What is Redux persist?

Key takeaways:

• Redux persist is a library that allows React and Redux applications to maintain the Redux store’s state across page reloads or app restarts, enhancing the user experience.

• It saves the Redux state to a storage backend like localStorage, AsyncStorage, or IndexedDB, enabling the application to rehydrate its state on startup.

• Users must install Redux persist and the desired storage backend to set it up in their project.

• The option for configuration are:

1. PersistConfig: Specifies options such as the storage key (e.g., 'root') under which the persisted state is saved.

2. PersistReducer: Enhances the rootReducer to handle state persistence automatically.

3. Persistor Object: Created using persistStore; it manages saving and restoring the state.

Redux persist is a library used in React and Redux applications to persist and rehydrateRehydrate refers to the process of restoring the Redux store's state from a previously persisted state after the page reloads or the app restarts. the Redux store’s state across page reloads or app restarts. It’s particularly useful in scenarios where we want to maintain the application’s state even after the user refreshes the page or closes and reopens the app.

Redux persist works by saving the Redux store state to a storage backend (such as localStorage, AsyncStorage, or IndexedDB) and then rehydrating the state from that storage when the application initializes.

Here’s a breakdown of how Redux persist works:

1. Installation: First, we need to install Redux persist and the storage backend we want to use. Let’s install Redux-persist along with localStorage as the storage backend:

2. Configuration: After installing Redux persist, we need to configure it in our Redux store setup. We typically create a persistor object using the persistStore function and pass it to our Redux store and configuration options.

Here’s an example of how we can configure Redux persist in our Redux store:

In this example:

• persistConfig specifies the configuration options for Redux persist. Here, the key is set as 'root', which is the key under which the persisted state will be stored in the chosen storage backend (localStorage by default, as storage is imported from redux-persist/lib/storage).

• persistReducer takes the rootReducer and the persistConfig and returns a new reducer that automatically manages to persist the state to storage and rehydrate (restore) the state into the Redux store when the app reloads.

• configureStore is used to create the Redux store. It simplifies setting up the store by automatically including common middleware, such as Redux DevTools and Thunk. The persistedReducer is passed as the reducer, and the middleware is customized by disabling the serializableCheck because Redux persist may handle non-serializable values (like the store state) that would otherwise trigger warnings.

• persistStore creates a persistor object, which is responsible for controlling the persistence of the Redux store. This object ensures that the state is both saved (persisted) and restored (rehydrated) when the application is reloaded or restarted.

3. Integration: Now that our Redux store is configured with Redux persist, we can integrate it into our React application. Typically, we would wrap our root component with the PersistGate component provided by Redux persist. This ensures our app doesn’t render until the persisted state has been retrieved and saved to the Redux store.

Here’s how we can integrate Redux persist into our React app:

In this integration:

• The Provider component from the react-redux library wraps our entire application, providing access to the Redux store for all components.

• The PersistGate component ensures that our app doesn’t render (loading={null}) until the persisted state has been retrieved and saved to the Redux store. It takes the persistor object we created earlier as a prop.

With Redux persist configured and integrated into our Redux store and React application, our Redux state will now persist across page reloads and app restarts, providing a seamless user experience. Take the quiz below to assess your understanding of the above concepts.

Quiz

Test your knowledge about Redux persist:

Conclusion

In conclusion, Redux persist is an invaluable tool for enhancing the user experience in React and Redux applications by ensuring that the application state is maintained across page reloads and app restarts. By saving the Redux store’s state to a chosen storage backend and rehydrating it on initialization, developers can create more resilient and user-friendly applications. With straightforward installation, configuration, and integration processes, Redux persist simplifies state management, allowing users to enjoy a seamless experience without the fear of losing their data. Implementing Redux persist is a strategic choice for any developer looking to improve the reliability of their application’s state handling.