Module:Redirect/sandbox

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This module contains functions to find the target of a redirect page.

Main

The main function accepts the name of a single page. It determines if the page is a redirect; if so it looks up the page, extracts the target, and returns the target name as text. Its usage is {{#invoke:redirect|main|page-name}}. If page-name does not exist or is not a redirect then page-name is returned. If page-name is blank then blank is returned.

The function normally neither takes nor gives square brackets, so to show the result as a link use [[{{#invoke:redirect|main|page-name}}]].

If the parameter bracket is given a nonblank value, brackets will be passed on if present.

Examples

• {{#invoke:redirect|main|WP:AFC}} → Wikipedia:Articles for creation
• {{#invoke:redirect|main|[[WP:AFD]]|bracket=yes}} → Wikipedia:Articles for deletion
• {{#invoke:redirect|main|Wikipedia:Articles for deletion}} → Wikipedia:Articles for deletion
• {{#invoke:redirect|main|Wikipedia:Articles for rumination}} → Wikipedia:Articles for rumination

Note: WP:AFC and WP:AFD are both redirects, but Wikipedia:Articles for deletion is not, and Wikipedia:Articles for rumination does not exist.

LuaMain

If you want to use the main function from another Lua module, you may want to use the luaMain function. This provides the same functionality as the main function, but doesn't require that a frame object be available.

To use this, first load the module.

local mRedirect = require('Module:Redirect')

Then use the function with the following syntax:

mRedirect.luaMain(rname, bracket)

rname is the name of the redirect page, and if bracket is anything but false or nil, the module will produce a link rather than just a page name.

IsRedirect

The isRedirect function is used from wiki pages to find out if a given page is a redirect or not. If the page is a redirect, the function returns "yes", and if not the output is blank. Its usage is {{#invoke:redirect|isRedirect|page-name}}.

Examples

• {{#invoke:redirect|isRedirect|WP:AFC}} → yes
• {{#invoke:redirect|isRedirect|Wikipedia:Articles for deletion}} →
• {{#invoke:redirect|isRedirect|Wikipedia:Articles for rumination}} →

LuaIsRedirect

The isRedirect can be accessed from other Lua modules in the same way as the main function:

local mRedirect = require('Module:Redirect')
mRedirect.luaIsRedirect(rname)

GetTarget

The getTarget function fetches the target page name of a redirect page, and is only usable from Lua. If the page specified is a redirect, then the target is returned; otherwise the function returns nil.

To use it, first load the module.

local mRedirect = require('Module:Redirect')

Then use the function with the following syntax:

mRedirect.getTarget(page)

page can be either the name of the redirect page as a string, or a mw.title object.

See also

• phab:T68974 - Provide a standard way to get the target of a redirect page
• mw:Extension:Scribunto/Lua reference manual#Title objects, the Scribunto interface for determining a page's redirect status
• Template:Get QID, which uses this module
• Template:Submit an edit request, which uses this module

The above documentation is transcluded from Module:Redirect/sandbox/doc. (edit | history)
Editors can experiment in this module's sandbox (edit | diff) and testcases (edit | run) pages.
Subpages of this module.

-- Given a single page name determines what page it redirects to and returns the target page name, or the
-- passed page name when not a redirect. The passed page name can be given as plain text or as a page link.
-- Returns page name as plain text, or when the bracket parameter is given, as a page link. Returns an
-- error message when page does not exist or the redirect target cannot be determined for some reason.

-- Thus these are roughly the same:
-- [[{{#invoke:redirect|main|redirect-page-name}}]] and {{#invoke:redirect|main|redirect-page-name|bracket=yes}}

local mArguments -- lazily initialise [[Module:Arguments]]

local p = {}

local function getTitle(...)
	local success, titleObj = pcall(mw.title.new, ...)
	if success then
		return titleObj
	else
		return nil
	end
end

function p.main(frame)
	mArguments = require('Module:Arguments')
	local args = mArguments.getArgs(frame)
	local rname, bracket = args[1], args.bracket
	return p._main(rname, bracket) or ''
end

function p._main(rname, bracket)
	if type(rname) ~= "string" or not rname:find("%S") then
		return nil
	end
	bracket = bracket and "[[%s]]" or "%s"
	rname = rname:match("%[%[(.+)%]%]") or rname
	local target = p.getTargetString(rname)
	if target then
		return bracket:format(target)
	else
		return bracket:format(rname)
	end
end

function p.getTarget(page)
	return getTitle(p.getTargetString)
end

function p.getTargetString(page)
	-- Get the title object. Both page names and title objects are allowed
	-- as input.
	local titleObj
	if type(page) == 'string' then
		titleObj = getTitle(page)
	elseif type(page) == 'table' and type(page.getContent) == 'function' then
		titleObj = page
	else
		local msg = 'invalid input to "getTarget":'
			.. 'the first parameter must be a string or a title object'
		error(msg, 2)
	end
	if not titleObj or not titleObj.isRedirect then
		return nil
	end
	
	-- Find the target by using string matching on the page content.
	local target = string.match(
		titleObj:getContent() or "",
		"^%s*#[Rr][Ee][Dd][Ii][Rr][Ee][Cc][Tt]%s*:?%s*%[%[([^%[%]]-)%]%]"
	)
	if target then
		-- Decode html entities and percent encodings.
		target = mw.text.decode(target, true)
		target = mw.uri.decode(target, 'WIKI')
		return target
	else
		-- The page is a redirect, but matching failed. This indicates a bug in
		-- the redirect matching pattern, so throw an error.
		local msg = 'could not parse redirect on page [[:'
			.. titleObj.prefixedText
			.. ']]'
		error(msg)
	end
end

return p