How can I get from firebase array of objects

Question

I need to get array of objects of sources from firebase grouped by category. Firebase structure is: enter image description here

Every authenticated user have its own array of sources. Security rules for db is: enter image description here Every source have array of articles and have category. I use vuefire to bind to firebase-database. I have written this, but I don't know what I should do next to get all sources grouped by category.

var sources=[];
var db=firebase.database();
var id=auth.user().uid;
var userDb=db.ref(id);

Answer 1

Maybe you can imagine how to retrieve your data from firebase database if I give you this example:

function getData(data) {
    var items = data.val();
    console.log(items, 'myItem') //here is your items that you need
}

function errData(err) {
    console.log('error:', err)
}

const id = firebase.auth().currentUser.uid;
const result = firebase.database().ref(id);
result.on('value', getData, errData)