Firebase on(child_added) some field 'undefined' - firebase

Question

I am working on a real time application and i am using firebase with pure html and javascript (not angularJS).
I am having a problem where i saved user's data to firebase with the given code by firebase :
var isNewUser = true;
ref.onAuth(function(authData) {
if (authData && isNewUser) {
authData['status'] = 'active';
authData['role'] = 'member';
ref.child("users").child(authData.uid).set(authData);
}
});
This will add the authData to the /users/ node. As you can see that i also appended some custom fields to the authData, status and role.
Now i am using this code to get the user's data from firebase and display them.
ref4.on("value", function(snapshot) {
var snapshotData = snapshot.val();
console.log('username: '+snapshotData.status);
});
If i use on('value'), the status get printed out on the console but if i do it this way,
ref4.on("child_added", function(snapshot) {
var snapshotData = snapshot.val();
console.log('status: '+snapshotData.status);
});
It is showing undefined for the status. May i know what's wrong and how to fix this problem. Thank you.

Answer 1

Since value is returning the path provided by ref4, and child_added is returning each child of that path, it's unlikely both are going to have a key status.
Consider this data structure:
{
"users": {
"brucelee": {
"status": "awesome"
},
"chucknorris": {
"status": "awesomerest"
}
}
}
If I now query for this according to your incomplete example:
var ref = new Firebase('https://<instance>firebaseio.com/users/brucelee');
ref.on('value', function(snap) {
// requests the brucelee record
console.log(snap.name(), ':', snap.val().status); // "brucelee: awesome"
});
ref.on('child_added', function(snap) {
// iterates children of the brucelee path (i.e. status)
console.log(snap.name(), ':', snap.val().status); // THROWS AN ERROR, because status is a string
});
So to do this on child_added with a data structure like this (and presumably somewhat like yours), it would look as follows:
ref.on('child_added', function(snap) {
// iterates children of the brucelee path (i.e. status)
console.log(snap.name(), ':', snap.val()); // "status: awesome"
});