states_rebuilder

A Flutter state management solution that allows you:

  • to separate your User Interface (UI) representation from your logic classes
  • to easily control how your widgets rebuild to reflect the actual state of your application.

This Library provides two classes and one method:

  • The StatesRebuilder class. Your logics classes will extend this class to create your own business logic BloC (equally can be called ViewModel or Model).
  • The rebuildStates method. You call it inside any of your logic classes that extends StatesRebuilder. It offers you two ways to rebuild any of your widgets. this is the signature of the rebuildState:
  rebuildStates({
      VoidCallback setState, // an optional VoidCallback to execute inside the Flutter setState() method 
      List<String> ids // First way to rebuild a particular widget indirectly by giving its id
      List<State> states, // Second way to rebuild a particular widget directly by giving its State
    })
  • The StateBuilder Widget. You wrap any part of your widgets with it to make it available inside your logic classes and hence can rebuild it using rebuildState method this is the constructor of the StateBuilder:
  StateBuilder( {
      Key key, 
      String stateID, // you define the ID of the state. This is the first way
      List<StatesRebuilder> blocs, // You give a list of the logic classes (BloC) you want this ID will be available.
      @required (State) → Widget builder,  // You define your top most Widget.
      (State) → void initState, // for code to be executed in the initState of a StatefulWidget
      (State) → void dispose, // for code to be executed in the dispose of a StatefulWidget
      (State) → void didChangeDependencies, // for code to be executed in the didChangeDependencies of a StatefulWidget
      (StateBuilder, State) → void didUpdateWidget // for code to be executed in the didUpdateWidget of a StatefulWidget
    });

For the first way you have to provide the stateID and blocs parameters. Whereas for the second way you have not. See prototype example bellow.

Prototype Example

your_bloc.dart file:

  import 'package:flutter/material.dart';
  import 'package:states_rebuilder/states_rebuilder.dart'

  class YourBloc extends StatesRebuilder{

      var yourVar;

      /// You have two ways:

      /// ************** First way: (ID way) **************

      yourMethod1() {
        // some logic staff;
        yourVar = yourNewValue;
        rebuildStates(ids : [“yourStateID1”]);
      }

      // example of fetching data and rebuilding widgets after obtaining the data
      fetchData1() async {
        await yourRepository.fetchDate();
        rebuildStates(ids : [“yourStateID1”]);
      }

      /// ************** Second way (state way) **************

      yourMethod2(State state) {
        // some logic staff;
        yourVar = yourNewValue;
        rebuildStates(states : [state]);
      }

      // example of fetching data and rebuild widgets after obtaining the data
      fetchData2(State state) async {
        await yourRepository.fetchDate();
        rebuildStates(states : [state]);
      }

      /// ************** Combination of first and second ways **************

      yourMethod3(State state) {
        // some logic staff;
        yourVar = yourNewValue;
        rebuildStates(states : [state], ids : [“yourStateID1”]);
      }
  }

your main.dart file:

  // ************** First way: (ID way) ************** 
  class Firstway extends StatelessWidget {
    @override
    Widget build(BuildContext context) {
      return Column(
            children: <Widget> [
              StateBuilder(
                stateID : "yourStateID1",
                blocs : [yourBloc],
                initState: (_)=> yourBloc.fetchData1(),
                builder: (_) => YourChildWidget(yourBloc.yourVar),
            ),
            RaisedButton(
              child: Text("first way"),
              onPressed : yourBloc.yourMethod1,
            )
          ],
      );
    }
  }

    // ************** Second way: (ID way) ************** 
    class Secondway extends StatelessWidget {
    @override
    Widget build(BuildContext context) {
      return StateBuilder(
              initState: yourBloc.fetchData2,
              builder: (State state) => Column(
                    children: <Widget> [
                      YourChildWidget(yourBloc.yourVar),
                      RaisedButton(
                        child: Text("Second way"),
                        onPressed :yourBloc.yourMethod2(state),
                      ), 
                    ],
                  ),
              );
    }
  }

Libraries

states_rebuilder