Form Schema Versioning

Emma uses a snapshot-based approach to versioning forms, which provides a simple yet powerful way to manage changes over time.

Snapshots

Every time you edit a form, Emma creates a new, immutable snapshot of the form’s schema. Each snapshot is identified by a timestamp and is stored as a separate asset in your R2 bucket. This means that every version of your form is independently deployable.

Viewing Form History

You can view the history of a form, including all its snapshots, using the emma history command:

emma history my-contact-form

This will display a list of all the snapshots for the specified form, along with their timestamps and a summary of the changes.

Deploying a Specific Snapshot

By default, emma deploy deploys the latest snapshot of a form. However, you can deploy a specific snapshot using the --snapshot option:

emma deploy my-contact-form --snapshot <timestamp>

This allows you to easily roll back to a previous version of a form if needed.

Breaking Changes

For minor changes, such as updating a field label or a validation message, you can simply edit the form to create a new snapshot. For major changes, such as adding or removing a required field, it is recommended to create a new form to avoid data inconsistencies.