Flutter BLoC - Designing State Management for Complex Q&A Sessions
A BLoC that just loads and displays a list isn’t hard. The challenge comes when you need to manage session-based workflows in a single BLoC – things like “create a session -> add questions -> receive answers -> complete.” Draw the States First Before coding the BLoC, define the states first. Listing all the states the UI needs to display for this workflow: Initial (nothing loaded) Session list loading Session list displayed Creating new session Session detail loading Session detail displayed (with question list) Adding question Submitting answer Error abstract class ReviewQaState {} class ReviewQaInitial extends ReviewQaState {} class ReviewQaLoading extends ReviewQaState {} class ReviewQaSessionListLoaded extends ReviewQaState { final List<QaSession> sessions; ReviewQaSessionListLoaded(this.sessions); } class ReviewQaSessionLoaded extends ReviewQaState { final QaSession session; final List<ReviewQuestion> questions; ReviewQaSessionLoaded({required this.session, required this.questions}); } class ReviewQaQuestionAdded extends ReviewQaState { final ReviewQuestion question; ReviewQaQuestionAdded(this.question); } class ReviewQaError extends ReviewQaState { final String message; ReviewQaError(this.message); } State classes need to be this specific so the UI can branch clearly with if (state is ReviewQaSessionLoaded). ...