AngularJS does not update after value change

Question

My intention is to update the navigation bar after the user login. Basically, it should change Login to Hi, {{usr.username}} right after the login.

Answer 1

Call $scope.$apply();

FirebaseRef.child("users").child(authData.uid).once('value', function(dataSnapshot) {

   $scope.$apply(function(){
      $scope.usr = dataSnapshot.val();
   });

});