Flutter, Google Wallet, and Back4App: Environmental Rewards App Tutorial

15min
Introduction
In this tutorial, we'll create a Flutter app that encourages users to take environmental actions, rewarding them with digital badges and event tickets stored in Google Wallet. We’ll integrate Back4app as the backend to manage user data and track environmental contributions. Each time a user completes a task, they receive a collectible badge or event ticket, which can be added to their Google Wallet for safekeeping.
Features
Users can log environmental tasks (e.g., recycling, volunteering).
Users earn digital badges and event passes based on their contributions.
Google Wallet stores and displays these digital assets.
Backend integration with Back4app for tracking and data management.
Prerequisites
Flutter Development Environment: Follow the Flutter installation guide.
Back4app Account: Sign up at Back4app.
Google Wallet API Access: Set up your project by following the Google Wallet API documentation.
Google Wallet API Keys: Generate and use the required API keys for accessing Google Wallet.
Step 1: Setting Up Back4app as Backend
1.1 Create a Back4app Project
Sign in to Back4app and create a new project.
Create a Parse Class called EnvironmentalActions with the following fields:
username (String): The username of the user.
actionType (String): Type of environmental action (e.g., Recycling, Tree planting).
timestamp (DateTime): The date when the user completed the action.
rewardIssued (Boolean): Whether a reward has been issued for the action.
1.2 Add Sample Data to Back4app
You can add some sample records for testing purposes, but the app will handle data entry later when users complete tasks.
Step 2: Initialize Parse SDK in Flutter
2.1 Create a New Flutter Project
Open your terminal and create a new Flutter project:
Bash
flutter create env_rewards_app
flutter create env_rewards_app
﻿
2.2 Add Dependencies
Open the pubspec.yaml file and add the required dependencies:
YAML
dependencies:
  flutter:
    sdk: flutter
  parse_server_sdk_flutter: latest_version
  http: ^0.13.3 # For networking
  google_wallet_pass: latest_version # Example package to handle Google Wallet Passes
dependencies:
  flutter:
    sdk: flutter
  parse_server_sdk_flutter: latest_version
  http: ^0.13.3 # For networking
  google_wallet_pass: latest_version # Example package to handle Google Wallet Passes
﻿
Run flutter pub get to install the packages.
2.3 Initialize Parse SDK in Main File
In lib/main.dart, initialize the Parse SDK by adding your Back4app credentials:
Dart
import 'package:flutter/material.dart';
import 'package:parse_server_sdk_flutter/parse_server_sdk_flutter.dart';

void main() async {
  WidgetsFlutterBinding.ensureInitialized();

  const keyApplicationId = 'YOUR_BACK4APP_APP_ID';
  const keyClientKey = 'YOUR_BACK4APP_CLIENT_KEY';
  const keyParseServerUrl = 'https://parseapi.back4app.com';

  await Parse().initialize(keyApplicationId, keyParseServerUrl,
      clientKey: keyClientKey, autoSendSessionId: true);

  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Environmental Rewards',
      home: EnvironmentalRewardsScreen(),
    );
  }
}
import 'package:flutter/material.dart';
import 'package:parse_server_sdk_flutter/parse_server_sdk_flutter.dart';

void main() async {
  WidgetsFlutterBinding.ensureInitialized();

  const keyApplicationId = 'YOUR_BACK4APP_APP_ID';
  const keyClientKey = 'YOUR_BACK4APP_CLIENT_KEY';
  const keyParseServerUrl = 'https://parseapi.back4app.com';

  await Parse().initialize(keyApplicationId, keyParseServerUrl,
      clientKey: keyClientKey, autoSendSessionId: true);

  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Environmental Rewards',
      home: EnvironmentalRewardsScreen(),
    );
  }
}
﻿
Replace YOUR_BACK4APP_APP_ID and YOUR_BACK4APP_CLIENT_KEY with your actual Back4app credentials.
Step 3: Build the UI for Logging Environmental Actions
We'll create a basic UI that allows users to log their environmental actions and view their digital rewards.
3.1 Create the EnvironmentalRewardsScreen Widget
Create a new widget in lib/environmental_rewards_screen.dart:
Dart
import 'package:flutter/material.dart';
import 'package:parse_server_sdk_flutter/parse_server_sdk_flutter.dart';
import 'package:intl/intl.dart'; // For formatting dates

class EnvironmentalRewardsScreen extends StatefulWidget {
  @override
  _EnvironmentalRewardsScreenState createState() => _EnvironmentalRewardsScreenState();
}

class _EnvironmentalRewardsScreenState extends State<EnvironmentalRewardsScreen> {
  final TextEditingController _usernameController = TextEditingController();
  String? _selectedAction;
  bool _loading = false;
  String? _rewardMessage;

  final List<String> _actions = ['Recycling', 'Tree Planting', 'Volunteering'];

  Future<void> _logAction() async {
    if (_usernameController.text.isEmpty || _selectedAction == null) {
      ScaffoldMessenger.of(context).showSnackBar(SnackBar(
        content: Text('Please enter a username and select an action.'),
      ));
      return;
    }

    setState(() {
      _loading = true;
    });

    // Save action to Back4app
    final actionObject = ParseObject('EnvironmentalActions')
      ..set('username', _usernameController.text)
      ..set('actionType', _selectedAction)
      ..set('timestamp', DateTime.now())
      ..set('rewardIssued', false);

    final response = await actionObject.save();

    if (response.success) {
      setState(() {
        _rewardMessage = 'Action logged! Check your rewards!';
      });
      // Call Google Wallet API to issue a reward here
      await _issueReward();
    } else {
      setState(() {
        _rewardMessage = 'Failed to log action.';
      });
    }

    setState(() {
      _loading = false;
    });
  }

  Future<void> _issueReward() async {
    // This is where you'd integrate the Google Wallet API to issue a digital badge
    // Use the Google Wallet SDK to generate a pass and add it to the user's wallet
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text('Environmental Rewards')),
      body: Padding(
        padding: const EdgeInsets.all(16.0),
        child: Column(
          children: [
            TextField(
              controller: _usernameController,
              decoration: InputDecoration(labelText: 'Username'),
            ),
            SizedBox(height: 16),
            DropdownButton<String>(
              value: _selectedAction,
              hint: Text('Select an environmental action'),
              items: _actions.map((String action) {
                return DropdownMenuItem<String>(
                  value: action,
                  child: Text(action),
                );
              }).toList(),
              onChanged: (String? newValue) {
                setState(() {
                  _selectedAction = newValue!;
                });
              },
            ),
            SizedBox(height: 16),
            ElevatedButton(
              onPressed: _loading ? null : _logAction,
              child: _loading ? CircularProgressIndicator() : Text('Log Action'),
            ),
            SizedBox(height: 16),
            if (_rewardMessage != null)
              Text(_rewardMessage!, style: TextStyle(color: Colors.green)),
          ],
        ),
      ),
    );
  }
}
import 'package:flutter/material.dart';
import 'package:parse_server_sdk_flutter/parse_server_sdk_flutter.dart';
import 'package:intl/intl.dart'; // For formatting dates

class EnvironmentalRewardsScreen extends StatefulWidget {
  @override
  _EnvironmentalRewardsScreenState createState() => _EnvironmentalRewardsScreenState();
}

class _EnvironmentalRewardsScreenState extends State<EnvironmentalRewardsScreen> {
  final TextEditingController _usernameController = TextEditingController();
  String? _selectedAction;
  bool _loading = false;
  String? _rewardMessage;

  final List<String> _actions = ['Recycling', 'Tree Planting', 'Volunteering'];

  Future<void> _logAction() async {
    if (_usernameController.text.isEmpty || _selectedAction == null) {
      ScaffoldMessenger.of(context).showSnackBar(SnackBar(
        content: Text('Please enter a username and select an action.'),
      ));
      return;
    }

    setState(() {
      _loading = true;
    });

    // Save action to Back4app
    final actionObject = ParseObject('EnvironmentalActions')
      ..set('username', _usernameController.text)
      ..set('actionType', _selectedAction)
      ..set('timestamp', DateTime.now())
      ..set('rewardIssued', false);

    final response = await actionObject.save();

    if (response.success) {
      setState(() {
        _rewardMessage = 'Action logged! Check your rewards!';
      });
      // Call Google Wallet API to issue a reward here
      await _issueReward();
    } else {
      setState(() {
        _rewardMessage = 'Failed to log action.';
      });
    }

    setState(() {
      _loading = false;
    });
  }

  Future<void> _issueReward() async {
    // This is where you'd integrate the Google Wallet API to issue a digital badge
    // Use the Google Wallet SDK to generate a pass and add it to the user's wallet
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text('Environmental Rewards')),
      body: Padding(
        padding: const EdgeInsets.all(16.0),
        child: Column(
          children: [
            TextField(
              controller: _usernameController,
              decoration: InputDecoration(labelText: 'Username'),
            ),
            SizedBox(height: 16),
            DropdownButton<String>(
              value: _selectedAction,
              hint: Text('Select an environmental action'),
              items: _actions.map((String action) {
                return DropdownMenuItem<String>(
                  value: action,
                  child: Text(action),
                );
              }).toList(),
              onChanged: (String? newValue) {
                setState(() {
                  _selectedAction = newValue!;
                });
              },
            ),
            SizedBox(height: 16),
            ElevatedButton(
              onPressed: _loading ? null : _logAction,
              child: _loading ? CircularProgressIndicator() : Text('Log Action'),
            ),
            SizedBox(height: 16),
            if (_rewardMessage != null)
              Text(_rewardMessage!, style: TextStyle(color: Colors.green)),
          ],
        ),
      ),
    );
  }
}
﻿
This UI allows the user to:
Enter their username.
Select an environmental action.
Log the action, which triggers the backend and issues a reward using the Google Wallet API.
Step 4: Integrating Google Wallet for Issuing Rewards
4.1 Set Up Google Wallet API
Follow the Google Wallet API documentation to set up the API and obtain your API keys.
4.2 Issue a Digital Badge with Google Wallet
In the _issueReward() method, you will implement the logic to create a digital badge (generic pass) and save it to the user's Google Wallet. Here's a basic structure:
Dart
Future<void> _issueReward() async {
  final badgeData = {
    'title': 'Environmental Hero',
    'description': 'Awarded for completing environmental actions.',
    // Add any additional information or metadata
  };

  // Call Google Wallet API to generate a pass
  // You can use the 'google_wallet_pass' package or direct API calls
  final response = await createGoogleWalletPass(badgeData); // Placeholder for actual implementation

  if (response.success) {
    ScaffoldMessenger.of(context).showSnackBar(SnackBar(
      content: Text('Badge issued! Check your Google Wallet.'),
    ));
  } else {
    ScaffoldMessenger.of(context).showSnackBar(SnackBar(
      content: Text('Failed to issue badge.'),
    ));
  }
}
Future<void> _issueReward() async {
  final badgeData = {
    'title': 'Environmental Hero',
    'description': 'Awarded for completing environmental actions.',
    // Add any additional information or metadata
  };

  // Call Google Wallet API to generate a pass
  // You can use the 'google_wallet_pass' package or direct API calls
  final response = await createGoogleWalletPass(badgeData); // Placeholder for actual implementation

  if (response.success) {
    ScaffoldMessenger.of(context).showSnackBar(SnackBar(
      content: Text('Badge issued! Check your Google Wallet.'),
    ));
  } else {
    ScaffoldMessenger.of(context).showSnackBar(SnackBar(
      content: Text('Failed to issue badge.'),
    ));
  }
}
﻿
Step 5: Running the App
Run the app using flutter run to start logging actions and receiving rewards.
When a user logs an action, it will be saved to Back4app, and a badge will be issued using the Google Wallet API.
Conclusion
This tutorial showed how to build an environmental rewards app using Flutter, Google Wallet, and Back4app. Users log environmental actions, and upon completion, they receive digital badges or event passes stored in their Google Wallet. This project could be expanded with social sharing features, leaderboards, or even location-based rewards using QR codes.
For more information, refer to:
﻿Flutter Documentation﻿
﻿Google Wallet API Documentation﻿
﻿Back4app Documentation﻿
﻿
Updated 05 Sep 2024
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