Network.Mom.Patterns.Basic.Publisher

Publish side of 'Publish/Subscribe'

Publisher

data Pub

Publisher data type

withPub :: Context -> String -> LinkType -> (Pub -> IO a) -> IO a

Create and link a publisher:

• Context - The zeromq context
• String - The service address
• LinkType - How to link (bind or connect)
• (Pub -> IO a) - The action, in whose scope the publisher lives

issue :: Pub -> [Service] -> Source -> IO ()

Publish data:

• Pub - The publisher
• [Service] - List of topics, to which these data should be published
• Source - Create the stream to publish. The first message segment contains the subscription header, i.e. the comma-separated list of topics

Forwarder

withForwarder :: Context -> Service -> [Service] -> (String, LinkType) -> (String, LinkType) -> OnError_ -> Control a -> IO a

A simple forwarder, i.e. a device that connects to a publisher and provides an additional endpoint for more subscribers to connect to. A forwarder, hence, is a means to extend the capacity of a publisher.

• Context - The zeromq context
• Service - The name of the forwarder
• (String, LinkType) - access point for subscribers; usually, you want to bind the address, such that subscribers connect to it.
• (String, LinkType) - access point for the publisher; usually, you want to connect to the publisher.
• OnError_ - Error handler
• Control a - Control loop