Module:Redirect: Difference between revisions

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en>Mr. Stradivarius
(handle apostrophes and other characters escaped by {{TALKPAGENAME}}, per protected edit request by User:Jackmcbarn)
en>Mr. Stradivarius
(add getTarget and isRedirect functions, format comments)
Line 1: Line 1:
-- Given a single page name determines what page it redirects to and returns the target page name, or the
-- This module provides functions for getting the target of a redirect page.
-- 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:
local p = {}
-- [[{{#invoke:redirect|main|redirect-page-name}}]] and {{#invoke:redirect|main|redirect-page-name|bracket=yes}}
 
-- 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).
local function getTitle(...)
local success, titleObj = pcall(mw.title.new, ...)
if success then
return titleObj
else
return nil
end
end
 
-- Gets the target of a redirect. If the page specified is not a redirect,
-- returns nil.
function p.getTarget(page)
-- Get the title object. Both page names and title objects are allowed
-- as input.
local titleObj
if type(page) == 'string' or type(page) == 'number' then
titleObj = getTitle(page)
elseif type(page) == 'table' and type(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
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
local targetTitle = getTitle(target)
if targetTitle then
return targetTitle.prefixedText
else
return nil
end
else
-- The page is a redirect, but matching failed. This indicates a bug in
-- the redirect matching pattern, so throw an error.
error(string.format(
'could not parse redirect on page "%s"',
titleObj.prefixedText
))
end
end


local p = {}
--[[
-- 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.
--]]
function p.luaMain(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.getTarget(rname)
local ret = target or rname
ret = getTitle(ret)
if ret then
ret = ret.prefixedText
return bracket:format(ret)
else
return nil
end
end


-- Provides access to the luaMain function from wikitext.
function p.main(frame)
function p.main(frame)
    -- If called via #invoke, use the args passed into the invoking
local args = require('Module:Arguments').getArgs(frame, {frameOnly = true})
    -- template, or the args passed to #invoke if any exist. Otherwise
return p.luaMain(args[1], args.bracket) or ''
    -- assume args are being passed directly in from the debug console
end
    -- 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 not rpage then
    -- mw.title.new failed, so use the passed page name.
    return mw.ustring.format(bracket, rname)
    elseif not rpage.isRedirect then
        -- the page is not a redirect, so use the normalized name of the page we
        -- were given.
        return mw.ustring.format(bracket, rpage.prefixedText)
    end


    local redirect = mw.ustring.match(rpage:getContent() or "", "^%s*#[Rr][Ee][Dd][Ii][Rr][Ee][Cc][Tt]%s*:?%s*%[%[([^%[%]]-)%]%]" )
-- Returns "yes" if the specified page is a redirect, and the blank string
    if redirect then
-- otherwise.
        -- Decode html entities and percent encodings.
function p.isRedirect(frame)
        redirect = mw.text.decode(redirect, true)
local args = require('Module:Arguments').getArgs(frame, {frameOnly = true})
        redirect = mw.uri.decode(redirect, 'WIKI')
local titleObj = getTitle(args[1])
        return mw.ustring.format(bracket, redirect)
if not titleObj then
    else
return ''
        return mw.ustring.format('<span class="error">[[Module:redirect]] error: could not parse redirect - [[%s]]</span>', rname)
end
    end
if titleObj.isRedirect then
return 'yes'
else
return ''
end
end
end


return p
return p

Revision as of 05:11, 11 June 2014

Documentation for this module may be created at Module:Redirect/doc

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

local p = {}

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

-- Gets the target of a redirect. If the page specified is not a redirect,
-- returns nil.
function p.getTarget(page)
	-- Get the title object. Both page names and title objects are allowed
	-- as input.
	local titleObj
	if type(page) == 'string' or type(page) == 'number' then
		titleObj = getTitle(page)
	elseif type(page) == 'table' and type(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
	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
		local targetTitle = getTitle(target)
		if targetTitle then
			return targetTitle.prefixedText
		else
			return nil
		end
	else
		-- The page is a redirect, but matching failed. This indicates a bug in
		-- the redirect matching pattern, so throw an error.
		error(string.format(
			'could not parse redirect on page "%s"',
			titleObj.prefixedText
		))
	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.
--]]
function p.luaMain(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.getTarget(rname)
	local ret = target or rname
	ret = getTitle(ret)
	if ret then
		ret = ret.prefixedText
		return bracket:format(ret)
	else
		return nil
	end
end

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

-- Returns "yes" if the specified page is a redirect, and the blank string
-- otherwise.
function p.isRedirect(frame)
	local args = require('Module:Arguments').getArgs(frame, {frameOnly = true})
	local titleObj = getTitle(args[1])
	if not titleObj then
		return ''
	end
	if titleObj.isRedirect then
		return 'yes'
	else
		return ''
	end
end

return p