fabrik_forms

The fabrik_forms package is a clean, testable, and UI-agnostic form state management system for Flutter.

It’s designed to support both reactive patterns and integration with any state management solution like BLoC, Riverpod, or Provider.

Installation

Add the package to your pubspec.yaml:

dependencies:
  fabrik_forms: ^0.1.0

Then run:

flutter pub get

Import fabrik_forms in your Dart files:

import 'package:fabrik_forms/fabrik_forms.dart';

---

Getting Started

Create a form with fields and validators:

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

Wrap your UI with FabrikFormBuilder:

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

    return Column(
      children: [
        TextFormField(
          onChanged: (val) => formNotifier.update('email', val),
          decoration: InputDecoration(
            labelText: 'Email',
            errorText: email.visibleError,
          ),
        ),
        TextFormField(
          onChanged: (val) => formNotifier.update('password', val),
          obscureText: true,
          decoration: InputDecoration(
            labelText: 'Password',
            errorText: password.visibleError,
          ),
        ),
        ElevatedButton(
          onPressed: form.isValid ? () => submit(form.values) : null,
          child: const Text('Sign In'),
        ),
      ],
    );
  },
);

---

Built-in Validators

RequiredValidator

RequiredValidator(message: 'This field is required');

MinLengthValidator

MinLengthValidator(min: 6, message: 'Too short');

MaxLengthValidator

MaxLengthValidator(max: 20, message: 'Too long');

EmailValidator

EmailValidator(
  isRequired: true,
  requiredMessage: 'Required',
  invalidMessage: 'Invalid email',
);

PasswordValidator

PasswordValidator(
  requireDigit: true,
  requireUppercase: true,
  requireSpecialChar: true,
);

---

Features

• ✅ Field-level validation with reusable validators
• ✅ Form-level state with .isValid, .isDirty, .isTouched, .values, .errors
• ✅ Notifier-based reactivity
• ✅ Builder widget for clean UI
• ✅ Works with or without a widget tree
• ✅ Fully testable without Flutter widgets