AngularJS - Update a variable of a factory from a controller - angularjs

Question

I am developping a web app with Ionic 1 and AngularJS 1.
In my factory (UserFact) :
.factory('UserFact', function() {
var user = [];
return {
'setUser': function(user) {
this.user = user;
console.log('(2) User set: ' + this.user);
console.log('(3) User id is now: ' + this.user.uid);
},
'updateSport': function(sportid, registered) {
console.log('Update sport: ' + sportid + ' --> ' + registered);
console.log('(4) For user uid: ' + this.user.uid);
var ref = firebase.database().ref('users/' + this.user.uid + '/sports/');
// sync down from server
var list = [];
ref.on('value', function(snap) { list = snap.val(); });
if(registered) {
list.splice(0, 0, {id: sportid});
} else {
}
ref.set(list);
}
};
})
In my controller :
function ($scope, $stateParams, $state, DatabaseFact, UserFact) {
// variables
$scope.sports = [];
$scope.sports = DatabaseFact.getSports();
// functions
$scope.updateSport = UserFact.updateSport;
// execution
firebase.auth().onAuthStateChanged(function(user) {
if (user) {
UserFact.setUser(user);
console.log('(1) Ctrl user uid: ' + user.uid);
}
});
}
According to the console: logs (1), (2) and (3) display a userid form my db but (4) is always undefined...
Any idea?
Thanks

Answer 1

UPDATE:
Manuel, sorry, I think I had missed the point of your question. You are correct, using a factory/service, is the correct way to store the state of your application. From the above, I do not see a reason for your code not work. The user must be getting re-assigned elsewhere for you to be seeing undefined in (4), if you are not seeing the same in (3). For simplicity sake, I removed references to firebase and created a working demo: https://plnkr.co/edit/vaN7ySche8GgRQmZgFsa?p=preview
While the demo may not solve your problem, I hope it illustrates that the factory variable (user) is persisted in memory and usable across multiple factory method calls.
ORIGINAL ANSWER (MISSED THE POINT) BELOW:
Update the state change handler to save the user on the controller scope:
firebase.auth().onAuthStateChanged(function(user) {
if (user) {
$scope.user = user;
UserFact.setUser(user);
console.log('(1) Ctrl user uid: ' + user.uid);
}
});
Then, in the template, invoke the updateSport method, using the user scope variable:
updateSport(user, true);
or
updateSport(user, false);

Answer 2

You need to pass the arguments while calling updateSport in controller,
$scope.updateSport = UserFact.updateSport(userid,registered);