How to replace cljs-http.client/get with js/fetch?

Community Center Beginners
2

I posted an example for fetch using js-await here.

Currently only available when using shadow-cljs though.

(defn init []
  (js-await [res (js/fetch "/cheshire-cat")]
    (js/console.log "res" res)
    (js-await [body (.json res)]
      (js/console.log "got some json" body))))

fetch returns a Promise which will provide the async result. You cannot access the result in a sync fashion. So, with your raw example maybe gets a bit cleaner with fn instead of #(). body is the JSON object result. You can only access it there, not from the init function that called all this.

(defn ^:export init []
  (-> (js/fetch "/cheshire-cat")
    (.then (fn [response]
             (-> (.json response)
               (.then (fn [body]
                        (js/console.log body)
                        )))))))

With promise chaining this could be written as

(defn ^:export init []
  (-> (js/fetch "/cheshire-cat")
    (.then #(.json %))
    (.then (fn [body]
             (js/console.log body)
             ))))
2 Likes