fabrik_forms #

A clean, UI-agnostic form state and validation system for Flutter.

What's included #

Installation #

dependencies:
  fabrik_forms: ^0.1.0

flutter pub get

Usage #

Setting up a form #

final formNotifier = FabrikFormNotifier<String>(
  FabrikForm({
    'email': FabrikField(
      value: '',
      validators: [const EmailValidator()],
    ),
    'password': FabrikField(
      value: '',
      validators: [
        const PasswordValidator(
          requireDigit: true,
          requireSpecialChar: true,
        ),
      ],
    ),
  }),
);

Building the UI #

FabrikFormBuilder<String>(
  formNotifier: formNotifier,
  builder: (context, form, get) {
    final emailField = get<String>('email');
    final passwordField = get<String>('password');

    return Column(
      children: [
        TextField(
          onChanged: (val) => formNotifier.update('email', val),
          decoration: InputDecoration(
            labelText: 'Email',
            errorText: emailField.visibleError,
          ),
        ),
        TextField(
          onChanged: (val) => formNotifier.update('password', val),
          obscureText: true,
          decoration: InputDecoration(
            labelText: 'Password',
            errorText: passwordField.visibleError,
          ),
        ),
        ElevatedButton(
          onPressed: () {
            if (formNotifier.isValid) {
              // submit formNotifier.values
            } else {
              formNotifier.markAllTouched(); // reveal all errors
            }
          },
          child: const Text('Sign In'),
        ),
      ],
    );
  },
);

Resetting a form #

// Restore all fields to initial values and clear touched/dirty state
formNotifier.reset();

Validators #

RequiredValidator #

RequiredValidator()
RequiredValidator(message: 'Name is required', trim: false)

EmailValidator #

EmailValidator()                          // required by default
EmailValidator(isRequired: false)         // optional — empty is valid
EmailValidator(invalidMessage: 'Bad email')

MinLengthValidator / MaxLengthValidator #

MinLengthValidator(min: 3)
MaxLengthValidator(max: 50, message: 'Keep it under 50 chars')

PasswordValidator #

PasswordValidator()                          // requires 8+ chars, non-empty
PasswordValidator(isRequired: false)         // optional password
PasswordValidator(
  minLength: 12,
  requireUppercase: true,
  requireDigit: true,
  requireSpecialChar: true,
)

UrlValidator #

UrlValidator()                          // accepts http and https
UrlValidator(requireHttps: true)        // https only
UrlValidator(isRequired: false)         // optional — empty is valid

PhoneValidator #

PhoneValidator()                        // required by default
PhoneValidator(isRequired: false)       // optional — empty is valid
// Accepts: +1 234 567 8900 · (123) 456-7890 · 123-456-7890 · 1234567890

RangeValidator #

RangeValidator(min: 1, max: 100)
RangeValidator(min: 0.0, max: 1.0, minMessage: 'Too low', maxMessage: 'Too high')

Custom validators #

class UsernameValidator extends FabrikValidator<String> {
  const UsernameValidator();

  @override
  String? call(String value) {
    if (value.contains(' ')) return 'No spaces allowed';
    return null;
  }
}

Field metadata #

Documentation #

Full API reference and guides at fabriktool.com

Contributing #

Found a bug or have a suggestion? Open an issue or pull request on GitHub.

Maintainers #

• Ashish Bhakhand