Om Next FAQ

How can I implement optimistic commits?

How can I delay loads?

How do I communicate with the server?

Provide a function to the :send key of the reconciler's parameter map (along with :state and :parser). This will be a function which takes two parameters: the EDN of the query expression fragment that will be passed to the server, and a callback to handle the response. Om will provide the callback, your function just needs to make the request and ensure that the callback receives, as its one argument, data in the format of an EDN result of a query expression -- for example by simply reading a transit-json response from the server back into EDN. Example:

(defn transit-post [url]
  (fn [{:keys [remote]} cb]
    (.send XhrIo url
      (fn [e]
        (this-as this
          (cb (t/read (t/reader :json) (.getResponseText this)))))
      "POST" (t/write (t/writer :json) remote)
      #js {"Content-Type" "application/transit+json"})))