Flutter Forms and Validation

class ContactForm extends StatefulWidget {
  const ContactForm({super.key});

  @override
  State<ContactForm> createState() => _ContactFormState();
}

class _ContactFormState extends State<ContactForm> {
  final _formKey = GlobalKey<FormState>();

  @override
  Widget build(BuildContext context) {
    return Form(
      key: _formKey,
      child: Column(
        children: [
          TextFormField(
            decoration: InputDecoration(labelText: 'Name'),
            validator: (value) =>
                value == null || value.isEmpty ? 'Enter a name' : null,
          ),
          TextFormField(
            decoration: InputDecoration(labelText: 'Email'),
            keyboardType: TextInputType.emailAddress,
            validator: (value) {
              if (value == null || value.isEmpty) return 'Enter email';
              if (!value.contains('@')) return 'Invalid email';
              return null;
            },
          ),
          ElevatedButton(
            onPressed: () {
              if (_formKey.currentState!.validate()) {
                ScaffoldMessenger.of(context).showSnackBar(
                  SnackBar(content: Text('Form submitted!')),
                );
              }
            },
            child: Text('Submit'),
          ),
        ],
      ),
    );
  }
}