ui: Add session update logic into Session

ui/src/Data/Session.elm

@@ -10,8 +10,10 @@ module Data.Session exposing
     )
 
 import Browser.Navigation as Nav
-import Json.Decode exposing (..)
+import Json.Decode as D
 import Json.Decode.Pipeline exposing (..)
+import Json.Encode as E
+import Ports
 import Url exposing (Url)
 
 
@@ -43,8 +45,10 @@ init key location persistent =
     Session key location.host "" True persistent
 
 
-update : Msg -> Session -> Session
+update : Msg -> Session -> ( Session, Cmd a )
 update msg session =
+    let
+        newSession =
             case msg of
                 None ->
                     session
@@ -77,6 +81,15 @@ update msg session =
                                 session.persistent
                         in
                         { session | persistent = { persistent | recentMailboxes = recent } }
+    in
+    if session.persistent == newSession.persistent then
+        -- No change
+        ( newSession, Cmd.none )
+
+    else
+        ( newSession
+        , Ports.storeSession (encode newSession.persistent)
+        )
 
 
 none : Msg
@@ -84,12 +97,19 @@ none =
     None
 
 
-decoder : Decoder Persistent
+decoder : D.Decoder Persistent
 decoder =
-    succeed Persistent
+    D.succeed Persistent
-        |> optional "recentMailboxes" (list string) []
+        |> optional "recentMailboxes" (D.list D.string) []
 
 
-decodeValueWithDefault : Value -> Persistent
+decodeValueWithDefault : D.Value -> Persistent
 decodeValueWithDefault =
-    decodeValue decoder >> Result.withDefault { recentMailboxes = [] }
+    D.decodeValue decoder >> Result.withDefault { recentMailboxes = [] }
+
+
+encode : Persistent -> E.Value
+encode persistent =
+    E.object
+        [ ( "recentMailboxes", E.list E.string persistent.recentMailboxes )
+        ]

ui/src/Main.elm

@@ -224,19 +224,11 @@ changeRouteTo route model =
 updateSession : ( Model, Cmd Msg, Session.Msg ) -> ( Model, Cmd Msg )
 updateSession ( model, cmd, sessionMsg ) =
     let
-        session =
+        ( session, newCmd ) =
             Session.update sessionMsg model.session
-
-        newModel =
-            { model | session = session }
     in
-    if session.persistent == model.session.persistent then
+    ( { model | session = session }
-        -- No change
+    , Cmd.batch [ newCmd, cmd ]
-        ( newModel, cmd )
-
-    else
-        ( newModel
-        , Cmd.batch [ cmd, Ports.storeSession session.persistent ]
     )
 
 

ui/src/Ports.elm

@@ -5,7 +5,6 @@ port module Ports exposing
     , storeSession
     )
 
-import Data.Session exposing (Persistent)
 import Json.Encode exposing (Value)
 
 
@@ -18,4 +17,4 @@ port monitorMessage : (Value -> msg) -> Sub msg
 port onSessionChange : (Value -> msg) -> Sub msg
 
 
-port storeSession : Persistent -> Cmd msg
+port storeSession : Value -> Cmd msg