JulianBissekkou

typedef Widget EmptyBuilder();
typedef Widget Builder<T>(T state);

typedef R Mapper<R, S>(S state);
typedef void Handler<T>(T event);

abstract class ViewModelWidgetState<W extends StatefulWidget,
    S extends Cloneable<S>, VM extends StateViewModel<S>> extends State<W> {
  final List<StreamSubscription> _subscriptionsList =
      List<StreamSubscription>();

JulianBissekkou

import 'dart:async';

import 'package:meta/meta.dart';
import 'package:timecoder_common/logic/view_model/state_holder.dart';

abstract class StateViewModel<T extends Cloneable<T>> {
  final List<StreamSubscription> _streamDisposeBag = List();

  final StateHolder<T> _stateHolder;

JulianBissekkou

import 'dart:async';

import 'package:rxdart/rxdart.dart';
import 'package:rxdart/subjects.dart';

abstract class Cloneable<T> {
  T copy();
}

typedef T Reducer<T>(T state);

JulianBissekkou

@immutable
class StreamWidget<T> extends StatelessWidget {
  final Stream<T> stream;
  final DataBuilder<T> builder;
  final LoadingBuilder loadingBuilder;
  final ErrorBuilder errorBuilder;

  StreamWidget(
      {@required this.stream,
      @required this.builder,

JulianBissekkou

class EmailValidator {
    static bool isEmailValid(String emailInput) {
    if (_containsSemicolon(emailInput)) return false;

    final String _emailRegex =
        r'^(([^<>()[\]\\.,;:\s@\"]+(\.[^<>()[\]\\.,;:\s@\"]+)*)|(\".+\"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$';

    RegExp emailRegExp = new RegExp(_emailRegex);

    return emailRegExp.hasMatch(emailInput);

JulianBissekkou

 // using "startWith" to ensure that the combined stream emitts even though 
 // on of two streams did not emmited any value yet
 var combinedStream = Observable.combineLatest2(
        title.startWith(""), 
        subtitle.startWith(""),
        (title, subtitle) => Pair<String, String>(title, subtitle));

    new StreamBuilder<Pair<String, String>>(
      stream: combinedStream,
      builder: (_, snapshot) {

JulianBissekkou

  @override
  Widget build(BuildContext context) {
    return Row(
      mainAxisAlignment: MainAxisAlignment.center,
      children: <Widget>[
        Expanded(
          child: StreamBuilder<String>(
            stream: _viewModel.outputErrorText,
            builder: (context, snapshot) {
              return MyTextField(

JulianBissekkou

  StreamBuilder<String>(
    stream: _viewModel.outputErrorText,
      builder: (context, snapshot) {
        return MyTextField(
          controller: controller,
           hintText: "Email",
           errorText: snapshot.data);
    }
  )

JulianBissekkou

class SubscriptionViewModelImpl implements SubscriptionViewModel {
  var _mailTextController = StreamController<String>.broadcast();

  @override
  Sink get inputMailText => _mailTextController;

  @override
  Stream<bool> get outputIsButtonEnabled => _mailTextController.stream
      .map((email) => EmailValidator.isEmailValid(email));

JulianBissekkou

abstract class SubscriptionViewModel {
  Sink get inputMailText;
  Stream<bool> get outputIsButtonEnabled;
  Stream<String> get outputErrorText;

  void dispose();
}