-------------------------------------------------------------------------------- -- Module:Hatnote -- -- -- -- This module produces hatnote links and links to related articles. It -- -- implements the {{hatnote}} and {{format hatnote link}} meta-templates, and -- -- includes helper functions for other Lua hatnote modules. -- --------------------------------------------------------------------------------  local libraryUtil = require('libraryUtil') local checkType = libraryUtil.checkType local mArguments -- lazily initialise [[Module:Arguments]] 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  function p.findNamespaceId(link, removeColon)  -- Finds the namespace id (namespace number) of a link or a pagename. This  -- function will not work if the link is enclosed in double brackets. Colons  -- are trimmed from the start of the link by default. To skip colon  -- trimming, set the removeColon parameter to true.  checkType('findNamespaceId', 1, link, 'string')  checkType('findNamespaceId', 2, removeColon, 'boolean', true)  if removeColon ~= false then  link = removeInitialColon(link)  end  local namespace = link:match('^(.-):')  if namespace then  local nsTable = mw.site.namespaces[namespace]  if nsTable then  return nsTable.id  end  end  return 0 end  function p.formatPages(...)  -- Formats a list of pages using formatLink and returns it as an array. Nil  -- values are not allowed.  local pages = {...}  local ret = {}  for i, page in ipairs(pages) do  ret[i] = p._formatLink(page)  end  return ret end  function p.formatPageTables(...)  -- Takes a list of page/display tables and returns it as a list of  -- formatted links. Nil values are not allowed.  local pages = {...}  local links = {}  for i, t in ipairs(pages) do  checkType('formatPageTables', i, t, 'table')  local link = t[1]  local display = t[2]  links[i] = p._formatLink(link, display)  end  return links end  function p.makeWikitextError(msg, helpLink, addTrackingCategory)  -- Formats an error message to be returned to wikitext. If  -- addTrackingCategory is not false after being returned from  -- [[Module:Yesno]], and if we are not on a talk page, a tracking category  -- is added.  checkType('makeWikitextError', 1, msg, 'string')  checkType('makeWikitextError', 2, helpLink, 'string', true)  yesno = require('Module:Yesno')  local title = mw.title.getCurrentTitle()  -- Make the help link text.  local helpText  if helpLink then  helpText = ' ([[' .. helpLink .. '|help]])'  else  helpText = ''  end  -- Make the category text.  local category  if not title.isTalkPage and yesno(addTrackingCategory) ~= false then  category = 'Hatnote templates with errors'  category = string.format(  '[[%s:%s]]',  mw.site.namespaces[14].name,  category  )  else  category = ''  end  return string.format(  '<strong class="error">Error: %s%s.</strong>%s',  msg,  helpText,  category  ) end  -------------------------------------------------------------------------------- -- 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 hatnote link}} template. --------------------------------------------------------------------------------  function p.formatLink(frame)  local args = getArgs(frame)  local link = args[1]  local display = args[2]  if not link then  return p.makeWikitextError(  'no link specified',  'แม่แบบ:Format hatnote link#Errors',  args.category  )  end  return p._formatLink(link, display) end  function p._formatLink(link, display)  -- Find whether we need to use the colon trick or not. We need to use the  -- colon trick for categories and files, as otherwise category links  -- categorise the page and file links display the file.  checkType('_formatLink', 1, link, 'string')  checkType('_formatLink', 2, display, 'string', true)  link = removeInitialColon(link)  local namespace = p.findNamespaceId(link, false)  local colon  if namespace == 6 or namespace == 14 then  colon = ':'  else  colon = ''  end   -- Find the display value.  if not display then  local page, section = link:match('^(.-)#(.*)$')  if page then  display = page .. ' § ' .. section  end  end   -- Assemble the link.  if display then  return string.format('[[%s%s|%s]]', colon, link, display)  else  return string.format('[[%s%s]]', colon, link)  end end  -------------------------------------------------------------------------------- -- Hatnote -- -- Produces standard hatnote text. Implements the {{hatnote}} template. --------------------------------------------------------------------------------  function p.hatnote(frame)  local args = getArgs(frame)  local s = args[1]  local options = {}  if not s then  return p.makeWikitextError(  'no text specified',  'แม่แบบ:Hatnote#Errors',  args.category  )  end  options.extraclasses = args.extraclasses  options.selfref = args.selfref  return p._hatnote(s, options) end  function p._hatnote(s, options)  checkType('_hatnote', 1, s, 'string')  checkType('_hatnote', 2, options, 'table', true)  local classes = {'hatnote'}  local extraclasses = options.extraclasses  local selfref = options.selfref  if type(extraclasses) == 'string' then  classes[#classes + 1] = extraclasses  end  if selfref then  classes[#classes + 1] = 'selfref'  end  return string.format(  '<div class="%s">%s</div>',  table.concat(classes, ' '),  s  ) end  return p