Verifying Uploaded File Type

Hey there! In this blog post, we'll walk through a simple yet effective way to verify file types before uploading them to your Xano workspace. This process ensures that only the desired file types are stored in your Xano files library, preventing any unwanted file types from sneaking in.

Why Verify File Types?

Imagine you're building an application that allows users to upload XML files for data processing. However, without proper verification, users might accidentally (or intentionally) upload other file types, like images or documents, which could cause issues with your application's functionality or even create potential security risks.

By implementing file type verification, you can ensure that only the intended file types are accepted and processed by your application, providing a smoother user experience and protecting your application's integrity.

Step 1: Get File Resource Data

The first step is to obtain the file resource data, which includes the file's contents, name, size, and most importantly, the file type. In Xano, you can achieve this using the `GetFileResourceData` function:

Here, `file_upload` is the input field where the user selects the file they want to upload.

Step 2: Check the MIME Type

Once you have the file resource data, you can access the MIME type (a standardized way to identify file types) and compare it against the desired file type(s) using a conditional statement.

In the example demonstrated in the video, the goal is to accept only XML files. The conditional statement checks if the MIME type matches the string `"application/xml"`:

You can modify the MIME type string to match the file type(s) you want to accept in your application.

Step 3: Store the File (or Handle Invalid Types)

If the file type is valid (i.e., the MIME type matches your desired file type), you can proceed with storing the file in your Xano files library and any additional processing required.

On the other hand, if the file type is invalid, you can stop the function and handle the situation accordingly. This could involve displaying an error message to the user, logging the attempt, or taking any other appropriate action based on your application's requirements.

Conclusion

By following these simple steps, you can easily implement file type verification in your Xano applications, ensuring that only the desired file types are uploaded and processed. This not only enhances the user experience but also helps maintain the integrity and security of your application.

Remember, the example provided in the video focuses on accepting XML files, but you can easily modify the MIME type string to match the file types you need. Additionally, Xano provides a comprehensive list of MIME types, which you can reference to ensure you're using the correct string for the file types you want to allow.

Happy coding, and happy verifying!