Mastering Redux: Persisting State for a Seamless User Experience

Introduction

Congratulations on creating a React application with Redux! However, you might have noticed a small hiccup—when you refresh the page, the Redux state resets. Fear not! In this guide, we’ll address this issue using Redux Persist, ensuring your application’s state persists through events like page refresh.

Installing Redux Persist

The first step is to install Redux Persist. Open your terminal and run:

npm install redux-persist

Now, let’s change your store.js and index.js files.

Enhancing the Redux Store

In your store.js, import persistReducer, storage, and autoMergeLevel2 from redux-persist. Create a persistedReducer constant, wrapping your original reducer using persistReducer. Define a persistConfig object to instruct Redux Persist on saving and storing your app’s data.

// store.js
import { createStore } from 'redux';
import { persistStore, persistReducer } from 'redux-persist';
import storage from 'redux-persist/lib/storage';
import autoMergeLevel2 from 'redux-persist/lib/stateReconciler/autoMergeLevel2';

const persistConfig = {
  key: 'root',
  storage,
  stateReconciler: autoMergeLevel2,
};

const persistedReducer = persistReducer(persistConfig, rootReducer);

export const configureStore = () => {
  const store = createStore(persistedReducer);
  const persistor = persistStore(store);
  return { store, persistor };
};

Integrating Redux Persist in index.js

In your index.js, import persistStore and PersistGate. Adjust your configureStore call, create a persistor, and wrap your App component in PersistGate.

// index.js
import { persistStore } from 'redux-persist';
import { PersistGate } from 'redux-persist/lib/integration/react';

const { store, persistor } = configureStore();

ReactDOM.render(
  <Provider store={store}>
    <PersistGate persistor={persistor} loading={<div>Loading</div>}>
      <App />
    </PersistGate>
  </Provider>,
  document.getElementById('root')
);

Testing the Persistence

Now, when you refresh your application, your Redux state should persist. Additionally, Redux Persist prevents data loss when navigating between different websites.

Handling Permacrash During Development

While persisting your store is immensely helpful, it can sometimes lead to development challenges. If you encounter a permacrash, delete the persisted data. In Chrome, navigate to the Application tab in the Inspect tool, locate “Local Storage,” and delete the persisted data, typically under the key “persist root.”

With these steps, you’ve mastered persisting your Redux state, ensuring a seamless and robust user experience.

Happy coding! 🚀

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