Module:Redirect

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|redirect-page-name}}.

The template normally neither takes nor gives square brackets, so to show the result as a link use [[{{#invoke:redirect|main|redirect-page-name}}]]. An error is produced if the redirect does not exist, but for versatility no error is given if the file is not a redirect (returns the original text) or if the file name is blank (returns blank).

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

Examples

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

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

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|redirect-page-name}}.

Examples

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

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

• bugzilla:66974 - 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:Submit an edit request, which uses 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 p = {}

function p.main(frame)
    -- If called via #invoke, use the args passed into the invoking
    -- template, or the args passed to #invoke if any exist. Otherwise
    -- assume args are being passed directly in from the debug console
    -- or from another Lua module.
    local origArgs
    if frame == mw.getCurrentFrame() then
        origArgs = frame:getParent().args
        for k, v in pairs( frame.args ) do
            origArgs = frame.args
            break
        end
    else
        origArgs = frame
    end
    -- Trim whitespace and remove blank arguments.
    local args = {}
    for k, v in pairs( origArgs ) do
        v = mw.text.trim( v )
        if v ~= '' then
            args[k] = v
        end
    end
    local rname, bracket = args[1], args.bracket
    
    if type(rname) ~= "string" or not mw.ustring.match(rname, "%S") then return end
    bracket = bracket and "[[%s]]" or "%s"
    rname = mw.ustring.match(rname, "%[%[(.+)%]%]") or rname
    
    -- Get the title object, passing the function through pcall 
    -- in case we are over the expensive function count limit.
    local noError, rpage = pcall(mw.title.new, rname)
    if not noError or noError and not rpage or not rpage.isRedirect then
        -- mw.title.new failed, or the page is not a redirect, so use the passed page name.
        return mw.ustring.format(bracket, rname)
    end

    local redirect = mw.ustring.match(rpage:getContent() or "", "^%s*#[Rr][Ee][Dd][Ii][Rr][Ee][Cc][Tt]%s*%[%[([^%[%]]-)%]%]" )
    if redirect then
        -- Decode html entities and percent encodings.
        redirect = mw.text.decode(redirect, true)
        redirect = mw.uri.decode(redirect, 'WIKI')
        return mw.ustring.format(bracket, redirect)
    else
        return mw.ustring.format('<span class="error">[[Module:redirect]] error: could not parse redirect - [[%s]]</span>', rname)
    end
end

return p