proof-of-concept: :on-request handler

If you need a handle on the raw goog.net.XhrIo object request object, use the
optional `:on-request` handler. It will be called with the request object as the
last value.

Author: kennethkalmer

src/day8/re_frame/http_fx.cljs

@@ -14,9 +14,10 @@
 ;; :handler       - not supported, see :on-success and :on-failure
 ;; :on-success    - event vector dispatched with result
 ;; :on-failure    - event vector dispatched with result
+;; :on-request    - event vector dispatched with raw xhrio object
 ;;
 ;; NOTE: if you need tokens or other values for your handlers,
-;;       provide them in the on-success and on-failure event e.g.
+;;       provide them in the on-success, on-failure & on-request events e.g.
 ;;       [:success-event "my-token"] your handler will get event-v
 ;;       [:success-event "my-token" result]
 
@@ -51,7 +52,11 @@
                             #(dispatch (conj on-success %))
                             #(dispatch (conj on-failure %))
                             api))
-        (dissoc :on-success :on-failure))))
+        (dissoc :on-success :on-failure :on-request))))
+
+(defn dispatch-on-request [request xhrio]
+  (if-let [on-request (:on-request request)]
+    (dispatch (conj on-request xhrio))))
 
 ;; Specs commented out until ClojureScript has a stable release of spec.
 ;
@@ -66,8 +71,9 @@
 ;
 ;(s/def ::on-success vector?)
 ;(s/def ::on-failure vector?)
+;(s/def ::on-request vector?)
 ;
-;(s/def ::request-map (s/and (s/keys :req-un [::method ::uri ::response-format ::on-success ::on-failure]
+;(s/def ::request-map (s/and (s/keys :req-un [::method ::uri ::response-format ::on-success ::on-failure ::on-request]
 ;                                    :opt-un [::format ::timeout ::params ::headers ::with-credentials])
 ;                            (fn [m] (if (contains? m :params)
 ;                                      (contains? m :format)
@@ -85,6 +91,7 @@
         #_ #_ seq-request-maps (if (= :seq-request-maps conform-val) v [v])
         seq-request-maps (if (sequential? request) request [request])]
     (doseq [request seq-request-maps]
-      (-> request request->xhrio-options ajax/ajax-request))))
+      (let [xhrio (-> request request->xhrio-options ajax/ajax-request)]
+        (dispatch-on-request request xhrio)))))
 
 (reg-fx :http-xhrio http-effect)

test/day8/re_frame/http_fx_test.cljs

@@ -72,6 +72,15 @@
     (done)
     db))
 
+;; setup request handler
+(re-frame/reg-event-db
+ ::on-http-request
+ (fn [db [_ id req]]
+   (is (= (type req) goog.net.XhrIo) "expected: request passed through")
+   (is (= id "my-id") "expected: id passed through")
+   (done)
+   db))
+
 (re-frame/reg-event-fx
   ::http-test
   (fn [_world [_ val]]
@@ -89,6 +98,7 @@
                                      :uri             "https://api.github.com/rate_limit"
                                      :timeout         5000
                                      :response-format (ajax/json-response-format {:keywords? true})
+                                     :on-request      [::on-http-request "my-id"]
                                      :on-success      [::good-http-result done "test-token1"]
                                      :on-failure      [::bad-http-result done "test-token1"]}])))