Module:Labelled list hatnote

--                              Labelled list                                -- --                                                                           -- -- This module does the core work of creating a hatnote composed of a list    -- -- prefixed by a colon-terminated label, i.e. "LABEL: [andList of pages]",   -- -- for and similar templates. --

local mHatnote = require('Module:Hatnote') local mHatlist = require('Module:Hatnote list') local mArguments --initialize lazily local yesno --initialize lazily local p = {}

-- Defaults global to this module local defaults = { label = 'See also', --Final fallback for label argument labelForm = '%s: %s', prefixes = {'label', 'label ', 'l'}, template = 'Module:Labelled list hatnote' }

-- Localizable message strings local msg = { errorSuffix = '#Errors', noInputWarning = 'no page names specified', noOutputWarning = "%s — no output: none of the target pages exist." }

-- Helper function that pre-combines display parameters into page arguments. -- Also compresses sparse arrays, as a desirable side-effect. function p.preprocessDisplays (args, prefixes) -- Prefixes specify which parameters, in order, to check for display options -- They each have numbers auto-appended, e.g. 'label1', 'label 1', & 'l1' prefixes = prefixes or defaults.prefixes local indices = {} local sparsePages = {} for k, v in pairs(args) do		if type(k) == 'number' then indices[#indices + 1] = k			local display for i = 1, #prefixes do display = args[prefixes[i] .. k]				if display then break end end sparsePages[k] = display and string.format('%s|%s', string.gsub(v, '|.*$', ''), display) or v		end end table.sort(indices) local pages = {} for k, v in ipairs(indices) do pages[#pages + 1] = sparsePages[v] end return pages end

--Helper function to get a page target from a processed page string --e.g. "Page|Label" → "Page" or "Target" → "Target" local function getTarget(pagename) local pipe = string.find(pagename, '|') return string.sub(pagename, 0, pipe and pipe - 1 or nil) end

-- Produces a labelled pages-list hatnote. -- The main frame (template definition) takes 1 or 2 arguments, for a singular -- and (optionally) plural label respectively: -- * -- The resulting template takes pagename & label parameters normally. function p.labelledList (frame) mArguments = require('Module:Arguments') yesno = require('Module:Yesno') local labels = {frame.args[1] or defaults.label} labels[2] = frame.args[2] or labels[1] labels[3] = frame.args[3] --no defaulting labels[4] = frame.args[4] --no defaulting local template = frame:getParent:getTitle local args = mArguments.getArgs(frame, {parentOnly = true}) local pages = p.preprocessDisplays(args) local options = { category = yesno(args.category), extraclasses = frame.args.extraclasses, ifexists = yesno(frame.args.ifexists), namespace = frame.args.namespace or args.namespace, selfref = yesno(frame.args.selfref or args.selfref), template = template }	return p._labelledList(pages, labels, options) end

function p._labelledList (pages, labels, options) if options.ifexists then for k = #pages, 1, -1 do --iterate backwards to allow smooth removals local v = pages[k] local title = mw.title.new(getTarget(v), namespace) if (v == '') or title == nil or not title.exists then table.remove(pages, k)			end end end labels = labels or {} label = (#pages == 1 and labels[1] or labels[2]) or defaults.label for k, v in pairs(pages) do 		if mHatnote.findNamespaceId(v) ~= 0 then label = (					#pages == 1 and					(labels[3] or labels[1] or defaults.label) or					(labels[4] or labels[2] or defaults.label)				) or defaults.label end end if #pages == 0 then if options.ifexists then mw.addWarning(				string.format( msg.noOutputWarning, options.template or defaults.template )			)			return '' else return mHatnote.makeWikitextError(				msg.noInputWarning,				(options.template or defaults.template) .. msg.errorSuffix,				options.category			) end end local text = string.format(		options.labelForm or defaults.labelForm,		label,		mHatlist.andList(pages, true)	) local hnOptions = { extraclasses = options.extraclasses, selfref = options.selfref }	return mHatnote._hatnote(text, hnOptions) end

return p