Problem Statement
What is the BLoC (Business Logic Component) pattern in Flutter?
Explanation
BLoC is an architectural pattern that separates business logic from presentation layer using streams and sinks. Widgets send events to the BLoC through sinks, the BLoC processes events and updates state, then emits new states through streams that widgets listen to for rebuilding. This creates unidirectional data flow where UI doesn't directly modify state, only sends events.
The pattern enforces clear separation of concerns making code more testable, maintainable, and reusable across platforms. Business logic in BLoCs is independent of Flutter, so you can test it without widget tests and potentially reuse it in other Dart applications. BLoC pattern is particularly popular in large enterprise applications requiring strict architecture and extensive testing.
Flutter_bloc package provides convenient wrappers like BlocProvider, BlocBuilder, and BlocListener that handle stream subscriptions and disposal automatically. While the core concept uses streams, flutter_bloc simplifies the implementation, making BLoC pattern more accessible while maintaining its architectural benefits of predictable state management and separation of concerns.
