google_sign_in_dartio 0.0.5

Flutter package for Google Sign-In, a secure authentication system for signing in with a Google account on Flutter platforms that support 'dart:io'.

example/lib/main.dart

// Copyright 2019 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// ignore_for_file: public_member_api_docs

import 'dart:async';
import 'dart:convert' show json;

import 'package:flutter/material.dart';
import 'package:google_sign_in/google_sign_in.dart';
import 'package:google_sign_in_dartio/google_sign_in_dartio.dart';
import 'package:http/http.dart' as http;

import 'platform_js.dart' if (dart.library.io) 'platform_io.dart';

GoogleSignIn _googleSignIn = GoogleSignIn(
  scopes: <String>[
    'email',
    'profile',
    'https://www.googleapis.com/auth/contacts.readonly',
  ],
);

Future<void> main() async {
  if (isDesktop) {
    await GoogleSignInPlatform.register(
      exchangeEndpoint:
          'https://us-central1-flutter-sdk.cloudfunctions.net/authHandler',
      clientId:
          '233259864964-go57eg1ones74e03adlqvbtg2av6tivb.apps.googleusercontent.com',
    );
  }

  runApp(
    MaterialApp(
      title: 'Google Sign In',
      home: SignInDemo(),
    ),
  );
}

class SignInDemo extends StatefulWidget {
  @override
  State createState() => SignInDemoState();
}

class SignInDemoState extends State<SignInDemo> {
  GoogleSignInAccount _currentUser;
  String _contactText;

  @override
  void initState() {
    super.initState();
    _googleSignIn.onCurrentUserChanged.listen((GoogleSignInAccount account) {
      setState(() {
        _currentUser = account;
      });
      if (_currentUser != null) {
        _handleGetContact();
      }
    });

    _googleSignIn.signInSilently();
  }

  Future<void> _handleGetContact() async {
    setState(() {
      _contactText = 'Loading contact info...';
    });
    final http.Response response = await http.get(
      'https://people.googleapis.com/v1/people/me/connections'
      '?requestMask.includeField=person.names',
      headers: await _currentUser.authHeaders,
    );
    if (response.statusCode != 200) {
      setState(() {
        _contactText = 'People API gave a ${response.statusCode} '
            'response. Check logs for details.';
      });
      print('People API ${response.statusCode} response: ${response.body}');
      return;
    }
    final Map<String, dynamic> data = json.decode(response.body);
    final String namedContact = _pickFirstNamedContact(data);
    setState(() {
      if (namedContact != null) {
        _contactText = 'I see you know $namedContact!';
      } else {
        _contactText = 'No contacts to display.';
      }
    });
  }

  String _pickFirstNamedContact(Map<String, dynamic> data) {
    final List<dynamic> connections = data['connections'];
    final Map<String, dynamic> contact = connections?.firstWhere(
      (dynamic contact) => contact['names'] != null,
      orElse: () => null,
    );
    if (contact != null) {
      final Map<String, dynamic> name = contact['names'].firstWhere(
        (dynamic name) => name['displayName'] != null,
        orElse: () => null,
      );
      if (name != null) {
        return name['displayName'];
      }
    }
    return null;
  }

  Future<void> _handleSignIn() async {
    try {
      await _googleSignIn.signIn();
    } catch (error) {
      print(error);
    }
  }

  Future<void> _handleSignOut() => _googleSignIn.disconnect();

  Widget _buildBody() {
    if (_currentUser != null) {
      return Column(
        mainAxisAlignment: MainAxisAlignment.spaceAround,
        children: <Widget>[
          ListTile(
            leading: ClipOval(
              child: Image.network(
                _currentUser.photoUrl ??
                    'https://lh3.googleusercontent.com/a/default-user=s160-c',
              ),
            ),
            title: Text(_currentUser.displayName ?? ''),
            subtitle: Text(_currentUser.email ?? ''),
          ),
          const Text('Signed in successfully.'),
          Text(_contactText ?? ''),
          RaisedButton(
            onPressed: _handleSignOut,
            child: const Text('SIGN OUT'),
          ),
          RaisedButton(
            onPressed: _handleGetContact,
            child: const Text('REFRESH'),
          ),
        ],
      );
    } else {
      return Column(
        mainAxisAlignment: MainAxisAlignment.spaceAround,
        children: <Widget>[
          const Text('You are not currently signed in.'),
          RaisedButton(
            onPressed: _handleSignIn,
            child: const Text('SIGN IN'),
          ),
        ],
      );
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Google Sign In'),
      ),
      body: ConstrainedBox(
        constraints: const BoxConstraints.expand(),
        child: _buildBody(),
      ),
    );
  }
}