[mod] [Aleph adapter] [#350] Experimental change to support Ring middleware (@g7s)

Author: ptaoussanis

src/taoensso/sente/server_adapters/aleph.clj

@@ -29,13 +29,14 @@
   (ring-req->server-ch-resp [sch-adapter ring-req callbacks-map]
     (let [{:keys [on-open on-close on-msg _on-error]} callbacks-map
           ws? (websocket-req? ring-req)]
-      (if ws?
-        (d/chain (aleph/websocket-connection ring-req opts)
-          (fn [s] ; sch
-            (when on-msg   (s/consume     (fn [msg] (on-msg   s ws? msg)) s))
-            (when on-close (s/on-closed s (fn []    (on-close s ws? nil))))
-            (when on-open  (do                      (on-open  s ws?)))
-            {:body s}))
+      (if-let [s (and ws? (try @(aleph/websocket-connection ring-req opts)
+                               (catch Exception e nil)))]
+        (do
+          (when on-msg   (s/consume     (fn [msg] (on-msg   s ws? msg)) s))
+          (when on-close (s/on-closed s (fn []    (on-close s ws? nil))))
+          (when on-open  (do                      (on-open  s ws?)))
+          {:body s})
+
         (let [s (s/stream)] ; sch
           (when on-close (s/on-closed s (fn [] (on-close s ws? nil))))
           (when on-open  (do                   (on-open  s ws?)))