cljc-http

A naive attempt at making a cljc wrapper around the well-known clj-http and cljs-http libs.

For a more production-ready libraries, see httpurr (doc) and cljs-ajax.

The main trick is to make clj-http calls be always async and returning a core.async channel, as per cljs-http conventions.

In case of errors, a response object is returned, as per cljs-http conventions. That means that for clj, we convert the thrown slingshot stone (i.e. Exception) back to a response object.

Cancelling requests is possible with cljc-http.core/abort!, modeled around cljs-http.core/abort!. Note that standard clj-http also supports cancelling async requests by cancelling the future object holding its job.

Usage

(ns test.ns
  #?(:cljs
     (:require-macros
      [cljs.core.async.macros :as asyncm :refer (go go-loop)]))
  (:require [clojure.core.async :as async]
            [cljc-http.client :as http-client]
            [cljc-http.core :as http-core]))


;; blocking sync request
;; (clj-only as `async/<!!` not available in cljs)
(let [resp (async/<!! (http-client/get "http://http://example.com/resource" {:accept :json}))
      http-status (:status resp)]
  (when-not (http-client/unexceptional-status? http-status)
    (throw (ex-info "Unexpected HTTP response code" {:ex-type ::unexpected-http-status,
                                                     :input http-status})))
  ;; ... do stuff w/ (:body resp)
  )

;; async request
(go
  (let [resp (async/<! (http-client/get "http://http://example.com/resource" {:accept :json}))
        http-status (:status resp)]
    (when-not (http-client/unexceptional-status? http-status)
      (throw (ex-info "Unexpected HTTP response code" {:ex-type ::unexpected-http-status,
                                                       :input http-status})))
    ;; ... do stuff w/ (:body resp)
    ))

;; canceling sync request
;; (clj-only as `async/alts!!` not available in cljs)
(let [request-channel (http-client/get "http://http://example.com/resource" {:accept :json})
      [resp alts-chan] (async/alts!! [request-channel (async/timeout 1000)])]
  (when (nil? resp)                     ; got timeout
    (http-core/abort! request-channel))

  ;; ... do stuff w/ resp
  )

;; canceling async request
(go
  (let [request-channel (http-client/get "http://http://example.com/resource" {:accept :json})
        [resp alts-chan] (async/alts! [request-channel (async/timeout 1000)])]
    (when (nil? resp)                   ; got timeout
      (http-core/abort! request-channel))

    ;; ... do stuff w/ resp
    ))

License

Released under the MIT License: http://www.opensource.org/licenses/mit-license.php