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dartarchitecture

How to create a "constant reference" getter in Dart?

Say I have a class ListContainer that contains and manages a list that must be accessible from outside. Since managing this list is complicated, I don't want to let anyone other than ListContainer modify it. In C++, I would create a function that returns const reference, but in Dart, const works completely differently. Just using getter will not prevent someone from modifying the list.

So how can I provide an access to the list values without allowing to modify the list?

I'm looking for something better than creating a getNth function because that would also require creating methods like length, map, and so on.

Solution

  • I think UnmodifiableListView is what you are looking for.

    check out UnmodifiableListView Documentation

    you can use it like this:

    List<int> _myList = [1, 2, 3];
UnmodifiableListView<int> get myList => UnmodifiableListView(_myList);