📎 Add service result wrapper

Allows attach metadata to values that does not implement the IObj
clojure interface.

backend/src/app/rpc.clj

@@ -31,9 +31,10 @@
 
 (defn- handle-response-transformation
   [response request mdata]
-  (if-let [transform-fn (:transform-response mdata)]
-    (p/do (transform-fn request response))
-    (p/resolved response)))
+  (let [response (if (sv/wrapped? response) @response response)]
+    (if-let [transform-fn (:transform-response mdata)]
+      (p/do (transform-fn request response))
+      (p/resolved response))))
 
 (defn- handle-before-comple-hook
   [response mdata]

backend/src/app/util/services.clj

@@ -11,6 +11,20 @@
    [app.common.data :as d]
    [cuerdas.core :as str]))
 
+(defrecord WrappedValue [obj]
+  clojure.lang.IDeref
+  (deref [_] obj))
+
+(defn wrap
+  ([]
+   (WrappedValue. nil))
+  ([o]
+   (WrappedValue. o)))
+
+(defn wrapped?
+  [o]
+  (instance? WrappedValue o))
+
 (defmacro defmethod
   [sname & body]
   (let [[docs body]  (if (string? (first body))