-------------------------------------------------------------------------------- -- Format link -- -- Makes a wikilink from the given link and display values. Links are escaped -- with colons if necessary, and links to sections are detected and displayed -- with " § " as a separator rather than the standard MediaWiki "#". Used in -- the {{format link}} template. -------------------------------------------------------------------------------- local libraryUtil = require('libraryUtil') local checkType = libraryUtil.checkType local checkTypeForNamedArg = libraryUtil.checkTypeForNamedArg local mArguments -- lazily initialise [[Module:Arguments]] local mError -- lazily initialise [[Module:Error]] local yesno -- lazily initialise [[Module:Yesno]]  local p = {}  -------------------------------------------------------------------------------- -- Helper functions --------------------------------------------------------------------------------  local function getArgs(frame)  -- Fetches the arguments from the parent frame. Whitespace is trimmed and  -- blanks are removed.  mArguments = require('Module:Arguments')  return mArguments.getArgs(frame, {parentOnly = true}) end  local function removeInitialColon(s)  -- Removes the initial colon from a string, if present.  return s:match('^:?(.*)') end  local function maybeItalicize(s, shouldItalicize)  -- Italicize s if s is a string and the shouldItalicize parameter is true.  if s and shouldItalicize then  return '<i>' .. s .. '</i>'  else  return s  end end  local function parseLink(link)  -- Parse a link and return a table with the link's components.  -- These components are:  -- - link: the link, stripped of any initial colon (always present)  -- - page: the page name (always present)  -- - section: the page name (may be nil)  -- - display: the display text, if manually entered after a pipe (may be nil)  link = removeInitialColon(link)   -- Find whether a faux display value has been added with the {{!}} magic  -- word.  local prePipe, display = link:match('^(.-)|(.*)$')  link = prePipe or link   -- Find the page, if it exists.  -- For links like [[#Bar]], the page will be nil.  local preHash, postHash = link:match('^(.-)#(.*)$')  local page  if not preHash then  -- We have a link like [[Foo]].  page = link  elseif preHash ~= '' then  -- We have a link like [[Foo#Bar]].  page = preHash  end   -- Find the section, if it exists.  local section  if postHash and postHash ~= '' then  section = postHash  end   return {  link = link,  page = page,  section = section,  display = display,  } end  local function formatDisplay(parsed, options)  -- Formats a display string based on a parsed link table (matching the  -- output of parseLink) and an options table (matching the input options for  -- _formatLink).  local page = maybeItalicize(parsed.page, options.italicizePage)  local section = maybeItalicize(parsed.section, options.italicizeSection)  if (not section) then  return page  elseif (not page) then  return mw.ustring.format('§&nbsp;%s', section)  else  return mw.ustring.format('%s §&nbsp;%s', page, section)  end end  local function missingArgError(target)  mError = require('Module:Error')  return mError.error{message =  'ข้อผิดพลาด: ไม่ได้ระบุลิงก์หรือเป้าหมาย! ([[' .. target .. '#ข้อผิดพลาด|วิธีใช้]])'  } end  -------------------------------------------------------------------------------- -- Main functions --------------------------------------------------------------------------------  function p.formatLink(frame)  -- The formatLink export function, for use in templates.  yesno = require('Module:Yesno')  local args = getArgs(frame)  local link = args[1] or args.link  local target = args[3] or args.target  if not (link or target) then  return missingArgError('แม่แบบ:รูปแบบลิงก์')  end   return p._formatLink{  link = link,  display = args[2] or args.display,  target = target,  italicizePage = yesno(args.italicizepage),  italicizeSection = yesno(args.italicizesection),  categorizeMissing = args.categorizemissing  } end  function p._formatLink(options)  -- The formatLink export function, for use in modules.  checkType('_formatLink', 1, options, 'table')  local function check(key, expectedType) --for brevity  checkTypeForNamedArg(  '_formatLink', key, options[key], expectedType or 'string', true  )  end  check('link')  check('display')  check('target')  check('italicizePage', 'boolean')  check('italicizeSection', 'boolean')  check('categorizeMissing')   -- Normalize link and target and check that at least one is present  if options.link == '' then options.link = nil end  if options.target == '' then options.target = nil end  if not (options.link or options.target) then  return missingArgError('Module:Format link')  end   local parsed = parseLink(options.link)  local display = options.display or parsed.display  local catMissing = options.categorizeMissing  local category = ''   -- Find the display text  if not display then display = formatDisplay(parsed, options) end   -- Handle the target option if present  if options.target then  local parsedTarget = parseLink(options.target)  parsed.link = parsedTarget.link  parsed.page = parsedTarget.page  end   -- Test if page exists if a diagnostic category is specified  if catMissing and (mw.ustring.len(catMissing) > 0) then  local title = nil  if parsed.page then title = mw.title.new(parsed.page) end  if title and (not title.isExternal) and (not title.exists) then  category = mw.ustring.format('[[หมวดหมู่:%s]]', catMissing)  end  end   -- Format the result as a link  if parsed.link == display then  return mw.ustring.format('[[:%s]]%s', parsed.link, category)  else  return mw.ustring.format('[[:%s|%s]]%s', parsed.link, display, category)  end end  -------------------------------------------------------------------------------- -- Derived convenience functions --------------------------------------------------------------------------------  function p.formatPages(options, pages)  -- Formats an array of pages using formatLink and the given options table,  -- and returns it as an array. Nil values are not allowed.  local ret = {}  for i, page in ipairs(pages) do  ret[i] = p._formatLink{  link = page,  categorizeMissing = options.categorizeMissing,  italicizePage = options.italicizePage,  italicizeSection = options.italicizeSection  }  end  return ret end  return p