Add a message when changing state

[rodrigodittrich]

Project Name
triple

Is your feature request related to a problem? Please describe.

Suggestion for assigning a message when the state changes. With this, it is possible to simply display a snackbar when the state changes.

my controller:

class PersonController extends Store<List<PersonEntity>> {
 //....Use Cases
 //....Constructor
 //....Variables

 Future insert() async {
   //.....
   //Insert person in list
   setMessage('Person inserted successfully');
   update(persons);
 }

 Future update() async {
   //.....
   //Update person list
   setMessage('Person updateded successfully');
   update(clientes);
 }

 Future delete() async {
   //.....
   //Remove person from list
   setMessage('Person deleted successfully')
   update(persons);
 }
}

observer on my page:

controller.observer(
  onLoading: (loading) => onLoading(loading),
  onError: (error) => showError(error.message),
  onState: (state, message) => onState(state, message)
);

void onState(state, message) {
  //Implements;
  showMessage(message),
}

A second suggestion:

• Deprecate onError and add onMessage
  Message can be used as error messages or success messages.

Exemplo:

Controller:

  Future update() async {
    setLoading(true);
    final result = await _updatePersonUseCase(person: personEntity);
    result.fold(
      (success) {
        persons.add(personEntity);
        update(persons);
        setMessage(PersonUpdatedEvent('Person updateded successfully'));
      }, 
      (failure) => setMessage(failure)
    );
    setLoading(false);
  }

Page:

controller.observer(
  onLoading: (loading) => onLoading(loading),
  onMessage: (message) => onMessage(message),
  onState: (state) => print(state)
);

void onMessage(message) {
  if(message is PersonUpdatedEvent) {
    showSucess(message.message);
  }
  if(message is PersonException) {
    showError(message.message);
  }
}

Note: It is possible to show error or success messages using the onError property, but it is conditioned more on errors.