keyed_form
// LIVE PLAYGROUND

See It Rebuild, Live

A real `KeyedFormController` — the same pure-Dart, zero-Flutter package the whole site talks about — driving plain HTML inputs right here in this page. Type into a field and watch its own rebuild counter move while every other field stays untouched. The panels on the right read the same controller live: the whole draft, the currently visible errors, and which fields have been touched.

// LIVE FORM — type into a field
Namerebuilds: 0
Emailrebuilds: 0
Agerebuilds: 0
Subscribe to the newsletterrebuilds: 0
Planrebuilds: 0
// WATCH — form.value.toMap()
{
  "name": "",
  "email": "",
  "age": null,
  "newsletter": false,
  "plan": "free"
}
// ERRORS — form.visibleErrorKeys
{}
// TOUCHED — form.touched
[]
Total controller notifications: 0 — every keystroke notifies once, but only the field(s) whose slice actually changed rebuild above.