Safe Haskell	Safe-Inferred
Language	Haskell2010

API

Description

Capability record for the NATS client surface.

Synopsis

Documentation

Client capabilities for publishing, subscribing, and lifecycle control.

Constructors

Fields

publish :: Subject -> [PublishOption] -> IO ()
Publish a message, optionally overriding publish options.
subscribe :: Subject -> [SubscribeOption] -> (Maybe MsgView -> IO ()) -> IO SID
Subscribe to a subject and handle delivered messages.
request :: Subject -> [SubscribeOption] -> (Maybe MsgView -> IO ()) -> IO SID
Subscribe with request semantics and auto-unsubscribe after a reply.
unsubscribe :: SID -> IO ()
Unsubscribe from a subscription by SID.
ping :: IO () -> IO ()
Send a ping and run the callback when a pong arrives.
flush :: IO ()
Flush buffered writes to the server.
reset :: IO ()
Reset the client connection state.
close :: IO ()
Close the client connection and release resources.

MsgView represents a MSG in the NATS protocol.

Constructors

MsgView
Fields subject :: ByteString The subject of the message. sid :: ByteString The SID (subscription ID) of the message. replyTo :: Maybe ByteString The replyTo subject, if any. payload :: Maybe ByteString The payload of the message, if any. headers :: Maybe [(ByteString, ByteString)] Headers associated with the message, if any.

Instances details

Show MsgView #
Instance details Defined in API Methods showsPrec :: Int -> MsgView -> ShowS # show :: MsgView -> String # showList :: [MsgView] -> ShowS #
Eq MsgView #
Instance details Defined in API Methods (==) :: MsgView -> MsgView -> Bool # (/=) :: MsgView -> MsgView -> Bool #

type PublishOption = CallOption PublishConfig #

type SubscribeOption = CallOption SubscribeConfig #

withSubscriptionExpiry sets the reply subscription expiry in seconds. Default: no expiry (reply subscriptions stay open until unsubscribe).

Examples:

{-# LANGUAGE OverloadedStrings #-}

subscribe client "events.created" [withSubscriptionExpiry 2] print

withPayload is used to set the payload for a publish operation. Default: no payload.

Examples:

{-# LANGUAGE OverloadedStrings #-}

publish client "updates" [withPayload "hello"]

withReplyCallback is used to set a callback for a reply to a publish operation. Default: no reply subscription; publishes are fire-and-forget.

Examples:

{-# LANGUAGE OverloadedStrings #-}

publish client "service.echo" [withReplyCallback print]

withHeaders is used to set headers for a publish operation. Default: no headers.

Examples:

{-# LANGUAGE OverloadedStrings #-}

publish client "updates" [withHeaders [("source", "test")]]