How to Resolve Unsupported Path Issues in React Native with Android 10

Discover how to overcome file download path issues in React Native after upgrading to Android 10. Learn about using DownloadManager and public directories effectively.
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Resolving Unsupported Path Issues in React Native on Android 10

If you're developing a mobile application using React Native and have upgraded your targetSDKVersion to 29, you may encounter an issue with downloading files to a custom path. Specifically, many developers have faced the "Unsupported path storage/emulated/0/test" error when attempting to save files. This problem is particularly pronounced when using libraries like rn-fetch-blob after updating to Android 10. In this guide, we’ll break down the issue and explore practical solutions to get your file downloads working seamlessly again.

Understanding the Problem

When you try to download files using a custom directory on the root of external storage, you might find that it no longer works after updating your app's SDK versions. This is due to the significant changes in how Android handles external storage permissions and file access in version 10.

Why Does this Happen?

Storage Permissions Change: With Android 10, Google introduced scoped storage which limits access to the filesystem. This affects how apps can access files stored on the device.

Legacy Support: Adding android:requestLegacyExternalStorage="true" may not always solve the issue, especially when dealing with custom paths.

Solutions to the Unsupported Path Issue

Let’s explore the best workarounds and practices to ensure smooth file downloads in your app.

1. Use Android's DownloadManager

The simplest solution to this problem is to use Android's built-in DownloadManager. It allows you to download files to public directories easily and handles notifications for completed downloads.

How to Implement DownloadManager

Choose a Public Directory: Instead of trying to download files to a custom folder, opt for one of the public storage directories provided by Android, such as:

Environment.DIRECTORY_DOWNLOADS (Downloads)

Environment.DIRECTORY_DOCUMENTS (Documents)

Environment.DIRECTORY_PICTURES (DCIM)

Sample Code Snippet:

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

No Need for Legacy Storage: It’s important to note that when using DownloadManager, you do not need to request legacy external storage, as it complies with the new scoped storage model.

2. Adjust Your Application’s File Saving Strategy

If you require more control over file storage, consider adapting your approach by saving files in app-specific directories rather than relying on external storage.

App-specific Directories: Use application-specific directories, which are accessible without any special permissions:

getFilesDir() for internal storage

getExternalFilesDir() for external storage specific to your app.

This method ensures that files are sandboxed and only accessible by your app, improving both security and stability.

3. Explore Alternative Libraries

If you find that rn-fetch-blob does not meet your needs anymore, consider exploring other libraries or native file management solutions that adhere to Android's new storage policies.

Conclusion

Upgrading to Android 10 brings new challenges to file management in React Native applications, especially when trying to save files to custom paths. By leveraging the DownloadManager and utilizing public directories, you can navigate around the "Unsupported path" issue effectively. Adapt your application to focus on compliant storage strategies to ensure it functions smoothly across all Android versions.

Implement these suggestions to resolve your file download issues, and keep on developing innovative applications with React Native!