repond-ajax

ajax.clj

(ns respond-ajax
  (:require [io.pedestal.interceptor :as interceptor]
            [cheshire.core :as json])


(defn base-response [content-type status]
  {:status (or status 200)
   :headers {"Content-type" content-type}})

(defmulti generate-response :content-type)

(defmethod generate-response "application/edn" [{:keys [obj status content-type]}]
  (assoc (base-response content-type 200) :body (pr-str obj)))

(defmethod generate-response "application/json" [{:keys [obj status content-type]}]
  (assoc (base-response content-type (or status 200))
         :body (json/generate-string obj)))

(defmethod generate-response :default [{:keys [obj status]}]
  (assoc (base-response "text/plain" (or status 200)) :body (pr-str obj)))

(defn respond-ajax [result-fn]
  "Creates an interceptor that generates a response based upon the content-type in the request"
  (interceptor
   {::name ::respond-ajax
    :enter (fn [{:keys [request] :as context}]
             (let [obj (result-fn request)]
               (assoc context :response (generate-response (-> request
                                                               (merge {:obj obj :status 200}))))))}))

;; Example usage

;; some function that returns data
;; needs to take a request map for passage of 
;; request params
(defn return-db-results [req]
  (let [params (-> req :edn-params)]
   (query-db params)))

;; in your defroutes
(defroutes routes 
  [[["/get-db-results" {:any [:db#get-results (respond-ajax return-db-results)]}]]])

;; curl http://localhost:8080/get-db-results -H "Content-type: application/edn" -d "{:some-param-to-data :param}"
;; curl http://localhost:8080/get-db-results -H "Content-type: application/json" -d "{:some-param-to-data :param}"