Module:Category see also

-- This module implements

local mHatnote = require('Module:Hatnote')

local p = {}

local function makeWikitextError(msg) return string.format( '', msg ) end

-- Gets the length of the sequence seq. Usually this should be done with the # -- operator, but we need to work with tables that get their values through an -- __index metamethod. local function getSequenceLength(seq) local length = 0 for i in ipairs(seq) do length = i end return length end

-- Given a table of options, returns a function that formats categories for -- those options. -- -- Options: -- project - a project code such as "fr" (for the French Wikipedia) -- showPrefix - a boolean value for whether to show the "Category:" prefix -- (and the project prefix if specified) -- -- This is implemented as a function generator rather than a simple function -- so that we can just process the options once, instead of every time we -- generate a category. local function newCategoryLinker(options) local formatString if options.project then if options.showPrefix then formatString = '' .. options.project .. ':Category:%s' else formatString = '%s' end else if options.showPrefix then formatString = 'Category:%s' else formatString = '%s' end end return function (category) local title = mw.title.new(category) local pageName, display if not title then -- category is not a valid title, usually because of invalid -- characters like < or [. Raise an error and suppress the stack -- level information so that we can catch it and format the error -- message as wikitext. error(string.format( "'%s' is not a valid category name", category ), 0) elseif title.namespace == 14 then -- Category namespace pageName = title.text display = title.text else pageName = title.prefixedText display = category end -- We can get away with using two arguments even when -- options.showDisplay is false, as string.format ignores extra -- arguments as long as there is an argument for each flag in the -- format string. return formatString:format(pageName, display) end end

function p._main(args) local nLinks = getSequenceLength(args)

if nLinks < 1 then return makeWikitextError('at least one parameter required') end

local makeCategoryLink = newCategoryLinker{ project = args.project, showPrefix = nLinks == 1, }

local links = {} for i, cat in ipairs(args) do local success, categoryLink = pcall(makeCategoryLink, cat) if success then links[i] = categoryLink else -- If there was an error, then categoryLink is the error message. return makeWikitextError(categoryLink) end end

local formatString if nLinks == 1 then formatString = '%s: %s.' else formatString = '%s: the categories %s.' end

-- Don't output a comma before the "and" if we have only two links. local conjunction if nLinks == 2 then conjunction = ' and ' else conjunction = ', and ' end

local hatnoteText = formatString:format( args.LABEL or 'See also', mw.text.listToText(links, ', ', conjunction) ) return mHatnote._hatnote(hatnoteText, {selfref = true}) end

function p.main(frame) local args = require('Module:Arguments').getArgs(frame, { wrappers = 'Template:Category see also', }) return p._main(args) end

return p