How to retrieve only new data?

Question

I'm trying to create simple notification system for my site admin, and I need to send only real-time messages to every admin user. But when I use firebase it loads old data on every page, and user see all messages from database. If I set limit(1) user will see last notification on every page reloading:

var eventsList = new Firebase('https://*****-messages.firebaseio.com/');  eventsList.on('child_added', function(message) {     var message = message.val();     $.notification(message.message); }); 

How I can load only new messages, without old notification history?

Answer 1

This is by design, in a real-time system there is no concept of the "latest" data because it's always changing. However, if you want to only display items added to the list after the page has loaded, you can do the following:

var newItems = false; var eventsList = new Firebase('https://*****-messages.firebaseio.com/');  eventsList.on('child_added', function(message) {   if (!newItems) return;   var message = message.val();   $.notification(message.message); }); eventsList.once('value', function(messages) {   newItems = true; });