[websockets] implement reconnection when WS closes

src/Gargantext/Components/App/App.purs

@@ -38,16 +38,12 @@ appCpt = here.component "container" cpt where
     -- |
 
     -- load Local Storage cache (if exists)
-    useFirstEffect' $
+    useFirstEffect' $ do
       R2.loadLocalStorageState R2.appParamsKey cache
 
     -- | Render
     -- |
-    pure $
-
-      hydrateStore
-      { cacheParams: cache'
-      }
+    pure $ hydrateStore { cacheParams: cache' }
 
 --------------------------------------------------------------
 
@@ -87,7 +83,6 @@ hydrateStoreCpt = here.component "hydrateStore" cpt where
 
 mainApp :: R2.Leaf ()
 mainApp = R2.leaf mainAppCpt
-
 mainAppCpt :: R.Component ()
 mainAppCpt = here.component "main" cpt where
   cpt _ _ = do

src/Gargantext/Components/Notifications.purs

@@ -14,6 +14,7 @@ import Data.Traversable (for, traverse)
 import Data.Tuple (Tuple(..))
 import Effect (Effect)
 import Effect.Ref as Ref
+import Effect.Timer (setTimeout)
 import Effect.Var (($=))
 import Effect.Var as Var
 import Foreign as F
@@ -292,6 +293,13 @@ connect ws@(WSNotification ws') url session = do
                            let subscription = WSSubscribe topic
                            here.log2 "[connect] pending subscription" subscription
                            send ws subscription)
+
+      conn.onclose $= (\_ -> do
+                          Ref.write Nothing ws'.connection
+                          void $ setTimeout 1000 $ do
+                            connect ws url session
+                      )
+        
       conn.onmessage $= onmessage
 
       pure unit