Event.hs

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-- | Functions exposed to end users in CallbackM
{-# LANGUAGE OverloadedStrings #-}

module Web.SocketIO.Event where

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import Web.SocketIO.Types

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import              Control.Applicative ((<$>))
import              Control.Monad.Reader
import qualified    Data.Aeson                          as Aeson
import qualified    Data.ByteString.Lazy                as BL

{-# DEPRECATED reply "use msg instead" #-}
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-- | This function is deprecated; use 'msg' instead
reply :: CallbackM [Aeson.Value]
reply = do
    Payload p <- callbackEnvPayload <$> ask
    return p

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-- | Extracts payload carried by the event
--
-- @
-- `on` \"echo\" $ do
--     payload <- msg
--     liftIO $ print payload
--     emit "echo" payload 
-- @
msg :: CallbackM [Aeson.Value]
msg = do
    Payload p <- callbackEnvPayload <$> ask
    return p

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-- | Lazy ByteString version of `msg`, convenient for Aeson decoding.
msg' :: CallbackM [BL.ByteString]
msg' = do
    Payload p <- callbackEnvPayload <$> ask
    return (map serialize p)

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-- | Name of the event
getEventName :: CallbackM EventName
getEventName = callbackEnvEventName <$> ask