【Flutter】FirebaseでTwitter認証（Auth）のやり方まとめ【スクショ・ソースあり】

<key>CFBundleURLTypes</key>
<array>
  <dict>
    <key>CFBundleURLSchemes</key>
    <array>
      <!-- もし consumerKeyが123456789なら、twitterkit-123456789となる-->
      <string>twitterkit-<consumerKey></string>
    </array>
  </dict>
</array>
<key>LSApplicationQueriesSchemes</key>
<array>
    <string>twitter</string>
    <string>twitterauth</string>
</array>

dependencies:
  firebase_auth: ^0.14.0+5
  flutter_twitter_login: ^1.1.0

$ flutter pub get

import 'package:flutter/material.dart';
import 'package:firebase_auth/firebase_auth.dart';
import 'package:flutter_twitter_login/flutter_twitter_login.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'auth sample',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: AuthPage(
        title: 'Auth Sample with Firebase',
      ),
    );
  }
}

class AuthPage extends StatefulWidget {
  AuthPage({
    Key key,
    this.title,
  }) : super(
          key: key,
        );

  final String title;

  @override
  _AuthPageState createState() => _AuthPageState();
}

class _AuthPageState extends State {
  final FirebaseAuth _auth = FirebaseAuth.instance;
  
  // APIキーを入力
  final TwitterLogin twitterLogin = TwitterLogin(
    consumerKey: consumerKey,
    consumerSecret: secretkey,
  );

  bool logined = false;

  void login() {
    setState(() {
      logined = true;
    });
  }

  void logout() {
    setState(() {
      logined = false;
    });
  }

  Future signInWithTwitter() async {
    // twitter認証の許可画面が出現
    final TwitterLoginResult result = await twitterLogin.authorize();

    //Firebaseのユーザー情報にアクセス & 情報の登録 & 取得
    final AuthCredential credential = TwitterAuthProvider.getCredential(
      authToken: result.session.token,
      authTokenSecret: result.session.secret,
    );

    //Firebaseのuser id取得
    final FirebaseUser user =
        (await _auth.signInWithCredential(credential)).user;

    assert(!user.isAnonymous);
    assert(await user.getIdToken() != null);

    final FirebaseUser currentUser = await _auth.currentUser();
    assert(user.uid == currentUser.uid);

    login();
  }

  void signOutTwitter() async {
    await twitterLogin.logOut();
    logout();
    print("User Sign Out Twittter");
  }

  @override
  Widget build(BuildContext context) {
    Widget logoutText = Text("ログアウト中");
    Widget loginText = Text("ログイン中");

    Widget loginBtnTwitter = RaisedButton(
      child: Text("Sign in with Twitter"),
      color: Color(0xFF1DA1F2),
      textColor: Colors.white,
      onPressed: signInWithTwitter,
    );
    Widget logoutBtnTwitter = RaisedButton(
      child: Text("Sign out with Twitter"),
      color: Color(0xFF1DA1F2),
      textColor: Colors.white,
      onPressed: signOutTwitter,
    );

    return Scaffold(
      appBar: AppBar(
        centerTitle: true,
        title: Text(widget.title),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            logined ? loginText : logoutText,
            logined ? logoutBtnTwitter : loginBtnTwitter,
          ],
        ),
      ),
    );
  }
}

 // additionalUserInfoMap.put("profile", info.getProfile());

platform :ios, '11.0'

  # flutter_twitter_login: ^1.1.0
  flutter_twitter_login:
    git:
      url: git://github.com/eudangeld/flutter_twitter_login.git

$ flutter pub get