Introduce ui settings and let user set page size for item search

modules/webapp/src/main/elm/Ports.elm

@@ -1,14 +1,22 @@
 port module Ports exposing
-    ( removeAccount
+    ( getUiSettings
+    , loadUiSettings
+    , onUiSettingsSaved
+    , removeAccount
     , scrollToElem
     , setAccount
     , setAllProgress
     , setProgress
+    , storeUiSettings
     )
 
 import Api.Model.AuthResult exposing (AuthResult)
+import Data.Flags exposing (Flags)
+import Data.UiSettings exposing (StoredUiSettings, UiSettings)
 
 
+{-| Save the result of authentication to local storage.
+-}
 port setAccount : AuthResult -> Cmd msg
 
 
@@ -22,3 +30,45 @@ port setAllProgress : ( String, Int ) -> Cmd msg
 
 
 port scrollToElem : String -> Cmd msg
+
+
+port saveUiSettings : ( AuthResult, UiSettings ) -> Cmd msg
+
+
+port receiveUiSettings : (StoredUiSettings -> msg) -> Sub msg
+
+
+port requestUiSettings : ( AuthResult, UiSettings ) -> Cmd msg
+
+
+port uiSettingsSaved : (() -> msg) -> Sub msg
+
+
+onUiSettingsSaved : msg -> Sub msg
+onUiSettingsSaved m =
+    uiSettingsSaved (\_ -> m)
+
+
+storeUiSettings : Flags -> UiSettings -> Cmd msg
+storeUiSettings flags settings =
+    case flags.account of
+        Just ar ->
+            saveUiSettings ( ar, settings )
+
+        Nothing ->
+            Cmd.none
+
+
+loadUiSettings : (UiSettings -> msg) -> Sub msg
+loadUiSettings tagger =
+    receiveUiSettings (Data.UiSettings.mergeDefaults >> tagger)
+
+
+getUiSettings : Flags -> Cmd msg
+getUiSettings flags =
+    case flags.account of
+        Just ar ->
+            requestUiSettings ( ar, Data.UiSettings.defaults )
+
+        Nothing ->
+            Cmd.none