Скачать или смотреть How to Dynamically Render a User's Name in Your React Navbar with JWT Handling

Learn how to display a user's name dynamically in your React Navbar while managing `JWT` for persistent login. This guide provides a step-by-step guide to help you achieve that.
---
This video is based on the question https://stackoverflow.com/q/70921396/ asked by the user 'jmvaswani' ( https://stackoverflow.com/u/17990041/ ) and on the answer https://stackoverflow.com/a/70921451/ provided by the user 'moshfiqrony' ( https://stackoverflow.com/u/9418800/ ) 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: Dynamic welcome user of navbar in reactJs

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.
---
Dynamic Welcome Messages in React: Displaying User Name in Navbar

If you're building a React application that requires user authentication, a common feature is to display a personalized welcome message in the Navbar. For example, displaying "Welcome, <user>" when a user is logged in enhances user experience. However, as you delve deeper into implementing this feature, you might encounter some challenges, especially regarding how to manage user authentication tokens like JWT (JSON Web Token) without unnecessarily re-rendering your entire application.

In this guide, we'll explore a solution for dynamically rendering the logged-in user's name in the Navbar of a React application while maintaining persistent login state using JWT.

The Challenge

In your React app structure, you have the following layout:

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

Current Approaches Considered

You've mentioned a few strategies to achieve the desired outcome, but you're concerned about re-rendering:

Passing as Props: Sending the user’s name into the Header as a prop is a straightforward approach. However, this method will require you to update the App state, leading to a complete re-render of the App component.

Using Redux: Storing the username in Redux allows the Header component to subscribe to changes. Since JWT needs persistent state across page refreshes, there might be concerns regarding the loss of data when using Redux if not managed properly.

Local Storage: Using local storage to keep the username can persist it across refreshes; however, the entire app still may need re-rendering to reflect the changes effectively.

Alternative and Effective Solution

Here’s a structured method to keep the user logged in and display their name without unnecessary re-renders:

Step 1: Store JWT in Local Storage

To maintain the user's state across sessions, the JWT should be saved in local storage. Here is how you can effectively manage it:

When a user logs in, save the JWT and the username to both your local storage and your Redux store if you are using it.

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

Step 2: Set Initial State from Local Storage

When your application initializes, retrieve the username from local storage. This will allow you to set the initial state of the user effectively:

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

This setup checks if there is a username already stored in the local storage. If it exists, it populates the state, indicating that the user is logged in.

Step 3: Handling Logout

When the user logs out, make sure to clean up data from both the local storage and the Redux state:

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

By doing this, you ensure that the Navbar will correctly display “Welcome, null” or simply nothing when the user is logged out.

Conclusion

Managing dynamic welcome messages based on user authentication in React can be straightforward when using local storage to maintain a persistent state. This approach ensures that you can easily retrieve and display the user's name in the Navbar without unnecessary re-renders of your app. With JWT handling and careful state management, you're now equipped to provide a seamless experience for your users.

Happy coding, and feel free to reach out if you have any further queries or need clarification on this subject!