# onChange method Null safety

1. @protected
2. @mustCallSuper

void onChange(

1. Change<SectionListState> change

)
@mustCallSuper, @protected, inherited

Called whenever a `change` occurs with the given `change`. A `change` occurs when a new `state` is emitted. onChange is called before the `state` of the `cubit` is updated. onChange is a great spot to add logging/analytics for a specific `cubit`.

Note: `super.onChange` should always be called first.

    @override
    void onChange(Change change) {
      // Always call super.onChange with the current change
      super.onChange(change);

      // Custom onChange logic goes here
    }

See also:

- `BlocObserver` for observing `Cubit` behavior globally.

## Implementation

    @protected
    @mustCallSuper
    void onChange(Change<State> change) {
      // ignore: invalid_use_of_protected_member
      _blocObserver.onChange(this, change);
    }