1     async facebookLogin() {
2       try {
3         // Log in to Facebook and request user data
4         let facebookResponse = await this.facebook.login(['public_profile', 'email']);
5         let facebookAuthData = {
6           id: facebookResponse.authResponse.userID,
7           access_token: facebookResponse.authResponse.accessToken,
8         };
9
10        // Request the user from parse
11        let toLinkUser = new Parse.User();
12        let user = await toLinkUser._linkWith('facebook', {authData: facebookAuthData});
13
14        // If user did not exist, updates its data
15        if (!user.existed()) {
16          let userData = await this.facebook.api('me?fields=id,name,email,first_name,picture.width(720).height(720).as(picture)', []);
17          user.set('username', userData.name);
18          user.set('name', userData.name);
19          user.set('email', userData.email);
20          await user.save();
21        }
22
23        this.navCtrl.setRoot('HomePage');
24      } catch (err) {
25        console.log('Error logging in', err);
26
27        this.toastCtrl.create({
28          message: err.message,
29          duration: 2000
30        }).present();
31      }
32    }

1   <div text-center>
2         <button ion-button color="facebook" (click)="facebookLogin()">
3           LOG IN WITH FACEBOOK
4         </button>
5       </div>