mapEventToState not called

[OnyemaAnthony]

here is my bloc class, when i trigger the SaveTaskEvent the event is called but the bloc and the repository is not called,am using Sqflite db as my repository

import 'dart:async'; import 'package:bloc/bloc.dart'; import 'package:equatable/equatable.dart'; import 'package:flutter/cupertino.dart'; import 'package:todo_list/models/todo_list_model.dart'; import 'package:todo_list/repository/database_repository.dart';

part 'task_event.dart';

part 'task_state.dart';

class TaskBloc extends Bloc<TaskEvent, TaskState> { DatabaseRepository _repository;

TaskBloc({@required DatabaseRepository repository}) : assert (repository != null), _repository = repository, super(TaskInitial());

@override TaskState get initialState => TaskInitial();

@override Stream mapEventToState(TaskEvent event,) async { if (event is FetchAllTaskEvent) { yield _mapFetchAllTAskEventToState(event); } else if (event is SaveTaskEvent) { _mapSaveTaskEventToState(event); } }

Stream _mapFetchAllTAskEventToState( FetchAllTaskEvent event) async* { yield TaskLoadingState(); TodoListModel task;

try {
  List tasks = await _repository.geAllTask();
  for (int i = 0; i < tasks.length; i++) {
    task = TodoListModel.map(tasks[i]);
  }
  yield TaskLoadedState(task);
} catch (e) {
  yield TaskErrorState(e.toString());
}

} Stream _mapSaveTaskEventToState(SaveTaskEvent event) async* { yield TaskLoadingState();

try {
  int result = await _repository.saveTask(event.task);

  yield TaskAddedState(result);
} catch (e) {
  yield TaskErrorState(e.toString());
}

} }

[mikededo]

Hello @OnyemaAnthony 😃

Here's the code properly formatted - more readable:

import 'dart:async';
import 'package:bloc/bloc.dart';
import 'package:equatable/equatable.dart';
import 'package:flutter/cupertino.dart';
import 'package:todo_list/models/todo_list_model.dart';
import 'package:todo_list/repository/database_repository.dart';

part 'task_event.dart';
part 'task_state.dart';

class TaskBloc extends Bloc<TaskEvent, TaskState> {
  DatabaseRepository _repository;

  TaskBloc({@required DatabaseRepository repository})
      : assert(repository != null),
        _repository = repository,
        super(TaskInitial());

  @override
  TaskState get initialState => TaskInitial();

  @override
  Stream mapEventToState(
    TaskEvent event,
  ) async* {
    if (event is FetchAllTaskEvent) {
      yield* _mapFetchAllTAskEventToState(event);
    } else if (event is SaveTaskEvent) {
      _mapSaveTaskEventToState(event);
    }
  }

  Stream _mapFetchAllTAskEventToState(FetchAllTaskEvent event) async* {
    yield TaskLoadingState();
    TodoListModel task;

    try {
      List tasks = await _repository.geAllTask();
      for (int i = 0; i < tasks.length; i++) {
        task = TodoListModel.map(tasks[i]);
      }
      yield TaskLoadedState(task);
    } catch (e) {
      yield TaskErrorState(e.toString());
    }
  }

  Stream _mapSaveTaskEventToState(SaveTaskEvent event) async* {
    yield TaskLoadingState();

    try {
      int result = await _repository.saveTask(event.task);

      yield TaskAddedState(result);
    } catch (e) {
      yield TaskErrorState(e.toString());
    }
  }
}

Do you have Equatable implemented in the TaskEvent class and subclasses? Could you debug the following, and see whether the app stops or not?

@override
Stream mapEventToState(
  TaskEvent event,
) async* {
  assert(event is SaveTaskEvent);

  if (event is FetchAllTaskEvent) {
    yield* _mapFetchAllTAskEventToState(event);
  } else if (event is SaveTaskEvent) {
    _mapSaveTaskEventToState(event);
  }
}

We would need a bit more of information in order to guess where the error may be 😄

[OnyemaAnthony]

@mikededo thanks for your reply, what more information do you need,I created a class where I performed CRUD with sqflite DB,I used the class as the repository of the bloc then I tried adding an item to the DB from the UI and it's working well but when I migrate it to bloc and trigger the SaveTaskEvent it's shows on the log that the event was trigger but the Bloc is not being called

[mikededo]

Are you using a BlocObserver which prints when onEvent is called? (Check this link from the docs).

[OnyemaAnthony]

Yea i used Bloc observer,am comfortable using Bloc with firebase Firestore as the repository, this is my first time of using sqflite and that is the first time am experiencing this error

[mikededo]

With this:

I tried adding an item to the DB from the UI and it's working well

Do you mean that your databse reflectes the changes? Or no new item is added? 🤔

[OnyemaAnthony]

No new item was added, the function that adds the item is in the repository and the function was never called

[OnyemaAnthony]

The function that adds the item is called from the mapSaveTaskToState function,due to the Bloc was not called the item was not saved

[mikededo]

The function that adds the item is called from the mapSaveTaskToState function,due to the Bloc was not called the item was not saved.

Yes, I expected that. It kind of strange, ngl. Could you attach some code, for instance, where do you call add the event? 👀

[OnyemaAnthony]

here is the code i use as my repository that is the sqflite file

import 'dart:io'; import 'package:flutter/material.dart'; import 'package:path_provider/path_provider.dart'; import 'package:sqflite/sqflite.dart'; import 'package:path/path.dart'; import 'package:todo_list/models/todo_list_model.dart'; import 'package:todo_list/utility/utilities.dart';

class DatabaseRepository { static final DatabaseRepository _instance = DatabaseRepository.internal();

factory DatabaseRepository() => _instance;

static Database _db;

DatabaseRepository.internal();

Future get db async { if (_db != null) { return _db; } _db = await initDb(); }

initDb() async { Directory documentDirectory = await getApplicationDocumentsDirectory();

String path = join(documentDirectory.path, 'tododb.db');

var dataBase = await openDatabase(path, version: 1, onCreate: _onCreate);

}

void _onCreate(Database db, int newVersion) async { await db.execute( "CREATE TABLE ${Utility.todoTable}(${Utility.id} INTEGER PRIMARY KEY, ${Utility.task} TEXT,${Utility.deadline}TEXT})"); }

Future saveTask(TodoListModel todoListModel) async { var dbClient = await db;

int result =
    await dbClient.insert(Utility.todoTable, todoListModel.toMap());
return result;

}

Future geAllTask() async { var dbClient = await db;

var result = await dbClient.rawQuery("SELECT * FROM ${Utility.todoTable}");

return result.toList();

}

Future getCount() async { var dbClient = await db;

return Sqflite.firstIntValue(
    await dbClient.rawQuery("SELECT COUNT(*) FROM ${Utility.todoTable}"));

}

Future getTask(int id) async { var dbClient = await db;

var result = await dbClient.rawQuery(
    "SELECT * FROM ${Utility.todoTable} WHERE ${Utility.id} = $id");

if (result.length == 0) {
  return null;
} else {
  return TodoListModel.fromMap(result.first);
}

}

Future deleteTask(int id) async { var dbClient = await db;

return await dbClient
    .delete(Utility.todoTable, where: "${Utility.id} = ?", whereArgs: [id]);

}

Future updateTask(TodoListModel todoListModel) async { var dbClient = await db; return await dbClient.update(Utility.todoTable, todoListModel.toMap(), where: "${Utility.id} = ?", whereArgs: [todoListModel.id]); }

Future close()async{ var dbClient = await db; return dbClient.close(); } }

[OnyemaAnthony]

here is the ui part where am calling the event, am adding the event in the saveTask function

import 'package:flutter/material.dart'; import 'package:flutter_bloc/flutter_bloc.dart'; import 'package:intl/intl.dart'; import 'package:todo_list/bloc/task/task_bloc.dart'; import 'package:todo_list/models/todo_list_model.dart'; import 'package:todo_list/repository/database_repository.dart'; import 'package:todo_list/utility/utilities.dart';

class AddTaskScreen extends StatefulWidget { @override _AddTaskScreenState createState() => _AddTaskScreenState(); }

class _AddTaskScreenState extends State<AddTaskScreen> { TaskBloc taskBloc;

TextEditingController taskController = TextEditingController(); TextEditingController dateController = TextEditingController(); TextEditingController timeController = TextEditingController(); final DateFormat formatter = DateFormat('dd, MMMM, yyyy');

// TodoListModel task = TodoListModel(deadLine: '', task: '');

@override Widget build(BuildContext context) { return BlocProvider( create: (BuildContext context) => TaskBloc(repository: DatabaseRepository()), child: Builder(builder: (BuildContext ctx) { return Scaffold( appBar: AppBar( centerTitle: true, title: Text('Add a new Task'), actions: [ GestureDetector( onTap:** () { saveTask(ctx); }, child: Container( margin: EdgeInsets.only(right: 20), child: Icon( Icons.check, size: 30, )), ) ], ), body: buildTask(ctx)); } ), ); }

Widget buildTaskForm(BuildContext ctx) { return Container( margin: EdgeInsets.all(20), child: Column( crossAxisAlignment: CrossAxisAlignment.start, children: [ Text("What need to be done?"), Row( children: [ Expanded( child: Container( width: 400, child: TextFormField( controller: taskController, textInputAction: TextInputAction.newline, keyboardType: TextInputType.multiline, maxLines: null, decoration: InputDecoration( hintText: 'Enter Task Here', //border: OutlineInputBorder(), ), ), ), ), SizedBox( width: 10, ), Icon( Icons.keyboard_voice, color: Theme.of(context).primaryColor, size: 28, ), ], ), SizedBox( height: 40, ), Center( child: Text( "Dead line", style: TextStyle(fontSize: 19), )), SizedBox( height: 10, ), Row( children: [ Expanded( child: Container( width: 400, child: TextFormField( onTap: () { _showDatePicker(context); }, controller: dateController, textInputAction: TextInputAction.newline, keyboardType: TextInputType.multiline, maxLines: null, decoration: InputDecoration( hintText: 'Enter Date', //border: OutlineInputBorder(), ), ), ), ), SizedBox( width: 10, ),

          Icon(
            Icons.date_range,
            color: Theme.of(context).primaryColor,
            size: 28,
          ),
          //  SizedBox(height: 10,),

          dateController.text.isEmpty
              ? Container()
              : Expanded(child: buildTime()),
        ],
      ),
    ],
  ),
);

}

Row buildTime() { return Row( children: [ Expanded( child: Container( width: 400, child: TextFormField( onTap: () { _selectTime(context); }, controller: timeController, textInputAction: TextInputAction.newline, keyboardType: TextInputType.multiline, decoration: InputDecoration( hintText: 'Enter Time', //border: OutlineInputBorder(), ), ), ), ), SizedBox( width: 10, ), Icon( Icons.timer, color: Theme.of(context).primaryColor, size: 28, ), ], ); }

Future _selectTime(BuildContext context) async { final TimeOfDay picked = await showTimePicker( context: context, initialTime: TimeOfDay.now(), ); if (picked != null) setState(() { timeController.text = picked.toString().substring(10, 15); }); }

void _showDatePicker(BuildContext context) { showDatePicker( context: context, initialDate: DateTime.now(), firstDate: DateTime(2020), lastDate: DateTime(3000)) .then((pickedDate) { if (pickedDate == null) { return; } setState(() { dateController.text = formatter.format(pickedDate).toString(); //task.deadLine = dateController.text; }); }); }

saveTask(BuildContext ctx) async { taskBloc = BlocProvider.of(ctx); taskBloc.add( SaveTaskEvent(TodoListModel( deadLine: dateController.text, task: taskController.text)), ); }

Widget buildTask(BuildContext context) { return BlocBuilder<TaskBloc, TaskState>( builder: (ctx, state) { if (state is TaskInitial) { return buildTaskForm(ctx); } else if (state is TaskLoadingState) { return Utility.showCirclarLoader(); } else if (state is TaskAddedState) { return buildTaskForm(ctx); } else if (state is TaskErrorState) { //return Utility.showLongErrorToast(state.message); } return Container(); }, ); } }```

[OnyemaAnthony]

@mikededo sir please i dont know how to format code this is my first time of reporting an issue here

[OnyemaAnthony]

i think the problem is coming from the repository because i did everything right in the bloc file and also the ui the same way i use to do when am using firebase the only thing different is the data base please if there is any other thing i need to do to connect bloc and sqflite db that i did not do you can tell me

[mikededo]

Here you have an explanation from the GitHub docs on how to write codeblocks in Markdown. Try editing your comments! 😄

In the function saveTask, you are calling BlocProvider.of(ctx) without specifying the BLoC type. As you can see in the documentation, you should be using BlocProvider.of<BlocA>(context). However, it is strange that your app does not show any error and that, as you say, the BlocObserver is called.

Could you try adding what I propsed before here? Aside from this, do you have a public repository of the project? Therefore I could fork it, try it and help you finding the issue (it's easier for me to debug if I can compile and run the app myself :wink:).

[OnyemaAnthony]

i have added the type of bloc but still the same thing is happening https://github.com/OnyemaAnthony/todo_list.git is the link to the repository you can clone it and switch to develop branch

[mikededo]

I have found the issue. I will provide a pull request explaining you the why! 💯

[OnyemaAnthony]

okay thank you sir i really appreciate

[mikededo]

It is a pleasure 😃

If everything works as expected, merge the pr and close both the issue and the pr 👋

[OnyemaAnthony]

Okay I will do just that but I haven't seen the pull request

[mikededo]

Go to the repository and open the Pull Requests tab. Here's the link

[OnyemaAnthony]

its working thank you sir God bless you,but i did not know the cause of the error

[mikededo]

As I have stated in the pr, the issue was not yielding the function inside mapEventToState.

Instead of:

  @override
  Stream<TaskState> mapEventToState(
    TaskEvent event,
  ) async* {
    if (event is FetchAllTaskEvent) {
      yield* _mapFetchAllTAskEventToState(event);
    } else if (event is SaveTaskEvent) {
      yield* _mapSaveTaskEventToState(event);
    }
  }

You were doing:

  @override
  Stream<TaskState> mapEventToState(
    TaskEvent event,
  ) async* {
    if (event is FetchAllTaskEvent) {
      yield* _mapFetchAllTAskEventToState(event);
    } else if (event is SaveTaskEvent) {
      _mapSaveTaskEventToState(event);  // <- Here's the issue
    }
  }

You were not yielding _mapSaveTaskToState, which would not call the function.

[OnyemaAnthony]

ohhhh now i get that is a very stupid mistake and i was not able to figure it out thanks anyways