Ring-WebSocket-Transit

A Clojure library for using the Transit data format over Ring's WebSocket API (currently in beta testing).

Installation

Add the following dependency to your deps.edn file:

org.ring-clojure/ring-websocket-transit {:mvn/version "0.1.0"}

Or to your Leiningen project file:

[org.ring-clojure/ring-websocket-transit "0.1.0"]

Usage

The wrap-websocket-transit middleware function converts incoming and outgoing WebSocket text messages to and from the Transit data format.

For example:

(require '[ring.websocket :as ws]
         '[ring.websocket.transit :as wst])

(def handler
  (wst/wrap-websocket-transit
   (fn [_request]
     {::ws/listener
      {:on-message
       (fn [socket message]
         (ws/send socket (update message :counter inc)))}})))

Instead of receiving a text message via the on-message listener event, a data structure decoded from Transit formatting is supplied instead. The socket argument is also wrapped, such that sending a data structure automatically encodes it.

This also works with libraries like Ring-WebSocket-Async:

(require '[clojure.core.async :as a :refer [<! >!]]
         '[ring.websocket.async :as wsa])

(def handler-async
  (wst/wrap-websocket-transit
    (fn [_request]
      (wsa/go-websocket [in out]
        (loop
          (when-let [message (<! in)]
            (>! out (update message :counter inc))
            (recur)))))))

License

Copyright © 2023 James Reeves

Released under the MIT license.