statecraft

🎯 Elegant, lightweight state handling for Flutter and flutter_bloc.

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statecraft provides simple yet powerful state models (AsyncState<T>, FormState<T>) that you can use in your Flutter apps, especially with flutter_bloc, Cubit, or any state management solution.

It removes boilerplate and helps you manage async operations (loading, success, failure) and form states cleanly.

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🚀 Features

• Typed AsyncState<T> and FormState<T> sealed classes
• Built-in when, maybeWhen, and whenOrNull APIs
• Designed for Dart 3 (sealed, final classes)
• Extremely lightweight (no code generation, no dependencies)
• Perfect companion for flutter_bloc and Cubit
• Fully extensible — Pagination state coming soon!

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📦 Installation

dart pub add statecraft

or manually in your pubspec.yaml:

dependencies:
  statecraft: ^0.1.0

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✨ Philosophy

Handling asynchronous states in Flutter is a repetitive task.Typically you create:

• Loading State
• Success State
• Error State

for every BLoC manually. This leads to boilerplate and messy switch-cases.

statecraft solves this by providing unified AsyncState you can reuse everywhere.

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🧩 Usage with flutter_bloc

Here’s a complete real-world example using AsyncState<T>:

1. Define your Cubit

import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:statecraft/statecraft.dart';

class ExampleCubit extends Cubit<AsyncState<String>> {
  final ExampleRepository repository;

  ExampleCubit(this.repository) : super(const AsyncInitial());

  Future<void> fetchData() async {
    emit(const AsyncLoading());
    try {
      final result = await repository.loadExampleData();
      emit(AsyncSuccess(result));
    } catch (e) {
      emit(AsyncFailure(e.toString()));
    }
  }
}

2. Use it in your Flutter Widget

import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:statecraft/statecraft.dart';

class ExampleScreen extends StatelessWidget {
  const ExampleScreen({super.key});

  @override
  Widget build(BuildContext context) {
    return BlocProvider(
      create: (_) => ExampleCubit(ExampleRepository()),
      child: Scaffold(
        appBar: AppBar(title: const Text('Async Example')),
        body: BlocBuilder<ExampleCubit, AsyncState<String>>(
          builder: (context, state) {
            return state.when(
              initial: () => const Center(child: Text('Press the button to load data')),
              loading: () => const Center(child: CircularProgressIndicator()),
              success: (data) => Center(child: Text('Result: $data')),
              failure: (error) => Center(child: Text('Failed: $error')),
            );
          },
        ),
        floatingActionButton: FloatingActionButton(
          onPressed: () => context.read<ExampleCubit>().fetchData(),
          child: const Icon(Icons.download),
        ),
      ),
    );
  }
}

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✨ AsyncState Lifecycle

State	Meaning
AsyncInitial	The initial idle state before anything starts
AsyncLoading	Represents an ongoing async operation
AsyncSuccess<T>	Represents a successful operation with T data
AsyncFailure	Represents a failure with an error message

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✨ FormState Lifecycle

Use FormState<T> to handle user form submission flows — from untouched to submission, success, or error.

State	Meaning
FormInitial	Form has not been submitted yet
FormSubmitting	Submission in progress
FormSuccess<T>	Submitted successfully, with result data
FormFailure	Submission failed with error message

🔄 Example: Form Cubit

class ProfileFormCubit extends Cubit<FormState<Profile>> {
  ProfileFormCubit() : super(const FormInitial());

  Future<void> submit(String name) async {
    emit(const FormSubmitting());
    try {
      await Future.delayed(const Duration(seconds: 2));
      emit(FormSuccess(Profile(name: name)));
    } catch (_) {
      emit(FormFailure('Submission failed.'));
    }
  }
}

🧱 In your Widget

BlocBuilder<ProfileFormCubit, FormState<Profile>>(
  builder: (context, state) {
    return Column(
      mainAxisAlignment: MainAxisAlignment.center,
      children: [
        state.when(
          initial: () => const Text('Please submit the form'),
          submitting: () => const CircularProgressIndicator(),
          success: (profile) => Text('Welcome ${profile.name}'),
          failure: (error) => Text('Error: $error'),
        ),
        const SizedBox(height: 16),
        ElevatedButton(
          onPressed: () => context.read<ProfileFormCubit>().submit('Samfan'),
          child: const Text('Submit'),
        ),
      ],
    );
  },
);

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📜 API Overview

All states expose:

• when — handle every case explicitly
• maybeWhen — handle some cases, fallback with orElse
• whenOrNull — handle only what you need, ignore others

Example:

state.maybeWhen(
  success: (data) => Text('Loaded: $data'),
  orElse: () => const CircularProgressIndicator(),
);

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🚧 Roadmap

• x AsyncState<T> – async loading/success/failure
• x FormState<T> – form submission lifecycle ✅
• PaginationState<T> – for infinite scroll & pagination

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📃 License

MIT License — free to use for personal or commercial projects.

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🌟 Why use statecraft?

• Stop writing Loading/Loaded/Error states manually.
• Smaller, readable, and reusable BLoC/Cubit logic.
• Type-safe state management with zero boilerplate.
• Grows with your app: Async, Form, Pagination states.

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Made with ❤️ for Flutter devs who love BLoC.