getField IntValue working

ihaskell-display/ihaskell-widgets/MsgSpec.md

 # IPython widget messaging specification version 2
 
+The model implemented is the Model State v8, for ipywidgets 7.4., @jupyter-widgets/base 1.1., and @jupyter-widgets/controls 1.4.*.
+
 > Largely based on: https://github.com/jupyter-widgets/ipywidgets/blob/master/packages/schema/messages.md
 
 > The messaging specification as detailed is riddled with assumptions the IHaskell widget
@@ -29,7 +31,7 @@ The initial state must *at least* have the following fields in the `data.state`
   - `_view_module_version`
   - `_view_name`
 
-You can see more info on the model state of widgets [here](https://github.com/jupyter-widgets/ipywidgets/blob/master/packages/schema/jupyterwidgetmodels.latest.md).
+You can see more info on the model state of widgets [here](https://github.com/jupyter-widgets/ipywidgets/blob/master/packages/schema/jupyterwidgetmodels.v8.md).
 
 > Warning!: By default there are two widgets modules: `@jupyter-widgets/controls` and `@jupyter-widgets/base`.
 

ihaskell-display/ihaskell-widgets/src/IHaskell/Display/Widgets/Common.hs

@@ -281,5 +281,5 @@ nestedObjectLookup :: Value -> [Text] -> Maybe Value
 nestedObjectLookup val [] = Just val
 nestedObjectLookup val (x:xs) =
   case val of
-    Object o -> maybe Nothing (`nestedObjectLookup` xs) $ HM.lookup x o
+    Object o -> (`nestedObjectLookup` xs) =<< HM.lookup x o
     _ -> Nothing

ihaskell-display/ihaskell-widgets/src/IHaskell/Display/Widgets/Int/BoundedInt/IntSlider.hs

@@ -58,7 +58,7 @@ mkIntSlider = do
 instance IHaskellWidget IntSlider where
   getCommUUID = uuid
   comm widget val _ =
-    case nestedObjectLookup val ["sync_data", "value"] of
+    case nestedObjectLookup val ["state", "value"] of
       Just (Number value) -> do
         void $ setField' widget IntValue (Sci.coefficient value)
         triggerChange widget

ihaskell-display/ihaskell-widgets/src/IHaskell/Display/Widgets/Types.hs

@@ -652,10 +652,10 @@ reflect = fromSing
 -- | A record representing a Widget class from IPython from the controls modules
 defaultControlWidget :: FieldType 'S.ViewName -> FieldType 'S.ModelName -> Rec Attr WidgetClass
 defaultControlWidget viewName modelName = (ViewModule =:: "@jupyter-widgets/controls")
-                                   :& (ViewModuleVersion =:: "2.0.0")
+                                   :& (ViewModuleVersion =:: "1.4.0")
                                    :& (ViewName =:: viewName)
                                    :& (ModelModule =:: "@jupyter-widgets/controls")
-                                   :& (ModelModuleVersion =:: "2.0.0")
+                                   :& (ModelModuleVersion =:: "1.4.0")
                                    :& (ModelName =:: modelName)
                                    :& (MsgThrottle =:+ 3)
                                    :& (DisplayHandler =:: return ())