList = require('Module:Hatnote list')

or similar, then access its methods through the mHatList variable (or whatever was used).

andList

andList takes a list in table form, and returns a string with the list separated with "and" and commas as appropriate.

orList

orList takes a list in table form, and returns a string with the list separated with "or" and commas as appropriate.

forSee

_forSee takes three arguments: a table of trimmed arguments with blanks removed, a "from" number with the index to start at, and an options table, and returns a string with a number of "For X, see [[Y]]" sentences. The links are formatted using the methods from Module:Hatnote.

As a convenience, the forSee method (without the leading underscore) takes the same arguments except with a frame instead of an args table, using getArgs() from Module:Arguments to preprocess the arguments.

--------------------------------------------------------------------------------
--                           Module:Hatnote list                              --
--                                                                            --
-- This module produces and formats lists for use in hatnotes. In particular, --
-- it implements the for-see list, i.e. lists of "For X, see Y" statements,   --
-- as used in {{about}}, {{redirect}}, and their variants. Also introduced    --
-- are andList & orList helpers for formatting lists with those conjunctions. --
--------------------------------------------------------------------------------

local mArguments --initialize lazily
local mFormatLink = require('Module:Format link')
local mHatnote = require('Module:Hatnote')
local libraryUtil = require('libraryUtil')
local checkType = libraryUtil.checkType
local p = {}

--------------------------------------------------------------------------------
-- List stringification helper functions
--
-- These functions are used for stringifying lists, usually page lists inside
-- the "Y" portion of "For X, see Y" for-see items.
--------------------------------------------------------------------------------

--default options table used across the list stringification functions
local stringifyListDefaultOptions = {
	conjunction = "and",
	separator = ",",
	altSeparator = ";",
	space = " ",
	formatted = false
}

--Searches display text only
local function searchDisp(haystack, needle)
	return string.find(
		string.sub(haystack, (string.find(haystack, '|') or 0) + 1), needle
	)
end

-- Stringifies a list generically; probably shouldn't be used directly
local function stringifyList(list, options)
	-- Type-checks, defaults, and a shortcut
	checkType("stringifyList", 1, list, "table")
	if #list == 0 then return nil end
	checkType("stringifyList", 2, options, "table", true)
	options = options or {}
	for k, v in pairs(stringifyListDefaultOptions) do
		if options[k] == nil then options[k] = v end
	end
	local s = options.space
	-- Format the list if requested
	if options.formatted then
		list = mFormatLink.formatPages(
			{categorizeMissing = mHatnote.missingTargetCat}, list
		)
	end
	-- Set the separator; if any item contains it, use the alternate separator
	local separator = options.separator
	for k, v in pairs(list) do
		if searchDisp(v, separator) then
			separator = options.altSeparator
			break
		end
	end
	-- Set the conjunction, apply Oxford comma, and force a comma if #1 has "§"
	local conjunction = s .. options.conjunction .. s
	if #list == 2 and searchDisp(list[1], "§") or #list > 2 then
		conjunction = separator .. conjunction
	end
	-- Return the formatted string
	return mw.text.listToText(list, separator .. s, conjunction)
end

--DRY function
function p.conjList (conj, list, fmt)
	return stringifyList(list, {conjunction = conj, formatted = fmt})
end

-- Stringifies lists with "and" or "or"
function p.andList (...) return p.conjList("and", ...) end
function p.orList (...) return p.conjList("or", ...) end

--------------------------------------------------------------------------------
-- For see
--
-- Makes a "For X, see [[Y]]." list from raw parameters. Intended for the
-- {{about}} and {{redirect}} templates and their variants.
--------------------------------------------------------------------------------

--default options table used across the forSee family of functions
local forSeeDefaultOptions = {
	andKeyword = 'and',
	title = mw.title.getCurrentTitle().text,
	otherText = 'other uses',
	forSeeForm = 'For %s, see %s.',
}

--Collapses duplicate punctuation
local function punctuationCollapse (text)
	local replacements = {
		["%.%.$"] = ".",
		["%?%.$"] = "?",
		["%!%.$"] = "!",
		["%.%]%]%.$"] = ".]]",
		["%?%]%]%.$"] = "?]]",
		["%!%]%]%.$"] = "!]]"
	}
	for k, v in pairs(replacements) do text = string.gsub(text, k, v) end
	return text
end

-- Structures arguments into a table for stringification, & options
function p.forSeeArgsToTable (args, from, options)
	-- Type-checks and defaults
	checkType("forSeeArgsToTable", 1, args, 'table')
	checkType("forSeeArgsToTable", 2, from, 'number', true)
	from = from or 1
	checkType("forSeeArgsToTable", 3, options, 'table', true)
	options = options or {}
	for k, v in pairs(forSeeDefaultOptions) do
		if options[k] == nil then options[k] = v end
	end
	-- maxArg's gotten manually because getArgs() and table.maxn aren't friends
	local maxArg = 0
	for k, v in pairs(args) do
		if type(k) == 'number' and k > maxArg then maxArg = k end
	end
	-- Structure the data out from the parameter list:
	-- * forTable is the wrapper table, with forRow rows
	-- * Rows are tables of a "use" string & a "pages" table of pagename strings
	-- * Blanks are left empty for defaulting elsewhere, but can terminate list
	local forTable = {}
	local i = from
	local terminated = false
	-- If there is extra text, and no arguments are given, give nil value
	-- to not produce default of "For other uses, see foo (disambiguation)"
	if options.extratext and i > maxArg then return nil end
	-- Loop to generate rows
	repeat
		-- New empty row
		local forRow = {}
		-- On blank use, assume list's ended & break at end of this loop
		forRow.use = args[i]
		if not args[i] then terminated = true end
		-- New empty list of pages
		forRow.pages = {}
		-- Insert first pages item if present
		table.insert(forRow.pages, args[i + 1])
		-- If the param after next is "and", do inner loop to collect params
		-- until the "and"'s stop. Blanks are ignored: "1|and||and|3" → {1, 3}
		while args[i + 2] == options.andKeyword do
			if args[i + 3] then 
				table.insert(forRow.pages, args[i + 3])
			end
			-- Increment to next "and"
			i = i + 2
		end
		-- Increment to next use
		i = i + 2
		-- Append the row
		table.insert(forTable, forRow)
	until terminated or i > maxArg
	
	return forTable
end

-- Stringifies a table as formatted by forSeeArgsToTable
function p.forSeeTableToString (forSeeTable, options)
	-- Type-checks and defaults
	checkType("forSeeTableToString", 1, forSeeTable, "table", true)
	checkType("forSeeTableToString", 2, options, "table", true)
	options = options or {}
	for k, v in pairs(forSeeDefaultOptions) do
		if options[k] == nil then options[k] = v end
	end
	-- Stringify each for-see item into a list
	local strList = {}
	if forSeeTable then
		for k, v in pairs(forSeeTable) do
			local useStr = v.use or options.otherText
			local pagesStr =
				p.andList(v.pages, true) or
				mFormatLink._formatLink{
					categorizeMissing = mHatnote.missingTargetCat,
					link = mHatnote.disambiguate(options.title)
				}
			local forSeeStr = string.format(options.forSeeForm, useStr, pagesStr)
			forSeeStr = punctuationCollapse(forSeeStr)
			table.insert(strList, forSeeStr)
		end
	end
	if options.extratext then table.insert(strList, punctuationCollapse(options.extratext..'.')) end
	-- Return the concatenated list
	return table.concat(strList, ' ')
end

-- Produces a "For X, see [[Y]]" string from arguments. Expects index gaps
-- but not blank/whitespace values. Ignores named args and args < "from".
function p._forSee (args, from, options)
	local forSeeTable = p.forSeeArgsToTable(args, from, options)
	return p.forSeeTableToString(forSeeTable, options)
end

-- As _forSee, but uses the frame.
function p.forSee (frame, from, options)
	mArguments = require('Module:Arguments')
	return p._forSee(mArguments.getArgs(frame), from, options)
end

return p