Network.AMQP.Worker.Message

Documentation

data Message a

a parsed message from the queue

Constructors

Message

Fields

• body :: ByteString
• value :: a

Instances

Eq a => Eq (Message a)

Defined in Network.AMQP.Worker.Message

Methods

(==) :: Message a -> Message a -> Bool

(/=) :: Message a -> Message a -> Bool

Show a => Show (Message a)

Defined in Network.AMQP.Worker.Message

Methods

showsPrec :: Int -> Message a -> ShowS

show :: Message a -> String

showList :: [Message a] -> ShowS

data ConsumeResult a

Constructors

Parsed (Message a)

Error ParseError

data ParseError

Constructors

ParseError String ByteString

type Microseconds = Int

jsonMessage :: ToJSON a => a -> Message

publishToExchange :: (ToJSON a, MonadIO m) => Connection -> Key Routing a -> a -> m ()

publish a message to a routing key, without making sure a queue exists to handle it or if it is the right type of message body

publishToExchange conn key (User "username")

publish :: (ToJSON a, MonadIO m) => Connection -> Key Routing a -> a -> m ()

send a message to a queue. Enforces that the message type and queue name are correct at the type level

publish conn (key "users" :: Key Routing User) (User "username")

consume :: (FromJSON msg, MonadIO m) => Connection -> Queue msg -> m (Maybe (ConsumeResult msg))

Check for a message once and attempt to parse it

res <- consume conn queue
case res of
  Just (Parsed m) -> print m
  Just (Error e) -> putStrLn "could not parse message"
  Nothing -> putStrLn "No messages on the queue"

consumeNext :: (FromJSON msg, MonadIO m) => Microseconds -> Connection -> Queue msg -> m (ConsumeResult msg)

Block while checking for messages every N microseconds. Return once you find one.

res <- consumeNext conn queue
case res of
  (Parsed m) -> print m
  (Error e) -> putStrLn "could not parse message"