Try to cache state

src/Provider.tsx

@@ -5,7 +5,7 @@ import { Provider as ReduxProvider } from 'react-redux';
 
 import { ER_INTERN_FLATE } from './constant';
 import FeatureToggle from './moduler/feature/FeatureToggle';
-import createStore from './store';
+import createStore, { getPreloadedStoreFromSessionStorage } from './store';
 
 interface Props {
     children: React.ReactNode;
@@ -33,7 +33,9 @@ const Provider = ({ children, setFnrRef, fnr: propFnr }: Props) => {
         };
     }, []);
 
-    const store = useMemo(createStore, [fnr]);
+    const store = useMemo(() => {
+        return createStore(getPreloadedStoreFromSessionStorage());
+    }, [fnr]);
 
     return (
         <FnrContext.Provider value={fnr}>

src/moduler/dialog/DialogFlateUtils.ts

@@ -1,6 +1,7 @@
 import { MouseEvent } from 'react';
 
 import { ARBEIDSRETTET_DIALOG_URL } from '../../constant';
+import { saveReduxStateToSessionStorage } from '../../store';
 
 interface DialogEventDetails {
     dialogId?: string;
@@ -18,14 +19,15 @@ export const byttTilDialogFlate = ({
     dialogId?: string;
 }) => {
     event.preventDefault();
+    saveReduxStateToSessionStorage();
     window.history.pushState('', 'Dialog', getDialogLenke({ erVeileder: true, aktivitetId, dialogId }));
     window.dispatchEvent(
         new CustomEvent<DialogEventDetails>('visDialog', {
             detail: {
                 dialogId: dialogId,
                 aktivitetId: aktivitetId,
             },
-        })
+        }),
     );
 };
 

src/store.ts

@@ -1,13 +1,39 @@
 import { configureStore } from '@reduxjs/toolkit';
 
 import reducer from './reducer';
+import { EnhancedStore } from '@reduxjs/toolkit/src/configureStore';
 
-const createStore = () =>
-    configureStore({
+type Store = ReturnType<typeof createStore>;
+
+let store: EnhancedStore | null = null;
+const createStore = (preloadedState: any = undefined): EnhancedStore => {
+    const newStore: EnhancedStore = configureStore({
         reducer: reducer,
+        preloadedState,
     });
+    store = newStore;
+    return newStore;
+};
+
+const key = 'aktivitetsplan-state';
+export const getPreloadedStoreFromSessionStorage = (): Store | undefined => {
+    const serializedState = sessionStorage.getItem(key);
+    if (serializedState) {
+        try {
+            console.log('Cache hit');
+            return JSON.parse(serializedState);
+        } catch (e) {
+            console.warn(e);
+            return undefined;
+        }
+    }
+    return undefined;
+};
+export const saveReduxStateToSessionStorage = () => {
+    const state = JSON.stringify(store?.getState());
+    sessionStorage.setItem(key, JSON.stringify(state));
+};
 
-type Store = ReturnType<typeof createStore>;
 export type RootState = ReturnType<Store['getState']>;
 export type Dispatch = Store['dispatch'];