web + ui: Pass init cookie from server to client

ui/src/Data/AppConfig.elm

@@ -0,0 +1,15 @@
+module Data.AppConfig exposing (AppConfig, decoder)
+
+import Json.Decode as D
+import Json.Decode.Pipeline as P
+
+
+type alias AppConfig =
+    { monitorVisible : Bool
+    }
+
+
+decoder : D.Decoder AppConfig
+decoder =
+    D.succeed AppConfig
+        |> P.required "monitor-visible" D.bool

ui/src/Data/Session.elm

@@ -4,11 +4,11 @@ module Data.Session exposing
     , Session
     , addRecent
     , clearFlash
-    , decodeValueWithDefault
     , decoder
     , disableRouting
     , enableRouting
     , init
+    , initError
     , showFlash
     )
 
@@ -54,6 +54,17 @@ init key location persistent =
     }
 
 
+initError : Nav.Key -> Url -> String -> Session
+initError key location error =
+    { key = key
+    , host = location.host
+    , flash = Just (Flash "Initialization failed" [ ( "Error", error ) ])
+    , routing = True
+    , zone = Time.utc
+    , persistent = Persistent []
+    }
+
+
 addRecent : String -> Session -> Session
 addRecent mailbox session =
     if List.head session.persistent.recentMailboxes == Just mailbox then
@@ -99,11 +110,6 @@ decoder =
         |> optional "recentMailboxes" (D.list D.string) []
 
 
-decodeValueWithDefault : D.Value -> Persistent
-decodeValueWithDefault =
-    D.decodeValue decoder >> Result.withDefault { recentMailboxes = [] }
-
-
 encode : Persistent -> E.Value
 encode persistent =
     E.object