Firebase retrieve returns undefined/object Object

Question

I'm currently working on retrieving a child from Firebase with this code:

function fetchUserdetails() {
  firebase.database().ref().child('login/').orderByChild('username').equalTo('ivanaldwin').on("value", function(snapshot) {
    document.getElementById('fullname').innerHTML = snapshot.val().username;
    console.log(snapshot.val()); //debug in console
    snapshot.forEach(function(data) {
        console.log(data.key);
        alert('yep im working dood');
    });
});
}

window.onload = fetchUserdetails();

But the code, if i use snapshot.val().username; will render undefined in the output. but if i use snapshot.val() only, the output will be [Object object]. Here's my firebase layout:

What do you get when you console.log(snapshot.val());?

Web Nexus
– Web Nexus

2019-01-27 15:22:14 +00:00
Commented Jan 27, 2019 at 15:22 — Web Nexus
– Web Nexus, Commented Jan 27, 2019 at 15:22
also undefined.

Ivan Cristobal
– Ivan Cristobal

2019-01-27 15:22:42 +00:00
Commented Jan 27, 2019 at 15:22 — Ivan Cristobal
– Ivan Cristobal, Commented Jan 27, 2019 at 15:22
How about console.log(typeof snapshot.val());?

Pointy
– Pointy

2019-01-27 15:23:28 +00:00
Commented Jan 27, 2019 at 15:23 — Pointy
– Pointy, Commented Jan 27, 2019 at 15:23
now [object Object] and object

Ivan Cristobal
– Ivan Cristobal

2019-01-27 15:24:56 +00:00
Commented Jan 27, 2019 at 15:24 — Ivan Cristobal
– Ivan Cristobal, Commented Jan 27, 2019 at 15:24

Web Nexus · Accepted Answer · 2019-01-27 15:28:44Z

2

To retrieve the username try the following:

snapshot.forEach(function(data) {
    let userName = data.val().username;
    console.log(data.key);
    alert('yep Im working dude');
});

Your snapshot is at node login, therefore after you loop using forEach you then can access the child attributes.

edited Jan 27, 2019 at 15:28

Web Nexus

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answered Jan 27, 2019 at 15:26

Peter Haddad

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1 Comment

Ivan Cristobal Over a year ago

This worked! Can't accept as answer yet though. Didn't know that the child attributes were sort of 'locked' at first.

Mocas · Accepted Answer · 2019-01-27 15:34:03Z

0

You need to use array index

document.getElementById('fullname').innerHTML = snapshot.val()[0].username;

But I think you would need the element 0 for that one, which you don't have. Maybe try

document.getElementById('fullname').innerHTML = snapshot.val().child('1').username

edited Jan 27, 2019 at 15:34

answered Jan 27, 2019 at 15:25

Mocas

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2 Comments

Ivan Cristobal Over a year ago

Ended up spitting the error Cannot read property 'username' of undefined

Mocas Over a year ago

the number 1 is a poor name for a node, as you can't reference it as an object child in your code. Either start from 0 so you would get an array where you can use my first line of code, or use names that are letters, where you can reference like snapshot.val().myNode.username

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