Server Sent Events

sse.clj

(defn- streaming-handler
  [_]
  (let [body (s/stream)]
    (future
      (dotimes [i 10]
        (s/put! body (format "data: %s \n\n" i))
        (Thread/sleep 200))
      (s/close! body))
    {:status 200
     :headers {"Content-Type" "text/event-stream"}
     :body body}))

(def server (http/start-server #'streaming-handler {:port 9999}))

(let [{:keys [body]} @(http/get "http://localhost:9999")
      rdr (clojure.java.io/reader body)]
  (doseq [l (line-seq rdr)]
    (prn l)))