Can now reload the Zone page and stay on the same tab.

src/App/Page/Zone.purs

@@ -17,11 +17,15 @@ module App.Page.Zone where
 
 import Prelude (Unit, unit, void
                , bind, pure
-               , not, comparing, discard, map, show
+               , not, comparing, discard, map, show, class Show
-               , (+), (&&), ($), (/=), (<<<), (<>), (==), (>), (#))
+               , (+), (&&), ($), (/=), (<<<), (<>), (==), (>), (#), (=<<))
 
---import Data.Generic.Rep (class Generic)
+import Data.Generic.Rep (class Generic)
---import Data.Show.Generic (genericShow)
+import Data.Show.Generic (genericShow)
+
+import Web.HTML (window) as HTML
+import Web.HTML.Window (sessionStorage) as Window
+import Web.Storage.Storage as Storage
 
 import Data.Eq (class Eq)
 import Data.Array as A
@@ -200,9 +204,9 @@ string_to_acceptedtype str = case str of
 
 data Tab = Zone | TheBasics | TokenExplanation
 derive instance eqTab :: Eq Tab
---derive instance genericTab :: Generic Tab _
+derive instance genericTab :: Generic Tab _
---instance showTab :: Show Tab where
+instance showTab :: Show Tab where
---  show = genericShow
+  show = genericShow
 
 type State =
   { _domain :: String
@@ -520,6 +524,9 @@ handleAction = case _ of
 
   -- | Change the current tab.
   ChangeTab new_tab -> do
+    -- Store the current tab we are on and restore it when we reload.
+    sessionstorage <- H.liftEffect $ Window.sessionStorage =<< HTML.window
+    H.liftEffect $ Storage.setItem "current-zone-tab" (show new_tab) sessionstorage
     H.modify_ _ { current_tab = new_tab }
 
   -- | Create modal (a form) for a resource record to update.
@@ -570,6 +577,16 @@ handleAction = case _ of
     message <- H.liftEffect $ DNSManager.serialize $ DNSManager.MkGetZone { domain: _domain }
     H.raise $ MessageToSend message
 
+    sessionstorage <- H.liftEffect $ Window.sessionStorage =<< HTML.window
+    old_tab <- H.liftEffect $ Storage.getItem "current-zone-tab" sessionstorage
+    case old_tab of
+      Nothing -> pure unit
+      Just current_tab -> case current_tab of
+        "Zone"             -> handleAction $ ChangeTab Zone
+        "TheBasics"        -> handleAction $ ChangeTab TheBasics
+        "TokenExplanation" -> handleAction $ ChangeTab TokenExplanation
+        _  -> H.raise $ Log $ ErrorLog $ "Reload but cannot understand old current_tab: " <> current_tab
+
   -- | Perform validation. In case the record is valid, it is added to the zone then the modal is closed.
   -- | Else, the different errors are added to the state.
   ValidateRR t -> do