{-#LANGUAGE RankNTypes#-}
module Yesod.Auth.Facebook.ServerSide
(
authFacebook
, facebookLogin
, facebookLogout
, getUserAccessToken
, setUserAccessToken
, deleteUserAccessToken
) where
import Control.Applicative ((<$>))
import Control.Monad (when)
import Control.Monad.Trans.Maybe (MaybeT(..))
import Data.Monoid (mappend)
import Data.Text (Text)
import Network.Wai (queryString)
import Yesod.Auth
import Yesod.Core
import qualified Data.Text as T
import qualified Facebook as FB
import qualified Yesod.Auth.Message as Msg
import qualified Yesod.Facebook as YF
facebookLogin :: AuthRoute
facebookLogin = PluginR "fb" ["login"]
facebookLogout :: AuthRoute
facebookLogout = PluginR "fb" ["logout"]
authFacebook :: (YesodAuth site, YF.YesodFacebook site)
=> [FB.Permission]
-> AuthPlugin site
authFacebook perms = AuthPlugin "fb" dispatch login
where
getRedirectUrl :: YF.YesodFacebook site => (Route site -> Text) -> (Route Auth -> Route site) -> AuthHandler site Text
getRedirectUrl render proute =
YF.runYesodFbT $ FB.getUserAccessTokenStep1 (render $ proute proceedR) perms
proceedR = PluginR "fb" ["proceed"]
dispatch :: (YesodAuth site, YF.YesodFacebook site) =>
Text -> [Text] -> AuthHandler site TypedContent
dispatch "GET" ["login"] = do
ur <- getUrlRender
tm <- getRouteToParent
y <- getYesod
when (redirectToReferer y) setUltDestReferer
redirect =<< getRedirectUrl ur tm
dispatch "GET" ["proceed"] = do
render <- getUrlRender
tm <- getRouteToParent
query <- queryString <$> waiRequest
let proceedUrl = render $ tm proceedR
query' = [(a,b) | (a, Just b) <- query, a == "code"]
token <- liftSubHandler $ YF.runYesodFbT $ FB.getUserAccessTokenStep2 proceedUrl query'
setUserAccessToken token
setCredsRedirect (createCreds token)
dispatch "GET" ["logout"] = do
y <- getYesod
mtoken <- getUserAccessToken
when (redirectToReferer y) (setUltDestReferer)
valid <- maybe (return False) (YF.runYesodFbT . FB.isValid) mtoken
case (valid, mtoken) of
(True, Just token) -> do
render <- getUrlRender
tm <- getRouteToParent
dest <- YF.runYesodFbT $ FB.getUserLogoutUrl token (render $ tm $ PluginR "fb" ["kthxbye"])
redirect dest
_ -> dispatch "GET" ["kthxbye"]
dispatch "GET" ["kthxbye"] =
do
m <- getYesod
deleteSession "_ID"
deleteUserAccessToken
onLogout
redirectUltDest $ logoutDest m
dispatch _ _ = notFound
login :: (YesodAuth site, YF.YesodFacebook site) =>
(Route Auth -> Route site)
-> WidgetFor site ()
login tm = do
ur <- getUrlRender
redirectUrl <- handlerToWidget $ YF.runYesodFbT $ FB.getUserAccessTokenStep1 (ur $ tm proceedR) perms
[whamlet|<a href="#{redirectUrl}">_{Msg.Facebook}
|]
createCreds :: FB.UserAccessToken -> Creds m
createCreds (FB.UserAccessToken (FB.Id userId) _ _) = Creds "fb" id_ []
where id_ = "http://graph.facebook.com/" `mappend` userId
setUserAccessToken :: MonadHandler m => FB.UserAccessToken
-> m ()
setUserAccessToken (FB.UserAccessToken (FB.Id userId) data_ exptime) = do
setSession "_FBID" userId
setSession "_FBAT" data_
setSession "_FBET" (T.pack $ show exptime)
getUserAccessToken :: MonadHandler m => m (Maybe FB.UserAccessToken)
getUserAccessToken = runMaybeT $ do
userId <- MaybeT $ lookupSession "_FBID"
data_ <- MaybeT $ lookupSession "_FBAT"
exptime <- MaybeT $ lookupSession "_FBET"
return $ FB.UserAccessToken (FB.Id userId) data_ (read $ T.unpack exptime)
deleteUserAccessToken :: MonadHandler m => m ()
deleteUserAccessToken = do
deleteSession "_FBID"
deleteSession "_FBAT"
deleteSession "_FBET"