Module:Hatnote

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--                              Module:Hatnote                                --
--                                                                            --
-- This module produces hatnote links and links to related articles. It       --
-- implements the {{hatnote}} and {{format link}} meta-templates and includes --
-- helper functions for other Lua hatnote modules.                            --
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local libraryUtil = require('libraryUtil')
local checkType = libraryUtil.checkType
local checkTypeForNamedArg = libraryUtil.checkTypeForNamedArg
local mArguments -- lazily initialise [[Module:Arguments]]
local yesno -- lazily initialise [[Module:Yesno]]
local formatLink -- lazily initialise [[Module:Format link]] ._formatLink

local p = {}

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-- Helper functions
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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.defaultClasses(inline)
 -- Provides the default hatnote classes as a space-separated string; useful
 -- for hatnote-manipulation modules like [[Module:Hatnote group]].
 return
  (inline == 1 and 'hatnote-inline' or 'hatnote') .. ' ' ..
  'navigation-not-searchable'
end

function p.disambiguate(page, disambiguator)
 -- Formats a page title with a disambiguation parenthetical,
 -- i.e. "Example" → "Example (disambiguation)".
 checkType('disambiguate', 1, page, 'string')
 checkType('disambiguate', 2, disambiguator, 'string', true)
 disambiguator = disambiguator or 'disambiguation'
 return mw.ustring.format('%s (%s)', page, disambiguator)
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 false.
 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.makeWikitextError(msg, helpLink, addTrackingCategory, title)
 -- 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')
 title = title or 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 -- Don't categorise talk pages
  and title.namespace ~= 2 -- Don't categorise userspace
  and yesno(addTrackingCategory) ~= false -- Allow opting out
 then
  category = 'Hatnote templates with errors'
  category = mw.ustring.format(
   '[[%s:%s]]',
   mw.site.namespaces[14].name,
   category
  )
 else
  category = ''
 end
 return mw.ustring.format(
  '<strong class="error">Error: %s%s.</strong>%s',
  msg,
  helpText,
  category
 )
end

local curNs = mw.title.getCurrentTitle().namespace
p.missingTargetCat =
 --Default missing target category, exported for use in related modules
 ((curNs ==  0) or (curNs == 14)) and
 'Articles with hatnote templates targeting a nonexistent page' or nil

function p.quote(title)
 --Wraps titles in quotation marks. If the title starts/ends with a quotation
 --mark, kerns that side as with {{-'}}
 local quotationMarks = {
  ["'"]=true, ['"']=true, ['“']=true, ["‘"]=true, ['”']=true, ["’"]=true
 }
 local quoteLeft, quoteRight = -- Test if start/end are quotation marks
  quotationMarks[string.sub(title,  1,  1)],
  quotationMarks[string.sub(title, -1, -1)]
 if quoteLeft or quoteRight then
  title = mw.html.create("span"):wikitext(title)
 end
 if quoteLeft  then title:css("padding-left",  "0.15em") end
 if quoteRight then title:css("padding-right", "0.15em") end
 return '"' .. tostring(title) .. '"'
end

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-- Hatnote
--
-- Produces standard hatnote text. Implements the {{hatnote}} template.
--------------------------------------------------------------------------------

function p.hatnote(frame)
 local args = getArgs(frame)
 local s = args[1]
 if not s then
  return p.makeWikitextError(
   'no text specified',
   'Template:Hatnote#Errors',
   args.category
  )
 end
 return p._hatnote(s, {
  extraclasses = args.extraclasses,
  selfref = args.selfref
 })
end

function p._hatnote(s, options)
 checkType('_hatnote', 1, s, 'string')
 checkType('_hatnote', 2, options, 'table', true)
 options = options or {}
 local inline = options.inline
 local hatnote = mw.html.create(inline == 1 and 'span' or 'div')
 local extraclasses
 if type(options.extraclasses) == 'string' then
  extraclasses = options.extraclasses
 end

 hatnote
  :attr('role', 'note')
  :addClass(p.defaultClasses(inline))
  :addClass(extraclasses)
  :addClass(options.selfref and 'selfref' or nil)
  :wikitext(s)

 return mw.getCurrentFrame():extensionTag{
  name = 'templatestyles', args = { src = 'Module:Hatnote/styles.css' }
 } .. tostring(hatnote)
end

return p