Section Link

-- This module implements {{section link}}. require('Module:No globals');  local checkType = require('libraryUtil').checkType  local p = {}  local function makeSectionLink(page, section, display) display = display or section page = page or '' -- MediaWiki doesn't allow these in `page`, so only need to do for `section` if type(section) == 'string' then section = string.gsub(section, "{", "{") section = string.gsub(section, "}", "}") end return string.format('[[%s#%s|%s]]', page, section, display) end  local function normalizeTitle(title) title = mw.ustring.gsub(mw.ustring.gsub(title, "'", ""), '"', '') title = mw.ustring.gsub(title, "%b<>", "") return mw.title.new(title).prefixedText end  function p._main(page, sections, options, title) -- Validate input. checkType('_main', 1, page, 'string', true) checkType('_main', 3, options, 'table', true) if sections == nil then sections = {} elseif type(sections) == 'string' then sections = {sections} elseif type(sections) ~= 'table' then error(string.format( "type error in argument #2 to '_main' " .. "(string, table or nil expected, got %s)", type(sections) ), 2) end options = options or {} title = title or mw.title.getCurrentTitle()  -- Deal with blank page names elegantly if page and not page:find('%S') then page = nil options.nopage = true end  -- Make the link(s). local isShowingPage = not options.nopage if #sections <= 1 then local linkPage = page or '' local section = sections[1] or 'Notes' local display = '§ ' .. section if isShowingPage then page = page or title.prefixedText if options.display and options.display ~= '' then if normalizeTitle(options.display) == normalizeTitle(page) then display = options.display .. ' ' .. display else error(string.format( 'Display title "%s" was ignored since it is ' .. "not equivalent to the page's actual title", options.display ), 0) end else display = page .. ' ' .. display end end return makeSectionLink(linkPage, section, display) else -- Multiple sections. First, make a list of the links to display. local ret = {} for i, section in ipairs(sections) do ret[i] = makeSectionLink(page, section) end  -- Assemble the list of links into a string with mw.text.listToText. -- We use the default separator for mw.text.listToText, but a custom -- conjunction. There is also a special case conjunction if we only -- have two links. local conjunction if #sections == 2 then conjunction = '​ and ' else conjunction = ', and ' end ret = mw.text.listToText(ret, nil, conjunction)  -- Add the intro text. local intro = '§§ ' if isShowingPage then intro = (page or title.prefixedText) .. ' ' .. intro end ret = intro .. ret  return ret end end  function p.main(frame) local yesno = require('Module:Yesno') local args = require('Module:Arguments').getArgs(frame, { wrappers = 'Template:Section link', valueFunc = function (key, value) value = value:match('^%s*(.-)%s*$') -- Trim whitespace -- Allow blank first parameters, as the wikitext template does this. if value ~= '' or key == 1 then return value end end })  for k, v in pairs(args) do-- replace underscores in the positional parameter values if 'number' == type(k) then if not yesno (args['keep-underscores']) then-- unless |keep-underscores=yes args[k] = mw.uri.decode (v, 'WIKI');-- percent-decode; replace underscores with space characters else args[k] = mw.uri.decode (v, 'PATH');-- percent-decode; retain underscores end end end  -- Sort the arguments. local page local sections, options = {}, {} for k, v in pairs(args) do if k == 1 then -- Doing this in the loop because of a bug in [[Module:Arguments]] -- when using pairs with deleted arguments. page = mw.text.decode(v, true) elseif type(k) == 'number' then sections[k] = v else options[k] = v end end  options.nopage = yesno (options.nopage);-- make boolean  -- Extract section from page, if present if page then local p, s = page:match('^(.-)#(.*)$') if p then page, sections[1] = p, s end end  -- Compress the sections array. local function compressArray(t) local nums, ret = {}, {} for num in pairs(t) do nums[#nums + 1] = num end table.sort(nums) for i, num in ipairs(nums) do ret[i] = t[num] end return ret end sections = compressArray(sections)  return p._main(page, sections, options) end  return p