Error Handling in Server-Side Rendering: A Comprehensive Guide

The Importance of Error Handling in SSR Apps

An application that handles errors gracefully will enable the flow of known or unknown errors in a controlled manner, helping both users and developers to identify and fix issues without blocking the app’s process. With SSR applications having both a client and server side, it’s essential to know how to handle errors on both ends to create a complete end-to-end error handling system.

Client-Side Error Handling: Catching Errors and Notifying Users

On the client side, try…catch blocks help catch errors in asynchronous calls, allowing you to notify users of potential errors and send them up via an error service. Interceptors for network errors, such as Axios, can also be used to handle errors in your app.

try {
  // Asynchronous call
} catch (error) {
  // Notify user and send error to error service
}

Additionally, tools like react-error-boundary in React and Vue.js’s errorCaptured hook provide a way to gracefully handle errors that occur in specific contexts.

Server-Side Error Handling: Catching Errors and Returning Status Codes

On the server side, catching errors in data fetchers is crucial. The early return pattern helps ensure that you can render pages correctly even if there’s an error during the request.

function fetchData() {
  try {
    // Data fetching logic
  } catch (error) {
    return {
      props: {},
      status: 500
    };
  }
}

In Next.js, you can use the getInitialProps function to handle errors, while in Nuxt.js, the fetch and asyncData hooks provide a way to handle errors. Error status codes, such as 400-500, should also be caught and logged, and redirecting to error pages can help provide a better user experience.

Handle and Log Everything: The Key to End-to-End Error Handling

In an SSR environment, it’s essential to handle and log errors from end to end, including middleware and serverMiddlewares in Nuxt or Next.js. This allows you to drill down to the origin and root cause of errors.

• Use a log engine to extract logs and analyze them in real-time.
• Report and log errors from all parts of the application.
• Implement error tracking and monitoring tools.

Modern Frameworks Make Error Handling Easier

Fortunately, modern frameworks like Next.js and Nuxt.js provide simple steps to handle errors, making it easier to create an elegant end-to-end error handling process in your app. By following best practices for client-side and server-side error handling, you can ensure that your SSR app is robust, efficient, and provides a great user experience.