How to connect facebook, firebase and flutter? - facebook

Question

I'm following the instructions for incorporating facebook with android projects found here https://developers.facebook.com/apps/318154048893918/fb-login/quickstart/ and there is a step to download the Facebook SDK, but after that, it doesn't tell me where to put the file. The import statement it tells me to add won't work (says target of uri doesn't exist).
I'm trying to add the facebook user to our firebase database when they log in. I'm using flutter in android studio.
There doesn't seem to be anything of use in the console log, except that print statement doesn't print anything. Any ideas?
Here's my code to log in the user.
import com.facebook.FacebookSdk;
import com.facebook.appevents.AppEventsLogger;
Future<FirebaseUser> initiateFacebookLogin() async {
final FacebookLoginResult result =
await facebookLogin.logInWithReadPermissions(['email', 'public_profile']);
FirebaseUser user =
await _auth.signInWithFacebook(accessToken: result.accessToken.token);
//Token: ${accessToken.token}
ProviderDetails userInfo = new ProviderDetails(
user.providerId, user.uid, user.displayName, user.photoUrl, user.email);
List<ProviderDetails> providerData = new List<ProviderDetails>();
providerData.add(userInfo);
print(user.displayName);
addToDatabase(user.uid, user.displayName, user.displayName, user.email);
return user;
}

Answer 1

In flutter you need use flutter_facebook_login plugin take a look here to see how to get the plugin and setup your flutter app to make use of this plugin. You can also check this article that is step-by-step about how setup you project and contains code example too but the API used is out of date.
Here a snippet with updated API showing how to achieve login in firebase with facebook account.
/// This mehtod makes the real auth
Future<FirebaseUser> firebaseAuthWithFacebook({#required FacebookAccessToken token}) async {
AuthCredential credential= FacebookAuthProvider.getCredential(accessToken: token.token);
FirebaseUser firebaseUser = await _authInstance.signInWithCredential(credential);
return firebaseUser;
}
In your code you're using _auth.signInWithFacebook method that is deprecated and you should replaced by signInWithCredential updating you firebase_auth plugin version.
///This object comes from facebook_login_plugin package
final facebookLogin = new FacebookLogin();
final facebookLoginResult = await facebookLogin
.logInWithReadPermissions(['email', 'public_profile']);
switch (facebookLoginResult.status) {
case FacebookLoginStatus.error:
print("Error");
break;
case FacebookLoginStatus.cancelledByUser:
print("CancelledByUser");
break;
case FacebookLoginStatus.loggedIn:
print("LoggedIn");
/// calling the auth mehtod and getting the logged user
var firebaseUser = await firebaseAuthWithFacebook(
token: facebookLoginResult.accessToken);
}
}