class EventForm extends StatefulWidget {
  @override
  State<EventForm> createState() => _EventFormState();
}

class _EventFormState extends State<EventForm> {
  final _formKey = GlobalKey<FormState>();
  final _titleController = TextEditingController();

  @override
  void dispose() {
    _titleController.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Form(
      key: _formKey,
      child: TextFormField(
        controller: _titleController,
        validator: (v) => v!.isEmpty ? 'Required' : null,
        textInputAction: TextInputAction.done,
      ),
    );
  }
}

// Sync
validator: (value) {
  if (value == null || value.isEmpty) return 'Required';
  if (value.length < 3) return 'Min 3 characters';
  return null;
}

// Email
validator: (value) {
  final regex = RegExp(r'^[^@]+@[^@]+\.[^@]+$');
  if (!regex.hasMatch(value!)) return 'Invalid email';
  return null;
}

TextFormField(
  textInputAction: TextInputAction.next,
  onFieldSubmitted: (_) => FocusScope.of(context).nextFocus(),
)

TextFormField(
  textInputAction: TextInputAction.done,
  onFieldSubmitted: (_) => _submit(),
)

TextInputType.emailAddress
TextInputType.phone
TextInputType.number
TextInputType.multiline

AutofillGroup(
  child: Column(
    children: [
      TextFormField(autofillHints: [AutofillHints.email]),
      TextFormField(autofillHints: [AutofillHints.password], obscureText: true),
    ],
  ),
)