Q:

Firebase: User.photoUrl to String

I'm trying to store all the user's profile photos in the realtime database, but I'm stucked with a problem.
When trying to upload the PhotoUrl with this code, this error shows up.
Code:
var user = firebase.auth().currentUser;

user.updateProfile({

  // Here, "name" and "imgUrl" are parameters of parent function.
  // I don't think this is the reason, but if it helps,
  // "imgUrl" always come from a <img> src.
  displayName: name,
  photoUrl: imgUrl

}).then(function(){

  // Here is where I try to upload all to the database
  firebase.database().ref("/Usuarios/" + user.uid).set({
    "email": email,
    "name": name,
    "photoUri": user.photoUrl, // This is where I think the problem originates.
    "uid": user.uid  // This calls user again, and it works perfectly.
  });

});

Error:
Uncaught Error: Firebase.set failed: First argument contains undefined in property 'Usuarios.kD1tD1NAmsaGiW0zj6lFz9GDWro1.photoUri'.

When I do alert(user.photoUrl), it shows as 'undefined'.
The first thing I thought was that it can't be saved in database because it isn't a String, so I tried calling toString() from it, but I can't.
toString() error:
Uncaught TypeError: Cannot read property 'toString' of undefined

So, how can I save the photoUrl from a user (as String) in Firebase Database?
Thanks in advance.

A:

For most I tried not to do this type of workarounds, ended up uploading the photo to Firebase Storage, then setting User.photoURL and "photoUri" DB field to the url of the uploaded image:
user = firebase.auth().currentUser;
avatarStgRef = firebase.storage().ref("Usuarios/" + user.uid + "/avatar.jpg");

// imgFile the Photo File.
avatarStgRef.put(imgFile).then(function(snapshot){
    snapshot.ref.getDownloadURL().then(function(url){  // Now I can use url
        user.updateProfile({
            photoURL: url       // <- URL from uploaded photo.
        }).then(function(){
            firebase.database().ref("Usuarios/" + user.uid).set({
              "photoUri": url   // <- URL from uploaded photo.
            });
        });
    });
});

