How to enforce storage limits for a user

In this guide, we'll show you how to set up storage limits for user uploads in your Xano application. This is a useful feature if you want to prevent users from consuming too much storage space with their uploads. We'll walk through the steps using a sample table called "uploads" that stores user uploads.

Step 1: Set Up the Uploads Table

First, let's create a table to store user uploads. In the Xano console, navigate to the Data section and create a new table called "uploads." Add the following columns:

• `userid` (Reference to User): This column will store a reference to the user who uploaded the file.
• `document` (Attachment): This column will store the uploaded file itself.

Step 2: Create a CRUD Endpoint for Uploads

Next, we'll create a CRUD (Create, Read, Update, Delete) endpoint to handle user uploads. Go to the API section in the Xano console and create a new CRUD endpoint called "uploads."

Step 3: Limit Storage for Authenticated Users

In the POST method of the "uploads" CRUD endpoint, we'll add the logic to enforce the storage limit for authenticated users. Here's how:

1. Get the Existing Storage Used by the User

We'll query the "uploads" table to get the sum of the sizes of all documents uploaded by the authenticated user. Add the following code in the POST method:

This query selects all records from the "uploads" table where the `userid` matches the authenticated user's ID, and then calculates the sum of the `document.size` values.

1. Check the Total Storage Against the Limit

Next, we'll add a precondition to check if the total storage (existing storage + new upload size) exceeds the desired limit. Replace the existing precondition in the POST method with the following code:

Here, we're checking if the sum of the existing storage and the size of the new upload is less than or equal to 10000000 bytes (10MB). If the condition is false, it will throw an error with the message "You have reached your storage limit."

Note: You can adjust the limit value (10000000 in this example) based on your requirements.

1. Create the Record

If the precondition passes, the record will be created with the uploaded file. The existing code for creating the record should work as-is.

That's it! Now, when an authenticated user tries to upload a file that would exceed their storage limit, they'll receive the "You have reached your storage limit" error. Otherwise, the upload will be successful.

Conclusion

By following these steps, you've learned how to enforce storage limits for user uploads in your Xano application. This feature ensures that users don't consume too much storage space, helping you manage your application's resources effectively. Feel free to customize the storage limit and error message to suit your application's needs.