Add retrieving account data, namely the notification setting.

src/Main.elm

@@ -12,6 +12,7 @@ import Scylla.UserData exposing (..)
 import Scylla.Notification exposing (..)
 import Scylla.Storage exposing (..)
 import Scylla.Markdown exposing (..)
+import Scylla.AccountData exposing (..)
 import Url exposing (Url)
 import Url.Parser exposing (parse)
 import Url.Builder

src/Scylla/AccountData.elm

@@ -0,0 +1,22 @@
+module Scylla.AccountData exposing (..)
+import Scylla.Sync exposing (AccountData, JoinedRoom, roomAccountData)
+import Json.Decode as Decode
+
+type NotificationSetting = Normal | MentionsOnly | None
+
+notificationSettingDecoder : Decode.Decoder NotificationSetting
+notificationSettingDecoder =
+    let
+        checkString s = case s of
+            "Normal" -> Decode.succeed Normal
+            "MentionsOnly" -> Decode.succeed MentionsOnly
+            "None" -> Decode.succeed None
+            _ -> Decode.fail "Not a valid notification setting"
+    in
+        Decode.andThen checkString Decode.string
+
+roomNotificationSetting : JoinedRoom -> NotificationSetting
+roomNotificationSetting jr = Maybe.withDefault Normal
+    <| Maybe.andThen Result.toMaybe
+    <| Maybe.map (Decode.decodeValue notificationSettingDecoder)
+    <| roomAccountData jr "com.danilafe.scylla.notifications"