Add Twitter

Yesod/Auth/OAuth2/Twitter.hs

@@ -0,0 +1,53 @@
+{-# LANGUAGE CPP #-}
+{-# LANGUAGE OverloadedStrings #-}
+module Yesod.Auth.OAuth2.Twitter
+    ( oauth2Twitter
+    , module Yesod.Auth.OAuth2
+    ) where
+
+#if __GLASGOW_HASKELL__ < 710
+import Control.Applicative ((<$>), (<*>))
+#endif
+
+import Control.Monad (mzero)
+import Data.Aeson
+import Data.Text (Text)
+import Data.Text.Encoding (encodeUtf8)
+import Yesod.Auth
+import Yesod.Auth.OAuth2
+
+data TwitterUser = TwitterUser
+    { twitterUserId :: Text
+    , twitterUserName :: Text
+    , twitterScreenName :: Text
+    }
+
+instance FromJSON TwitterUser where
+    parseJSON (Object o) = TwitterUser
+        <$> o .: "id_str"
+        <*> o .: "name"
+        <*> o .: "screen_name"
+
+    parseJSON _ = mzero
+
+oauth2Twitter :: YesodAuth m
+              => Text -- ^ Client ID
+              -> Text -- ^ Client Secret
+              -> AuthPlugin m
+oauth2Twitter clientId clientSecret = authOAuth2 "twitter"
+    OAuth2
+        { oauthClientId = encodeUtf8 clientId
+        , oauthClientSecret = encodeUtf8 clientSecret
+        , oauthOAuthorizeEndpoint = "https://api.twitter.com/oauth/authorize"
+        , oauthAccessTokenEndpoint = "https://api.twitter.com/oauth/access_token"
+        , oauthCallback = Nothing
+        }
+    $ fromProfileURL "twitter" "https://api.twitter.com/1.1/account/verify_credentials.json"
+    $ \user -> Creds
+        { credsPlugin = "twitter"
+        , credsIdent = twitterUserId user
+        , credsExtra =
+            [ ("name", twitterUserName user)
+            , ("screen_name", twitterScreenName user)
+            ]
+        }

yesod-auth-oauth2.cabal

@@ -40,6 +40,7 @@ library
     exposed-modules: Yesod.Auth.OAuth2
                      Yesod.Auth.OAuth2.Github
                      Yesod.Auth.OAuth2.Spotify
+                     Yesod.Auth.OAuth2.Twitter
                      Yesod.Auth.OAuth2.Upcase
 
     ghc-options:     -Wall