apiKey

Find its value from the `firebase_options.dart` file and paste here.

appId

messagingSenderId

projectId

authDomain

storageBucket

iosClientId

iosBundleId

measurementId

Gain insights into using Flutter and Dart to build visually stunning, high-performance Android and iOS apps. Delve into UI/UX design, networking, state management, Firebase, testing, and deployment.

hello.tar.gz

Flutter_Web

Flutter_Web-copy

Flutter_Web-Firebase

Flutter_Web_build_runner

Flutter_Web_Testing

Flutter_API_Server

Flutter_API_Server-copy

Get ready to unlock the potential of Flutter and Dart as you learn to craft visually stunning and high-performance applications for both Android and iOS.

This course will teach you to plan, build, and deploy interactive Flutter applications. You’ll start by developing user interfaces and handling gestures. Next, you’ll explore navigation and routing to smoothly move around your app. You’ll then dive into networking and HTTP to connect your app to the internet and implement data persistence. You’ll use Firebase services for authentication and storing data. State management comes next, helping you manage the different pieces of your app efficiently. Then, you’ll focus on testing, analytics, and crash reporting. You’ll then explore accessibility and internationalization, making your app usable by everyone and suitable for different languages. Lastly, you’ll learn app deployment.

The course wraps up with a project: you will create an online furniture store, combining all the skills you’ve learned.

The Complete Guide to Flutter

# Solutions
Great job on completing all the steps in the previous challenge! Feel free to compare your code solutions with the solutions below:

dependencies:
  flutter:
    sdk: flutter
  cupertino_icons: ^1.0.4
  http: ^0.13.4
  intl: ^0.17.0
  web_socket_channel: ^2.1.0

pubspec.yaml

import 'dart:convert';
import 'package:intl/intl.dart';
import 'package:flutter/material.dart';
import 'package:web_socket_channel/web_socket_channel.dart';
import 'app_drawer_widget.dart';

class TransactionsScreen extends StatefulWidget {
  const TransactionsScreen({Key? key}) : super(key: key);
  static const route = '/transactions';

  @override
  State<TransactionsScreen> createState() => _TransactionsScreenState();
}

class _TransactionsScreenState extends State<TransactionsScreen> {
  List<Map<String, dynamic>> latestTransactions = [];
  late WebSocketChannel channel;

  @override
  void initState() {
    channel = WebSocketChannel.connect(Uri.parse('wss://ws.blockchain.info/inv'));
    channel.sink.add('{"op": "unconfirmed_sub"}');
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Transactions'),
      ),
      drawer: const AppDrawerWidget(),
      body: Padding(
        padding: const EdgeInsets.all(8.0),
        child: Column(
          children: [
            Row(
              mainAxisAlignment: MainAxisAlignment.spaceBetween,
              children: [
                Text(
                  "Hash",
                  style: Theme.of(context).textTheme.headline4,
                ),
                Text("Time", style: Theme.of(context).textTheme.headline4),
                Text("Bitcoin", style: Theme.of(context).textTheme.headline4),
              ],
            ),
            Expanded(
              child: StreamBuilder(
                stream: channel.stream,
                builder: (context, snapshot) {
                  if (snapshot.hasData) {
                    getLatestTransactions(snapshot.data);
                    return ListView.builder(
                      itemCount: latestTransactions.length,
                      itemBuilder: (context, index) => Padding(
                        padding: const EdgeInsets.symmetric(vertical: 8.0),
                        child: Row(
                          mainAxisAlignment: MainAxisAlignment.spaceAround,
                          children: [
                            Expanded(
                              child: Text(latestTransactions[index]['x']['hash']
                                  .toString()
                                  .substring(0, 12)),
                            ),
                            Expanded(
                              child: Text(
                                DateFormat.Hms().format(
                                  DateTime.fromMillisecondsSinceEpoch(
                                      (latestTransactions[index]['x']['time']
                                              as int) *
                                          1000),
                                ),
                                textAlign: TextAlign.center,
                              ),
                            ),
                            Expanded(
                              child: Text(
                                latestTransactions[index]['trxTotal']
                                    .toString(),
                                textAlign: TextAlign.right,
                              ),
                            ),
                          ],
                        ),
                      ),
                    );
                  }
                  if (snapshot.hasError) {
                    return Text('Error: ${snapshot.error.toString()}');
                  }
                  return const Center(
                      child: CircularProgressIndicator.adaptive());
                },
              ),
            ),
          ],
        ),
      ),
    );
  }

  getLatestTransactions(data) {
    Map<String, dynamic> snapData = jsonDecode(data as String);

    snapData = {
      ...snapData,
      'trxTotal': ((snapData['x']['out'] as List)
              .map((e) => e['value'] as int)
              .fold(0, (int value, int element) => value + element) /
          100000000)
    };

    latestTransactions = [
      snapData,
      ...latestTransactions,
    ];
  }

  @override
  void dispose() {
    channel.sink.add('{"op": "unconfirmed_unsub"}');
    channel.sink.close();
    super.dispose();
  }
}

lib/presentation/transactions_screen.dart

Explore solutions to the real-time Bitcoin transactions challenge. 


Introduction

User Interface

Navigation and Routing

Networking and HTTP

Persisting Data

State Management

Firebase for Flutter

Essential Tools to Enhance Your Flutter Workflow

Quality Assurance

Accessibility and Internalization

Deployment

Project: Build an Online Furniture Store

Next Steps

Solution: Real-Time Bitcoin Transactions

Solutions