How to listen to variable changes in a provider class?

Question

When using providers, how can I listen to a value change in the provider class? In the code below, when _myData changes, I want to change _allData as well. (I know I can just change them both together, but the code below is a stripped version of what I have)

class CoolProvider extends ChangeNotifier {
  List<String> _allData = [];
  List<String> _myData = [];

  List<OrdersResponse> get allData => _allData;
  List<OrdersResponse> get myData => _myData;

  void changeData()  {
      _allData = ['yo', 'bro'];
      notifyListeners();
  }
}

Have a look at [this](https://stackoverflow.com/a/71295321/11003497) answer. Where the **getter/setter method** is being overwritten. — Paul, Mar 04 '22 at 09:18

score 1 · Answer 1 · answered Sep 11 '20 at 21:08

1

You can use addListener for instance of your class.

CoolProvider coolProvider = CoolProvider();

void f() {
 // access new data
}

coolProvider.addListener(f);

answered Sep 11 '20 at 21:08

BeHappy

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I'm looking for a way to listen to `_myData` is it the same idea? – Jessica Sep 11 '20 at 22:26
then you can access new data in callback function. – BeHappy Sep 12 '20 at 07:43

How to listen to variable changes in a provider class?

1 Answers1