src/Twitter/User.hs

   1 -- | Functions and data for working with Twitter users.
   2 module Twitter.User (
   3   User(..),
   4   screen_name_to_timeline_url )
   5 where
   6
   7 import Control.Applicative ( (<$>) )
   8 import Data.Aeson ( (.:), FromJSON(..), Value(Object) )
   9 import Data.Text ( pack )
  10 import Data.Monoid ( mempty )
  11
  12
  13 -- | Represents a Twitter user, and contains the only attribute
  14 --   thereof that we care about: the screen (user) name.
  15 --
  16 data User = User { screen_name :: String } deriving (Eq, Show)
  17
  18 instance FromJSON User where
  19   -- | Parse the JSON we get from the Twitter API into a 'User' if we
  20   --   can.
  21   --
  22   parseJSON (Object u) =
  23     User <$> (u .: screen_name_field)
  24     where
  25       screen_name_field = pack "screen_name"
  26
  27   -- Do whatever.
  28   parseJSON _ = mempty
  29
  30
  31 -- | Get the URL for the given screen name's timeline.
  32 --
  33 --   Examples:
  34 --
  35 --   >>> screen_name_to_timeline_url "washington_irving"
  36 --   "http://twitter.com/washington_irving"
  37 --
  38 screen_name_to_timeline_url :: String -> String
  39 screen_name_to_timeline_url =
  40   ("http://twitter.com/" ++)