what causes “permission denied”-message with FIREBASE and FLUTTER

问题

I've got the error

'W/SyncTree(31625): Listen at /address failed: DatabaseError: Permission denied'

while sending a request to firebase with an anonymous firebase user and without fancy firebase database rules :) . ..and i want to find out what causes this message.

EDIT: error is the same with an existing user, means user signIn seems to work but accessing database not.

What i've done so far:

Set up firebase (including adding google_service.json, dependencies in pubspec.yaml) - works so far

creating login as follows (like in example from google link):

Future<String> _testSignInAnonymously() async {
  final FirebaseUser user = await _auth.signInAnonymously();
  assert(user != null);
  assert(user.isAnonymous);
  assert(!user.isEmailVerified);
  assert(await user.getIdToken() != null);
  assert(user.providerData.length == 1);
  assert(user.providerData[0].providerId == 'firebase');
  assert(user.providerData[0].uid != null);
  assert(user.providerData[0].displayName != null);
  assert(user.providerData[0].photoUrl == null);
  assert(user.providerData[0].email != null);

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

  return 'signInAnonymously succeeded: $user';
}

the print statement provides a userId (and this id is also in firebase auth section) --> seems to me that i've got an logged in user

implement kind of initialization like in the google example (link):

Future<void> main() async {
  final FirebaseApp app = await FirebaseApp.configure(
    name: 'mydbName',
    options: const FirebaseOptions(
       googleAppID: 'myAppId',
       apiKey: 'myApiKey',
       databaseURL: 'myUrl',
    ),
 );
 runApp(new MyApp(app));
}

on another stateful widget in state i try to request some firebase data:

void initState() {
  final FirebaseDatabase database = new FirebaseDatabase(app: widget.app);
  database.reference().child('address').once().then((DataSnapshot snapshot) {
    print('Connected to database and read ${snapshot.value}');
  });
  super.initState();
}

i've removed all rules in firebase except:

".read": "auth != null",
".write": "auth != null",

i use an SHA-1 certificate/fingerprint in my firebase android app
i use the same firebase database with an firebase ios app without any problem while using anonymous users

What i need:

I need some hint how to find out if there's any problem with that initialization code or with the user login or something else

回答1:

It seems the database is not correctly addressed in FirebaseApp.configure(

FirebaseDatabase.instance.reference().child(...)

would use the default database of the project configured in google-services.json

来源：https://stackoverflow.com/questions/52203529/what-causes-permission-denied-message-with-firebase-and-flutter

标签

android

firebase

firebase-realtime-database

firebase-authentication

Flutter