Module:Category see also
Appearance
This Lua module is used on approximately 45,000 pages and changes may be widely noticed. Test changes in the module's /sandbox or /testcases subpages, or in your own module sandbox. Consider discussing changes on the talk page before implementing them. |
This module implements {{Category see also}}. It produces see also links to categories which look something like this:
For full documentation, see Template:Category see also.
-- This module implements {{Category see also}}
local mHatnote = require('Module:Hatnote')
local p = {}
local function makeWikitextError(msg)
return string.format(
'<strong class="error">Error: %s ([[Template:Category see also]])</strong>',
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 = '[[:' .. options.project .. ':Category:%s|%s]]'
end
else
if options.showPrefix then
formatString = '[[:Category:%s]]'
else
formatString = '[[:Category:%s|%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