Скачать или смотреть How to Fix the render() Function Issues in React Authentication Forms

Discover why your React `render()` function may render unwanted components and learn how to effectively manage loading states for a better user experience in your authentication flows.
---
This video is based on the question https://stackoverflow.com/q/62850240/ asked by the user 'Soham Gadhave' ( https://stackoverflow.com/u/11281658/ ) and on the answer https://stackoverflow.com/a/62850639/ provided by the user 'Grey' ( https://stackoverflow.com/u/5689172/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: render() fucntion not working properly in react

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l...
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Understanding the Problem

Are you working with a React application using the MERN stack, and you've noticed that your render() function is behaving strangely? Specifically, when users visit the /login route after already being authenticated, the login form momentarily flashes before redirecting to the /products page? This is a common issue developers face when handling user authentication states. It can be frustrating, as it disrupts the user experience.

In this guide, we’ll offer a structured solution to this problem by managing component rendering effectively based on authentication states. Let’s dive into how to enhance your React component to ensure that your users don’t see the login form if they’re already logged in.

The Core of the Issue

The underlying problem happens because of the asynchronous nature of your API calls. When you first hit the /login route, your component is mounted and your componentDidMount() function is triggered—this function checks the user’s logged-in status by making an API call to the backend. Before this call completes, the initial render still takes place, which means the login form is displayed momentarily even if the user is authenticated.

The Current Implementation

Let’s look at the current structure of the relevant parts of the code:

[[See Video to Reveal this Text or Code Snippet]]

The code above checks if the user is logged in, but due to the timing of API calls, it results in a flickering effect of the login form.

The Solution: Adding a Loading State

To resolve this, we will introduce an additional state property to manage a loading status. This will allow us to prevent rendering the login form until we have confirmation about the user’s authentication status.

Step-by-Step Implementation

Update Component State: Add a loading state to track if your authentication check is in progress.

[[See Video to Reveal this Text or Code Snippet]]

Modify the getLoggedInStatus Method: Update the state after checking logged-in status, and set loading to false once the check is complete.

[[See Video to Reveal this Text or Code Snippet]]

Update the render Method: Modify the render logic to account for the loading state so that you can show a loading indicator while the status is being fetched.

[[See Video to Reveal this Text or Code Snippet]]

Benefits of This Approach

User Experience: The loading state provides users with immediate feedback, rather than displaying a flicker of the login form.

Code Clarity: This clear division of rendering logic for loading and state-driven conditions makes the code easier to read and maintain.

Conclusion

Incorporating a loading state in your React components can significantly improve user experience by removing unwanted flickers in the user interface and guiding the user through the authentication process seamlessly. Following these steps will ensure your application behaves as expected when users navigate between logged-in and logged-out states.

By addressing potential issues directly and implementing clear solutions, you can enhance the quality of your applications and maintain a smooth user experience. Happy coding!