resocket

JDK11 Clojure WebSocket client with core.async API

Features

• core.async API with input and output channels for receiving/sending messages, and closed promise-chan with details about the closing of the connection.
• Automatically send ping frames to the server at given intervals, abort connections that do not pong within a certain timeout.
• Close a connection by closing output channel, abort within a certain timeout if on-close is not received from the server.
• Specify input and output parsers to take/put your preferred data structure on the channels (maps, vecs, ...) and use the parser for json/edn parsing, etc.
• Minimal dependencies, just clojure and core.async.
• reconnector process to create new connections when the previous ones have been closed, returning a core.async connections channel to take new connections from.
• Small codebase, around ~300 LOC docstrings included.

Install

Leiningen/Boot

[io.github.bortexz/resocket "0.1.0"]

Clojure CLI/deps.edn

io.github.bortexz/resocket {:mvn/version "0.1.0"}

Usage

See the docs for more detailed information about all the options available.

Quick introduction

Connection:

(require '[bortexz.resocket :as resocket])

(let [{:keys [input output closed error]} (a/<!! (resocket/connection "ws://<service>" {}))]
    (when-not error
      (a/<!! input) ;; Take new messages
      (a/>!! output "Hi from client") ;; Send messages
      (a/close! output) ;; Close connection
      (a/<!! closed)) ;; {:close-type :on-close :status 1000 :description ""}
    )

Reconnector:

(let [{:keys [connections close closed?]} (resocket/reconnector {:get-url (constantly "ws://<service>")})]
    (a/go-loop []
      (when-let [conn (a/<! connections)] ;; get new connections until reconnector closed
        (loop []
          (when-let [v (a/<! (:input conn))]
            ;; Process messages
            (recur)))
        (recur)))
    ;; Somewhere else, when tired of receiving new connections
    (a/close! close) ; Closes current connection (if any) and the reconnector

    ;; Listen to closed? in a different place than the connections handler
    (when (a/<! closed?) "Reconnector has been closed.")
  )

Credits

• hato as this library borrows some code from hato's websocket client.

License

Copyright © 2022 Alberto Fernandez

Distributed under the Eclipse Public License version 1.0.