♻️ Refactor embed resouces

frontend/src/app/util/cache.cljs

@@ -0,0 +1,26 @@
+;; This Source Code Form is subject to the terms of the Mozilla Public
+;; License, v. 2.0. If a copy of the MPL was not distributed with this
+;; file, You can obtain one at http://mozilla.org/MPL/2.0/.
+;;
+;; Copyright (c) UXBOX Labs SL
+
+(ns app.util.cache
+  (:require
+   [app.util.time :as dt]
+   [beicon.core :as rx]))
+
+(defonce cache (atom {}))
+
+(defn with-cache
+  [{:keys [key max-age]} observable]
+  (let [entry (get @cache key)
+        age   (when entry
+                (dt/diff (dt/now)
+                         (:created-at entry)))]
+    (if (and (some? entry) (< age max-age))
+      (rx/of (:data entry))
+      (->> observable
+           (rx/tap
+            (fn [data]
+              (let [entry {:created-at (dt/now) :data data}]
+                (swap! cache assoc key entry))))))))