How to do it...

To implement separation of concerns for views and models, follow these steps: 

1. The best place to start is the data layer. This will give you a clear view of your app, without going into the details of your user interface. In the models folder, create a file called task.dart and create the Task class. This should have a description string and a complete Boolean, as well as a constructor. This class will hold the task data for our app. Add the following code:

class Task {
  String description;
  bool complete;

  Task({
    this.complete = false,
    this.description = '',
  });
}

2. We also need a plan that will hold all our tasks. In the models folder, create plan.dart and insert this simple class:

import './task.dart';

class Plan {
  String name = '';
  final List<Task> tasks = [];
}

3. We can wrap up our data layer by adding a file that will export both models. That way, our imports will not get too bloated as the app grows...