Module:Redirect

 -- This module provides functions for getting the target of a redirect page.

 localp={}

 -- Gets a mw.title object, using pcall to avoid generating script errors if we
 -- are over the expensive function count limit (among other possible causes).
 localfunctiongetTitle(...)
 localsuccess,titleObj=pcall(mw.title.new,...)
 ifsuccessthen
 returntitleObj
 else
 returnnil
 end
 end

 -- Gets the name of a page that a redirect leads to, or nil if it isn't a
 -- redirect.
 functionp.getTargetFromText(text)
 localtarget=string.match(
 text,
 "^%s*#[Rr][Ee][Dd][Ii][Rr][Ee][Cc][Tt]%s*:?%s*%[%[([^%[%]|]-)%]%]"
 )orstring.match(
 text,
 "^%s*#[Rr][Ee][Dd][Ii][Rr][Ee][Cc][Tt]%s*:?%s*%[%[([^%[%]|]-)|[^%[%]]-%]%]"
 )
 returntargetandmw.uri.decode(target,'PATH')
 end

 -- Gets the target of a redirect. If the page specified is not a redirect,
 -- returns nil.
 functionp.getTarget(page,fulltext)
 -- Get the title object. Both page names and title objects are allowed
 -- as input.
 localtitleObj
 iftype(page)=='string'ortype(page)=='number'then
 titleObj=getTitle(page)
 elseiftype(page)=='table'andtype(page.getContent)=='function'then
 titleObj=page
 else
 error(string.format(
 "bad argument #1 to 'getTarget'"
 .." (string, number, or title object expected, got %s)",
 type(page)
 ),2)
 end
 ifnottitleObjthen
 returnnil
 end
 localtargetTitle=titleObj.redirectTarget
 iftargetTitlethen
 iffulltextthen
 returntargetTitle.fullText
 else
 returntargetTitle.prefixedText
 end
 else
 returnnil
 end
 end

 --[[
 -- 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.
 --]]
 functionp.luaMain(rname,bracket,fulltext)
 iftype(rname)~="string"ornotrname:find("%S")then
 returnnil
 end
 bracket=bracketand"[[%s]]"or"%s"
 rname=rname:match("%[%[(.+)%]%]")orrname
 localtarget=p.getTarget(rname,fulltext)
 localret=targetorrname
 ret=getTitle(ret)
 ifretthen
 iffulltextthen
 ret=ret.fullText
 else
 ret=ret.prefixedText
 end
 returnbracket:format(ret)
 else
 returnnil
 end
 end

 -- Provides access to the luaMain function from wikitext.
 functionp.main(frame)
 localargs=require('Module:Arguments').getArgs(frame,{frameOnly=true})
 returnp.luaMain(args[1],args.bracket,args.fulltext)or''
 end

 -- Returns true if the specified page is a redirect, and false otherwise.
 functionp.luaIsRedirect(page)
 localtitleObj=getTitle(page)
 ifnottitleObjthen
 returnfalse
 end
 iftitleObj.isRedirectthen
 returntrue
 else
 returnfalse
 end
 end

 -- Provides access to the luaIsRedirect function from wikitext, returning 'yes'
 -- if the specified page is a redirect, and the blank string otherwise.
 functionp.isRedirect(frame)
 localargs=require('Module:Arguments').getArgs(frame,{frameOnly=true})
 ifp.luaIsRedirect(args[1])then
 return'yes'
 else
 return''
 end
 end

 returnp