MVVM Design Pattern in Flutter

Question

we try to develop a flutter app and we create a stateful widget as a page .
we want to separate build function from other state variable and state function in 2 different fi

Answer 1

The mvvm package, A Flutter MVVM (Model-View-ViewModel) implementation.

import 'package:flutter/widgets.dart';
import 'package:mvvm/mvvm.dart';
import 'dart:async';

// ViewModel
class Demo1ViewModel extends ViewModel {

  Demo1ViewModel() {
      // define bindable property
      propertyValue(#time, initial: "");
      // timer
      start();
  }

  start() {
      Timer.periodic(const Duration(seconds: 1), (_) {
        var now = DateTime.now();
        // call setValue
        setValue(#time, "${now.hour}:${now.minute}:${now.second}");
      });
  }
}

// View
class Demo1 extends View {
  Demo1() : super(Demo1ViewModel());

  @override
  Widget buildCore(BuildContext context) {
    return Container(
        margin: EdgeInsets.symmetric(vertical: 100),
        padding: EdgeInsets.all(40),

        // binding
        child: $.watchFor(#time, 
            builder: $.builder1((t) => 
              Text(t, textDirection: TextDirection.ltr))));
  }
}

// run
void main() => runApp(Demo1());

full example