Form validation and progressive enhancement

Validate where it counts, enhance where it helps

Client-side validation is a convenience for the user. Server-side validation is the one that protects your data, because the client one can simply be skipped. Parse the submitted form data against a schema at the top of the action and return structured errors when it fails.

Because a form wired to a Server Action submits as an ordinary HTML form, it works before the page has hydrated. That is real progressive enhancement rather than a slogan: a slow connection degrades to a full page submit instead of a dead button.

Pending state comes from the framework hooks rather than from your own state variable, which keeps it correct when a submission is interrupted or replayed.