Redux Thunk example

// pubspec.yaml
dependencies:
  http: ^0.12.1
  flutter_redux: 0.5.0
  redux_thunk: ^0.2.1

// appstate.dart
class AppState {
  final List<String> persons;
  final String lastError;

  AppState({this.persons, this.lastError});
  // it's strongly recommended to override ==/hashCode
}

// actions.dart
class PersonsFetchedAction {
  final List<String> persons;
  PersonsFetchedAction(this.persons);
}

class FetchErrorAction {
  final String error;
  FetchErrorAction(this.error);
}

// ajax.dart
import 'dart:convert';
import 'package:http/http.dart' as http;
import 'package:guap_mobile/person.dart';

class Ajax {
  static final baseUrl = "http://mitrakoff.com:8888/varlam";

  static Future<List<String>> fetchPersons() async {
    final headers = {"username": "Tommy", "token": "33dbd779129f406bbbb003aecd23e96f"};
    final response = await http.get("$baseUrl/person/list", headers: headers);
    if (response.statusCode == 200) {
      final personResponse = PersonResponse.fromJson(json.decode(response.body)); // you have to implement 'fromJson'
      return personResponse.getPersons();
    } else throw Exception("Failed to load persons (http code ${response.statusCode})");
  }
}

// thunks.dart
import 'package:redux/redux.dart';
import 'package:redux_thunk/redux_thunk.dart';
import 'package:guap_mobile/redux/ajax.dart';
import 'package:guap_mobile/redux/actions.dart';

class Thunk {
  static ThunkAction<AppState> fetchPersons() {
    return (Store<AppState> store) async {
      try {
        store.dispatch(PersonsFetchedAction(await Ajax.fetchPersons()));
      } catch(e) {
        store.dispatch(FetchErrorAction(e.toString()));
      }
    };
  }
}

// reducers.dart
import 'package:redux/redux.dart';
import 'package:guap_mobile/redux/actions.dart';
import 'package:guap_mobile/redux/appstate.dart';

class AppReducer {
  static AppState personsFetchedReducer(AppState state, PersonsFetchedAction action) {
    return AppState(persons: action.persons, lastError: "");
  }
  static AppState fetchErrorReducer(AppState state, FetchErrorAction action) {
    return AppState(persons: [], lastError: action.error);
  }

  static Reducer<AppState> reducer = combineReducers<AppState>([
    TypedReducer<AppState, PersonsFetchedAction>(personsFetchedReducer),
    TypedReducer<AppState, FetchErrorAction>(fetchErrorReducer)
  ]);
}

// main.dart
import 'package:flutter/material.dart';
import 'package:flutter_redux/flutter_redux.dart';
import 'package:redux/redux.dart';
import 'package:redux_thunk/redux_thunk.dart';
import 'package:guap_mobile/redux/appstate.dart';
import 'package:guap_mobile/redux/reducers.dart';
import 'package:guap_mobile/redux/thunks.dart';

void main() {
  final store = new Store<AppState>(
    AppReducer.reducer,
    initialState: AppState(persons: [], lastError: ""),
    middleware: [thunkMiddleware]
  );

  runApp(MyApp(store: store));
}

class MyApp extends StatelessWidget {
  final Store<AppState> store;

  const MyApp({Key key, this.store}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return StoreProvider<AppState>(store: store, child: MaterialApp(
        title: "Guap",
        home: Scaffold(appBar: AppBar(
            title: Text("Guap application")),
            body: Column(
              crossAxisAlignment: CrossAxisAlignment.center,
              children: <Widget>[
                RaisedButton(child: Text("Push me!"), onPressed: () => store.dispatch(Thunk.fetchPersons())),
                StoreConnector<AppState, AppState>(
                  distinct: true,
                  converter: (store) => store.state,
                  builder: (context1, state) {
                    return Expanded(child: ListView.builder(
                        itemCount: state.lastError.isNotEmpty ? 1 : state.persons.length,
                        itemBuilder: (ctxt, i) {
                          final item = state.lastError.isNotEmpty ? state.lastError : state.persons[i];
                          return ListTile(title: Text(item));
                        })
                    );
                  }
                )
              ],
            )
        )
    ));
  }
}