Solving the SharedPreferences Clearing Issue in Flutter Web

Discover how to tackle the `SharedPreferences` auto-clear issue in Flutter Web by serving from production mode.
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Solving the SharedPreferences Clearing Issue in Flutter Web

When developing applications with Flutter Web, you might encounter a frustrating issue: your SharedPreferences are automatically cleared when you close and then relaunch the browser. While this doesn’t happen when you just reload the application, the situation can lead to unexpected data loss and confusion for users. Let’s delve into this problem and explore the solution to ensure your data persists even after the browser is closed.

Understanding the Problem

SharedPreferences is commonly used in Flutter applications to store key-value pairs, allowing for simple data persistence across app sessions. However, in the context of Flutter Web, this persistence behaves differently:

Occurrence of the Issue: Every time you close the browser, the local storage utilized by SharedPreferences can be cleared.

Reload vs. Restart: While reloading the Flutter Web application does not affect SharedPreferences, a complete browser closure does, leading to potential data loss.

This issue can severely impact user experience, especially if your application relies on stored preferences between sessions.

The Solution

Fortunately, there is a straightforward workaround for this problem. The key lies in serving your Flutter application from the production build rather than a development environment. Here’s how to do it:

Step-by-Step Guide

Build Your Web Application for Production:
To ensure your application runs correctly with SharedPreferences, you need to create a production build. You can accomplish this with the following command in your terminal:

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

Serve the Production Build:
After building your application, you will find the generated files inside the build/web directory. To see the changes in effect, serve these files:

You can use any web server to serve the contents of the build/web directory. Popular choices include:

Python HTTP server:

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

Any static file server.

Access Your Application:

Additional Tips

Testing Your Application: Always test your application in production mode before deploying it to ensure that all features, especially SharedPreferences, work as intended.

Consider Browser Settings: Keep in mind that users' browser settings, such as enabling incognito mode or setting preferences for clearing cache/cookies, can still affect data persistence regardless of this solution.

Conclusion

By following these steps, you can effectively resolve the SharedPreferences clearing issue in your Flutter Web application. Serving your app in production mode not only enhances the functionality of SharedPreferences but also prepares your application for a better user experience.

Don’t let browser behaviors hinder your application’s performance – implement this solution and keep your user data safe!