how to return true or false from Angularfire2 facebook Authentication

问题

Ok so I'm pretty new to AngularFire2 and Angular2 in general, I'm learning the authentication method that AngularFire2 provides.

So far I have successfully implemented logging in with Facebook, my code currently resides in a service.

So the code is simple (May look disgusting to you), I login via Facebook retrieve the users access token, and their facebookId, make a call to Facebook graph and retrieve Firstname, Lastname, Gender, Email etc then save this data within Firebase this is my code for doing the above:

loginWithFacebook(): FirebaseListObservable<string> {

  return FirebaseListObservable.create(obs => {
      this.af.auth.login({
          provider: AuthProviders.Facebook,
          method: AuthMethods.Popup,
          scope: ['public_profile']
      }).then((authState: any) => {

      let userRef = this.af.database.object('/users/' + authState.uid); // get user profile

       userRef.subscribe(user => {

       let url = `https://graph.facebook.com/v2.8/${user.facebookId}?fields=first_name,last_name,gender,email&access_token=${user.accessToken}`;

       this.http.get(url).subscribe(response => {

          let result = response.json()
             userRef.update({
               first_name: result.first_name,
               last_name: result.last_name,
               gender: result.gender,
               email_address: result.email,
               facebookId: user.facebookId
              })
            })
         })

          obs.next(userRef);

        }).catch(err => {
            obs.throw(err)
        });
    });

I call this from my login.component as shown:

 loginFacebook() {
       this.loginSubscription = this.service.loginWithFacebook().subscribe(data => {
          console.log('after finish', data);  
        });
    }

Issue I have is I want to capture if the login with facebook fails or passes I've tried populating the Observable within the Service method, however when I console.log 'after finish', data I see the following:

Can someone shed any light into how I go about returning true / false from this method? If anyone can see a cleaner way of doing this I would be highly appreciative.

回答1:

Cannot test right now, you could do it like this:

loginWithFacebook(): Observable<boolean> {

   return this.af.auth.login({
          provider: AuthProviders.Facebook,
          method: AuthMethods.Popup,
          scope: ['public_profile']
      })
      .map((authState: any) => {
         if (!authState) return false;

         let userRef = this.af.database.object('/users/' + authState.uid); // get user profile

         userRef.subscribe(user => {

            let url = `https://graph.facebook.com/v2.8/${user.facebookId}?fields=first_name,last_name,gender,email&access_token=${user.accessToken}`;

            this.http.get(url).subscribe(response => {

               let result = response.json();
               userRef.update({
                  first_name: result.first_name,
                  last_name: result.last_name,
                  gender: result.gender,
                  email_address: result.email,
                  facebookId: user.facebookId
               })
            })
         })

         return true;    
      }).catch(err => {
         return Observable.of(false);
      });
}

loginFacebook() {
   this.loginSubscription = this.service.loginWithFacebook().subscribe(data => {
      console.log('after finish', data);  
   });
}

来源：https://stackoverflow.com/questions/41971144/how-to-return-true-or-false-from-angularfire2-facebook-authentication

标签

angular

authentication

angularfire2