I have a function that calls a Future in it. Now I am not sure if the first function needs to be a future too to await for the data. Here is my code:

  FireBaseHandler handler = FireBaseHandler();

  saveRows() {
    handler.saveRows(plan.planId, plan.rows); ///this is a future
  }

In my FireBaseHandler class I have this Future:

  final CollectionReference usersCol =
      FirebaseFirestore.instance.collection('users');

  Future saveRows(String id, data) async {
    return await usersCol.doc(myUser.uid).collection('plans').doc(id)
        .update({'rows': data});
  }

So does the first function needs to be a Future too?

CodePudding user response：

You can have async function inside a sync function. But this way you lose ability to await for the result. And await is allowed only in functions marked as async, which leads us to Future as a the result of that function. So, yes, if you need to wait for the result, both functions have to be Future functions.

Edit: If you need your wrapper function to be sync, but still be able to retrieve the result from inner async function, you can use a callback:

  saveRows(Function(dynamic) callback) {
    handler.saveRows(plan.planId, plan.rows).then((result){
      callback(result);
});
  }

This way the result will be retrieved at any point of time after calling the function (the code is not awaited)