How to Build SPAs With React Suspense

Single Page Applications (SPAs) are increasingly popular due to their ability to deliver a seamless user experience by loading content dynamically without refreshing the entire page. One of the key features in building SPAs with React is React Suspense, which simplifies data fetching. This article delves into the steps required to build SPAs using React Suspense and provides practical insights into its implementation.

Understanding React Suspense

React Suspense is a feature that allows developers to handle asynchronous tasks more gracefully. It helps in managing loading states in applications where data-fetching is involved. With Suspense, you can create components that 'wait' for something before rendering, improving user experience by displaying fallback content while waiting for data.

Setting Up Your React Environment

To begin building SPAs with React Suspense, you first need to ensure that your development environment is set up correctly. Make sure you have Node.js and npm installed. You can create a new React project quickly using Create React App:

npx create-react-app my-spa

Installing React Router

Since SPAs typically handle routing in the client-side, installing React Router is essential. You can do this by running the following command in your project directory:

npm install react-router-dom

React Router will help manage navigation and allow different components to be rendered based on the URL.

Implementing React Suspense

Next, you should implement React Suspense in your application. Start by creating a simple component that fetches data. Here’s an example of how to create a data-fetching component:

import React, { Suspense, lazy } from 'react';
const UserList = lazy(() => import('./UserList'));
function App() {
  return (
    
      User Data
      Loading...}>


  );
}
export default App;

In this code, the UserList component is lazy-loaded. The fallback prop in the Suspense component displays a loading message until the UserList component is fully fetched and ready to render.

Creating the Data Fetching Logic

You need to handle the data fetching logic inside the UserList component. Below is a simple example that fetches user data from an API:

import React, { useEffect, useState } from 'react';
const UserList = () => {
  const [users, setUsers] = useState([]);
  
  useEffect(() => {
    const fetchData = async () => {
      const response = await fetch('https://jsonplaceholder.typicode.com/users');
      const data = await response.json();
      setUsers(data);
    };
    
    fetchData();
  }, []);
  
  return (
    
      {users.map(user => (
        {user.name}
      ))}
    
  );
};
export default UserList;

This component fetches user data from an external API and stores it using the useState hook. When the data is retrieved, it renders the list of users.

Improving User Experience with Error Boundaries

While React Suspense handles loading states, it's also critical to manage error states. You can use Error Boundaries to catch errors in rendering. Here’s a basic implementation:

import React from 'react';
class ErrorBoundary extends React.Component {
  constructor(props) {
    super(props);
    this.state = { hasError: false };
  }
static getDerivedStateFromError(error) {
    return { hasError: true };
  }
componentDidCatch(error, errorInfo) {
    console.error('Error caught in Error Boundary:', error, errorInfo);
  }
render() {
    if (this.state.hasError) {
      return Something went wrong.;
    }
return this.props.children; 
  }
}

You can implement this ErrorBoundary in your main component to handle scenarios where errors occur during data fetching or rendering.

Finalizing Your SPA

Now that you have the core components in place, you can build out your SPA further. Consider adding routing functionality using React

How to Build SPAs With React Suspense