Unlocking the Power of Cached Data: A Step-by-Step Guide to Using useLazyQuery in RTK Query

Are you tired of repeatedly fetching data from your server, only to end up with a slow and sluggish application? Do you wish there was a way to harness the power of cached data to boost performance and user experience? Look no further! In this comprehensive guide, we’ll dive into the world of RTK Query and explore how to use cached data in a different component using the `useLazyQuery` hook.

What is RTK Query?

RTK Query is a data fetching and caching library for React applications. It provides a robust and efficient way to manage data fetches, caching, and retries. By leveraging the power of caching, you can significantly reduce the number of network requests, improve performance, and provide a seamless user experience.

What is useLazyQuery?

The `useLazyQuery` hook is a part of the RTK Query library that allows you to fetch data lazily, i.e., only when it’s actually needed. This hook is particularly useful when you need to fetch data in a component that’s not immediately rendered or when you want to fetch data conditionally. By using `useLazyQuery`, you can delay data fetching until the component is rendered or a specific condition is met.

The Problem: Sharing Cached Data Across Components

One of the common challenges in using RTK Query is sharing cached data across different components. By default, RTK Query caches data per-component, which means that each component has its own cache. This can lead to duplicate data fetches and wasted resources.

But fear not! With `useLazyQuery`, you can overcome this limitation and share cached data across components. In this guide, we’ll explore how to do just that.

Step 1: Create an RTK Query API

To get started, you need to create an RTK Query API that defines the endpoints for your data fetches. In this example, we’ll create a simple API that fetches a list of users.

import { createApi, fetchBaseQuery } from '@reduxjs/toolkit/query/react';

const api = createApi({
  reducerPath: 'api',
  baseQuery: fetchBaseQuery({ baseUrl: 'https://example.com/api' }),
  endpoints: (builder) => ({
    getUsers: builder.query({
      query: () => '/users',
    }),
  }),
});

export const { useGetUsersQuery } = api;

Step 2: Create a Component that Fetches Data with useLazyQuery

Next, create a component that fetches the list of users using the `useLazyQuery` hook. In this example, we’ll create a `UsersList` component that fetches the users when the component is rendered.

import React from 'react';
import { useGetUsersQuery } from './api';

const UsersList = () => {
  const { data, error, isLoading } = useGetUsersQuery();

  if (isLoading) {
    return 
Loading...
;
  }

  if (error) {
    return 
Error: {error.message}
;
  }

  return (
    

{data.map((user) => (
• {user.name}
))}

); }; export default UsersList;

Step 3: Create a Component that Uses Cached Data

Now, let’s create a component that uses the cached data fetched by the `UsersList` component. In this example, we’ll create a `UserProfile` component that displays the user profile information.

import React from 'react';
import { useGetUsersQuery } from './api';

const UserProfile = ({ userId }) => {
  const { data } = useGetUsersQuery();

  if (!data) {
    return 
User not found
;
  }

  const user = data.find((user) => user.id === userId);

  if (!user) {
    return 
User not found
;
  }

  return (
    

      
{user.name}
      
{user.email}
    
  );
};

export default UserProfile;

How it Works

Here’s what’s happening behind the scenes:

• The `UsersList` component fetches the list of users using the `useLazyQuery` hook.
• RTK Query caches the fetched data in the component’s cache.
• The `UserProfile` component uses the same `useGetUsersQuery` hook to fetch the users.
• RTK Query checks the cache and finds the cached data fetched by the `UsersList` component.
• RTK Query returns the cached data to the `UserProfile` component, bypassing the network request.

Benefits of Using Cached Data

By using cached data, you can:

• Reduce the number of network requests, improving application performance.
• Improve user experience by providing faster data access.
• Reduce server load and bandwidth usage.
• Enable offline support by storing data locally.

Best Practices for Using Cached Data

To get the most out of cached data, follow these best practices:

• Use caching for frequently accessed data.
• Implement cache invalidation strategies to ensure data freshness.
• Use cache headers to control cache behavior.
• Monitor cache performance and optimize as needed.

Conclusion

In this guide, we’ve explored the world of RTK Query and discovered how to use cached data in a different component using the `useLazyQuery` hook. By leveraging the power of caching, you can create faster, more efficient, and more scalable React applications. Remember to follow best practices for using cached data and optimize your cache performance for maximum benefit.

Happy coding!

Keyword	Description
RTK Query	A data fetching and caching library for React applications.
useLazyQuery	A hook that allows you to fetch data lazily, i.e., only when it’s actually needed.
Cached Data	Data that’s stored locally in the component’s cache, reducing the need for network requests.

Frequently Asked Question

Get ready to dive into the world of caching and efficient data fetching with RTK Query! Here are the top 5 FAQs on how to use cached data in a different component using useLazyQuery.