Bloc: [Help] BlocBuilder does not get called. Updates on Hot Reload though

[JoseGeorges8]

Hey!

I got this bloc and a group of buttons. Each button has a Note attached to it and for now all I'm doing is when tapped, I add an UpdateNote event.

When I tap the button nothing happens, but as soon as I HR the UI updates so the event is getting triggered and the list is being updated, however the BlocBuilder does not detect a change on the state. Why is this happening?

This is my state

This is the Note model

Update:

So I've noticed that when I update the value of an item inside the list, for some reason the current state's list gets automatically updated as well..

so inside my previously shown bloc...

  Stream<NotesState> _mapUpdateNoteToState(UpdateNote event) async* {
    print(state.notes); //This list got already updated
    final List<Note> updatedNotes = notes.map(
            (note) => note.value == event.updatedNote.value ? event.updatedNote : note
    ).toList();
    print(updatedNotes); // Now this list is the same as the other one
    yield NotesState(notes: updatedNotes);
  }

when I press a note button this is what I call:

onTap: () {
  final Note updatedNote = note;
  updatedNote.isSelected = true;
  _notesBloc.add(UpdateNote(updatedNote));
},

Update 2

I've changed things a bit more and got a bit closer but I still can't get the BlockBuilder to be called

I changed my _mapUpdateNoteToState to this...

 Stream<NotesState> _mapUpdateNoteToState(UpdateNote event) async* {
    final List<Note> updatedNotes = state.notes.map((note) {
      return note.value == event.updatedNote.value ? event.updatedNote : note;
    }).toList();
    print(NotesState(notes: updatedNotes) == state); //This prints false
    yield NotesState(notes: updatedNotes);
    _notesRepository.updateNote(note: event.updatedNote);
    print(NotesState(notes: updatedNotes) == state); //This prints true
  }

[JoseGeorges8]

I got it to work now by removing _notesRepository.updateNote(note: event.updatedNote); from the call... I'm a bit unsure as to why is this causing an issue. All this line does is update the repositories list..

my data provider

class NotesBasicProvider extends NotesBaseProvider{

  ///All the available notes
  final List<Note> _notes = [
    Note(value: 'C', isSelected: false, isSharp: false),
    Note(value: 'Db', isSelected: false, isSharp: true),
    Note(value: 'D', isSelected: false, isSharp: false),
    Note(value: 'Eb', isSelected: false, isSharp: true),
    Note(value: 'E', isSelected: false, isSharp: false),
    Note(value: 'F', isSelected: false, isSharp: false),
    Note(value: 'Gb', isSelected: false, isSharp: true),
    Note(value: 'G', isSelected: false, isSharp: false),
    Note(value: 'Ab', isSelected: false, isSharp: true),
    Note(value: 'A', isSelected: false, isSharp: false),
    Note(value: 'Bb', isSelected: false, isSharp: true),
    Note(value: 'B', isSelected: false, isSharp: false),
  ];

  @override
  List<Note> getNotes() => _notes;

  @override
  Future<List<Note>> getAsyncNotes() async => _notes;

  @override
  void updateNote(Note updatedNote) {
    _notes.firstWhere((note) => note.value == updatedNote.value).isSelected = updatedNote.isSelected;
  }
}

Even though i've resolved the issue, could you tell me why that line was stopping the ui from updating?

[felangel]

Hi @JoseGeorges8 👋
Thanks for opening an issue!

I'm glad you resolved the problem and the reason updateNote is causing the problem is because you're mutating _notes instead of creating a copy and updating the value. You can create a copy using List.from(_notes)..firstWhere(...). Hope that helps 👍

[JoseGeorges8]

Thanks! I'll try that instead soon and let you know!

[felangel]

Closing for now but feel free to comment with additional information/questions and I'm happy to continue the conversation 👍

[JoseGeorges8]

Hey sorry to come this late but that worked great for a different part of the app! thank you!