bloc

Instalar pacote

flutter pub add bloc

Visão geral do pacote

Orientação gerada a partir de informações públicas. Apenas para referência.

Bloc é uma biblioteca de gerenciamento de estado para Flutter que implementa o padrão de design BLoC (Componente de Lógica de Negócio), promovendo mudanças de estado previsíveis e testáveis. Separa a lógica de negócios da interface do usuário, tornando mais fácil gerenciar estados complexos em aplicativos. Usando streams e sinks, o Bloc permite um tratamento eficiente de eventos assíncronos e transições de estado. Suporta recarregamento quente e se integra bem com outras ferramentas do Flutter. A biblioteca é amplamente adotada para aplicações escaláveis e sustentáveis.

Casos de uso

Gerenciando estados complexos de aplicativos
Manipulação de interações do usuário com operações assíncronas
Separar a interface do usuário da lógica de negócios
Construindo aplicativos escaláveis do Flutter
Testando transições de estado
Reutilização da lógica de negócios entre plataformas

Principais recursos

Gerenciamento de estado baseado em fluxo
Transições de estado previsíveis
Integração com a árvore de widgets do Flutter
Suporte para recarregamento quente
Capacidades extensas de teste
Separação clara de responsabilidades

Indicado para

Aplicativos Flutter em grande escala
Equipes que exigem código mantido
Desenvolvedores usando programação reativa
Projetos que precisam de gerenciamento robusto de estado
Aplicações com fluxos de trabalho complexos
Desenvolvimento multiplataforma

Considerações

Curva de aprendizado mais acentuada para iniciantes
Requer conhecimento sobre streams e sinks
Mais código boilerplate do que soluções mais simples
Pode ser excessivo para aplicativos pequenos
Requer uma arquitetura cuidadosa para evitar complexidade
Depende de pacotes externos como o equatable para igualdade de valor

README original

Snapshot do README original do repositório-fonte vinculado. Consulte o repositório para o conteúdo mais recente.

Bloc

A predictable state management library that helps implement the BLoC design pattern.

Package	Pub
angular_bloc
bloc
bloc_concurrency
bloc_lint
bloc_test
bloc_tools
flutter_bloc
hydrated_bloc
replay_bloc

Overview

Bloc Architecture

The goal of this library is to make it easy to separate presentation from business logic, facilitating testability and reusability.

Documentation

Migration

Migration Guide

Examples

Dart

Counter - an example of how to create a CounterBloc (pure dart).

Flutter

Counter - an example of how to create a CounterBloc to implement the classic Flutter Counter app.
Form Validation - an example of how to use the bloc and flutter_bloc packages to implement form validation.
Bloc with Stream - an example of how to hook up a bloc to a Stream and update the UI in response to data from the Stream.
Complex List - an example of how to manage a list of items and asynchronously delete items one at a time using bloc and flutter_bloc.
Infinite List - an example of how to use the bloc and flutter_bloc packages to implement an infinite scrolling list.
Login Flow - an example of how to use the bloc and flutter_bloc packages to implement a Login Flow.
Firebase Login - an example of how to use the bloc and flutter_bloc packages to implement login via Firebase.
Github Search - an example of how to create a Github Search Application using the bloc and flutter_bloc packages.
Weather - an example of how to create a Weather Application using the bloc and flutter_bloc packages. The app uses a RefreshIndicator to implement "pull-to-refresh" as well as dynamic theming.
Todos - an example of how to create a Todos Application using the bloc and flutter_bloc packages.
Timer - an example of how to create a Timer using the bloc and flutter_bloc packages.
Shopping Cart - an example of how to create a Shopping Cart Application using the bloc and flutter_bloc packages based on flutter samples.
Dynamic Form - an example of how to use the bloc and flutter_bloc packages to implement a dynamic form which pulls data from a repository.
Wizard - an example of how to build a multi-step wizard using the bloc and flutter_bloc packages.
Bloc Concurrency Visualizer - an example of visualizing the various bloc_concurrency transformers.
Fluttersaurus - an example of how to use the bloc and flutter_bloc packages to create a thesaurus app -- made for Bytconf Flutter 2020.
I/O Photo Booth - an example of how to use the bloc and flutter_bloc packages to create a virtual photo booth web app -- made for Google I/O 2021.
I/O Pinball - an example of how to use the bloc and flutter_bloc packages to create a pinball web app -- made for Google I/O 2022.
I/O Holobooth - an example of how to use the bloc and flutter_bloc packages to create a virtual photobooth experience -- made for Flutter Forward.
I/O Flip - an example of how to use the bloc, flutter_bloc, and flame_bloc packages to create a card game -- made for Google I/O 2023.

Web

Counter - an example of how to use a CounterBloc in an AngularDart app.
Github Search - an example of how to create a Github Search Application using the bloc and angular_bloc packages.

Flutter + Web

Github Search - an example of how to create a Github Search Application and share code between Flutter and AngularDart.

Articles

Bloc package - An intro to the bloc package with high level architecture and examples.
Login tutorial with flutter_bloc - How to create a full login flow using the bloc and flutter_bloc packages.
Unit testing with bloc - How to unit test the blocs created in the flutter login tutorial.
Infinite list tutorial with flutter_bloc - How to create an infinite list using the bloc and flutter_bloc packages.
Code sharing with bloc - How to share code between a mobile application written with Flutter and a web application written with AngularDart.
Weather app tutorial with flutter_bloc - How to build a weather app which supports dynamic theming, pull-to-refresh, and interacting with a REST API using the bloc and flutter_bloc packages.
Todos app tutorial with flutter_bloc - How to build a todos app using the bloc and flutter_bloc packages.
Firebase login tutorial with flutter_bloc - How to create a fully functional login/sign up flow using the bloc and flutter_bloc packages with Firebase Authentication and Google Sign In.
Flutter timer tutorial with flutter_bloc - How to create a timer app using the bloc and flutter_bloc packages.
Firestore todos tutorial with flutter_bloc - How to create a todos app using the bloc and flutter_bloc packages that integrates with cloud firestore.

Books

Flutter Complete Reference - A book about the Dart programming language (version 2.10, with null safety support) and the Flutter framework (version 1.20). It covers the bloc package (version 6.0.3) in all flavors: bloc, flutter_bloc hydrated_bloc, replay_bloc, bloc_test and cubit.

Extensions

IntelliJ - extends IntelliJ/Android Studio with support for the Bloc library and provides tools for effectively creating Blocs for both Flutter and AngularDart apps.
VSCode - extends VSCode with support for the Bloc library and provides tools for effectively creating Blocs for both Flutter and AngularDart apps.

Community

Learn more at the following links, which have been contributed by the community.

Packages

Bloc.js - A port of the bloc state management library from Dart to JavaScript, by Felix Angelov.
Firebase Auth - A Web, Mobile Firebase Auth Plugin, by Rody Davis.
Form Bloc - An easy way to create forms with BLoC pattern without writing a lot of boilerplate code, by Giancarlo.
Flame Bloc - Bloc integration for the Flame game engine, by Flame Engine.

Video Tutorials

Bloc Library: Basics and Beyond 🚀 - Talk given at Flutter Europe about the basics of the bloc library, by Felix Angelov.
Flutter Bloc Library Tutorial - Introduction to the Bloc Library, by Reso Coder.
Flutter Youtube Search - How to build a Youtube Search app which interacts with an API using the bloc and flutter_bloc packages, by Reso Coder.
Flutter Bloc - AUTOMATIC LOOKUP - v0.20 (and Up), Updated Tutorial - Updated Tutorial on the Flutter Bloc Package, by Reso Coder.
Dynamic Theming with flutter_bloc - Tutorial on how to use the flutter_bloc package to implement dynamic theming, by Reso Coder.
Persist Bloc State in Flutter - Tutorial on how to use the hydrated_bloc package to automatically persist app state, by Reso Coder.
State Management Foundation - Introduction to state management using the flutter_bloc package, by Techie Blossom.
Flutter Football Player Search - How to build a Football Player Search app which interacts with an API using the bloc and flutter_bloc packages, by Techie Blossom.
Learning the Flutter Bloc Package - Learning the flutter_bloc package live, by Robert Brunhage
Bloc Test Tutorial - Tutorial on how to unit test blocs using the bloc_test package, by Reso Coder.
Bloc - from Zero to Hero - Playlist which includes everything needed to get started with bloc, by Flutterly.
Bloc (Full Course, 11+ Hours) - Flutter State Management Course - 11+ hour video tutorial on Bloc and Flutter Bloc. In this video you will learn how to create fully fledged production-ready apps with Bloc and Firebase as your backend, by Vandad Nahavandipoor.

Written Resources

DevonFw Flutter Guide - A guide on building structured & scalable applications with Flutter and BLoC, by Sebastian Faust
Using Google´s Flutter Framework for the Development of a Large-Scale Reference Application - Scientific paper describing how to build a large-scale Flutter application with BLoC, by Sebastian Faust

Extensions

Feature Scaffolding for VSCode - A VSCode extension inspired by Reso Coder's clean architecture tutorials, which helps quickly scaffold features, by Kiritchouk Clément.