This is a simple test with 🔥base which has a study purpose. The matter is simple: understand what is able to do a realtime distributed NoSQL database, which recently acquired by Google, who can send global updates about data to all subscribers.

Go to Firebase website and create an new profile. They'll provide you an URL for database access with a pattern like:

https://someFancyNameHere.firebaseio.com/

Create a simple connection to the database using: var db = new Firebase('https://firebaseDbFancyNameHere.firebaseio.com/');

var collection = db.child('students');

To perform a database write there are 4 methods: set(), update(), transition() e push().

• set(): writes or overwrites data, used also to remove data

db.child('name').set('Andrea');
db.child('poets').set({
  BBrecht: {
    firstName: 'Bertolt',
    lastName: 'Brecht',
    age: 55
  },
  OWilde: {
    firstName: 'Oscar',
    lastName: 'Wilde',
    age 35
  }
});
db.child('poets/OWilde').set({});

• update(): updates data overwriting data nested in

db.child('poets').update({
  'BBrecht/firstname': 'B.',
  'OWilde/firstname': 'O.'
});

• push(): adds and object to a collection using an auto generated key

db.child('posts').push({
  author: 'BBrecht',
  text: 'Hello to everyone'
});

• transaction(): perform a database transaction, preventing race conditions

db.child('fixNumber').transaction(function(value){
  return (value || 0) + 1;
});

On every set / update an event will be fired letting the other clients to get updated data.

Event handlers allow to receive updates from other clients using event handlers like value, child_added, child_changed, child_removed or child_moved. Every callback will receive a DataSnapshot object with a snapshot of the situation at that time. DataSnapshot can be inspected with key() and val() methods to gain key and value associated.

db.child('poets').on('value', function(snapshot){
  snapshot.forEach(function(poet){
    console.log("Key: " + poet.key() + " Value: " + poet.val());
  });
});