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 {{see also}} and similar templates.                                    -- --------------------------------------------------------------------------------  local mHatnote = require('Module:Hatnote') local mHatlist = require('Module:Hatnote list') local mArguments --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' }  -- 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 pages = {} for k, v in pairs(args) do if type(k) == 'number' then local display for i = 1, #prefixes do display = args[prefixes[i] .. k] if display then break end end local page = display and string.format('%s|%s', string.gsub(v, '|.*$', ''), display) or v pages[#pages + 1] = page end end return pages 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: -- * {{#invoke:Labelled list hatnote|labelledList|Singular label|Plural label}} -- The resulting template takes pagename & label parameters normally. function p.labelledList (frame) mArguments = require('Module:Arguments') local labels = {frame.args[1] or defaults.label} labels[2] = frame.args[2] or labels[1] local template = frame:getParent():getTitle() local args = mArguments.getArgs(frame, {parentOnly = true}) local pages = p.preprocessDisplays(args) local options = { extraclasses = frame.args.extraclasses, category = args.category, selfref = frame.args.selfref or args.selfref, template = template } return p._labelledList(pages, labels, options) end  function p._labelledList (pages, labels, options) labels = labels or {} if #pages == 0 then return mHatnote.makeWikitextError( 'no page names specified', (options.template or defaults.template) .. '#Errors', options.category ) end label = (#pages == 1 and labels[1] or labels[2]) or defaults.label 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